WO2014121697A1 - Method and device for controlling user equipment to take measurements - Google Patents

Abstract

Disclosed are a method and device for controlling a user equipment (UE) to take measurements. The method comprises: a UE measuring jamming intensity on a resource element (RE) corresponding to a first downlink signal, and determining whether to start to measure a non-serving cell based on the jamming intensity or not.

Description

 Method and device for controlling user equipment for measurement

 The present invention relates to the field of wireless communications, and in particular, to a method and apparatus for controlling user equipment (UE, User Equipment) to perform measurements. Background technique

 In a Long Term Evolution (LTE) system, a UE needs to measure a received signal of a serving cell for radio resource management. Currently, in order to reduce the power consumption and computational overhead consumed by the UE to measure the received signal of the cell, the UE does not need to always measure the non-serving cell of the same frequency/inter-frequency, and only needs to detect the reference signal received power of the serving cell (RSRP). When the Reference Signal Received Power is lower than the preset threshold, the UE starts to measure the non-serving cell of the same frequency/inter-frequency.

 However, with the development of wireless communication technologies, there are gradually emerging types of base stations that can adapt to multiple coverage areas, including: large coverage base stations deployed to provide communication for a wide range of UEs, whose serving cells are usually called macro cells ( Macro Cell ); In addition, some small-capacity, low-transmitting '』, type base stations or transmission points (TP, Transmission Point) are provided, and nodes corresponding to small base stations are low-power nodes (LPN, Low Power Node). ), the cells corresponding to these LPNs are also called Small Cells. When the macro cell and the small cell coexist at the same time, the small cell may be deployed as a hot spot in the non-edge location of the macro cell. If the UE served by the macro cell (macro UE) still uses the RSRP control based on the serving cell to enable the same frequency/different For the measurement of the frequency non-serving cell, the RSRP of the macro cell measured by the macro UE located at the non-edge location inside the macro cell may be directly higher than the threshold for starting the measurement of the non-serving cell, so the UE will not The measurement of the non-serving cell is initiated, and finally the UE cannot discover the small cell that is close to the hotspot area.

It can be seen that, in the prior art, when the UE does not start the measurement function of the same-frequency/inter-frequency non-serving cell in real time, the UE cannot discover the small cell in the macro cell in time, and the load of the macro cell cannot be reduced, and the service to the UE cannot be improved. quality. Summary of the invention

 In view of this, the embodiments of the present invention provide a method and a device for controlling a UE to perform measurement, and can detect a small cell in a macro cell in time when the UE does not open the measurement function of the same-frequency/inter-frequency non-serving cell in real time, and reduce the macro. The load of the cell improves the quality of service to the UE.

 The embodiment of the invention provides a method for controlling a UE to perform measurement, and the method includes:

 The UE measures the interference strength on the RE corresponding to the first downlink signal, and determines whether to open the measurement of the non-serving cell based on the interference strength.

 In the above solution, before the UE measures the interference strength of the signal on the RE corresponding to the specified first downlink signal, the method further includes:

 Receiving, by the UE, measurement configuration information of the first downlink signal;

 The measurement configuration information is resource location information of the first downlink signal, and includes at least one of the following: subframe configuration information, frequency domain configuration information, and port information; the first downlink signal includes: channel state information reference Signal CSI-RS, or cell level reference signal CRS, or synchronization signal SS, or discovery signal.

 In the above solution, the UE measures the interference strength on the RE corresponding to the first downlink signal, and includes:

 The UE measures the reception strength on the RE corresponding to the zero-power first downlink signal and uses it as the interference strength.

 In the above solution, the UE measures the interference strength on the RE corresponding to the first downlink signal, and includes:

 The UE measures the received strength on the RE corresponding to the first downlink signal and the received power of the first downlink signal, and uses the difference between the two as the interference strength.

 In the above solution, the UE measures the interference strength on the RE corresponding to the first downlink signal, and includes:

The UE measures the reception strength on the RE corresponding to the first downlink signal after performing the interference cancellation operation on the first downlink signal, and uses the received strength as the interference strength. In the foregoing solution, determining, according to the interference strength, whether to enable measurement of a non-serving cell, includes:

 The UE measures the received power of the specified second downlink signal, and determines whether to measure the non-serving cell according to a ratio between the received power of the second downlink signal and the interference strength;

 The received power of the second downlink signal is a reference signal received power RSRP, or a channel state information reference signal received power CSI-RSRP, or a synchronous signal received power.

 In the foregoing solution, the determining whether to enable the measurement of the non-serving cell includes: when the UE determines that the interference strength is higher or lower than a threshold for starting measurement on the non-serving cell, the non-serving cell Make measurements.

 In the foregoing solution, the determining whether to enable measurement of the non-serving cell includes: using the interference strength, a ratio between a received power of the second downlink signal and an interference strength, RSRP, RSRQ, and CSI-RSRP At least two parameters control the measurement of the non-serving cell.

 In the foregoing solution, after determining, according to the interference strength, whether to enable measurement of a non-serving cell, the method further includes: enabling measurement of the non-serving cell;

 The measuring the non-serving cell includes:

 The UE initiates measurement of the non-serving cell by itself;

 Alternatively, the UE reports a measurement result or sends a strong interference indication to the serving base station, and the serving base station configures measurement of the non-serving cell.

 In the above solution, before the UE receives the measurement configuration information of the first downlink signal, the method further includes:

 The serving base station corresponding to the macro cell in which the UE is located and the small base station corresponding to the small cell coordinate the configuration of the first downlink signal through the X2 interface, or the S1 interface, or the network management OAM, or the UE.

 In the above solution, the resources of the first downlink signal include: resources of a licensed frequency band and resources of an unlicensed frequency band;

When the resource of the first downlink signal is a resource of the unlicensed band, except for the The interference strength determines whether to enable measurement of the non-serving cell, and the method further includes: selecting the UE to aggregate the carrier, and activating and configuring the secondary cell scell.

 An embodiment of the present invention further provides an apparatus for controlling a UE to perform measurement, where the apparatus includes: a measurement module and a decision module;

 a measurement module, configured to measure an interference strength on the RE corresponding to the specified first downlink signal, and send the interference strength to the decision module;

 The decision module is configured to determine whether to open the measurement of the non-serving cell according to the interference strength of the first downlink signal on the RE sent by the measurement module.

 In the above solution, the device further includes: a receiving module, configured to receive and save measurement configuration information of the first downlink signal, and send the measurement configuration information of the first downlink signal to the measurement module; correspondingly, the measurement The module is configured to receive and save the measurement configuration information sent by the receiving module, where the measurement configuration information is resource location information of the first downlink signal, and includes at least one of the following: subframe configuration information, frequency domain configuration information, and port The first downlink signal includes: a channel state information reference signal CSI-RS, or a cell level reference signal CRS, or a synchronization signal SS, or a discovery signal.

 In the above solution, the measuring module is configured to measure the receiving strength on the RE corresponding to the zero-power first downlink signal and use the interference strength as the interference strength.

 In the above solution, the measuring module is configured to measure a receiving strength on the RE corresponding to the first downlink signal and a received power of the first downlink signal, and use the difference between the two as the interference strength.

 In the above solution, the measuring module is configured to measure a receiving strength on the RE corresponding to the first downlink signal after performing the interference canceling operation on the first downlink signal, and use the receiving strength as the interference strength.

In the above solution, the determining module is configured to measure a received power of the specified second downlink signal, and determine whether to enable the right or not according to a ratio between the received power of the second downlink signal and the interference strength and a determination criterion. The measurement of the serving cell; wherein, the received power of the second downlink signal is a reference signal received power RSRP, or a channel state information reference signal received power CSI-SRP, or sync signal received power.

 In the foregoing solution, the determining module is configured to execute a determining criterion, where the determining criterion includes: when the UE determines that the interference strength is higher or lower than the starting to measure the non-serving cell For the limit, measurements are made for non-serving cells.

 In the foregoing solution, the determining module is configured to execute a determining criterion, where the determining criterion includes: using the interference strength, a ratio between a receiving strength of the second downlink signal and an interference strength, RSRP, RSRQ And at least two parameters in the CSI-RSRP, controlling the measurement of the non-serving cell.

 In the foregoing solution, the determining module is configured to enable measurement of the non-serving cell, where the measuring the non-serving cell is: the UE starts the measurement of the non-serving cell by itself; or The serving base station reports a measurement result or a strong interference indication so that the serving base station configures measurements for non-serving cells.

 In the above solution, the resources of the first downlink signal include: resources of a licensed frequency band and resources of an unlicensed frequency band;

 The determining module is configured to: when the resource of the first downlink signal is a resource of the unlicensed frequency band, select, according to the interference strength, whether to enable measurement of a non-serving cell, select an aggregate carrier, and Activate and configure the secondary cell scell.

 The method and device for controlling measurement by a UE according to an embodiment of the present invention can determine whether a current UE is close to a small cell in a macro cell by measuring a received strength of a signal on a resource unit (RE) corresponding to the specified first downlink signal. If it is close, the signal measurement on the small cell is started. Otherwise, the signal measurement on the small cell is not turned on, so that the measurement function of the same-frequency/inter-frequency non-serving cell can be started in real time, and the macro cell is timely discovered. The small cell in the network reduces the load on the macro cell and improves the quality of service to the UE. DRAWINGS

 FIG. 1 is a schematic flowchart 1 of a method for controlling a UE to perform measurement according to an embodiment of the present invention;

2 is a schematic structural diagram of a device for controlling a measurement performed by a UE according to an embodiment of the present invention; 3 is a schematic flowchart 2 of a method for controlling measurement by a UE according to an embodiment of the present invention; FIG. 4 is a schematic diagram of resource coordination when a macro cell and a small cell coexist in an embodiment of the present invention; FIG. 5 is a schematic diagram of a macro cell and a small embodiment according to an embodiment of the present invention; FIG. 6 is a schematic diagram of resource coordination when a macro cell and a small cell coexist in the embodiment of the present invention; FIG. detailed description

 The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

 The method for controlling the measurement by the UE in the embodiment of the present invention, as shown in FIG. 1 , includes the following steps: Step 101: The UE measures the interference strength on the RE corresponding to the specified first downlink signal.

 Here, the first downlink signal may be a zero-power downlink signal of the current serving cell, or may be a non-zero-power downlink signal of the current serving cell; wherein the zero-power downlink signal may be: a zero-power CSI-RS ( Including CSI Interference Measurement Resource (CSI-IMR), or zero-power CRS, or zero-power SS, or zero-power discovery signal; the non-zero-power downlink signal may be: non-zero-power CSI-RS, or non-zero Power CRS, or non-zero power sync signal, or non-zero power discovery signal.

 The RE corresponding to the specified first downlink signal is configured by the UE according to the measured configuration information of the received first downlink signal;

 The measurement configuration information of the first downlink signal may be sent to the UE by the macro base station, and includes: a resource configuration list of the first downlink signal, subframe configuration information, and a threshold for starting measurement on the non-serving cell. Value, etc.

 The measurement is prior art and will not be described here.

 Preferably, before performing step 101, the base station of the serving cell further performs resource coordination with the small base station of the small cell, and may perform through an X2 interface, an S1 interface, or through a network management (OAM) or even a UE (but not limited to these interfaces).

Step 102: The UE determines, according to the interference strength, whether to enable measurement of a non-serving cell. An apparatus for controlling a UE to perform measurement according to an embodiment of the present invention, as shown in FIG. 2, includes: a measurement module 21 and a decision module 22;

 The measuring module 21 is configured to measure the received strength of the signal on the RE corresponding to the specified first downlink signal, and send the received strength of the signal to the decision module 22;

 The decision module 22 is configured to determine whether to open the measurement of the non-serving cell according to the receiving strength of the first downlink signal on the RE sent by the measuring module 21.

 The device further includes: a receiving module 23 configured to receive and save measurement configuration information of the first downlink signal, and send the measurement configuration information of the first downlink signal to the measurement module 21; correspondingly, the measurement module 21 And configuring, to receive and save the measurement configuration information sent by the receiving module 23, where the measurement configuration information is resource location information of the first downlink signal, and includes at least one of the following: subframe configuration information, frequency domain configuration information, Port information; the first downlink signal includes: a CSI-RS, or a CRS, or an SS, or a discovery signal.

 The measuring module 21 is configured to measure a receiving strength on the RE corresponding to the first downlink signal and a received power of the first downlink signal, and use the difference between the two as the interference strength.

 The measuring module 21 is configured to measure a receiving strength on the RE corresponding to the first downlink signal after performing the interference cancellation operation on the first downlink signal, and use the received strength as the interference strength.

 The determining module 22 is configured to measure a received power of the specified second downlink signal, determine, according to a ratio between the received power of the second downlink signal and the interference strength, and a determination criterion, whether to enable the non-serving cell The receiving power of the second downlink signal is a reference signal received power RSRP, or a channel state information reference signal received power CSI-RSRP, or a synchronization signal received power.

 The determining module 22 is configured to execute a determining criterion, where the determining criterion includes: when the UE determines that the interference strength is higher or lower than a threshold value for starting to measure a non-serving cell , measure the non-serving cell.

The determining module 22 is configured to execute a determining criterion, where the determining criterion includes: using the interference strength, a ratio between a receiving strength of the second downlink 't number and an interference strength, At least two parameters of RSRP, RSRQ, and CSI-RSRP control the measurement of the non-serving cell. The determining module 22 is configured to enable measurement of the non-serving cell. The measuring the non-serving cell includes: the UE starts the measurement of the non-serving cell by itself; or the UE reports to the serving base station. The measurement result or strong interference indication is such that the serving base station configures measurements for non-serving cells.

 Both the measurement module 21 and the decision module 22 described above can be implemented by hardware such as a CPU or a DSP. Embodiment 1

 An embodiment of the method for controlling the UE to perform measurement may be as shown in FIG. 3, and a schematic diagram of the current macro cell and the small cell picol and pico2 coexisting is shown in FIG. 4, wherein the Macro Cell has a larger The coverage, pico l and pico2 have a smaller coverage.

 Step 301: Perform resource coordination between the Macro Cell and the small cell.

 Specifically, the macro cell and the small cell coordinate, for example, through an X2 interface, an S1 interface, or through an network management (OAM), or a UE (not limited to a UE that needs to perform small cell discovery).

 Taking the coordination of the X2 interface as an example, the macro cell can pass the X2 Setup flow message, ENB.

The configuration update process message, or the X2 message such as the Load Information message, directly or indirectly (through the X2 gateway or the proxy X2 gateway, X2 proxy) indicates the configuration information of the zero-power CSI-RS of the macro cell to the small cell (the macro cell can also be prepared by handover) The RRC information between the base stations carried in the flow message, for example, AS-Config notifies the small cell of the configuration information of the zero-power CSI-RS of the macro cell, or the macro cell recommends the non-zero power to the small cell (the small cell) through the X2 message. The configuration information of the CSI-RS, after receiving the configuration information, the small cell can configure its own non-zero power CSI-RS to complete the coordination between the cells. Conversely, the small cell can also indicate its non-zero power CSI to the macro cell directly or indirectly (via X2 gateway or proxy X2 gateway, X2 proxy) through X2 Setu flow message, ENB Configuration Update flow message, or Load Information message. - The configuration of the RS, the macro cell then configures the corresponding zero-power CSI-RS measurement for the UE through the air interface.

A method for coordinating inter-cell configuration through an S1 interface or other interfaces includes: The MME and/or the gateway (eg, HeNB GW, S1 GW) delivers the configuration of the zero-power CSI-RS or the configuration of the recommended non-zero-power CSI-RS to the opposite base station, and/or the small base station passes the MME and/or the gateway ( The gateway, for example HeNB GW, S 1 GW ), communicates the configuration of the non-zero power CSI-RS or the configuration of the recommended zero power CSI-RS to the macro base station.

 The method for coordinating inter-cell configuration by the network management system includes: the network management system indicates a zero-power CSI-RS configuration to the macro base station, and the network management system indicates a non-zero-power CSI-RS configuration to the small base station; or the network management system sends the small cell to the macro base station. The zero-power CSI-RS configuration information sends the zero-power CSI-RS configuration information of the macro cell to the small base station. The specific manner of transmitting the macro and the small cell by the UE includes: the macro UE sends the zero-power CSI-RS configuration information configured by the previous macro cell to the small cell after switching to the small cell, or the small cell switches to the macro cell. The non-zero-power CSI-RS configuration information configured by the small cell is sent to the macro cell, or the macro base station allows the UE to receive system information of the small cell, including non-zero-power CSI-RS configuration information, by using a measurement process, and Reported by the UE to the macro base station.

 Preferably, since the CSI-RS brings a certain overhead, in order to reduce the CSI-RS overhead of the small cell without affecting the accuracy of the non-serving cell measurement control based on the interference strength, the small cell may also be in the macro cell. The data (data) or the dummy data (dummy) is transmitted at the RE location corresponding to the ZP CSI-RS. For example, if the small cell on the PRB corresponding to the measurement bandwidth has data transmission, the data is normally transmitted, otherwise the dummy RE is sent; or the pico always sends the dummy RE, the dummy RE at the RE position corresponding to the macro cell ZP CSI-RS. Data can be transferred normally on other REs.

In addition, the small cells may also be grouped, and the CSI-RS time-frequency resources of the small cells in the same group are aligned, or both correspond to the same ZP CSI-RS configuration of the macro cell. The basis of the grouping may be determined according to the deployment needs, for example: grouping according to geographical area, grouping according to the power size or coverage of the small base station, grouping according to the type of backhaul, or CSG according to the small cell (closed user group, closed Subscriber group) attribute grouping, for example, open mode small cell, closed mode small cell, hybrid mode small cell, where any user of open small cell can access normally, closed type Small cells can only be used by member users. Access, non-member users can not access, hybrid small cells preferential access and services for member users, non-member users can also access. For a small cell of a packet, etc., the macro base station can be configured with multiple

For ZP-CSI-RSSI or CSI-RSRQ measurements, each measurement configuration can have different ZP-CSI-RS resource configurations.

 Step 302: The UE receives measurement configuration information sent by the macro base station.

 Here, the measurement configuration information includes: resource configuration information (interference measurement resource configuration information) of the first downlink signal, where the zero power resource configuration list and the zero power subframe configuration information are included. The measurement configuration information further includes a start measurement threshold for controlling whether to initiate measurement for the non-serving cell, and/or parameter information k for filtering the measured value.

 The measurement configuration information of the first downlink signal sent by the macro base station may be: the macro base station sends the measurement configuration information of the first downlink signal by using a radio link reconfiguration message (RRCConnectionReconfiguration).

 The first downlink signal is a zero power CSI-RS;

 The selection of the RE corresponding to the first downlink signal includes: as shown in FIG. 4, each transmission node has a downlink resource block (RB), and the RB is composed of a series of REs, and each RE is composed of (k, 1) Two-dimensional coordinate representation, where k represents the subcarrier index of the frequency domain and 1 represents the symbol index of the time domain. When 1=5, 6 , the number from the top to the bottom (counting from 1) The 2 REs corresponding to the 3rd subcarrier correspond to the non-zero power channel state information reference signal of the macro cell (CSI-RS, Channel State Information) -Reference Signal ), the two REs corresponding to the fourth subcarrier from the top correspond to the zero-power CSI-RS. In picol and pico2, when 1=5 and 6, the two REs corresponding to the third subcarrier from the top correspond to the zero-power CSI-RS of the small cell, and the fourth subcarrier corresponding to the top from the top. The 2 REs correspond to the non-zero power CSI-RS of the small cell. That is, the RE position of the zero-power CSI-RS of the Macro Cell corresponds to the position of the non-zero power CSI-RS of picol and pico2, and the RE position of the non-zero power CSI-RS of the macro corresponds to the picol and pico2 The location of the power CSI-RS.

The RE corresponding to the specified first downlink signal is indicated by the measurement configuration information of the first downlink signal that is sent by the macro base station of the serving cell. The zero base power CSI-RS measurement configuration of the macro base station for the UE may further include a bandwidth of zero power CSI-RSSI measurement;

 Here, the configuration of the bandwidth measured by the zero-power CSI-RSSI includes measuring a center frequency point and a bandwidth (the number of RBs), an RB start index and an end index, an RB start index, and an RB number, and the like. In this way, even if the macro cell and the small cell are different in frequency, as long as the spectrums of the macro cell and the small cell overlap, it is possible to determine whether or not the small cell of the different frequency is close by measuring on the overlapping bandwidth, thereby starting the inter-frequency. Measurement of small cells.

 Step 303: The UE measures the receiving strength on the RE corresponding to the zero-power CSI-RS according to the measurement configuration information.

 The measurement includes: the UE is based on physical layer measurement, that is, zero power CSI-RS on the measured bandwidth.

(or the interference measurement resource) a linear average of the total received power on the RE, and the measurement data is filtered using a calculation formula to obtain the reception strength of the first downlink signal on the RE. The calculation formula is ^ ¹ - " ^ " ^ "; where a = l / 2 ^{(k / 4} M „ the latest measurement from the physical layer, F „ is the updated filtered measurement.

 Step 304: The UE determines, according to the receiving strength of the first downlink signal on the RE, whether to enable measurement of the non-serving cell.

 Specifically, the UE determines whether the receiving strength of the first downlink signal on the RE is not lower than or higher than a starting measurement threshold, and if yes, the UE starts to measure the non-serving cell;

The UE does not measure non-serving cells or small cells of the same frequency and different frequency.

Taking FIG. 4 as an example, the macro UE0 is far away from picol and pico2, and the measured reception strength of the first downlink signal on the RE may be lower than the starting measurement threshold, so the non-monthly The measurement of the cell (or small cell); while the macro UE1 and the macro UE2 are close to picol and pico2, respectively, the received downlink signal on the RE has a higher reception strength, and as they are close to picol and pico2 The UE1 and the UE2 each start a non-serving cell (or a small cell) when the received strength of the first downlink signal on the RE that is measured by each of them is greater than the start measurement threshold. Measurement. The UE starts to perform measurement on the non-serving cell, and includes: the UE directly starts to perform measurement on the non-serving cell; or, when the UE determines that the reporting condition of the base station configuration is met, the UE reports the measurement result to the serving base station, and the serving base station performs non-serving according to the measurement result. The measurement configuration of the cell (or small cell) and/or the initiation of the measurement.

 The above measurement based on ZP-CSI-RSSI reflects the received signal strength of the non-serving cell. Considering the relative value of the signal strength of the serving cell and the neighboring cell, which is usually used for decision making in radio resource management, the channel can also be defined. The status information reference signal reception quality (CSI-RSRQ) is the channel state information reference signal reception power (CSI-RSRP, and the physical layer measurement is based on the power contribution of the CSI-RS on the RE corresponding to the CSI-RS on the measured bandwidth. Linear average) is the ratio of the interference intensity ZP-CSI-RSSI. It can be seen that the CSI-RSRQ calculated by the UE is the ratio of CSI-RSRP and ZP-CSI-RSSI measured by the UE on different REs. This value reflects the ratio of the signal power of the serving cell to the signal strength of the non-serving cell. Therefore, it can reflect whether the UE is away from the serving macro cell or whether the UE is close to the small cell. Therefore, the UE can also control the measurement of the non-serving cell based on the measurement of the CSI-RSRQ defined above. When the CSI-RSRQ is lower than (or less than or equal to) the threshold configured by the base station, the UE initiates measurement of the non-serving cell, otherwise the UE may not measure the non-serving cell.

 In a large-scale radio access network, the performance of small cell discovery can also be improved through a large-scale coordination, for example, aligning REs corresponding to zero-power CSI-RSs of multiple Macro cells, so that the UE detects the ZP. - The CSI-RSSI only reflects the power strength of the small cell, which can improve the accuracy of starting small cell measurements. On the other hand, usually the initiation of small cell discovery does not need to be initiated alone, the small cell discovery can be performed in the non-serving cell measurement, and the measurement of the non-serving cell not only needs to consider the needs of small cell discovery, but also needs to be considered in the macro. The need for UE mobility (e.g., handover) for small intervals, for which a joint decision criterion can be employed.

The joint decision criterion includes: combining ZP-CSI-RSSI or CSI-RSRQ with at least two of RSRP (CRS-based), RSRQ or CSI-RSRP-based measurements to control a co-frequency/inter-frequency non-serving cell Measurement of (adjacent cell). For example, mode 1: if ZP-CSI-RSSI>threshold, or RSRP is less than the threshold configured by a certain base station, start to non-service Measurement of the cell; Mode 2: When ZP-CSI-RSSI>threshold, or CSI-RSRP is smaller than the threshold configured by a certain base station, start measurement of the non-serving cell; Mode 3: If CSI-RSRQ<thresholdl or RSRP is smaller than a certain The threshold configured by the base station starts the measurement of the non-serving cell; mode 4: If the CSI-RSRQ<threshold1, or the CSI-RSRP is smaller than the threshold configured by a certain base station, the measurement of the non-serving cell is started. If the measurement is initiated only for small cell discovery, at least two of ZP-CSI-RSSL CSI-SRQ. RSRP (CRS-based), RSRQ, and CSI-RSRP may be combined to control the measurement of the small cell. The example changes the "or" relationship of the conditional judgments in the above four ways to the "and" relationship. Using a single conditional criterion, the joint decision criterion is executed when the criterion of the single condition is satisfied. The specific examples are as follows: First or default, the CRS-based RSRP decision criterion is adopted, when the RSRP based on the CRS measurement value is smaller than the predefined or When the base station configures the threshold, the joint decision criterion is executed to determine whether to initiate the same or different frequency measurement by a new measurement (for example, measurement of ZP-CSI-RSSI or CSI-RSRQ). As another example, UEs in a particular transmission mode use joint decision criteria for measurement control. The base station may also indicate, by means of signaling, the UE to perform joint determination criteria, including Radio Resource Control (RRC) layer IE, MAC layer control element control element, and downlink control information (abbreviation). For DCI).

In addition, the above determination condition is that the comparison between the measured value and the threshold value is used as a determination basis (or one of the judgment criteria), and this method may be referred to as an intensity determination method. In addition, it is also conceivable to use the increment of the measured value as the discriminating condition for starting the intra-frequency/inter-frequency measurement. This method is called the incremental decision method. According to ZP-CSI-RSSI or CSI-RSRQ in a certain time increment: The measured ZP-CSI-RSSI increase means that the non-serving cell signal (or interference signal) is enhanced in intensity, if ZP-CSI-RSSI continues to increase, It may be that the distance is closer and closer to another cell, and the measurement may be considered; or, the decrease of CSI-RSRQ means that the interference strength increases and/or the signal strength of the serving cell decreases. If the CSI-RSRQ continues to decrease, the distance may be indicated. The serving cell is getting farther and farther, and getting closer and closer to the neighboring cell, you can consider starting the measurement. Incremental decision method and intensity judgment method can also be linked Together, it is determined whether to initiate non-serving cell or small cell measurement. Embodiment 2

 Fig. 5 is a diagram showing the coexistence of a macro cell (macro in the figure) and a small cell (pico l and pico2 in the figure). As can be seen, the macro has a larger coverage, and pico l and pico2 have a smaller coverage (because of its smaller transmission power). Due to the huge difference in the coverage of the macro cell and the small cell, the macro UE continuously measures the non-serving cell (including the small cell) at any place, which results in a large user equipment power consumption and computational overhead. Therefore, it is necessary to have a more power-saving method to judge whether the macro user equipment is close to the small cell, thereby starting measurement of the non-serving cell (or small cell) including the small cell.

 In FIG. 5, each transmission node has a downlink RB, and the resource block RB is composed of a series of resource units RE, each RE is represented by (k, 1) two-dimensional coordinates, where k represents a frequency domain subcarrier ( Subcarrier ) index, 1 represents the symbol index of the time domain. When 1=0, the number from the top to the bottom (counting from 1) corresponds to the non-zero power cell-level reference signal (CRS) of the macro cell. The RE corresponding to the fourth subcarrier of the upper and lower numbers corresponds to a zero power CRS. Looking at pico l and pico2, it can be found that when 1=0, the RE corresponding to the 4th subcarrier from top to bottom corresponds to the non-zero power CRS of the small cell. That is, the E position of the macro zero power CRS corresponds to the position of the non-zero power CRS of picol and pico2.

 Step 401: Perform resource coordination between the Macro Cell and the small cell.

 Specifically, the resource coordination between the Macro Cell and the small cell is performed through the X2 interface, the S1 interface, the network management (OAM), and even the UE (not limited to the UE that needs to perform small cell discovery).

Taking the coordination of the X2 interface as an example, the macro cell can directly or indirectly (through the X2 gateway or the proxy X2 gateway, X2 proxy) to indicate the macro to the small cell through an X2 Setup flow message, an ENB Configuration Update flow message, or an X2 message such as a Load Information message. Configuration information of the zero-power CRS of the cell (the macro cell can also allocate the zero-power CRS of the macro cell through the RC information between the base stations carried in the handover preparation flow message, for example, AS-Config The small cell informs the small cell), or the macro cell recommends the configuration information of the non-zero power CRS (small cell) to the small cell through the X2 message, and the small cell can perform its own non-zero power CRS after receiving the configuration information. Configure to complete coordination between cells. Conversely, the small cell can also indicate its non-zero power CRS to the macro cell directly or indirectly (via X2 gateway or proxy X2 gateway, X2 proxy) through X2 Setup flow message, ENB Configuration Update flow message, or Load Information message. The configuration, the macro cell then configures the corresponding zero-power CRS measurement for the UE through the air interface. The method for coordinating the inter-cell configuration through the S1 interface or other interfaces includes the macro base station transmitting a zero-power CRS configuration or recommending a non-zero-power CRS to the opposite base station through the MME and/or the gateway (eg, HeNB GW, S1 GW) Configuration, and Z or, the small base station transmits the configuration of the non-zero power CRS or the configuration of the recommended zero power CRS to the macro base station through the MME and/or the gateway (eg, HeNB GW, S1 GW). The method for coordinating inter-cell configuration by the network management system includes: the network management system indicates a zero-power CRS configuration to the macro base station, and the network management system indicates a non-zero-power CRS configuration to the small base station; or the network management system sends the non-zero-power CRS configuration of the small cell to the macro base station. Information, transmitting zero-power CRS configuration information of the macro cell to the small base station. The specific mode of transmitting the macro between the macro and the small cell by the UE includes: after the handover to the small cell, the macro UE sends the zero-power CRS configuration information configured by the previous macro cell to the small cell, or the small cell switches to the macro cell. The non-zero-power CRS configuration information configured by the small cell is sent to the macro cell, or the macro base station allows the UE to receive the system information of the small cell, including the non-zero-power CRS configuration information, and is reported by the UE to the macro base station. . The manner in which the neighbor cell configuration information reported by the UE is also referred to as a self-organizing/self-optimization network.

Since the CRS brings a certain overhead, in order to reduce the CRS overhead of the small cell without affecting the accuracy of the subsequent non-serving cell measurement control, the small cell may also transmit data at the RE location corresponding to the macro cell ZP CRS. (data) or imitation data (dummy). For example, if the small cell on the PRB corresponding to the measurement bandwidth has data transmission, the data is normally sent, otherwise the dummy RE is sent; or the pico always sends the dummy RE and the dummy RE at the RE position corresponding to the macro cell ZP CS. The data can be transmitted normally on E. In a large-scale radio access network, the performance of small cell discovery can also be improved through a large-scale coordination, for example, aligning REs corresponding to zero-power CRSs of multiple macro cells (constituting a coordinated discovery area) (macro The small interval can transmit the zero-power CRS configuration information through the X2 interface or the network management system, so that the ZP CRS measured by the UE reflects only the power strength of the small cell, which can improve the accuracy of starting the small cell measurement.

 In addition, the small cells may also be grouped, and the CRS time-frequency resources of the small cells in the same group are aligned, or both correspond to the same ZP CRS configuration of the macro cell. The basis of the grouping may be determined according to the deployment needs, for example, according to the geographical area, or according to the power level or coverage of the small base station, or grouped according to the type of backhaul, or according to the CSG of the small cell (closed subscriber group, closed subscriber Group ) attribute grouping, for example, open mode small cell, closed mode small cell, hybrid mode small cell, where any user of open small cell can access normally, closed small Only the member users can access the cell, and the non-member users cannot access the hybrid cell. The hybrid small cell preferentially accesses and services the member users, and the non-member users can also access the cell.

 Step 402: The UE receives measurement configuration information sent by the macro base station.

 Here, the measurement configuration information may include: configuration information of zero-power CRS (interference measurement resource configuration information); configuration information of the zero-power CRS includes zero-power subframe configuration information, zero-power CRS frequency domain offset, or The configuration information of the zero-power CRS corresponding to the zero-power CRS frequency domain offset may also include the port number or the port number.

 Preferably, the measurement configuration information may further include: a threshold parameter (control) for controlling whether to start measurement on the non-serving cell, and parameter information k for filtering the measurement value.

The macro base station can not only measure the default bandwidth for the ZP CS measurement configuration of the macro UE, and the macro base station can also configure the bandwidth measured by the ZP-CRS-RS SI. The configuration can be expressed by the following method, for example, measuring the center frequency + bandwidth ( RB number), RB start index and end index, RB start index and RB number, and so on. In this way, even if the macro cell and the small cell have different frequencies (that is, the center frequencies of the two cells are different), as long as the spectrum of the macro cell and the small cell overlap, the bandwidth can be over the overlapping bandwidth. The measurement determines whether the macro UE is close to the small cell of the different frequency, thereby starting the measurement of the small cell of the different frequency.

 The receiving configuration information sent by the UE to the macro base station may be: receiving, by the UE, the measurement configuration information sent by the macro base station by using a radio link reconfiguration message (RRCConnectionReconfiguration), step 403: the UE measures zero according to the measurement configuration information. The interference strength on the RE corresponding to the power CRS.

 According to these measurement configurations, the macro UE receives the signal on the RE corresponding to the zero-power CRS (or interference measurement resource) (for example, the RE corresponding to the fourth sub-carrier of the symbol 0 from the top in FIG. 3) The intensity is measured. Since the macro cell has zero power on these REs, it means that the received signal strength measured by the macro UE on these REs represents the signal strength of the non-serving cell (in the example of FIG. 4, the signals of the CRS including picol and pico2 are included). Intensity), or it can also be called interference strength (for the serving cell, the signals of these non-serving cells are interference). This measurement can be referred to as the zero-power-CRS-based SSI (abbreviated as ZP-CRS-RSSI) based on the zero-power small-area reference signal.

Measurement based on L1 physical layer (the measurement of the physical layer is based on the linear average of the total received power on the RE corresponding to the zero-power CRS on the measured bandwidth), and the macro UE uses the formula = (1_"Χ- _{1 +} " · Μ „Filtering layer ₃ , where _α= , Μ„ is the most from the physical layer

2 ⁴

The new measurement result, F„ is the updated filtered measurement result, which is the measurement result after the last filtration.

 Step 404: The UE determines, according to the interference strength of the first downlink signal on the RE, whether to enable measurement of the non-serving cell. If yes, perform step 405; otherwise, end the processing process.

Specifically, if ZP-CRS-RSSI>=threshold (or ZP-CRS-RSSI>threshold is also possible), the macro UE initiates measurement of the non-serving cell (or small cell), otherwise the macro UE may not measure the same frequency. And non-serving cells or small cells with different frequencies (may also be non-service small in other systems) District, or small community). Taking Figure 4 as an example, the macro UE0 is far away from picol and pico2, and the measured ZP-CRS-RSSI may be lower than the threshold, so the measurement of the non-serving cell (or small cell) will not be initiated (small cell The measurement configuration may be the same as or different from the measurement configuration of the non-serving cell; and the macro UE1 and macro UE2 are close to picol and pico2, respectively, and the detected ZP-CRS-RSSI is due to the power of the CRS including the pico (that is, the interference strength). ), will be relatively high, and tend to increase as they are close to picol and pico2, respectively, when their respective measured ZP-CRS-RSSI is greater than threshold, UE1, UE2 will each initiate a non-serving cell Measurement of (or small cell), thereby discovering and identifying a non-serving cell or a small cell (i.e., picol or pico2 in the figure) through cell search.

 The above measurement based on ZP-CRS-RSSI reflects the received signal strength of the non-serving cell, considering that the relative value of the signal strength of the serving cell and the neighboring cell is usually used for decision making in radio resource management (for example, in handover decision) Therefore, it is also possible to define RS Q*=RS P/ZP-CRS- SSI, where RSRQ* is the newly defined reference signal reception quality, and RSRP is the cell-level reference signal reception power (measured on the RE corresponding to the non-zero power CRS) The measurement of the physical layer is based on a linear average of the power contribution of the CRS on the RE corresponding to the CRS on the measured bandwidth). It can be seen that the RSRQ* calculated by the UE is the ratio of the RSRP and the ZP-CRS-RSSI measured by the UE on different REs. This value reflects the ratio of the signal power of the serving cell to the signal strength of the non-serving cell. Therefore, it can reflect whether the UE is away from the serving macro cell or whether the UE is close to the small cell. Therefore, the UE can also control the measurement of the non-serving cell based on the measurement of the RSRQ* defined above. For example, when the RSRQ* is lower than the threshold configured by the base station, the UE initiates measurement of the non-serving cell, otherwise the UE may not measure the non-serving cell.

In addition, the above determination condition is that the comparison between the measured value and the threshold value is used as a determination basis (or one of the judgment criteria), and this method may be referred to as an intensity determination method. In addition, it is also conceivable to use the increment of the measured value as one of the discriminating conditions for starting the intra-frequency/inter-frequency measurement. This method is called an incremental decision method. According to the increment of ZP-CSI-RSSI or CSI-RSRQ within a certain time: The measured increase of ZP-CSI-RSSI means that the strength of the non-serving cell signal (or interference signal) is enhanced, if the ZP-CSI-RSSI continues to enhance, May indicate that it is getting closer and closer to another cell, you can consider starting Measurement; or, the decrease of CSI-RSRQ means that the interference strength increases and/or the serving cell signal strength decreases. If the CSI-RSRQ continues to decrease, it may indicate that the distance from the serving cell is getting farther and farther, and the distance from the neighboring cell is coming. The closer you are, the more you can consider starting the measurement. The incremental decision method and the strength determination method can also be combined to determine whether to initiate non-serving cell or small cell measurement.

Generally, the initiation of small cell discovery does not need to be initiated alone, and small cell discovery can be performed in non-serving cell measurement, while the measurement of non-serving cells needs to consider not only the needs of small cell discovery but also the UE between macro cells. The need for mobility (eg, handover), for which a joint decision criterion, ie, measurement of ZP-CRS-RSSI or RSRQ*, RSRP (CRS-based), RSRQ, or CSI-RSRP-based measurements, may be employed. At least two jointly control the measurement of the co-frequency/inter-frequency non-serving cell (adjacent cell). For example, mode 1: If the ZP-C S-RS SI>threshold, or the RSRP is smaller than the threshold configured by a certain base station, start measurement of the non-serving cell; Mode 2: When ZP-CRS-RSSI>threshold, or CSI-RSRP If the threshold is less than the configuration of a certain base station, start the measurement of the non-serving cell; Mode 3: If RSRQ*<threshold1, or the RSRP is smaller than the threshold configured by a certain base station, start the measurement of the non-serving cell; Mode 4: If RSRQ*< Threshold1, or CSI-RSRP is less than the threshold configured by a certain base station, and starts measurement of the non-serving cell. If the start of the measurement is only for small cell discovery, it is also possible to combine the measurement of ZP-CRS-RS SI or RSRQ* with at least two of RSRP (CRS-based), RSRQ or CSI-RSRP-based measurements. For the measurement of the small cell, specifically, the "or" relationship of the conditional judgments in the above four methods is changed to the "and" relationship. Using a single conditional criterion, the joint decision criterion is performed when the criterion of the single condition is satisfied. The specific example is as follows: First or default, the CRS-based RSRP criterion is used, when the RSRS measurement value is smaller than the RSRP. When a predefined or base station configured threshold is used, a joint decision criterion is then performed to determine whether to initiate the same or different frequency measurement by a new measurement, such as a ZP-CRS-RSSI or RSRQ* measurement. As another example, UEs in a particular transmission mode use joint decision criteria for measurement control. The base station may also indicate, by means of signaling, the UE to perform joint determination criteria, including adio Resource Control (RRC) layer IE, MAC layer control element. Control element, downlink control information (abbreviated as DCI).

 Step 405: The UE starts measurement of the non-serving cell.

 The method for specifically starting the measurement of the non-serving cell (or the small cell) is as follows: In the first mode, the serving base station has configured the measurement of the non-serving cell (or small cell) for the UE, but the measurement needs to wait for the UE to specifically The determination of the condition can be started. In the second mode, the UE reports the measurement result to the serving base station or sends a specific indication (such as a strong interference indication) after determining that the (base station configured) reporting condition is met, and the base station according to the measurement result or a specific indication (for example, strong) Interference indication) Perform measurement configuration (and/or start of measurement) of a non-serving cell (or small cell). In this way, the macro UE can perform measurement on the non-serving cell/small cell only in a local area close to the small cell, and does not need to perform measurement on the non-serving cell/small cell in most areas away from the small cell, thereby It not only reduces the power consumption and computational overhead caused by the measurement, but also can detect the small cell in time and improve the quality of service (including the throughput) by switching/diverting to the small cell or using the small cell as the secondary carrier to reduce the load of the macro cell. . Embodiment 3

 Fig. 6 is a diagram showing the coexistence of a macro cell (macro in the figure) and a small cell (icol and pico2 in the figure). As can be seen, the macro has a larger coverage, and the coverage of picol and pico2 is smaller (due to its smaller transmission power). Due to the huge difference in the coverage of the macro cell and the small cell, the macro UE continuously measures the non-serving cell (including the small cell) at any place, which results in a large user equipment power consumption and computational overhead. Therefore, it is necessary to have a more power-saving method to determine whether the macro user equipment is close to the small cell, thereby starting measurement of the non-serving cell including the small cell.

In FIG. 6, each transmission node (subframe 0, or subframe 5) has a downlink resource block (abbreviated as RB), and the resource block RB is composed of a series of resource units RE. Composition, each RE is represented by (k, 1) two-dimensional coordinates, where k represents the subcarrier index of the frequency domain, and 1 represents the symbol index of the time domain. For the macro node, when When 1=5, 7 of the 12 REs are zero-power secondary synchronization (synchronous signal, abbreviated as SSS); when 1=6, 12 REs carry zero-power primary synchronization sequence! j ( primary Synchronization signal, abbreviated as PSS). Looking at ico and ico2, it can be found that when 1=5, 7 of the 12 REs are part of the secondary synchronization signal (SSS); when 1=6, the 12 REs are carried. Is the rimary synchronization signal (abbreviated as PSS). That is, the RE position of the macro's zero-power PSS/SSS corresponds to the position of the non-zero power PSS/SSS of picol and pico2.

 Step 501: Perform resource coordination between the Macro Cell and the small cell.

Here, the step 501 is an optional step; specifically, through an X2 interface, an S1 interface, or through an OAM or even a UE (not limited to a UE that needs to perform small cell discovery). Taking the coordination of the X2 interface as an example, the macro cell can directly or indirectly (through the X2 gateway or the proxy X2 gateway, X2 proxy) to the small cell through the X2 Setu flow message, the ENB Configuration Update flow message, or the X2 message such as the Load Information message. The configuration information of the zero-power SS of the cell (the macro cell may also notify the small cell of the configuration information of the zero-power SS of the macro cell by using the RRC information between the base stations carried in the handover preparation flow message, for example, AS-Config), or the macro cell passes the above The X2 message recommends the configuration information of the non-zero power SS (small cell) to the small cell. After receiving the configuration information, the small cell can configure its own non-zero power SS to complete the coordination between the cells. In turn, the small cell can also indicate its non-zero power SS to the macro cell directly or indirectly (via X2 gateway or proxy X2 gateway, X2 proxy) through X2 Setu flow message, ENB Configuration Update flow message, or Load Information message. The configuration, the macro cell then configures the corresponding zero-power SS measurement for the UE through the air interface. The method for coordinating the inter-cell configuration through the S1 interface or other interfaces includes the macro base station transmitting a zero-power SS configuration or recommending a non-zero-power SS configuration to the opposite base station through the MME and/or a gateway (eg, HeNB GW, S1 GW). And/or, the small base station transmits the configuration of the non-zero power SS or the configuration of the recommended zero power SS to the macro base station through the MME and/or the gateway (eg, HeNB GW, S1 GW). A method for coordinating inter-cell configuration through a network management system includes: The system indicates a zero-power SS configuration to the macro base station, and the network management system indicates a non-zero-power SS configuration to the small base station; or the network management system sends the non-zero-power SS configuration information of the small cell to the macro base station, and sends the zero-power SS configuration of the macro cell to the small base station. information. The specific mode of transmitting the macro between the macro and the small cell by the UE includes: after the handover to the small cell, the macro UE sends the zero-power SS configuration information configured by the previous macro cell to the small cell, or the small cell switches to the macro cell. The non-zero-power SS configuration information configured by the small cell is sent to the macro cell, or the macro base station allows the UE to receive the system information of the small cell, including the non-zero-power SS configuration information, and is reported by the UE to the macro base station. . The manner in which the neighbor cell configuration information reported by the UE is also referred to as a self-organizing/self-optimization network.

 In a large-scale radio access network, the performance of small cell discovery can also be improved through a wide range of coordination, for example, aligning REs corresponding to zero-power PSS/SSS of multiple macro cells (constituting a coordinated discovery area) (The zero-power PSS/SSS configuration information can be transmitted between the macro cells through the X2 interface or the network management system, etc.), so that the ZP SS-RSSI measured by the UE only reflects the power strength of the small cell, which can improve the accuracy of starting the small cell measurement. .

 Step 502: The UE receives measurement configuration information sent by the macro base station.

The macro base station first performs measurement configuration for the macro UE, and includes configuration information of the zero power SS (interference measurement resource configuration information) in the measurement configuration information, and configuration information of the zero power SS includes zero power subframe configuration information. (The zero-power PSS/SSS has a small interval, for example, a zero-power PSS/SSS occurs every 10 frames, that is, 100 ms or more, and the zero-power PSS/SSS has little effect on other UEs. Other methods can also To reduce the impact on other UEs, for example, zero power of PSS/SSS can be alternately generated, for example, zero-power PSS occurs when system frame number modulo 10 is equal to 0, and zero-power SSS is when system frame number modulo 10 is equal to 5. When present, zero-power PSS and zero-power SSS can also be configured at different times, for example, only zero-power PSS is configured, and once every 100 ms. When only zero-power PSS or zero-power SSS is configured, the UE only measures zero-power. The signal strength measurement information on the RE corresponding to the synchronization signal further includes a threshold parameter (threshold) for controlling whether to start measurement on the non-monthly service cell. The measurement configuration information may also include parameter information k for filtering the measured values. The macro base station is configured to measure the ZP PSS/SSS measurement of the macro UE. The default bandwidth of the PSS/SSS is 6 RBs. When the center frequency of the small cell is different from that of the macro base station, the macro base station The center frequency of the ZP-SS-RSSI measurement can also be configured so that the RB measured by the ZP-SS-RSSI is the center 6 RBs of the small cell (the macro base station can know the center frequency of the small cell through the X2 interface). In this way, even if the macro cell and the small cell have different frequencies (that is, the center frequency points of the two are different), as long as the spectrum of the macro cell and the small cell overlap, the macro UE can be determined by measurement on the overlapping bandwidth. Close to the small cell of the different frequency, thereby starting the measurement of the small cell with different frequency.

 The macro UE receives the radio link reconfiguration message (RRCConnection econfiguration) of the macro base station, and includes the above measurement configuration information.

 Step 503: The UE measures the interference strength on the RE corresponding to the zero power PSS/SSS according to the measurement configuration information.

Based on these measurement configurations, the macro UE measures the received strength of the signal on the RE corresponding to the zero power PSS/SSS (or interference measurement resource) (eg, including symbol 5 symbol 6 in Figure 6). Since the macro cell has zero power on these REs, it means that the received signal strength measured by the macro UE on these REs represents the signal strength of the non-serving cell (for example, in Figure 6, the PSS/SSS including picol and pico2) The signal strength), or it can also be called the interference strength (for the serving cell, the signals of these non-serving cells are interference). This measurement can be referred to as a zero-power-SS-based RSSI (abbreviated as ZP SS-RSSI). Measurement based on the L1 physical layer (the measurement of the physical layer is based on the linear average of the total received power on the RE corresponding to the zero power SS over the measured bandwidth), the macro UE uses the formula ^F « = 0 _ ") · Layer 3 Filtration, where α, Μ„ is the latest measurement from the physical layer, F„ is more

The filtered result after the new filter is the result of the last filter.

 Step 504: The UE determines, according to the interference strength of the first downlink signal on the RE, whether to enable measurement of the non-serving cell. If yes, perform step 505; otherwise, end the processing process.

Based on the filtered ZP-SS-RSSI, the macro UE controls the measurement of the non-serving cell. Specifically, If ZP-SS-SSI>=threshold (or ZP-SS-SSI>threshold is also possible), the macro UE initiates measurement of the non-serving cell (or small cell), otherwise the macro UE may not measure the same frequency and different frequency. A non-serving cell or a small cell (may also be a non-serving cell of another standard, or a small cell). Taking Figure 6 as an example, the macro UE0 is far away from picol and pico2, and the measured ZP-SS-RSSI may be lower than the threshold, so the measurement of the non-serving cell (or small cell) will not be started (small cell The measurement configuration may be the same as or different from the measurement configuration of the non-serving cell; while the macro UE1 and macro UE2 are close to picol and pico2, respectively, and the measured ZP-SS-RSSI includes the power of the PSO/SSS including the pico (ie The interference strength) will be relatively high, and will tend to increase as they are close to picol and pico2. When their respective measured ZP-SS-RSSI is greater than threshold, UE1 and UE2 will each start the right Measurement of a serving cell (or small cell) to discover and identify a non-serving cell or a small cell (i.e., picol or pico2 in the figure) through cell search.

 The above measurement based on ZP-SS-RSSI reflects the received signal strength (ie, the interference strength) of the non-serving cell, and it is considered that the relative value of the signal strength of the serving cell and the neighboring cell is usually used for decision making in radio resource management ( For example, switching the decision), so it can also be defined

SSRQ=SSRP/ZP-SS-RSSI, where SSRQ (synchronization signal received quality) is the newly defined synchronization signal receiving shield, SSRP (synchronization signal received power) is the synchronization signal receiving power (corresponding to non-zero power PSS/SSS) On the RE measurement, the measurement of the physical layer is based on the linear average of the power contribution of the synchronization signal on the RE corresponding to the SS over the measured bandwidth). It can be seen that the SSRQ calculated by the UE is the ratio of the SSRP and the ZP-SS-RSSI measured by the UE on different REs. This value reflects the ratio of the signal power of the serving cell to the signal strength of the non-serving cell. Therefore, it can reflect whether the UE is away from the serving macro cell or whether the UE is close to the small cell. Therefore, the UE can also control the measurement of the non-serving cell based on the measurement of the SSRQ defined above. For example, when the SSRQ is lower than the threshold configured by the base station, the UE initiates measurement of the non-serving cell, otherwise the UE may not measure the non-serving cell.

In addition, the above determination condition is that the comparison between the measured value and the threshold value is used as a determination basis (or one of the judgment criteria), and this method may be referred to as an intensity determination method. In addition, you can also consider According to the increment of the measured value, as one of the discriminating conditions for starting the same-frequency/inter-frequency measurement, this method is called an incremental decision method. Incremental (variation) according to ZP-SS-RSSI or SSRQ within a certain time: The measured ZP-SS-RSSI increase means that the non-serving cell signal (or interference) strength is enhanced, if ZP-SS-RSSI is continuously enhanced , may indicate that it is getting closer to another cell, and may consider starting the measurement; or, the decrease of SSRQ means that the interference strength increases and/or the signal strength of the serving cell decreases. If the SSRQ continues to decrease, it may indicate that the distance from the serving cell is more The farther it is, and the closer it is to the neighboring cell, the start of the measurement can be considered. The incremental decision method and the strength determination method can also be combined to determine whether to initiate non-serving cell or small cell measurement.

 Generally, the initiation of small cell discovery does not need to be initiated alone, and small cell discovery can be performed in non-serving cell measurement, while the measurement of non-serving cells needs to consider not only the needs of small cell discovery but also the UE between macro cells. The need for mobility (such as handover), for which a decision criterion can be used, that is, the measurement of ZP-SS-RSSI or SSRQ is combined with at least two of RSRP (CRS-based), RS Q or SSRP measurements. Measurement of co-frequency/inter-frequency non-serving cells (adjacent cells). For example, mode 1: If ZP-SS-RSSI>threshold, or RSRP is less than the threshold configured by a certain base station, start measurement of the non-serving cell; Mode 2: When ZP-SS-RSSI>threshold, or SSRP is less than a certain threshold (may be configured by the base station), initiate measurement of the non-serving cell; Mode 3: If SSRQ<thresholdl, or RSRP is less than the threshold configured by a certain base station, start measurement of the non-serving cell; Mode 4: If SSRQ<thresholdl, or The SSRP is less than a certain threshold (possibly configured by the base station) to initiate measurements on non-serving cells. If the measurement is initiated only for small cell discovery, the measurement of ZP-SS-RSSI or SSRQ can also be combined with RSRP (CRS-based) or RSRQ, SSRP measurements to control the measurement of small cells. The specific example will be In the four ways, the "or" relationship of the conditional judgment is changed to the "and" relationship.

The above criterion can be executed under specific conditions. For example, the criterion of a single condition can be used first or by default, and the joint decision criterion is executed when the criterion of the single condition is satisfied. The specific example is as follows: first or default CRS-based RSRP decision criterion, when the CRS measurement value RSRP is less than a predefined or base station configured threshold, then the joint determination criterion is executed Whether a co-frequency or inter-frequency measurement is initiated is determined by a new measurement, such as a ZP-SS-RSSI or SSRQ measurement. As another example, UEs in a particular transmission mode use joint decision criteria for measurement control. The base station may also indicate, by means of signaling, the UE to perform joint determination criteria, including Radio Resource Control (RRC) layer IE, MAC layer control element control element, and downlink control information (abbreviation). For DCI).

 Step 505: The UE starts measurement of the non-serving cell.

 The method for specifically starting the measurement of the non-serving cell (or the small cell) is as follows: In the first mode, the serving base station has configured the measurement of the non-serving cell (or small cell) for the UE, but the measurement needs to wait for the UE to specifically The determining of the condition can be started. In the second manner, the UE reports the measurement result or the strong interference indication to the serving base station after determining that the reporting condition is met (the configuration of the base station), and the base station performs the non-serving cell (or small cell) according to the measurement result or the strong interference indication. Measurement configuration (and / or measurement startup). In this way, the macro UE can perform measurement on the non-serving cell/small cell only in a local area close to the small cell, and does not need to perform measurement on the non-serving cell/small cell in most areas away from the small cell, thereby It not only reduces the power consumption and computational overhead caused by the measurement, but also can detect the small cell in time and improve the quality of service (including the throughput) by switching/diverting to the small cell or using the small cell as the secondary carrier to reduce the load of the macro cell. .

 Preferably, the method based on the discovery signal is similar to the method based on the synchronization signal. The main difference lies in the details of the signal pattern, the transmission period, the bandwidth of the discovery signal and the synchronization signal, and the macro base station also needs to send the configuration information of the zero power discovery signal to The macro UE may include information such as the period of the discovery signal, the time offset, and the bandwidth. The basic process is similar to the process based on the synchronization signal, and details are not described herein again. Embodiment 4

 Step 601: Resource coordination between the Macro Cell and the small cell.

 Here, step 601 is an optional step; specifically includes:

In the scenario where the macro cell and the small cell coexist, if the macro cell and the small cell have the same frequency (the same center frequency point) and the field boundary is aligned, the PSS/SSS of the macro cell and the time frequency of the PSS/SSS of the small cell The resources are aligned, and the interference strength measured by the macro UE includes the synchronization signal power of the small cell, and if the two frequencies are different or the field boundaries are not aligned, the PSS/SSS occupied by the macro cell may correspond to a small RE. Other downlink signals (such as data areas) of the cell, in order to ensure the accuracy of the measurement and the discovery of the small cell is not affected by its load (even if the small cell can be found when the small cell is under load or no load), it is better to pass some kind of The method allows the small cell to have a downlink signal transmission on the RE corresponding to the PSS/SSS of the macro cell (since the PSS/SSS is transmitted on the center 6 RBs of the system bandwidth, so RB can also be said), for example, the small cell can be in the macro The downlink data is transmitted on the 6 RBs corresponding to the PSS/SSS of the cell (which can be achieved by corresponding scheduling), or the second downlink synchronization signal (which is different from the downlink synchronization signal transmitted according to the system default configuration). The macro cell and the small cell can coordinate with the small cell to learn the B corresponding to the PSS/SSS of the macro cell. Such coordination can be performed through the X2 interface, the S1 interface, or through the OAM or even the UE (not limited to the UE that needs to perform small cell discovery). ) get on.

Taking the coordination of the X2 interface as an example, the macro cell can directly or indirectly (through the X2 gateway or the proxy X2 gateway, X2 proxy) to indicate the macro to the small cell through an X2 Setup flow message, an ENB Configuration Update flow message, or an X2 message such as a Load Information message. The configuration information of the SS of the cell (the macro cell may also notify the small cell of the configuration information of the SS of the macro cell by using the RRC information between the base stations carried in the handover preparation flow message, for example, AS-Config), or the macro cell is small through the X2 message. The cell recommendation (small cell) configuration information of the SS, after receiving the configuration information, the small cell can configure its own SS to complete the coordination between the cells. Conversely, the small cell can also indicate the configuration of its SS to the macro cell directly or indirectly (via X2 gateway or proxy X2 gateway, X2 proxy) through X2 Setup flow message, ENB Configuration Update flow message, or Load Information message. The macro cell then configures the corresponding SS measurement for the UE through the air interface. The method for coordinating the inter-cell configuration through the S1 interface or other interfaces includes: the macro base station transmits the configuration of the SS or the configuration of the recommended SS to the opposite base station through the MME and/or the gateway (eg, HeNB GW, S1 GW), and/or, The small base station transmits the configuration of the SS or the configuration of the recommended SS to the macro base station through the MME and/or the gateway (eg, HeNB GW, S1 GW). Coordinating the cell through the network management system The configuration method includes: the network management system indicates the SS configuration to the macro base station, and the network management system indicates the SS configuration to the small base station; or the network management system sends the SS configuration information of the small cell to the macro base station, and sends the SS configuration information of the macro cell to the small base station. The specific mode of transmitting the macro between the macro and the small cell by the UE includes: after the handover to the small cell, the macro UE sends the SS configuration information configured by the previous macro cell to the small cell, or the small cell switches to the macro cell and then small The SS configuration information of the cell is sent to the macro cell, or the macro base station allows the UE to receive the system information of the small cell, including the SS configuration information, and is reported by the UE to the macro base station. The manner in which the neighbor cell configuration information reported by the UE is also referred to as a self-organizing/self-optimization network.

 Step 602: The UE receives measurement configuration information of the first downlink signal sent by the macro base station.

 The macro base station first performs measurement configuration for the macro UE, and includes configuration information (interference measurement resource configuration information) of the SS in the measurement configuration information, and the measurement configuration information further includes a threshold parameter (threshold for controlling whether to start measurement on the non-serving cell) ). The measurement configuration information may also include parameter information k for filtering the measured values. The macro UE receives a radio link reconfiguration message (RRCConnectionReconfiguration) of the macro base station, which includes the above measurement configuration information.

 Step 603: The UE measures the interference strength on the RE corresponding to the SS according to the measurement configuration information.

The macro UE measures the received signal strength on the resource unit corresponding to the downlink synchronization signal of the serving cell (ie, the macro cell) (including the primary synchronization signal PSS and the secondary synchronization signal SSS, or only one of them) (or the interference measurement resource) ( The synchronization signal - received signal strength indicator, abbreviated as SS-RSSI, the measurement of the physical layer is based on the linear average of the total received power on the RE corresponding to the SS over the measured bandwidth, and the received signal of the synchronization signal of the serving cell is measured. Power (received signal received power, abbreviated as SSRP, the measurement of the physical layer is based on the linear average of the power contribution of the synchronization signal on the RE corresponding to the SS over the measured bandwidth), the difference between the two (SS-RSSI minus SSRP, The SS-RSSI') is the interference strength measured by the macro UE, that is, the received signal strength of the non-serving cell, and may include signal power from adjacent small cells, and signal power from neighboring macro cells. The UE performs L3 (Layer 3) filtering on the SS-RSSI measured by the physical layer, and also filters SS-RSSI and SSRP separately, and then calculates the SS-RSSI by using the filtered value. The specific filtering formula is:

F _n ^ (\ - a) - F _n _ _{l +} a - M^ where _{a =} ^, is the latest measurement result from the physical layer, ^ is the updated filtered measurement result, which is the last filtered Measurement results.

 Step 604: The UE determines, according to the interference strength of the first downlink signal on the RE, whether to enable measurement of the non-serving cell. If yes, execute step 605; otherwise, end the processing process.

(或者 SS- SSr>threshold也可以） ， 则宏 UE启 动对非服务小区 （或小小区） 的测量， 否则宏 UE可以不测量同频和异频的 非服务小区或小小区 （也可以是其他制式的非服务小区， 或小小区） 。 当宏 UE0离 picol和 pico2都比较远时， 测得的 SS-RSSI'可能会低于 threshold, 因此不会启动对非服务小区 （或小小区）的测量（小小区的测量配置可能与 非服务小区的测量配置相同， 也可能不同 ) ； 而如果宏 UE1和宏 UE2分别 靠近 picol和 pico2，测到的 SS-RSSI'由于包括了 pico的 PSS/SSS的功率（也 就是干扰强度） ， 会相对较高， 并且随着它们各自靠近 picol 和 pico2, 会 趋向于增大， 当它们各自测到的 SS-RSSI'大于 threshold时， UE1、 UE2各 自就会启动对非服务小区 （或小小区）的测量， 从而通过小区搜索发现并识 别非服务小区或小小区 （即图中的 picol或 pico2 ) 。 Based on the filtered SS-RSSI', the macro UE controls the measurement of the non-serving cell. Specifically, if

(or SS-SSr>threshold is also possible), then the macro UE initiates measurement of the non-serving cell (or small cell), otherwise the macro UE may not measure the non-serving cell or the small cell of the same frequency and different frequency (may be other a non-serving cell of a standard, or a small cell). When macro UE0 is far away from picol and pico2, the measured SS-RSSI' may be lower than threshold, so measurement of non-serving cell (or small cell) will not be initiated (small cell measurement configuration may be non-serving) The measurement configuration of the cell is the same or different); and if the macro UE1 and the macro UE2 are close to picol and pico2, respectively, the measured SS-RSSI' will be relatively more due to the power of the PSS/SSS including the pico (that is, the interference strength). High, and as they are close to picol and pico2, they tend to increase. When their respective measured SS-RSSI' is greater than threshold, UE1 and UE2 each initiate a non-serving cell (or small cell). Measure, thereby discovering and identifying non-serving cells or small cells (ie, picol or pico2 in the figure) through cell search.

The above measurement based on SS-RSSI' reflects the interference strength, that is, the received signal strength of the non-serving cell, considering that the relative value of the signal strength of the serving cell and the neighboring cell (usually switched) is generally used for decision making in radio resource management. In the judgment), it is also possible to define SSRQ=SSRP/SS-RSSI, where SSRQ (synchronization signal received quality) is the newly defined synchronization signal reception quality, SSRP (synchronization signal received power) is the synchronization signal reception power (at non-zero The measurement on the RE corresponding to the power PSS/SSS is based on the linear average of the power contribution of the synchronization signal on the RE corresponding to the SS on the measured bandwidth. This value reflects The ratio of the signal power of the serving cell to the interference strength (the signal strength of the non-serving cell), therefore, can reflect whether the UE is away from the serving macro cell, and can also reflect whether the UE is close to the small cell. Therefore, the UE can also control the measurement of the non-serving cell or the small cell based on the measurement of the SSRQ defined above. For example, when the SSRQ is lower than the threshold configured by the base station, the UE initiates measurement of the non-serving cell or the small cell, otherwise the UE may not measure the non-serving cell or the small cell.

 In addition, the above determination condition is that the comparison between the measured value and the threshold value is used as a determination basis (or one of the judgment criteria), and this method may be referred to as an intensity determination method. In addition, it is also possible to consider the increment of the measured value as one of the discriminating conditions for starting the same-frequency/inter-frequency measurement. This method is called the incremental decision method. Incremental (variation) according to SS-RSSI' or SSRQ within a certain time: The measured SS-RSSI' increase means that the non-serving cell signal (or interference) strength is enhanced, if SS-RSSI' continues to increase, it may be explained Closer to another cell, you can consider starting the measurement; or, the reduction of SSRQ means that the interference strength increases and/or the signal strength of the serving cell decreases. If the SSRQ continues to decrease, it may indicate that it is farther away from the serving cell. , and getting closer and closer to the neighboring cell, you can consider starting the measurement. The incremental decision method and the strength decision method can also be combined to determine whether to initiate non-serving cell or small cell measurement.

Generally, the initiation of small cell discovery does not need to be initiated alone. The small cell discovery can be performed in the non-serving cell measurement, and the measurement of the non-serving cell needs not only the needs of small cell discovery but also the UE between macro cells. The need for mobility (eg, handover), for which a joint decision criterion may be employed, ie, the SS-RSSI' or SSRQ measurement is combined with at least two of the RSRP (CRS-based) or SSRP measurements to control the pair. Measurement of co-frequency/inter-frequency non-serving cells (adjacent cells). For example, mode 1: if SS-RSSr>threshold, or RSRP is smaller than a threshold configured by a certain base station, start measurement of a non-serving cell; mode 2: when SS-RSSF>thresliold, or SSRP is less than a certain threshold (possibly by base station (Configuration), initiate measurement of the non-serving cell; Mode 3: If SSRQ<thresholdl, or RSRP is less than the threshold configured by a certain base station, start measurement of the non-serving cell; Mode 4: If SS Q<thresholdl, or SSRP is smaller than some A threshold (possibly configured by the base station) initiates measurements on non-serving cells. If the start of the measurement is only for small cell discovery, you can also measure SS-RSSI' or, SSRQ with, RSRP (CRS-based) or, At least two of the SSRP measurements are combined to control the measurement of the small cell. Specifically, the example changes the "or" relationship of the conditional judgments in the above four modes to the "and" relationship. Using a single conditional criterion, the joint decision criterion is executed when the criterion of the single condition is satisfied. The specific examples are as follows: First or default, the CRS-based RSRP decision criterion is adopted, when the RSRP based on the CRS measurement value is smaller than the predefined one. Or when the base station configures the threshold, the joint decision criterion is executed to determine whether to initiate the same or different frequency measurement by a new measurement (such as SS-RSSI' or SSRQ measurement). As another example, UEs in a particular transmission mode use joint decision criteria for measurement control. The base station may also indicate, by means of signaling, the UE to perform joint determination criteria, including Radio Resource Control (C) layer IE, MAC layer control element control element, and downlink control information (abbreviation). For DCI).

 Step 605: The UE starts measurement of the non-serving cell.

 There are at least two ways to start the measurement of the non-serving cell (or the small cell). In the first mode, the serving base station has configured the measurement of the non-serving cell (or small cell) for the UE, but the measurement needs to wait for the specific condition of the UE. The method can be started. In the second manner, the UE reports the measurement result to the serving base station or sends a specific indication (for example, a strong interference indication) after determining that the (base station configured) reporting condition is met, and the base station performs the measurement according to the measurement result or the specific indication received. Measurement configuration (and/or measurement start) of a non-serving cell (or small cell). In this way, the macro UE can perform measurement on the non-serving cell/small cell only in a local area close to the small cell, and does not need to perform measurement on the non-serving cell/small cell in most areas away from the small cell, thereby It not only reduces the power consumption and computational overhead caused by the measurement, but also can detect the small cell in time and improve the quality of service (including throughput) by switching/diverting to the small cell or using the small cell as the secondary carrier, reducing the load of the macro cell. .

 Embodiment 5

 Step 701: Perform resource coordination between the Macro Cell and the small cell.

Specifically, resource coordination between the Macro Cell and the small cell is performed through the X2 interface, the S1 interface, the network management (OAM), or even the UE (not limited to the UE that needs to perform small cell discovery). Taking the coordination of the X2 interface as an example, the macro cell can pass the X2 Setu process message, ENB Configuration The update process message, or the X2 message such as the Load Information message, directly or indirectly (through the X2 gateway or the proxy X2 gateway, the X2 proxy) indicates the configuration information of the CRS of the macro cell to the small cell (the macro cell can also be carried in the handover preparation flow message) The RRC information between the base stations, for example, AS-Config notifies the configuration information of the CRS of the macro cell to the small cell, or the macro cell recommends the configuration information of the CRS (small cell) to the small cell through the X2 message, and the small cell receives the configuration information. After that, its own CRS can be configured to complete coordination between cells. Conversely, the small cell can also indicate the configuration of the CRS to the macro cell directly or indirectly (via the X2 gateway or the proxy X2 gateway, X2 proxy) through the X2 Setu flow message, the ENB Configuration Update flow message, or the X2 message such as the Load Information message. The macro cell then configures the corresponding CRS measurement for the UE through the air interface. The method for coordinating the inter-cell configuration through the S1 interface or other interfaces includes: the macro base station transmits the CRS configuration or the recommended CRS configuration to the opposite base station through the MME and/or the gateway (eg, HeNB GW, S1 GW), and/or The small base station transmits the configuration of the CRS or the configuration of the recommended CRS to the macro base station through the MME and/or the gateway (for example, HeNB GW, S 1 GW ). The method for coordinating the inter-cell configuration by the network management system includes: the network management system indicates the CRS configuration to the macro base station, and the network management system indicates the CRS configuration to the small base station; or the network management system sends the CRS configuration information of the small cell to the macro base station, and sends the macro cell to the small base station. CRS configuration information. The specific mode of transmitting the macro and the small cell by the UE includes: after the handover to the small cell, the macro UE sends the CRS configuration information configured by the previous macro cell to the small cell, or the small cell switches to the macro cell and then small The CRS configuration information that is configured by the cell is sent to the macro cell, or the macro base station allows the UE to receive the system information of the small cell, including the CRS configuration information, and is reported by the UE to the macro base station. The manner in which the neighbor cell configuration information reported by the UE is also referred to as a self-organizing/self-optimization network.

If the CRS time-frequency resources of the macro cell and the small cell are aligned (ie, CRS-colliding scenario), the interference strength measured by the macro UE includes the CRS signal power of the small cell, and if the two are not aligned, the macro cell The RE of the CRS may correspond to other downlink signals (such as data areas) of the small cell, in order to ensure the accuracy of the measurement and the discovery of the small cell is not affected by the load (even A small cell may also be found when the small cell is under low load or no load. Preferably, the small cell has a downlink signal on the RE corresponding to the CRS of the macro cell, for example, the small cell may be in the CRS with the macro cell. The downlink data (which can be reached by the corresponding scheduling) or the dummy data (dummy) is transmitted on the corresponding RE. For example, if the small cell on the PRB corresponding to the measurement bandwidth has data transmission, the data is normally sent, otherwise the dummy RE is sent; or The pico always transmits a dummy RE at the RE position corresponding to the macro cell CRS, and the data can be normally transmitted on the RE of the dummy RE. Or it is also possible to transmit a second CRS signal (unlike the CRS transmitted according to the system default configuration). The macro cell and the small cell can coordinate the configuration of the CRS corresponding to the macro cell by the small cell, including the physical cell ID (PCI), the number of ports (or port number), and the measurement bandwidth (for example, the center frequency of the measurement bandwidth and the RB). Number)) Such coordination can be performed through the X2/S1 interface or the network management system or even the UE.

 Step 702: The UE receives measurement configuration information sent by the macro base station.

 Here, the measurement configuration information includes: CRS configuration information (interference measurement resource configuration information); the CRS configuration information may include subframe configuration information, CRS frequency domain offset, or corresponding to a CRS frequency domain offset The physical cell identifier (PCI, Physical Cell Identity), the configuration information of the CRS may also include the port number or port number. Preferably, the measurement configuration information may further include: a threshold parameter for controlling whether to start measurement on the non-serving cell, and parameter information k for filtering the measurement value.

 The macro base station configures the CRS measurement of the macro UE not only to measure the default bandwidth, but also the macro base station can configure the bandwidth of the interference strength measurement. The configuration can be expressed by the following method, for example, measuring the center frequency + bandwidth (the number of RBs). RB start index and end index, RB start index and RB number, and so on. In this way, even if the macro cell and the small cell have different frequencies (that is, the center frequency points of the two are different), as long as the spectrum of the macro cell and the small cell overlap, the macro UE can be determined by measurement on the overlapping bandwidth. Close to the small cell of the different frequency, thereby starting the measurement of the small cell with different frequency.

The receiving, by the UE, the measurement configuration information sent by the macro base station may be: receiving, by the UE, the measurement configuration information sent by the macro base station by using a radio link reconfiguration message (RRCConnectionReconfiguration) Step 703: The UE measures the interference strength on the RE corresponding to the CRS according to the measurement configuration information.

 In a scenario where the macro cell and the small cell coexist, the macro UE measures the received signal strength (CRS - received signal strength indicator) on the resource unit corresponding to the cell level reference signal CRS (or interference measurement resource) of the serving cell (ie, the macro cell). , abbreviated as CRS-RSSI, the measurement of the physical layer is based on the linear average of the total received power on the RE corresponding to the CRS on the measured bandwidth), and the received signal power RSRP of the CRS of the serving cell is measured (the measurement of the physical layer is Based on the linear average of the power contribution of the CRS on the RE corresponding to the CRS on the measured bandwidth, the difference between the two (CRS-RSSI minus RSRP, referred to as CRS-RSSI') is the non-serving cell measured by the macro UE. The received signal strength may include signal power from neighboring small cells, as well as signal power from neighboring macro cells.

The UE performs L3 (layer 3) filtering on the CRS-RSSI' measured by the physical layer, and may also filter the CRS-RSSI and the RSRP separately, and then calculate the CRS-RSSI' by using the filtered value. The specific filtering formula is: F _n = (\ - a) - F _n _ _{l +} a - M _n ^ where _{a =} i _/2 (k/4) , ^ is the latest measurement from the physical layer, Fn is After the updated filtered measurement, F _n _i is the measurement result after the last filter.

 Step 704: The UE determines, according to the interference strength measured on the CRS RE, whether to enable measurement of the non-serving cell. If yes, execute step 705; otherwise, end the processing flow.

Specifically, if CRS-RSSI, >=threshold (or CRS-RSSI, >threshold is also possible), the macro UE initiates measurement of the non-serving cell (or small cell), otherwise the macro UE may not measure the same frequency and different A non-serving cell or a small cell (which may also be a non-serving cell of another standard, or a small cell). If the macro UE0 is far away from ico and ico2, the measured CRS-RSSI' may be lower than the threshold, so the measurement of the non-serving cell (or small cell) will not be initiated (the measurement configuration of the small cell may be related to the non-serving cell) The measurement configuration is the same or different); and if macro UE1 and macro UE2 are close to picol and ico2 respectively, the measured CRS-RSSI' will be relatively high due to the power of the CRS including the pico (that is, the interference strength), and With their respective Close to picol and pico2, it tends to increase. When their respective measured CRS-RSSI' is greater than threshold, UE1 and UE2 each initiate measurement of non-serving cells (or small cells), so that they can be found through cell search. And identify the non-serving cell or small cell (ie picol or pico2 in the figure).

 The above measurement based on CRS-RSSI' reflects the interference strength, that is, the received signal strength of the non-serving cell, considering that the relative value of the signal strength of the serving cell and the neighboring cell (usually switched) is generally used for decision making in radio resource management. In the judgment), it is therefore also possible to define RSRQ, =RSRP/CRS-SSF, where RSRQ is the quality of the newly defined reference signal reception. This value reflects the ratio of the signal power of the serving cell to the interference strength (the signal strength of the non-serving cell). Therefore, it can reflect whether the UE is away from the serving macro cell or whether the UE is close to the small cell. Therefore, the UE can also control the measurement of the non-serving cell or the small cell based on the measurement of the RSRQ defined above. For example, when the RSRQ is lower than the threshold configured by the base station, the UE initiates measurement of the non-serving cell or the small cell, otherwise the UE may not measure the non-serving cell or the small cell.

 In addition, the above determination condition is that the comparison between the measured value and the threshold value is used as a determination basis (or one of the judgment criteria), and this method may be referred to as an intensity determination method. In addition, it is also possible to consider the increment of the measured value as one of the discriminating conditions for starting the same-frequency/inter-frequency measurement. This method is called the incremental decision method. According to CRS-RSSI' or RSRQ, the increment in a certain time: the measured CRS-RSSI' increase means that the strength of the non-serving cell signal (or interference signal) is enhanced, and if the CRS-RSSI' is continuously enhanced, it may indicate the distance from another A cell is getting closer and closer, and you can consider starting measurements. The incremental decision method and the strength decision method can also be combined to determine whether to initiate non-serving cell or small cell measurement.

Generally, the initiation of small cell discovery does not need to be initiated alone. The small cell discovery can be performed in the non-serving cell measurement, and the measurement of the non-serving cell needs not only the needs of small cell discovery but also the UE between macro cells. The need for mobility (such as handover), for which reason, the joint decision criterion can be used, that is, at least two of CRS-RSSI', RSRQ', RS P (based on CRS), RSRQ, and CSI-RSRP are combined to control the pair. Measurement of co-frequency/inter-frequency non-serving cells (adjacent cells). For example, mode 1: If CRS-RSSr>threshoW, or RSRP is smaller than the threshold configured by a certain base station, start measurement of the non-serving cell; Mode 2: When CRS-RSSI,>threshold, Or the CSI-RSRP is smaller than the threshold configured by a certain base station, and starts the measurement of the non-serving cell; Mode 3: If the RSRQ, <threshold1, or RSRP is smaller than the threshold configured by a certain base station, the measurement of the non-serving cell is started; If the RSRQ, <threshold1, or CSI-RSRP is less than the threshold configured by a certain base station, the measurement of the non-serving cell is initiated. If the measurement is initiated only for small cell discovery, CRS-RSSI, RSRQ, RSRP (CRS-based), RSRQ, CSI-RSRP measurements can also be combined to control the measurement of small cells. The specific example will be the above. The "or" relationship of the conditional judgments in the four ways is changed to the "and" relationship. Using a single conditional criterion, the joint decision criterion is executed when the criterion of the single condition is satisfied. The specific examples are as follows: First or default, the CRS-based RSRP decision criterion is adopted, when the RSRP based on the CRS measurement value is smaller than the predefined or When the base station is configured with a threshold, the joint decision criterion is executed to determine whether to initiate the same or different frequency measurement by a new measurement (for example, CRS-RSSI, or RSRQ). As another example, UEs in a particular transmission mode use joint decision criteria for measurement control. The base station may also implicitly indicate, by means of signaling, that the UE performs joint determination criteria, including a Radio Resource Control (RRC) layer IE, a MAC layer control element control element, and downlink control information (abbreviated as DCI).

 Step 705: The UE starts measurement of the non-serving cell.

The method for specifically starting the measurement of the non-serving cell (or the small cell) is as follows: In the first mode, the serving base station has configured the measurement of the non-serving cell (or small cell) for the UE, but the measurement needs to wait for the UE to specifically The determination of the condition can be started. In the second manner, the UE reports the measurement result to the serving base station or sends a specific indication (for example, a strong interference indication) after determining that the (base station configured) reporting condition is met, and the base station according to the measurement result or the specific indication received. The measurement configuration (and/or the start of the measurement) of the non-serving cell (or small cell) is performed. In this way, the macro UE can perform measurement on the non-serving cell/small cell only in a local area close to the small cell, and does not need to perform measurement on the non-serving cell/small cell in most areas away from the small cell, thereby It not only reduces the power consumption and computational overhead caused by the measurement, but also can detect the small cell in time and improve the quality of service (including throughput) by switching/diverting to the small cell or using the small cell as the secondary carrier, reducing the macro size. The load of the area. Embodiment 6

 Step 801: Perform resource coordination between the Macro Cell and the small cell.

 If the CSI-RS time-frequency resources of the macro cell and the small cell are aligned (ie, CSI-RS-colliding scenario), the interference strength measured by the macro UE includes the CSI-RS signal power of the small cell, and if the two are not Alignment, the CSI-RS occupied by the macro cell may correspond to other downlink signals (such as data areas) of the small cell, in order to ensure the accuracy of the measurement and the discovery of the small cell is not affected by the load (even in the small cell) A small cell may also be found when the load is loaded or not, and the small cell is preferably sent by a downlink signal on the RE corresponding to the CSI-RS of the macro cell. For example, the small cell may be in the CSI-RS with the macro cell. The corresponding RE transmits downlink data (which can be reached by corresponding scheduling) or dummy data (dummy RE). The macro cell and the small cell can coordinate the small cell to learn the CSI-RS and the measurement related configuration of the macro cell, including the CSI-RS subframe configuration information, and measure the bandwidth (for example, the center frequency and the RB number of the measurement bandwidth). Such coordination may be performed through an X2/S1 interface (eg, through an X2 setup procedure or an eNB configuration update procedure or other X2/S1 signaling procedure) or a network management system or even a UE (not limited to UEs requiring small cell discovery).

Taking the coordination of the X2 interface as an example, the macro cell can directly or indirectly (through the X2 gateway or the proxy X2 gateway, X2 proxy) to indicate the macro to the small cell through an X2 Setup flow message, an ENB Configuration Update flow message, or an X2 message such as a Load Information message. The configuration information of the CSI-RS of the cell (the macro cell may also notify the small cell of the configuration information of the CSI-RS of the macro cell by using the RRC information between the base stations carried in the handover preparation flow message, for example, AS-Config), or the macro cell passes the above The X2 message recommends the configuration information of the non-zero-power CSI-RS to the small cell (small cell). After receiving the configuration information, the small cell can configure its own non-zero-power CSI-RS to complete the inter-cell coordination. . In turn, small cells can also pass X2 Setup flow messages, ENB Configuration Update process messages, or Load Information messages, etc. X2 messages directly or indirectly (via X2 gateway or proxy X2 gateway, The X2 proxy indicates the configuration of the non-zero power CSI-RS to the macro cell, and the macro cell then configures the corresponding CSI-RS measurement for the UE through the air interface. The method for coordinating the inter-cell configuration through the S1 interface or other interfaces includes: the macro base station transmits the CSI-RS configuration or the recommended non-zero power CSI-RS to the opposite base station through the MME and/or the gateway (eg, HeNB GW, S1 GW). The configuration, and/or, the small base station transmits the configuration of the non-zero power CSI-RS or the configuration of the recommended macro base station CSI-RS to the macro base station through the MME and/or the gateway (eg, HeNB GW, S1 GW). The method for coordinating the inter-cell configuration by the network management system includes: the network management system indicates the CSI-RS configuration to the macro base station, and the network management system indicates the non-zero power CSI-RS configuration to the small base station; or the network management system sends the non-zero power of the small cell to the macro base station. The CSI-RS configuration information is used to send CSI-RS configuration information of the macro cell to the small base station. The specific mode of transmitting the macro and the small cell by the UE includes: after the handover to the small cell, the macro UE sends the CSI-RS configuration information configured by the previous macro cell to the small cell, or after the small cell switches to the macro cell, The non-zero-power CSI-RS configuration information configured by the small cell is sent to the macro cell, or the macro base station allows the UE to receive the system information of the small cell, including non-zero-power CSI-RS configuration information, by the UE. Reported to the macro base station.

 In a large-scale radio access network, the performance of small cell discovery can also be improved through a large-scale coordination, for example, aligning REs corresponding to CSI-RSs of multiple macro cells (constituting a coordinated discovery area) (macro The small-area may transmit CSI-RS configuration information through an X2/S1 interface or a network management system. The serving macro base station may also configure CSI-RS information of the neighboring macro base station for the UE, so that the UE will include the service when measuring the interference strength. The signal power of the macro base station and the adjacent macro base station are all reduced, so that the interference strength only reflects the power strength of the small cell, which can improve the accuracy of starting small cell measurement.

 Step 802: The UE receives measurement configuration information sent by the macro base station.

Here, the measurement configuration information includes first downlink signal configuration information (interference measurement resource configuration information), where the first downlink signal is a non-zero power CSI-RS, and the measurement configuration information of the first downlink signal includes: Zero-power CSI-RS resource configuration identifier (, resource configuration information (res. urceC.nfig), subframe configuration information (frameConfig), antenna port number (antennaPortsCount), scrambling identity (scramblingldentity), quasi-co-location information with CRS (qcl-CRS-Info). The measurement configuration information further includes a start measurement threshold (threshold) for controlling whether to initiate measurement of the non-serving cell, and/or parameter information k for filtering the measured value.

 The measurement configuration information of the first downlink signal sent by the macro base station may be: the macro base station sends the measurement configuration information of the first downlink signal by using a radio link reconfiguration message (RRCConnectionReconfiguration).

 Step 803: The UE measures the interference strength on the RE corresponding to the CSI-RS according to the measurement configuration information.

 The macro UE measures the resource unit corresponding to the channel state information reference signal CSI-RS (or the interference measurement resource) of the serving cell (ie, the macro cell) (the measurement configuration information of the CSI-RS sent by the macro base station of the serving cell received by the UE) CSI-RS - received signal strength indicator (CSI-RSSI), the measurement of the physical layer is based on the linear average of the total received power on the RE corresponding to the CSI-RS on the measured bandwidth. And measuring the received signal power CSI-RSRP of the CSI-RS configured by the serving cell for the UE (the measurement of the physical layer is based on a linear average of the power contributions of the CSI-RS on the RE corresponding to the CSI-RS on the measured bandwidth) ), the difference between the two (CRS-RSSI minus CSI-RSRP, called CSI-RSSI') is the interference strength measured by the macro UE, that is, the received signal strength of the non-serving cell, and may include signals from adjacent small cells. Power, and signal power from neighboring macro cells.

The UE performs L3 (layer 3) filtering on the CSI-RSSI' measured by the physical layer, or filters the CSI-RSSI and CSI-RSRP reported by the physical layer to L3, and calculates the CSI-RSSI by using the filtered value. The specific filtering formula is: = (1 - , where _a = i/ ₂ (k 4) , M _n is the latest measurement from the physical layer, and F _n is the updated filtered result, which is old ( The last time) the filtered measurement result. The macro base station can also configure the measurement bandwidth for the measurement of the UE, and is not limited to the measurement on the center 6 RBs of the system bandwidth, but can be as needed (for example, measuring the macro cell and the small cell spectrum) The overlapping part is configured to measure the bandwidth, which can support not only the scenario where the macro cell and the small cell are at the same frequency, but also the scenario where the macro cell and the small cell have different frequencies but the spectrum partially overlaps. Step 804: The UE determines whether to enable measurement of the non-serving cell based on the interference strength of the first downlink signal on the RE. If yes, perform step 805; otherwise, end the processing flow.

 If the CSI-RSSI' is higher (or greater than or equal to) a specific threshold, the macro UE initiates measurements on (same frequency and/or inter-frequency) neighboring cells or small cells, otherwise the macro UE may not measure neighboring cells or small Community.

 The above measurement based on CSI-RSSI' reflects the interference strength or the received signal strength of the non-serving cell. Considering the relative value of the signal strength of the serving cell and the neighboring cell, which is usually used for decision making in radio resource management, The channel state information reference signal reception quality (CSI-RSRQ) may be defined as the channel state information reference signal received power (CSI-RSRP, and the physical layer measurement is based on the CSI-RS on the RE corresponding to the CSI-RS on the measured bandwidth. The linear average of the power contributions) is the ratio of the interference intensity CSI-RSSI'. This value reflects the ratio of the signal power of the serving cell to the interference strength. Therefore, it can reflect whether the UE is far away from the serving macro cell, and can also reflect whether the UE is close to the small cell. Therefore, the UE can also control the measurement of the non-serving cell based on the measurement of the CSI-RSRQ defined above. When the CSI-RSRQ is lower than (or less than or equal to) the threshold configured by the base station, the UE initiates measurement of the non-serving cell, otherwise the UE may not measure the non-serving cell.

 In addition, the above determination condition is that the comparison between the measured value and the threshold value is used as a determination basis (or one of the judgment criteria), and this method may be referred to as an intensity determination method. In addition, it is also conceivable to use the increment of the measured value as the discriminating condition for starting the same-frequency/inter-frequency measurement. This method is called the incremental decision method. According to CSI-RSSI' or CSI-RSRQ in a certain time increment: The measured CSI-RSSI' increase means that the non-serving cell signal (or interference signal) strength is enhanced, if the CSI-RSSI' continues to increase, it may indicate the distance Another cell is getting closer and closer, and it is considered to initiate measurement; or, the decrease of CSI-RSRQ means that the interference strength increases and/or the signal strength of the serving cell decreases. If the CSI-RSRQ continues to decrease, it may indicate that the distance from the serving cell is more The farther it is, and the closer it is to the neighboring cell, the start of the measurement can be considered. The incremental decision method and the strength decision method can also be combined to determine whether to initiate non-serving cell or small cell measurement.

On the other hand, usually the start of small cell discovery does not need to be started alone, small cell discovery can In the non-serving cell measurement, the measurement of the non-serving cell needs to consider not only the needs of small cell discovery, but also the need for UE mobility (such as handover) between macro cells.

 The joint decision criterion includes: combining CSI-RSSr or CSI-RSRQ with at least two of RSRP (CRS-based), RSRQ or CSI-RSRP-based measurements to control a co-frequency/inter-frequency non-serving cell (phase) Measurement of neighboring cells). For example, mode 1: if CSI-RSSI, >threshold, or RSRP is smaller than a threshold configured by a certain base station, start measurement of a non-serving cell; mode 2: when CSI-SSI'>threshold, or CSI-RSRP is smaller than a certain base station The configured threshold is used to initiate measurement on the non-serving cell. Mode 3: If CSI-RSRQ<threshold1, or RSRP is smaller than the threshold configured by a certain base station, start measurement of the non-serving cell; Mode 4: If CSI-SQ<thresholdl, Or the CSI-RSRP is smaller than the threshold configured by a certain base station, and the measurement of the non-serving cell is started. If the initiation of the measurement is only for small cell discovery, at least two of CSI-RSSI, CSI-RSRQ, RSRP (CRS-based), RSRQ, and CSI-RSRP may be combined to control measurement of the small cell, specifically The example changes the "or" relationship of the conditional judgments in the above four ways to the "and" relationship. Using a single conditional criterion, the joint decision criterion is executed when the criterion of the single condition is satisfied. The specific examples are as follows: First or default, the CRS-based RSRP decision criterion is adopted, when the RSRP based on the CRS measurement value is smaller than the predefined or When the base station configures the threshold, the joint decision criterion is executed to determine whether to initiate the same or different frequency measurement by a new measurement (for example, CSI-RSSI' or CSI-RSRQ measurement). For another example, UEs in a particular transmission mode use joint decision criteria for measurement control. The base station may also indicate, by means of signaling, the UE to perform joint determination criteria, including adio Resource Control (RRC) layer IE, MAC layer control element control element, and downlink control information (abbreviation). For DCI).

 Step 805: The UE starts measurement of the non-serving cell.

There are at least two ways to specifically initiate measurements on neighboring cells (or small cells): First, the serving base station has configured the measurement of the neighboring cell (or the small cell) for the UE, but the measurement needs to wait for the UE to determine the specific condition to start; the second mode, after the UE determines that the (base station configured) reporting condition is met, The serving base station reports the measurement result or sends a specific indication (for example, a strong interference indication), and the base station performs measurement configuration (and/or measurement start) of the neighboring cell (or small cell) according to the measurement result or a specific indication (for example, a strong interference indication). ). In this way, the macro UE can perform measurement on the non-serving cell/small cell only in a local area close to the small cell, and does not need to perform measurement on the non-serving cell/small cell in most areas away from the small cell, thereby It not only reduces the power consumption and computational overhead caused by the measurement, but also can detect small cells in time and improve the quality of service (including throughput) by switching/diverting to small cells or using small cells as secondary carriers, reducing the load of macro cells. . Example VII.

Step 901: Perform resource coordination between the Macro Cell and the small cell. (This step is optional.) In the scenario where the macro cell and the small cell coexist, if the macro cell and the small cell have the same frequency (the same center frequency point) and the field boundaries are aligned, the PSS/SSS of the macro cell and the PSS of the small cell/ The time-frequency resources of the SSS are aligned, and the interference strength measured by the macro UE includes the synchronization signal power of the small cell, and if the two frequencies are different or the frame boundaries are not aligned, the PSS/SSS of the macro cell may occupy the RE. Corresponding to other downlink signals (such as data areas) of the small cell, in order to ensure the accuracy of the measurement and the discovery of the small cell is not affected by its load (even when the small cell is under low load or no load, the small cell can be found), In a certain way, the small cell has a downlink signal (such as a small cell) on the RE corresponding to the PSS/SSS of the macro cell (since the PSS/SSS is transmitted on the center 6 RBs of the system bandwidth, so RB can also be said). The downlink data may be transmitted on 6 RBs corresponding to the PSS/SSS of the macro cell (which may be achieved by corresponding scheduling), or may also transmit the second downlink synchronization signal (different from the default according to the system) Set the downlink synchronization signal transmitted). Between the macro cell and the small cell, the small cell can be informed of the RB corresponding to the PSS/SSS of the macro cell, and the coordination can be performed through the X2 interface, the S1 interface, or through the OAM or even the UE (not limited to the UE that needs to perform small cell discovery). ) get on. Taking the coordination of the X2 interface as an example, the macro cell can directly or indirectly (through the X2 gateway or the proxy X2 gateway, X2 proxy) to indicate the macro to the small cell through an X2 Setup flow message, an ENB Configuration Update flow message, or an X2 message such as a Load Information message. The configuration information of the SS of the cell (the macro cell may also notify the small cell of the configuration information of the SS of the macro cell by using the RRC information between the base stations carried in the handover preparation flow message, for example, AS-Config), or the macro cell is small through the X2 message. The cell recommendation (small cell) configuration information of the SS, after receiving the configuration information, the small cell can configure its own SS to complete the coordination between the cells. Conversely, the small cell can also indicate the configuration of its SS to the macro cell directly or indirectly (via X2 gateway or proxy X2 gateway, X2 proxy) through X2 Setup flow message, ENB Configuration Update flow message, or Load Information message. The macro cell then configures the corresponding SS measurement for the UE through the air interface. The method for coordinating the inter-cell configuration through the S1 interface or other interfaces includes: the macro base station transmits the configuration of the SS or the configuration of the recommended SS to the opposite base station through the MME and/or the gateway (eg, HeNB GW, S1 GW), and/or, The small base station transmits the configuration of the SS or the configuration of the recommended SS to the macro base station through the MME and/or the gateway (eg, HeNB GW, S1 GW). The method for coordinating the inter-cell configuration by the network management system includes: the network management system indicates the SS configuration to the macro base station, and the network management system indicates the SS configuration to the small base station; or the network management system sends the SS configuration information of the small cell to the macro base station, and sends the macro cell to the small base station. SS configuration information. The specific mode of transmitting the macro between the macro and the small cell by the UE includes: after the handover to the small cell, the macro UE sends the SS configuration information configured by the previous macro cell to the small cell, or the small cell switches to the macro cell and then small The SS configuration information of the cell is sent to the macro cell, or the macro base station allows the UE to receive the system information of the small cell, including the SS configuration information, and is reported by the UE to the macro base station. The manner in which the neighbor cell configuration information reported by the UE is also referred to as a self-organizing/self-optimization network.

 Step 902: The UE receives measurement configuration information of the first downlink signal sent by the macro base station.

The macro base station first performs measurement configuration for the macro UE, and optionally includes configuration information of the SS (interference measurement resource configuration information) in the measurement configuration information. Measurement configuration information is also included to control whether Start the threshold parameter (threshold) for measuring the non-serving cell. The measurement configuration information may also include parameter information k for filtering the measured values. The macro UE receives a radio link reconfiguration message (RRCConnectionReconfiguration) of the macro base station, which includes the above measurement configuration information.

 Step 903: The UE measures the interference strength on the RE corresponding to the SS (or the interference measurement resource) according to the measurement configuration information.

 In a scenario where the macro cell and the small cell coexist, the macro UE measures the downlink synchronization signal of the serving cell (ie, the macro cell) (including the primary synchronization signal PSS and the secondary synchronization signal SSS, and may also measure only one of the resource elements). The received signal strength, wherein the measured received signal is the residual signal after the downlink signal of the serving cell is cancelled. In other words, the UE first performs interference cancellation on the signal received at the synchronization signal resource location based on the primary synchronization and secondary synchronization sequences of the serving cell (using the interference cancellation receiver IC receiver), and then measures the strength of the remaining signals ( Interference recorded synchronization signal - received signal strength indicator, abbreviated as ICSS-RSSI, the measurement of the physical layer is based on the linear average of the total received power of the residual signal after IC cancellation on the RE corresponding to the SS over the measured bandwidth. Thus, the macro UE measures the interference strength, i.e., the received signal strength of the non-serving cell, possibly including the signal power from the neighboring small cells, and the signal power from the neighboring macro cells.

The UE performs L3 (Layer 3) filtering on the ICSS-RSSI measured by the physical layer. The specific filter formula is: = (1 _ F„— _{1 +} · Μ„, where _{a =} i _/2 (k") , _Mn is the latest measurement from the physical layer, F _n is the updated filtered The measurement result is the old (previous) filtered measurement result.

 Step 904: The UE determines, according to the interference strength of the first downlink signal on the RE, whether to enable measurement of the non-serving cell. If yes, execute step 905; otherwise, end the processing process.

Based on the filtered ICSS-RSSI, the macro UE controls the measurement of the non-serving cell. Specifically, if ICSS-RSSI>=threshold (or ICSS-RSSI>threshold is also available), the macro UE initiates pair (same frequency and/or inter-frequency) neighboring cells (or non-serving cells, or small cells) measuring, Otherwise, the macro UE may not measure non-serving cells or small cells of the same frequency and different frequency (may also be non-serving cells of other standards, or small cells). When the macro UE0 is far away from picol and pico2, the measured ICSS-RSSI may be lower than the threshold, so the measurement of the non-serving cell (or small cell) will not be initiated (the measurement configuration of the small cell may be related to the non-serving cell) The measurement configuration is the same or different); and if macro UE1 and macro UE2 are close to ico and ico2 respectively, the measured ICSS-RSSI will be relatively high due to the power of the PSS/SSS including the pico (ie, the interference strength). And as they are close to picol and pico2, they tend to increase. When their respective measured ICSS-RSSI is greater than threshold, UE1 and UE2 each initiate measurement of the non-serving cell (or small cell). Non-serving cells or small cells (ie picol or pico2) are discovered and identified by cell search.

 The above ICSS-RSSI-based measurement reflects the interference strength, that is, the received signal strength of the non-serving cell. Considering the relative value of the signal strength of the serving cell and the neighboring cell, which is usually used for decision making in radio resource management (for example, switching) In the judgment), it is therefore also possible to define SSRQ=SSRP/ICSS-RSSI, where SSRQ (synchronization signal received quality) is the newly defined synchronization signal reception quality, SSRP (synchronization signal received power) is the synchronization signal reception power (at non-zero power) The measurement on the RE corresponding to the PSS/SSS is based on the linear average of the power contribution of the synchronization signal on the RE corresponding to the SS on the measured bandwidth. This value reflects the ratio of the signal power of the serving cell to the interference strength (signal strength of the non-serving cell). Therefore, it can reflect whether the UE is away from the serving macro cell or whether the UE is close to the neighboring cell or the small cell. Therefore, the UE can also control the measurement of the non-serving cell or the small cell based on the measurement of the SSRQ defined above. For example, when the SSRQ is lower than the threshold configured by the base station, the UE initiates measurement of the non-serving cell or the small cell, otherwise the UE may not measure the non-serving cell or the small cell.

Generally, the initiation of small cell discovery does not need to be initiated alone, and small cell discovery can be performed in non-serving cell measurement, while the measurement of non-serving cells needs to consider not only the needs of small cell discovery but also the UE between macro cells. The need for mobility (such as handover), for which you can use joint decision criteria, ie, ICSS-RSSI or, SSRQ measurements, and RSRP (CRS-based) Or, RSRQ, SSRP measurements jointly control the measurement of co-frequency/inter-frequency non-serving cells (adjacent cells or small cells). For example, Mode 1: If ICSS-RSSI>threshold, or RSRP is less than the threshold configured by a certain base station, initiate measurement of the non-serving cell; Mode 2: When ICSS-RSSI>threshold, or SSRP is less than a certain threshold (possibly by base station (Configuration), initiate measurement of the non-serving cell; Mode 3: If SSRQ<thresholdl, or RSRP is less than the threshold configured by a certain base station, start measurement of the non-serving cell; Mode 4: If SSRQ<thresholdl, or SSRP is smaller than a certain Threshold (possibly configured by the base station) to initiate measurements on non-serving cells. If the measurement is initiated only for small cell discovery, the measurement of ICSS-RSSI or SSRQ may be combined with the measurement of RS P (CRS based) or RSRQ, SSRP to control the measurement of small cells, specifically For example, it is sufficient to change the "or" relationship of the conditional judgments in the above four ways to the "and" relationship. Using a single conditional criterion, the joint decision criterion is executed when the criterion of the single condition is satisfied. The specific examples are as follows: First or default, the CRS-based RSRP decision criterion is adopted, when the RSRP based on the CRS measurement value is smaller than the predefined or When the base station configures the threshold, the joint decision criterion is executed to determine whether to initiate the same or different frequency measurement by a new measurement (such as the measurement of ICSS-RSSI or SSRQ). As another example, UEs in a particular transmission mode use joint decision criteria for measurement control. The base station may also indicate, by means of signaling, the UE to perform joint determination criteria, including Radio Resource Control (RRC) layer IE, MAC layer control element control element, and downlink control information (abbreviation). For DCI).

In addition, the above determination condition is that the comparison between the measured value and the threshold value is used as a determination basis (or one of the judgment criteria), and this method may be referred to as an intensity determination method. In addition, it is also conceivable to use the increment of the measured value as one of the discriminating conditions for starting the intra-frequency/inter-frequency measurement. This method is called an incremental decision method. According to the ICSS-RSSI or SSRQ increment in a certain period of time: the measured ICSS-RSSI increase means that the strength of the non-serving cell signal (or interference signal) is enhanced. If the ICSS-RSSI continues to increase, it may indicate that the distance from another cell is coming. The closer you are, the more you can start measuring. The incremental decision method and the strength determination method can also be combined to determine whether to initiate non-serving cell or small cell measurement. Step 905: The UE starts measurement of the non-serving cell.

 There are at least two ways to start the measurement of the non-serving cell (or the small cell). In the first mode, the monthly service base station has configured the measurement of the non-serving cell (or small cell) for the UE, but the measurement needs to wait for the UE to The determination of the specific condition can be started. In the second manner, after determining that the reporting condition is met (the configuration of the base station), the UE reports the measurement result to the serving base station or sends a specific indication (for example, a strong interference indication), and the base station determines the specific result according to the measurement result or the received Indicates the measurement configuration (and/or the start of the measurement) of the non-serving cell (or small cell). In this way, the macro UE can perform measurement on the non-serving cell/small cell only in a local area close to the small cell, and does not need to perform measurement on the non-serving cell/small cell in most areas away from the small cell, thereby It not only reduces the power consumption and computational overhead caused by the measurement, but also can detect the small cell in time and improve the quality of service (including throughput) by switching/diverting to the small cell or using the small cell as the secondary carrier, reducing the load of the macro cell. . Example VIII.

 Step 1001: Resource coordination between the Macro Cell and the small cell.

If the CRS time-frequency resources of the macro cell and the small cell are aligned (ie, CRS-colliding scenario), the interference strength measured by the macro UE will include the CRS signal power of the small cell, and if the two are not aligned, the macro cell The RE of the CRS may correspond to other downlink signals (such as data areas) of the small cell, in order to ensure the accuracy of the measurement and the discovery of the small cell is not affected by the load (even when the small cell is under load or no load) Small cell), preferably, the small cell has a downlink signal on the RE corresponding to the CRS of the macro cell, for example, the RE corresponding to the CRS of the macro cell of the macro cell (measured by the macro UE) The downlink data is transmitted (either by corresponding scheduling), or the second CRS signal (which is different from the CRS transmitted according to the system default configuration). The macro cell and the small cell can coordinate the configuration of the CRS corresponding to the macro cell by the small cell, including the physical cell ID (PCI), the number of ports (or port number), and the measurement bandwidth (for example, the center frequency of the measurement bandwidth and the RB). The number of resources between the Macro Cell and the small cell can be performed through the X2 interface, the S1 interface, the network management (OAM), or even the UE (not limited to the UE that needs to perform small cell discovery). Taking the coordination of the X2 interface as an example, the macro cell can directly or indirectly (through the X2 gateway or the proxy X2 gateway, X2 proxy) to indicate the macro to the small cell through an X2 Setup flow message, an ENB Configuration Update flow message, or an X2 message such as a Load Information message. The configuration information of the CRS of the cell (the macro cell may also notify the small cell of the configuration information of the CRS of the macro cell by using the RRC information between the base stations carried in the handover preparation flow message, for example, AS-Config), or the macro cell is small through the X2 message. The CRS configuration information of the cell recommendation (small cell), after receiving the configuration information, the small cell can configure its own CRS to complete the coordination between the cells. Conversely, the small cell can also indicate the configuration of its CRS to the macro cell directly or indirectly (via X2 gateway or proxy X2 gateway, X2 proxy) through an X2 Setup flow message, an ENB Configuration Update flow message, or an X2 message such as a Load Information message. The macro cell then configures the corresponding CRS measurement for the UE through the air interface. A method for coordinating inter-cell configuration through an S1 interface or other interfaces includes: a macro base station through an MME and/or a gateway

(gateway, for example, HeNB GW, S1 GW) delivers the configuration of the CRS or the configuration of the recommended CRS to the base station, and/or the small base station transmits the CRS to the macro base station through the MME and/or the gateway (eg, HeNB GW, S1 GW) Configuration or recommend the configuration of the CRS. The method for coordinating the inter-cell configuration by the network management system includes: the network management system indicates the CRS configuration to the macro base station, and the network management system indicates the CRS configuration to the small base station; or the network management system sends the CRS configuration information of the small cell to the macro base station, and sends the macro cell to the small base station. CRS configuration information. The specific mode of transmitting the macro between the macro and the small cell by the UE includes: after the handover to the small cell, the macro UE sends the CRS configuration information configured by the previous macro cell to the small cell, or the small cell switches to the macro cell and then small The CRS configuration information configured by the cell is sent to the macro cell, or the macro base station allows the UE to receive the system information of the small cell, including the CRS configuration information, and is reported by the UE to the macro base station. The manner in which the neighbor cell configuration information reported by the UE is also referred to as a self-organizing/self-optimization network.

 Step 1002: The UE receives measurement configuration information sent by the macro base station.

Here, the measurement configuration information includes: CRS configuration information (interference measurement resource configuration information); the CRS configuration information may include subframe configuration information, CRS frequency domain offset, or The physical cell identifier (PCI, Physical Cell Identity) corresponding to the CRS frequency domain offset,

The configuration information of the CRS may also include the port number or port number.

 Preferably, the measurement configuration information may further include: a threshold parameter (control) for controlling whether to start measurement on the non-serving cell, and parameter information k for filtering the measurement value.

 The macro base station configures the CRS measurement of the macro UE not only to measure the default bandwidth, but also the macro base station can configure the bandwidth of the interference strength measurement. The configuration can be expressed by the following method, for example, measuring the center frequency + bandwidth (the number of RBs). RB start index and end index, RB start index and RB number, and so on. In this way, even if the macro cell and the small cell have different frequencies (that is, the center frequency points of the two are different), as long as the spectrum of the macro cell and the small cell overlap, the macro UE can be determined by measurement on the overlapping bandwidth. Close to the small cell of the different frequency, thereby starting the measurement of the small cell with different frequency.

 The receiving, by the UE, the measurement configuration information sent by the macro base station may be: receiving, by the UE, measurement configuration information sent by the macro base station by using a radio link reconfiguration message (RRC Connection Reconfiguration).

 Step 1003: The UE measures the interference strength on the RE corresponding to the CRS (or the interference measurement resource) according to the measurement configuration information.

 In a scenario where the macro cell and the small cell coexist, the macro UE measures the received signal strength on the resource unit corresponding to the cell level reference signal CRS of the serving cell (ie, the macro cell), where the measured received signal is used to eliminate the serving cell. Remaining signal after CRS. In other words, the UE first performs interference cancellation based on the CRS sequence of the serving cell for the signal received on the CRS RE (using the interference cancellation receiver IC receiver), and then measures the strength of the remaining signal (Interference cancelled CRS - received signal). The strength indicator, abbreviated as IC-CRS-RSSI, is based on the linear average of the total received power of the residual signal after interference cancellation on the CRS corresponding to the CRS on the measured bandwidth. Thus, the macro UE measures the interference strength, i.e., the received signal strength of the non-serving cell, possibly including the signal power from the adjacent small cell, and the signal power from the adjacent macro cell.

The UE performs L3 (Layer 3) filtering on the IC-CRS-RSSI measured by the physical layer. Specific filtering The formula is: = (1 - ")·υ" · , where a = l/2( ^k/4) , M _n is the latest measurement from the physical layer, and F _n is the updated filtered result. F _n _i is the measurement result after the last filter.

 Step 1004: The UE determines, according to the interference strength measured on the CRS RE, whether to enable measurement of the non-serving cell. If yes, execute step 1005; otherwise, end the processing flow.

 Specifically, if the IC-CRS-RSSI>=threshold (or IC-CRS-RSSI>threshold is also possible), the macro UE initiates measurement of the non-serving cell (or small cell), otherwise the macro UE may not measure the same frequency. And a non-serving cell or a small cell of an inter-frequency (may also be a non-serving cell of another standard, or a small cell). If the macro UE0 is far away from picol and pico2, the measured IC-CRS-RSSI may be lower than the threshold, so the measurement of the non-serving cell (or small cell) will not be initiated (the measurement configuration of the small cell may be non-serving) The measurement configuration of the cell is the same or different); and if macro UE1 and macro UE2 are close to picol and pico2 respectively, the measured IC-CRS-RSSI will be relatively high due to the power of the CRS including the pico (that is, the interference strength). And as they are close to picol and pico2, they tend to increase. When their respective measured IC-CRS-RSSI is greater than threshold, UE1 and UE2 each initiate a non-serving cell (or small cell). Measured to discover and identify non-serving cells or small cells (ie picol or pico2) by cell search.

 The above IC-CRS-RSSI-based measurement reflects the interference strength, that is, the received signal strength of the non-serving cell, considering that the relative value of the signal strength of the serving cell and the neighboring cell is usually used for decision making in radio resource management (for example, In the handover decision), it is therefore also possible to define RSRQ, =RSRP/IC-CRS-RSSI, where RSRQ is the newly defined reference signal reception quality. This value reflects the ratio of the signal power of the serving cell to the interference strength (the signal strength of the non-serving cell). Therefore, it can reflect whether the UE is away from the serving macro cell or whether the UE is close to the small cell. Therefore, the UE can also control the measurement of the non-serving cell or the small cell based on the measurement of the RSRQ' defined above. For example, when the RSRQ' is lower than the threshold configured by the base station, the UE initiates measurement of the non-serving cell or the small cell, otherwise the UE may not measure the non-serving cell or the small cell.

Generally, the initiation of small cell discovery does not need to be initiated alone, the small cell discovery can be performed in the non-serving cell measurement, and the measurement of the non-serving cell not only needs to consider the needs of small cell discovery, It is also necessary to consider the need for UE mobility (e.g., handover) between macro cells. To this end, a joint decision criterion, that is, measurement of IC-CRS-RSSIZP-CSI-RSSI or RSRQ'CSI-RSRQ, RSRP ( CRS-based, RSRQ, or CSI-RSRP-based measurements jointly control the measurement of co-frequency/inter-frequency non-serving cells (adjacent cells). For example, mode 1: if the IC-CRS-SSI ZP-CSI-RSSI>threshold, or the RSRP is smaller than the threshold configured by a certain base station, initiate measurement of the non-serving cell; mode 2: when IC-CRS-RSSI ZP-CSI- SSI>threshold, or CSI-RSRP is smaller than the threshold configured by a certain base station, and starts measurement of the non-serving cell; Mode 3: If RSRQ, CSI-RS Q<thresholdl, or RSRP is smaller than the threshold configured by a certain base station, start the right Measurement of the serving cell; Mode 4: If the RSRQ, CSI-SQ<threshold1, or CSI-RSRP is less than the threshold configured by a certain base station, the measurement of the non-serving cell is initiated. If the measurement is initiated only for small cell discovery, the measurement of IC-CRS-RSSIZP-CRS-RSSI or RSRQ'RSRQ* can also be combined with RSRP (CRS-based) or based, or CSI-RSRP-based measurements. For the measurement of the small cell, specifically, the "or" relationship of the conditional judgments in the above four methods is changed to the "and" relationship. Using a single conditional criterion, the joint decision criterion is executed when the criterion of the single condition is satisfied. The specific examples are as follows: First or default, the CRS-based RSRP decision criterion is adopted, when the RSRP based on the CRS measurement value is smaller than the predefined or When the base station is configured with a threshold, a joint decision criterion is executed to determine whether to initiate the same or different frequency measurement by a new measurement (for example, measurement of IC-CRS-RSSI or RSRQ). As another example, UEs in a particular transmission mode use joint decision criteria for measurement control. The base station may also implicitly indicate to the UE to perform joint determination criteria by signaling, including the Radio Resource ControK RRC layer IE, the MAC layer control element control element, and the downlink control information (abbreviated as DCI). ).

In addition, the above determination condition is that the comparison between the measured value and the threshold value is used as a determination basis (or one of the judgment criteria), and this method may be referred to as an intensity determination method. In addition, it is also conceivable to use the increment of the measured value as one of the discriminating conditions for starting the intra-frequency/inter-frequency measurement. This method is called an incremental decision method. Incremental over a certain period of time based on IC-CRS-RSSI: IC-CRS-RSSI measured The increase means that the strength of the non-serving cell signal (or interference signal) is enhanced. If the IC-CRS-RSSI continues to increase, it may indicate that it is getting closer and closer to another cell, and it may be considered to start measurement and the like. The incremental decision method and the strength determination method can also be combined to determine whether to initiate non-serving cell or small cell measurement.

 Step 1005: The UE starts measurement of the non-serving cell.

 The method for specifically starting the measurement on the neighboring cell (or the small cell) is as follows: In the first mode, the serving base station has configured the measurement of the neighboring cell (or small cell) for the UE, but the measurement needs to wait for the UE to specifically The determination of the condition can be started. In the second mode, the UE reports the measurement result to the serving base station or sends a specific indication (such as a strong interference indication) after determining that the (base station configured) reporting condition is met, and the base station according to the measurement result or a specific indication (for example, strong) Interference indication) Perform measurement configuration (and/or start of measurement) of a neighboring cell (or small cell). In this way, the macro UE can perform measurement on the non-serving cell/small cell only in a local area close to the small cell, and does not need to perform measurement on the non-serving cell/small cell in most areas away from the small cell, thereby It not only reduces the power consumption and computational overhead caused by the measurement, but also can detect small cells in time and improve the quality of service (including throughput) and reduce the load of the macro cell by switching/diverting to small cells or using small cells as secondary carriers. . Example IX.

 Step 1101: Resource coordination between the Macro Cell and the small cell.

If the CSI-RS time-frequency resources of the macro cell and the small cell are aligned (ie, CSI-RS-colliding scenario), the interference strength measured by the macro UE includes the CSI-RS signal power of the small cell, and if the two are not Alignment, the CSI-RS occupied by the macro cell may correspond to other downlink signals (such as data areas) of the small cell, in order to ensure the accuracy of the measurement and the discovery of the small cell is not affected by the load (even in the small cell) A small cell may also be found when the load is loaded or not, and the small cell is preferably sent by a downlink signal on the RE corresponding to the CSI-RS of the macro cell. For example, the small cell may be in the CSI-RS with the macro cell. The corresponding RE transmits downlink data (which can be reached by corresponding scheduling) or dummy data (dummy RE). Between the macro cell and the small cell Coordinating the small cell to know the CSI-RS and measurement related configuration of the macro cell, including the CSI-RS subframe configuration information, and measuring the bandwidth (for example, the center frequency and the number of RBs of the measurement bandwidth), such coordination can be performed by X2/S1 The interface is performed (for example, by an X2 setup procedure or an eNB configuration update procedure or other X2/S1 signaling procedure) or by a network management system or even a UE (not limited to a UE requiring small cell discovery).

Taking the coordination of the X2 interface as an example, the macro cell can directly or indirectly (through the X2 gateway or the proxy X2 gateway, X2 proxy) to indicate the macro to the small cell through an X2 Setup flow message, an ENB Configuration Update flow message, or an X2 message such as a Load Information message. The configuration information of the CSI-RS of the cell (the macro cell may also notify the small cell of the configuration information of the CSI-RS of the macro cell by using the RRC information between the base stations carried in the handover preparation flow message, for example, AS-Config), or the macro cell passes the above The X2 message recommends the configuration information of the non-zero-power CSI-RS to the small cell (small cell). After receiving the configuration information, the small cell can configure its own non-zero-power CSI-RS to complete the inter-cell coordination. . Conversely, the small cell can also indicate its non-zero power CSI to the macro cell either directly or indirectly (via X2 gateway or proxy X2 gateway, X2 proxy) through X2 Setup flow message, ENB Configuration Update flow message, or Load Information message. - The configuration of the RS, the macro cell then configures the corresponding CSI-RS measurement for the UE through the air interface. The method for coordinating the inter-cell configuration through the S1 interface or other interfaces includes the macro base station transmitting the CSI-RS configuration or recommending the non-zero power CSI to the opposite base station through the MME and/or the gateway (eg, HeNB GW, S1 GW). The configuration of the RS, and/or the small base station transmits the configuration of the non-zero power CSI-RS or the configuration of the recommended macro base station CSI-RS to the macro base station through the MME and/or the gateway (eg, HeNB GW, S1 GW). The method for coordinating the inter-cell configuration by the network management system includes: the network management system indicates the CSI-RS configuration to the macro base station, and the network management system indicates the non-zero power CSI-RS configuration to the small base station; or the network management system sends the non-zero power of the small cell to the macro base station. The CSI-RS configuration information is used to send CSI-RS configuration information of the macro cell to the small base station. The specific mode of transmitting the macro and the small cell by the UE includes: after the handover to the small cell, the macro UE sends the CSI-RS configuration information configured by the previous macro cell to the small cell, or after the small cell switches to the macro cell, Non-zero power CSI-RS configuration information previously configured by the small cell The macro base station is configured to receive the system information of the small cell, including the non-zero power CSI-RS configuration information, and report the information to the macro base station.

 In a large-scale radio access network, the performance of small cell discovery can also be improved through a large-scale coordination, for example, aligning REs corresponding to CSI-RSs of multiple macro cells (constituting a coordinated discovery area) (macro The small-area may transmit CSI-RS configuration information through an X2/S1 interface or a network management system. The serving macro base station may also configure CSI-RS information of the neighboring macro base station for the UE, so that the UE will include the service when measuring the interference strength. The signal power of the macro base station and the adjacent macro base station are eliminated (or the zero-power CSI-S of other neighboring macro cells corresponding to the CSI-RS of the serving cell, so that the UE only needs to eliminate the CSI-RS signal of the serving cell. It is ok), so that the interference intensity only reflects the power intensity of the small cell, which can improve the accuracy of starting the small cell measurement.

 Step 1102: The UE receives measurement configuration information sent by the macro base station.

 Here, the measurement configuration information includes measurement configuration information (interference measurement resource configuration information) of the first downlink signal, where the first downlink signal is a non-zero power CSI-RS, and the measurement configuration information of the first downlink signal includes : non-zero power CSI-RS resource configuration identifier (CSI-RS-Id tityNZP), resource configuration information (resourceConfig), subframe configuration information (frameConfig), antenna port number (antennaPortsCount), scrambling code identification (scramblingldentity), and CRS Quasi-co-location information (qcl-CRS-Info). The measurement configuration information also includes a start measurement threshold (threshold) for controlling whether to initiate measurement for the non-serving cell, and/or parameter information k for filtering the measured value.

 The measurement configuration information of the first downlink signal sent by the macro base station may be: the macro base station sends the measurement configuration information of the first downlink signal by using a radio link reconfiguration message (RRCConnectionReconfiguration).

 The macro base station may also configure the measurement bandwidth for the measurement configuration of the UE, and is not limited to performing measurement on the center 6 RBs of the system bandwidth, but may perform measurement bandwidth according to requirements (for example, measuring a portion where the macro cell and the small cell spectrum overlap). Configuration, which can support not only the scenario where the macro cell and the small cell are at the same frequency, but also the scenario where the macro cell and the small cell have different frequencies but the spectrum partially overlaps.

Step 1103: The UE measures a CSI-RS (or an interference measurement resource) according to the measurement configuration information. The interference strength on the corresponding RE.

 In a scenario where the macro cell and the small cell coexist, the macro base station configures parameters for CSI-RSRP and CSI-RSSI measurement for the UE, including subframe configuration information of the CSI-RS. The macro UE measures the resource unit corresponding to the channel state information reference signal CSI-RS of the serving cell (ie, the macro cell) (indicated by the measurement configuration information of the first downlink signal sent by the macro base station of the serving cell of the UE) The received signal strength, wherein the measured received signal is the residual signal after the CSI-RS of the serving cell is cancelled. In other words, the UE first performs interference cancellation based on the CSI-RS sequence of the serving cell based on the signal received on the CSI-RS RE (using the interference cancellation receiver IC receiver), and then measures the strength of the remaining signals (Interference). The received CSI-RS - received signal strength indicator, abbreviated as IC-CSI-RSSI, is based on the total of the residual signals after interference cancellation on the CSI-RS on the RE corresponding to the CSI-RS on the measured bandwidth. Linear average of power). Thus, the macro UE measures the received signal strength of the non-serving cell, possibly including the signal power from the adjacent small cell, and the signal power from the adjacent macro cell.

The UE performs L3 (Layer 3) filtering on the IC-CSI-RSSI measured by the physical layer. The specific filtering formula is: = (1 _ ") - where _{a =} J^, M„ is the latest measurement from the physical layer, is the filtered filtered result, and is the last filtered result.

 Step 1104: The UE determines, according to the interference strength of the first downlink signal on the RE, whether to enable measurement of the non-serving cell. If yes, execute step 1105; otherwise, end the processing flow.

 If the IC-CSI-RSSI is above (or greater than or equal to) a particular threshold, the macro UE initiates measurements on (co-frequency and/or inter-frequency) neighbor cells, otherwise the macro UE may not measure neighbor cells.

The above measurement based on IC-CSI-RSSI reflects the interference strength or the received signal strength of the non-serving cell. Considering the relative value of the signal strength of the serving cell and the neighboring cell, which is usually used for decision making in radio resource management, It is also possible to define channel state information reference signal reception quality (CSI-RSRQ) as channel state information reference signal reception power (CSI-RSRP, and physical layer measurement is based on CSI-RS on RE corresponding to CSI-RS on the measured bandwidth) Linear contribution of power contribution Mean) The ratio of the interference intensity IC-CSI-RSSI. This value reflects the ratio of the signal power of the serving cell to the interference strength. Therefore, it can reflect whether the UE is away from the serving macro cell or whether the UE is close to the small cell. Therefore, the UE can also control the measurement of the non-serving cell based on the measurement of the CSI-RSRQ defined above. When the CSI-RSRQ is lower than (or less than or equal to) the threshold configured by the base station, the UE initiates measurement of the non-serving cell, otherwise the UE may not measure the non-serving cell.

 In addition, the above determination condition is that the comparison between the measured value and the threshold value is used as a determination basis (or one of the judgment criteria), and this method may be referred to as an intensity determination method. In addition, it is also conceivable to use the increment of the measured value as the discriminating condition for starting the same-frequency/inter-frequency measurement. This method is called the incremental decision method. Incremental over a certain period of time according to IC-CSI-RSSI or CSI-RSRQ: The measured increase in IC-CSI-SSI means that the strength of the non-serving cell signal (or interference signal) is enhanced, if the IC-CSI-RSSI continues to increase, It may be that the distance is closer and closer to another cell, and the measurement may be considered; or, the decrease of CSI-RSRQ means that the interference strength increases and/or the signal strength of the serving cell decreases. If the CSI-RSRQ continues to decrease, the distance may be indicated. The serving cell is getting farther and farther, and getting closer and closer to the neighboring cell, you can consider starting the measurement. The incremental decision method and the strength decision method may also be combined to determine whether to initiate non-serving cell or small cell measurement.

On the other hand, usually the initiation of small cell discovery does not need to be initiated alone, the small cell discovery can be performed in the non-serving cell measurement, and the measurement of the non-serving cell not only needs to consider the needs of small cell discovery, but also needs to be considered in the macro. The need for small-area UE mobility (such as handover), for this purpose,

The joint decision criterion includes: combining IC-CSI-RSSI or CSI-RSRQ with at least two of RSRP (CRS-based), RSRQ, and CSI-RSRP to control a co-frequency/inter-frequency non-serving cell (adjacent Measurement of the cell). For example, mode 1: if IC-CSI-RSSI>threshold, or RSRP is smaller than a threshold configured by a certain base station, start measurement of a non-serving cell; mode 2: when IC-CSI-SSI>threshold, or CSI-RSRP is smaller than a certain A threshold configured by a base station, starting measurement of a non-serving cell; mode 3: if CSI-RSRQ<thresholdl, or RSRP is smaller than a threshold configured by a certain base station, starting measurement of a non-serving cell; mode 4: if CSI-RSRQ< Threshold Or the CSI-RSRP is smaller than the threshold configured by a certain base station, and the measurement of the non-serving cell is started. If the start of the measurement is only for small cell discovery, at least two of IC-CSI-RSSI, CSI-RSRQ, RSRP (CRS-based), RSRQ, and CSI-RSRP may be combined to control measurement of the small cell, specifically The example changes the "or" relationship of the conditional judgments in the above four ways to the "and" relationship. Using the criterion of a single condition, the joint decision criterion is executed when the criterion of the single condition is satisfied. The specific examples are as follows: First or default, the criterion of RSRP based on CRS is adopted, when the RSRP based on the CRS measurement value is less than the pre- When a defined or base station configured threshold is used, a joint decision criterion is then performed to determine whether to initiate an intra-frequency or inter-frequency measurement by a new measurement, such as an IC-CSI-RSSI or CSI-RSRQ measurement. As another example, UEs in a particular transmission mode use joint decision criteria for measurement control. The base station may also indicate, by means of signaling, the UE to perform joint determination criteria, including Radio Resource Control (RRC) layer IE, MAC layer control element control element, and downlink control information (abbreviation). For DCI).

 Step 1105: The UE starts measurement of the non-serving cell.

The method for specifically starting the measurement on the neighboring cell (or the small cell) is as follows: In the first mode, the serving base station has configured the measurement of the neighboring cell (or small cell) for the UE, but the measurement needs to wait for the UE to specifically The determination of the condition can be started. In the second mode, the UE reports the measurement result to the serving base station or sends a specific indication (such as a strong interference indication) after determining that the (base station configured) reporting condition is met, and the base station according to the measurement result or a specific indication (for example, strong) Interference indication) Perform measurement configuration (and/or start of measurement) of a neighboring cell (or small cell). In this way, the macro UE can perform measurement on the non-serving cell/small cell only in a local area close to the small cell, and does not need to perform measurement on the non-serving cell/small cell in most areas away from the small cell, thereby It not only reduces the power consumption and computational overhead caused by the measurement, but also can detect small cells in time and improve the quality of service (including throughput) by switching/diverting to small cells or using small cells as secondary carriers, reducing the load of macro cells. . -, In the above example, the serving cell or the small cell can use not only the licensed frequency band (for example, the IMT frequency band) but also the unlicensed frequency band (for example, the frequency band that the wireless local area network WLAN can use), that is, the resource unit corresponding to the specified downlink signal by the UE. The measurement of the received strength of the signal on (RE) can be performed in an unlicensed band. In this case, when the serving cell is an LTE cell (for example, LTE unlicensed band LTE-unlicensed is abbreviated as LTE-U cell), the small cell may be a WLAN cell or other LTE-U cell; thus, the UE pairs the LTE-U cell. On the resource unit (RE) corresponding to the designated downlink signal, the measurement of the received strength of the signal can determine whether there is a neighboring small cell (such as an LTE-U cell or a WLAN cell), and the signal strength of the adjacent small cell ( That is, the total signal strength of the neighboring cells, which can be used to initiate measurement of neighboring small cells, as well as selection of UE aggregated carriers, and activation and configuration of scells.

 The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

claims 1. A method for controlling user equipment UE to perform measurements. The method includes: The UE measures the interference intensity on the resource unit RE corresponding to the first downlink signal, and determines whether to enable measurement of the non-serving cell based on the interference intensity. 2. The method according to claim 1, wherein before the UE measures the interference strength of the signal on the RE corresponding to the designated first downlink signal, the method further includes: The UE receives measurement configuration information of the first downlink signal; Wherein, the measurement configuration information is the resource location information of the first downlink signal, including at least one of the following: subframe configuration information, frequency domain configuration information, port information; the first downlink signal includes: channel state information reference The signal CSI-RS, or the cell-level reference signal CRS, or the synchronization signal SS, or the discovery signal. 3. The method according to claim 2, wherein the UE measures the interference intensity on the RE corresponding to the first downlink signal, including: The UE measures the reception intensity on the RE corresponding to the zero-power first downlink signal and uses it as the interference intensity. 4. The method according to claim 2, wherein the UE measures the interference intensity on the RE corresponding to the first downlink signal, including: The UE measures the received strength on the RE corresponding to the first downlink signal and the received power of the first downlink signal, and uses the difference between the two as the interference strength. 5. The method according to claim 2, wherein the UE measures the interference intensity on the RE corresponding to the first downlink signal, including: The UE measures the reception intensity on the RE corresponding to the first downlink signal after performing the interference cancellation operation on the first downlink signal, and uses the reception intensity as the interference intensity. 6. The method according to claim 2, wherein the determining whether to enable measurement of non-serving cells based on the interference intensity includes: The UE measures the received power of the specified second downlink signal, according to the second downlink signal The ratio between the received power and the interference intensity determines whether to enable measurement of non-serving cells; Wherein, the received power of the second downlink signal is reference signal received power RSRP, or channel state information reference signal received power CSI-RSRP, or synchronization signal received power. 7. The method according to claim 1, wherein the determining whether to enable measurement of non-serving cells includes: When the UE determines that the interference intensity is higher than or not lower than the threshold value for initiating measurement of the non-serving cell, measurement is performed on the non-serving cell. 8. The method according to claim 6, wherein the determining whether to enable measurement of non-serving cells includes: The measurement of the non-serving cell is controlled using at least two parameters among the interference intensity, the ratio between the received power of the second downlink signal and the interference intensity, RSRP, RSRQ, and CSI-RSRP. 9. The method according to any one of claims 1 to 8, wherein, after determining whether to enable measurement of non-serving cells based on the interference intensity, the method further includes: enabling measurement of non-serving cells; Wherein, the enabling of measurement of non-serving cells includes: The UE automatically initiates measurement of non-serving cells; Alternatively, the UE reports the measurement result or sends a strong interference indication to the serving base station, and the serving base station configures the measurement of the non-serving cell. 10. The method according to claim 2, wherein before the UE receives the measurement configuration information of the first downlink signal, the method further includes: The serving base station corresponding to the macro cell where the UE is located and the small base station corresponding to the small cell coordinate the configuration of the first downlink signal through the X2 interface, or S1 interface, or network management OAM, or the UE. 11. The method according to any one of claims 1 to 8, wherein the resources of the first downlink signal include: resources of a licensed frequency band and resources of an unlicensed frequency band; When the resource of the first downlink signal is the resource of the unlicensed frequency band, in addition to the resource based on the interference In addition to determining whether to enable measurement of non-serving cells based on interference intensity, the method also includes: selecting a UE aggregation carrier, and activating and configuring the secondary cell scell. 12. A device for controlling a UE to perform measurements, the device includes: a measurement module and a decision-making module; wherein, The measurement module is configured to measure the interference intensity on the RE corresponding to the specified first downlink signal, and send the interference intensity to the decision-making module; The decision-making module is configured to determine whether to enable measurement of the non-serving cell based on the interference intensity of the first downlink signal on the RE sent by the measurement module. 13. The device according to claim 12, wherein the device further includes: a receiving module configured to receive and save the measurement configuration information of the first downlink signal, and send the measurement configuration information of the first downlink signal to measurement module; Correspondingly, the measurement module is configured to receive and save the measurement configuration information sent by the receiving module, wherein the measurement configuration information is the resource location information of the first downlink signal, including at least one of the following: subframe configuration information, Frequency domain configuration information, port information; The first downlink signal includes: channel state information reference signal CSI-RS, or cell-level reference signal CRS, or synchronization signal SS, or discovery signal. 14. The device according to claim 13, wherein, The measurement module is configured to measure the reception intensity on the RE corresponding to the zero-power first downlink signal and use it as the interference intensity. 15. The device according to claim 13, wherein, The measurement module is configured to measure the reception intensity on the RE corresponding to the first downlink signal and the first downlink signal reception power, and use the difference between the two as the interference intensity. 16. The device according to claim 13, wherein, The measurement module is configured to measure the reception strength on the RE corresponding to the first downlink signal after the interference cancellation operation is performed on the first downlink signal, and use the reception strength as the interference strength. 17. The device according to claim 13, wherein, The decision-making module is configured to measure the received power of a designated second downlink signal, and determine whether to enable measurement of non-serving cells based on a ratio between the received power of the second downlink signal and the interference intensity and a determination criterion. ; Wherein, the received power of the second downlink signal is reference signal received power RSRP, or channel state information reference signal received power CSI-RSRP, or synchronization signal received power. 18. The device according to claim 12, wherein, The decision-making module is configured to execute determination criteria; wherein, the determination criteria include: when the UE determines that the interference intensity is higher than or not lower than the threshold value for initiating measurement of non-serving cells, Measurements are performed on non-serving cells. 19. The device according to claim 17, wherein, The decision-making module is configured to execute decision criteria; wherein, the decision criteria include: using the interference intensity, the ratio between the reception intensity of the second downlink signal and the interference intensity, RSRP, RSRQ, and CSI- At least two parameters in RSRP control the measurement of non-serving cells. 20. The device according to any one of claims 12 to 19, wherein, The decision-making module is configured to enable measurement of non-serving cells; Wherein, the turning on the measurement of the non-serving cell includes: the UE automatically initiates the measurement of the non-serving cell; or, the UE reports the measurement result or strong interference indication to the serving base station so that the serving base station configures the measurement of the non-serving cell. Measurements of the neighborhood. 21. The device according to any one of claims 12 to 19, wherein the resources of the first downlink signal include: resources of a licensed frequency band and resources of an unlicensed frequency band; The decision-making module is configured to select an aggregation carrier when the resource of the first downlink signal is a resource of the unlicensed frequency band, in addition to determining whether to enable measurement of non-serving cells based on the interference intensity, and Activate and configure the secondary cell scell.