TWI594652B - Method of radio resource scheduling in unlicensed spectrum and related apparatuses using the same - Google Patents

Description

Radio resource scheduling method, base station and authorized auxiliary access node in unlicensed frequency band

The present invention relates to a method for scheduling radio resources in an unlicensed frequency band and a base station and an authorized auxiliary access node using the method.

Traditionally, wireless communication systems operate in a proprietary radio frequency (RF) band in which base stations and wireless terminals communicate via dedicated radio frequency bands that are licensed to wireless carriers. However, there has been discussion about extending the use of wireless communication systems to unlicensed frequency bands, such as the Industrial, Medical and Medical RF spectrum (ISM band) or other free frequency bands. The possibility of Long Term Evolution (LTE) communication system or LTE advanced (LTE-advanced) communication system entering unlicensed frequency bands has attracted the attention of telecom equipment manufacturers and operators. This is called "Licensed-Assisted Access (LAA)." At present, efforts have been made to obtain unauthorised A single global solution framework for Authorized Access Access (LAA). One reason for this interest is that the licensed band is potentially overcrowded. In order to provide high-throughput services to more users, entering an unlicensed band may alleviate the overcrowding of the wireless communication system. However, such efforts will require solutions for countless difficulties.

Unlicensed bands are increasingly seen by cellular operators as complementary radio resources for extending their services. According to 3GPP TR 36.899 and RP-141664, the LAA can be considered as a component carrier (CC) integrated into LTE. However, high priority should be given to the completion of the downlink (DL) scheme.

Unlike LTE, where the operator has a specific set of operating channels, the unlicensed bands will need to be shared and shared by almost any wireless communication access technology. A person who initiates communication on an unlicensed band may need to go through a competitive phase in order to use the frequency of the unlicensed band. The winner of the competition will have the right to communicate on the frequency for a limited period of time, the time of which is defined by regional regulations, for example in Japan, each occupied 4ms, and in parts of Europe, Each time it takes 10ms. Therefore, when someone wants to communicate on an unlicensed band, the availability of unlicensed bands is uncertain. For the 5 GHz band, LAA nodes operating on unlicensed bands can range from 50 m to 100 m.

In view of this, the present invention relates to a radio in an unlicensed frequency band A method of resource scheduling and a base station using the method and an authorized auxiliary access node.

The invention provides a method for scheduling radio resources in an unlicensed frequency band, which is suitable for a base station. The method includes, but is not limited to, transmitting node control information before receiving the occupancy notification, the node control information may include an occupation mode of a radio resource of an unlicensed band; before receiving the occupancy notification, transmitting device control information, the device control information includes The occupancy pattern of the radio resources in the licensed band; the packet data is transmitted using the radio resources of the unlicensed band before receiving the occupancy notification; and the occupancy notification is received, and the occupancy notification informs the availability of the radio resources of the unlicensed band.

The present invention provides a method of scheduling radio resources in an unlicensed frequency band, suitable for authorizing a secondary access (LAA) node. The method includes, but is not limited to, receiving node control information before transmitting the occupancy notification, the node control information includes an occupation mode of the radio resource of the unlicensed band; receiving the packet data before the transmission of the occupancy notification, and using the unlicensed band for the packet data Radio resources; determining the availability of radio resources in unlicensed bands; and transmitting the occupancy notice to inform the availability of radio resources in unlicensed bands.

The present invention provides a base station including, but not limited to: a transmitter, a receiver, and a processor coupled to the transmitter and the receiver and configured at least to: prior to receiving the occupancy notification, via The transmitter transmits node control information, and the node control information includes an occupation mode of the radio resource of the unlicensed band; before receiving the occupancy notification, the device control information is transmitted via the transmitter, and the device control information includes an occupation mode of the radio resource of the unlicensed band; Receive occupancy notice Previously, the packet data was transmitted via the transmitter using the radio resources of the unlicensed band; and the occupancy notification was received via the receiver, the occupancy notification notifying the availability of the radio resources of the unlicensed band.

The present invention provides an authorized auxiliary access node, including but not limited to: a first transceiver and a processor, the processor being coupled to the first transceiver and at least for: transmitting an occupancy notification Previously, the node control information is received via the first transceiver, the node control information includes an occupation mode of the radio resource of the unlicensed band; before the transmission of the occupancy notification, the packet data is received via the first transceiver, and the packet data uses the radio resource of the unlicensed band Determining the availability of radio resources for unlicensed bands; and transmitting occupancy notifications via the first transceiver to inform the availability of radio resources for unlicensed bands.

The above described features and advantages of the invention will be apparent from the following description.

100‧‧‧radio access network

101‧‧‧LTE eNB

102‧‧‧User equipment

103‧‧‧LAA node

104‧‧‧X2-LAA interface/X2-LAA network interface

200‧‧‧Base Station

250‧‧‧Processing unit

251‧‧‧Digital-to-analog converter

252‧‧‧transmitter

253‧‧‧ Analog-Digital Converter

254‧‧‧ Receiver

255‧‧‧Antenna unit

256‧‧‧ Non-transitory storage media/storage media

257‧‧‧Return link transceiver

261‧‧‧Processing unit

262‧‧‧LTE-U transceiver

263‧‧‧Return link transceiver

264‧‧‧ Non-transitory storage media/storage media

301‧‧‧LTE Coordinator

302‧‧‧LTE buffer

303‧‧‧LAA buffer

304‧‧‧LAA Coordinator

401‧‧‧PDCCH

402‧‧‧ Radio resources

411‧‧‧ePDCCH

412‧‧‧ Radio resources

511‧‧‧Occupy time/child box

512‧‧‧ Blank sub-frame

521‧‧‧ occupancy mode

601‧‧‧ subframe

602‧‧‧ subframe

604‧‧‧ subframe

622‧‧‧

661‧‧‧ Mapping Information #1

662‧‧‧ Mapping Information #2

663‧‧‧ Mapping Information #3

664‧‧‧ Mapping Information #4

671‧‧‧There is a place

672‧‧‧ Reserved interval

804‧‧‧Child frame

P30‧‧‧Time

S11‧‧ steps

S31‧‧‧Steps

S201~S205‧‧‧Steps

S211~S214‧‧‧Steps

S221~S224‧‧‧Steps

S501~S504‧‧‧Steps

S522‧‧‧Steps

S531~S532‧‧‧Steps

S541~S542‧‧‧Steps

S611~S616‧‧‧Steps

S621~S623‧‧‧Steps

Step S651‧‧‧

S681~S684‧‧‧Steps

S701~S703‧‧‧Steps

S706~S708‧‧‧Steps

S712~S713‧‧‧Steps

S801~S803‧‧‧Steps

S901~S903‧‧‧Steps

S905~S906‧‧‧Steps

S1001~S1003‧‧‧ steps

TDD#0~TDD#6‧‧‧TDD configuration

T01~t03‧‧‧Time

T32-t31‧‧‧One-way transmission delay

FIG. 1A illustrates an exemplary network that facilitates authorized secondary access.

Figure 1B illustrates the concept of a backhaul link having a delay greater than the occupancy period defined by the specification.

Figure 1C illustrates the concept of data forwarding required because the delay of the backhaul link is greater than the occupancy period.

2A illustrates an evolution of LTE in accordance with one of the exemplary embodiments of the present invention. A signaling diagram of the overall process of coordination and radio resource allocation between an Node B (eNB), an LAA node, and a user equipment (UE).

2B illustrates a method of radio resource scheduling in an unlicensed frequency band from the perspective of a base station, in accordance with one of the exemplary embodiments of the present invention.

2C illustrates an exemplary base station in accordance with one of the exemplary embodiments of the present invention.

2D illustrates a method of radio resource scheduling in an unlicensed frequency band from the perspective of an Authorized Auxiliary Access (LAA) node, in accordance with one of the exemplary embodiments of the present invention.

2E illustrates an exemplary authorized secondary access node in accordance with one of the exemplary embodiments of the present invention.

3 illustrates a protocol stack in an LTE eNB and an LAA node, in accordance with one of the exemplary embodiments of the present invention.

4A illustrates sub-frame content in an LAA buffer of an LTE buffer or LAA node of an LTE eNB based on cross-carrier scheduling.

4B illustrates an example of subframe content in an LAA buffer of an LTE buffer or LAA node of an LTE eNB based on the same carrier schedule.

FIG. 5A illustrates a pre-scheduling concept in accordance with one of the exemplary embodiments of the present invention.

FIG. 5B illustrates pre-scheduling in the case of frequency domain duplex (FDD) operation in accordance with one exemplary embodiment of the present invention.

5C is a signaling diagram illustrating an LTE eNB transmitting data to a UE in accordance with one of the exemplary embodiments of the present invention.

5D illustrates the behavior of an LTE eNB, a LAA node, and a UE in an occupancy failure scenario, in accordance with one of the exemplary embodiments of the present invention.

6A illustrates radio resource scheduling in an unlicensed frequency band in the case of an FDD mode in accordance with one of the exemplary embodiments of the present invention.

6B illustrates radio resource scheduling in an unlicensed frequency band in the case of an FDD mode or a time domain duplex (TDD) mode, according to an exemplary embodiment of the present invention.

FIG. 6C illustrates an eNB transmitting mapping information according to one of the exemplary embodiments of the present invention.

Figure 6D illustrates the occupancy mechanism in more detail in accordance with one of the exemplary embodiments of the present invention.

FIG. 6E illustrates the eNB transmitting mapping information in more detail in accordance with one of the exemplary embodiments of the present invention.

FIG. 6F illustrates the content of mapping information in accordance with one of the exemplary embodiments of the present invention.

FIG. 6G illustrates a technique for delivering mapping information in accordance with one of the exemplary embodiments of the present invention.

6H illustrates that an LAA node delivers mapping information to a UE in accordance with one of its exemplary embodiments of the present invention.

Figure 7 illustrates the situation in a TDD mode in accordance with one of the exemplary embodiments of the present invention. Radio resource scheduling mechanism in the unlicensed band.

FIG. 8 illustrates another exemplary embodiment of a radio resource scheduling mechanism in an unlicensed band in the case of a TDD mode.

Figure 9 illustrates a radio resource scheduling mechanism performed one by one by subframes in accordance with one of the exemplary embodiments of the present invention.

Figure 10 illustrates a classification of a deployment environment for LAA nodes in accordance with one of the exemplary embodiments of the present invention.

FIG. 11 illustrates an occupancy mode of TDD configuration 0 in accordance with one of the exemplary embodiments of the present invention.

FIG. 12 illustrates an occupancy mode of the TDD configuration 1 in accordance with one of the exemplary embodiments of the present invention.

FIG. 13 illustrates an occupancy mode of the TDD configuration 2 in accordance with one of the exemplary embodiments of the present invention.

FIG. 14 illustrates an occupancy mode of the TDD configuration 3 in accordance with one of the exemplary embodiments of the present invention.

FIG. 15 illustrates an occupancy mode of the TDD configuration 4 in accordance with one of the exemplary embodiments of the present invention.

FIG. 16 illustrates an occupancy mode of the TDD configuration 5 in accordance with one of the exemplary embodiments of the present invention.

FIG. 17 illustrates an occupancy mode of the TDD configuration 6 in accordance with one of the exemplary embodiments of the present invention.

FIG. 18 illustrates the occupation of an LTE eNB according to one exemplary embodiment of the present invention. Switch from mode TDD configuration 0 to configuration 1 in mode.

FIG. 19 illustrates that the occupancy mode of an LTE eNB is switched from TDD configuration 1 to configuration 2 in accordance with one of the exemplary embodiments of the present invention.

20 illustrates handover of an occupancy mode of an LTE eNB from TDD configuration 1 to configuration 3, in accordance with one of the exemplary embodiments of the present invention.

21 illustrates handover of an occupancy mode of an LTE eNB from TDD configuration 1 to configuration 4, in accordance with one of the exemplary embodiments of the present invention.

22 illustrates handover of an occupancy mode of an LTE eNB from TDD configuration 1 to configuration 5, in accordance with one of the exemplary embodiments of the present invention.

23 illustrates handover of an occupancy mode of an LTE eNB from TDD configuration 1 to configuration 6 in accordance with one of the exemplary embodiments of the present invention.

The exemplified embodiments are described in detail below with reference to the drawings, and the same reference numerals and

1A illustrates an exemplary radio access network (RAN) 100 in which user equipment (UE) 102 supported by LAA node 103 is located within the coverage of LTE eNB 101 operating on licensed bands. . The RAN is related to the following parts of the mobile communication system, including: a radio access node (e.g., eNB, small) for performing at least one radio access technology (e.g., 3G, LTE, or Wi-Fi) to provide radio communication services for the UE. Base station, or Wi-Fi access point). The LTE eNB 101 may be a large eNB. LAA node 103 can A small base station that is deployed for operation on an unlicensed band. The LAA node 103 can be centrally controlled by the LTE eNB 101.

The LAA node 103 can be associated with devices deployed to operate on an unlicensed or licensed band within the coverage of the LTE eNB 101, which can include a large base station, a small base station, and a remote radio head (remote radio) Head, RRH), or WiFi access point. In this illustration, there may be at least one UE 102 and at least one LAA node 103 within the coverage of the eNB 101. Since the UE 102 is both within the coverage of both the LTE cells of the LTE eNB 101 and the LAA cells of the LAA node 103, the UE 102 may be served by one or both of the LTE eNB 101 and the LAA node 103. The eNB 101 can coordinate with the LAA node 103 to serve the UE 102.

In order to perform signaling and data transmission between the eNB 101 and the LAA node 103, it is necessary to have a network interface between the LTE eNB 101 and the LAA node 103, such as the X2-LAA interface 104 shown in FIG. 1A. The X2-LAA network interface 104 can be supported by both the eNB 101 and the LAA node 103 because the X2-LAA network interface 104 will be deployed within the coverage of both the LTE eNB 101 and the LAA node 103. The signal and data traffic of the X2-LAA interface 104 may be transmitted via a connection between the LTE eNB 101 and the LAA node 103 (which is hereinafter referred to as a "backhaul").

The backhaul link or connection between the LTE eNB 101 and the LAA node 103 can be either physical or logically wired or wireless. The backhaul link can be further classified as an ideal backhaul link or non-defined in 3GPP TR 36.932 Ideal backhaul link. See 3GPP TR 36.932, ideal backhaul links with very high throughput and very low latency backhaul links (eg dedicated point-to-point connections using fiber optics); non-ideal backhaul links are associated with widespread use in the market Typical backhaul links, such as xDSL, microwave, and other backhaul links (such as relays) that can have longer delays and limited capacity.

For example, the connection or backhaul link between the LTE eNB 101 and the LAA node 103 can be a physical dedicated wireline such that the signal and data traffic of the X2-LAA interface 104 can be connected via the LTE eNB 101 to the LAA node 103. Transfer. For example, a connection or backhaul link between the LTE eNB 101 and the LAA node 103 can be implemented via wireless communication. In other words, the signal and data traffic of the X2-LAA interface 104 can be transmitted between the LTE eNB 101 and the LAA 103 by transmitting and/or receiving electromagnetic waves conforming to the agreed X2-LAA interface 104.

For example, the connection or backhaul link between LTE eNB 101 and LAA node 103 may be a logical connection implemented through a plurality of different physical/logical connections including at least LTE eNB and core network elements An entity/logical connection between, and another physical/logical connection between the LAA node and the core network element. Thus, the signal and data traffic of the X2-LAA interface 104 can be transmitted between the LTE eNB 101 and the LAA node 103 via the logical connection/backhaul link between the LTE eNB 101 and the LAA node 103.

For example, the connection or backhaul link between the LTE eNB 101 and the LAA node 103 can be a logical connection implemented through a plurality of different physical/logical connections through the LTE eNB 101 and the router. At least one real The physical/logical connection, and at least one physical/logical connection between the LAA node 103 and the router is implemented. The signal and data traffic of the X2-LAA interface can be transmitted between the LTE eNB 11 and the LAA node 103 through such a logical connection.

In general, it may not be assumed that an ideal backhaul link is between the LTE eNB and the LAA node. Considering the operator's existing backhaul link deployment, it is more reasonable to have a non-ideal backhaul link between the LTE eNB and the LAA node, and future deployments should consider non-ideal backhaul links. The latency or delay caused by the connection or backhaul link between the LTE eNB and the LAA node may include, but is not limited to, signal propagation time, network transmission time, transmission delay, queuing delay in each network node or component. And the processing time required in each network node or component of the connection.

One difficulty associated with deploying a non-ideal backhaul link between an LTE eNB and a LAA node is that it is less likely that the radio resource configuration and scheduling will be performed on a normal basis. The reason is that when the LAA node has successfully occupied the operating frequency of the unlicensed band, the LTE eNB may not immediately know the availability of the unlicensed band. In this scenario, the LTE eNB will be less able to transmit UE scheduling data or signaling on the operating frequency occupied by the LAA node. Moreover, the utilization of the occupied frequency may exceed a critical value of 80%, making it difficult for the LAA node to occupy the operating frequency and transmit data on the operating frequency. Therefore, the problem of obtaining and using radio resources in an unlicensed band while taking into account the backhaul link delay has not been solved, especially when the delay is longer than the channel occupation time.

FIG. 1B is a diagram illustrating the concept that the delay of the backhaul link link is greater than the occupation period defined by the specification. In this example, the backhaul link delay is assumed to be 5ms and The occupation time is 4ms. If the channel in the unlicensed band is successfully occupied at time t01 and it is assumed that the LAA 103 immediately issues a notification when the channel is successfully occupied at time t01 in step S11, the eNB 103 will not receive the notification until time t03. However, at time t03, the LAA has released the channel of the unlicensed band at time t02 according to the regional regulations. Therefore, if the LTE eNB 101 schedules the radio resources of the LAA node 103 on the basis of receiving the occupancy notification from the LAA node 103, the LTE eNB 101 typically performs radio resources due to the long backhaul link transmission delay of the non-ideal backhaul link. The time allocated will be too late.

FIG. 1C is a diagram illustrating the concept of forwarding data because the delay of the backhaul link link is greater than the occupation period. In the illustration of Figure 1C, the LAA node can be a small base station operating on an unlicensed band. The communication between the LTE eNB and the LAA node is implemented through the X2-LAA interface. The LAA node can be centrally controlled by the LTE eNB through a direct connection or through a cloud radio access network. It is assumed that the one-way transmission delay (t32-t31) between the LTE eNB and the LAA node is 7 ms, and it is assumed that the grant occupation time (P30) on the unlicensed band is 4 ms. Since the occupation time (P30) is 4 ms, when the transmission delay of 7 ms is taken into consideration, the data needs to be forwarded or transmitted from the LTE eNB to the LAA node in advance, as shown in S31.

Carrier aggregation (or channel aggregation) can be used together to provide high data transmission rates for multiple carriers or channels. In the case of carrier aggregation, the carrier aggregation controller or coordinator needs to know the status of each carrier immediately, including the availability of radio frequency and the quality of radio resources. In order to achieve inter-node communication carrier aggregation via a non-ideal backhaul link with delay and limited capacity, carrier aggregation between nodes can be considered. Use pre-scheduled technology. However, since pre-scheduling can cause timing and signaling inconsistencies between the LTE eNB and the LAA node, the challenges involved in pre-scheduling the LAA operation using the non-ideal backhaul link can include how the LTE eNB knows the unauthorized Whether the frequency band is available, how the LTE eNB configures the LAA node for data transmission (such configuration includes but not limited to backhaul link delay and channel occupation time), and how the LTE eNB identifies and corrects the poor channel quality or the occupation failure. Error data (eg HARQ NACK from UE). The backhaul link delay can be, for example, about 5 ms for Fiber access 3, and according to 3GPP TR 36.889, the channel occupancy time can be, for example, 4 ms in Japan or 10 ms in Europe. In addition, in order to overcome non-instantaneous configuration and scheduling due to backhaul link delay, and to schedule retransmission of data immediately after receiving HARQ NACK due to poor channel quality or occupancy failure from the UE, it can be designed A new radio resource scheduling mechanism in an unlicensed band.

Since the LAA node is responsible for running channel occupancy and scanning band usage, the LAA node will notify the LTE eNB of the success of the channel occupation and the frequency band usage scan result. In addition, the LAA node can perform dynamic frequency selection (DFS) and transmit power control (TPC) to reduce or avoid interference in unlicensed bands. Both the UE and the LAA node can be temporally aligned with the LTE eNB by performing transmission synchronization. Through the configuration between the LTE eNB and the LAA node, the LTE eNB can know the time point at which the LAA node can start signaling and data transmission if the LAA node has successfully occupied the operating frequency, so that the LTE eNB can be without immediate feedback or from the LAA. Node indication In the case of the LAA radio resource scheduling to the UE. The LAA node may only need to have a PHY module and the required control functions, and the PHY module may be a module with a physical layer protocol stack and associated functions. The radio resource scheduling and retransmission will be performed by the LTE eNB; therefore, the UE can receive control signaling from the LTE eNB via the PDCCH or ePDCCH through the cross-carrier scheduling. Control signaling can be sent from the LAA node through self-carrier scheduling. The LAA node is controlled by the LTE eNB, such as what data or which data to transmit or when to transmit.

The present invention proposes a solution that includes coordination between LAA nodes and LTE eNBs, as well as including radio resource scheduling. The proposed radio resource scheduling can be designed to maximize the utilization of occupied radio resources and overcome the effects of non-ideal backhaul link delays. The LTE eNB may schedule the LAA radio resource and send the packet data to the LAA node before the LTE eNB receives the occupancy notification from the LAA node. Pre-scheduling can be accompanied by an occupancy mode. The proposed coordination and scheduling solution can be applied to system architectures with ideal backhaul links or non-ideal backhaul links.

2A is a signaling diagram illustrating a process of coordinating an LTE eNB with an LAA node in accordance with one of the exemplary embodiments of the present invention. In order to provide service to the user equipment, the LTE eNB may communicate with the UE supporting the LAA to assist the UE in discovering the LAA node and utilizing the LAA cells of the LAA node. One LAA node can operate on multiple licensed/unlicensed bands. The LAA node can form logical LAA cells in each of the licensed/unlicensed bands.

In step S201, the LTE eNB can communicate with the LAA by exchanging control information. The nodes coordinate. Coordination between the LAA node and the LTE eNB includes transmitting the occupancy mode from the LTE eNB to the LAA node as part of the node control information to configure the LAA node to perform specific functions during the scheduled channel occupancy time. The occupancy mode may be based on the configuration of the LTE TDD eNB uplink/downlink. This coordination (that is, node control information) may include sending an occupancy notification from the LAA node to the LTE eNB to inform the LTE eNB whether the LAA node has successfully occupied the radio resources and discerning the reason for the HARQ NACK from the UE, for example due to poor The signal quality is caused by HARQ NACK or HARQ NACK due to channel/frequency occupancy failure. This coordination may include exchanging channel information, including band frequency, channel, channel quality, occupancy success rate, and the like. The LAA node and the LTE eNB can exchange information related to backhaul link delay information (such as transmission delay and round trip delay), synchronization information (such as subframe ID, SFN, transmission delay, transmission power, and channel information), and Start or stop the indication of channel occupancy for network traffic.

In step S202, the UE may perform various measurements and report the result to the LTE eNB. More specifically, in step S202, the LTE eNB may transmit an instruction to perform measurement to the UE, and the instruction may include a measurement frequency band and a channel in an unlicensed frequency band to be measured, a cell ID of the LAA node, and Synchronization information synchronized by the UE and the LAA node. The LTE eNB may then receive UE information including measurement reports, frequency band combinations supported by the UE, cross-carrier scheduling capabilities of the UE, and cell IDs of the detected LAA nodes. Then, the UE may send the specific cell-specific reference signal (CRS) measurement or control information sent by the LAA node when it successfully occupies the unauthorized channel. An indication of whether the unlicensed band is successfully occupied. The UE may further inform the LTE eNB of the channel occupancy result in the LAA node.

In step S203, the decision step is performed by the LTE eNB. The decision step can include assigning one or more LAA cells to which the UE attaches to the LAA node based on the report from the UE in step S202. In step S203, the LTE eNB transmits the configuration to the UE. The configuration transmitted to the UE may include help information for connecting the UE to the LAA node. The help information may include, for example, a frequency band, a specific channel number, a LAA Cell Index/Identification Code (ID), an occupancy pattern used in the LAA node, and a backhaul link delay between the LTE eNB and the LAA node. In step S205, the UE connects to the LAA node by performing synchronization with the LAA cells of the LAA node.

The X2-LAA interface (eg, 104) can perform functions for transmitting control plane information and user plane information. Control plane information can include synchronization information, occupancy patterns, and occupancy notifications. The user plane information may include a data block format of a transport block (TB) or a sub-frame. The packet data can be represented as a data form of a protocol data unit, a transport block (TB), or a sub-frame.

2B illustrates a method of radio resource scheduling in an unlicensed frequency band from the perspective of a base station, in accordance with one of the exemplary embodiments of the present invention. In step S211, the base station transmits node control information before receiving the occupancy notification, and the node control information may include an occupation mode of radio resources of the unlicensed band. In step S212, the base station transmits device control information before receiving the occupancy notification, and the device control information includes an occupation mode of radio resources of the unlicensed band. In step S213, the base station utilizes the unlicensed frequency before receiving the occupancy notification. The radio resource of the segment transmits the packet data. In step S214, the base station receives an occupancy notification that informs the availability of radio resources of the unlicensed band.

According to one of the exemplary embodiments, the base station of FIG. 2B may further determine the starting subframe by at least according to the occupancy mode, and according to the delay and the occupancy mode, the packet data is sent before the initial subframe. The packet is transmitted to an authorized secondary access node, and the packet data is pre-scheduled for transmission on radio resources of an unlicensed band. Transmitting the packet data to the authorized secondary access node may involve transmitting a physical downlink control channel (PDCCH) via the physical downlink control channel (PDCCH) for the same subframe scheduling or cross subframe scheduling. Downlink control information (DCI) of the user equipment.

According to one of the exemplary embodiments, the occupancy mode may include: a continuous period, the continuous period is limited by the regional maximum occupancy period; and a blank period, the blank period is used for the idle channel evaluation, or the random backoff period.

According to an exemplary embodiment, the transmitting the device control information may further include: transmitting, in the device control information, first mapping information corresponding to the first subframe in each consecutive subframe. The first mapping information may include: an presence bit, a presence bit indicating whether the authorized auxiliary access node will deliver the packet data, and a reserved interval indicating a section of the continuous subframe.

According to one of the exemplary embodiments, the base station may initialize a channel occupation mechanism of a radio resource of an unlicensed band by means including: transmitting a first indicator to start a channel occupation mechanism, transmitting an occupancy mode, and/or Or send the packet data. The base station can stop unauthorized by means including the following Channel occupancy mechanism for radio resources in the band: transmitting a second indicator to stop the channel occupancy mechanism; and not transmitting packet data.

According to one of the exemplary embodiments, the base station may receive an ACK signal or a NACK signal for each subframe in the continuous cycle, and then determine the cause of the failure based on the NACK signal and the occupancy notification. In response to receiving the NACK signal, if the occupancy notification indicates that the radio resource of the unlicensed band is unavailable, the reason for the failure is that the occupation fails, and the packet data can be determined as a new transmission due to the occupation failure. In response to receiving the NACK signal, if the occupancy notification indicates that the radio resource of the unlicensed band is available, the reason for the failure is determined as a non-occupation related failure, and the packet data may be determined to be a failure due to the non-occupation related failure. transmission.

According to one of the exemplary embodiments, the base station may transmit the packet data via the configured scheduling message to schedule another consecutive subframe according to the occupancy notification that the radio resource representing the unlicensed band is received.

2C illustrates an exemplary base station in accordance with one of the exemplary embodiments of the present invention. The base station 200 can be represented by, but not limited to, the functional elements shown in FIG. 2C, and includes a processing unit 250, an analog-to-digital (A/D) converter 253, and a digital-to-analog (D). /A) Converter 251, transmitter 252, receiver 254, storage medium 256, antenna unit 255, and backhaul link transceiver 257. Transmitter 252 and receiver 254 are used to transmit and receive radio frequency (RF) signals, respectively. Transmitter 252 and receiver 254 may also perform operations such as low noise amplification, impedance matching, mixing, upconversion or downconversion, filtering, amplification, and the like. Antenna unit 255 can be packaged One or more antennas are coupled to the transmitter 252 and the receiver 254 and coupled to the backhaul link transceiver 257 as needed.

Processing unit 250 may include one or more processors and is used to process digital signals and to control and perform the proposed methods, such as those described in FIG. 2B and in subsequent descriptions associated with the base station. Processing unit 250 can optionally be coupled to non-transitory storage medium 256 for storing programming code, device configuration, codebooks, buffered data, or persistent data. The functions of processing unit 250 may be implemented using programmable units such as microprocessors, microcontrollers, digital signal processor (DSP) chips, field programmable gate arrays (FPGAs), and the like. The functionality of processing unit 250 can also be implemented by a separate electronic device or integrated circuit (IC), and the functions performed by processing unit 250 can also be implemented in a hardware or software domain.

The backhaul link transceiver 257 can be a transceiver that facilitates wireless connectivity, fiber optic connections, or cable connections. The backhaul link transceiver 257 can be used to connect to another small base station via a backhaul link, such as the X2-LAA interface 104 described previously.

2D illustrates a method of radio resource scheduling in an unlicensed frequency band from the perspective of a self-authorized secondary access node as proposed by one of the exemplary embodiments of the present invention. In step S221, the auxiliary access node is authorized to receive the node control information before the transmission of the occupancy notification, and the node control information includes the occupation mode of the radio resource of the unlicensed band. In step S222, the auxiliary access node is authorized to receive the packet data, and the packet data uses the radio resource of the unlicensed band before transmitting the occupancy notification. In step S223, the auxiliary access node is authorized to determine the wireless of the unlicensed band. Availability of electrical resources. In step S224, the secondary access node is authorized to transmit an occupancy notification to inform the availability of the radio resources of the unlicensed band.

According to one of the exemplary embodiments, the authorized auxiliary access node may transmit the packet data when the radio resource of the unlicensed band is determined to be available, and discard the packet data when the radio resource of the unlicensed band is determined to be unavailable.

According to one of the exemplary embodiments, the authorized auxiliary access node may receive downlink control destined for user equipment via a physical downlink control channel for the same subframe scheduling or cross subframe scheduling News.

According to one of the exemplary embodiments, the occupancy mode may include: a continuous period, the continuous period is limited by the regional maximum occupancy period; and a blank period for the idle channel evaluation or the random backoff period. The first mapping information of the device control information may correspond to the first subframe of each consecutive subframe. The first mapping information may include: a presence bit, a presence bit indicating whether the authorized auxiliary access node will deliver the packet data; and a reserved interval, the reserved interval indicating a section of the continuous subframe.

According to one of the exemplary embodiments, a channel occupancy mechanism of a radio resource of an unlicensed band is performed in response to one or more of the following events: receiving a first indicator to start a channel occupancy mechanism, receiving an occupancy mode, and receiving a packet data .

According to one of the exemplary embodiments, the authorized secondary access node may stop the channel occupancy mechanism of the radio resource of the unlicensed band in response to one or more of the following events: receiving the second indicator to stop the channel occupancy mechanism; Do not receive packet data.

According to one of the exemplary embodiments, the authorized secondary access node may receive the packet data via the configured scheduling signaling to schedule another consecutive subframe according to an occupancy notification that the radio resource representing the unlicensed band is available. The authorized auxiliary access node may also transmit the reserved signal in response to the radio resource occupying the unlicensed band before setting the transmission time of the packet data to reserve the radio resource of the unlicensed band.

2E illustrates an exemplary authorized secondary access node in accordance with one of the exemplary embodiments of the present invention. Authorized secondary access nodes may include, but are not limited to, processing unit 261, non-transitory storage medium 264, and one or more transceivers (ie, 262263). The first transceiver may be a backhaul link transceiver 263 to communicate with other devices (e.g., a base station) through a backhaul link, and the second transceiver may be an LTE-U transceiver 262. Processing unit 261 is used to control and implement the method set forth in Figure 2D and in the following description associated with authorizing an auxiliary access node. The LTE-U transceiver 262 can be used to communicate with UEs, hubs or base stations on unlicensed bands. The functions of storage medium 264 and backhaul link transceiver 263 are similar to base station storage medium 256 and backhaul link transceiver 257 and will not be described again.

3 illustrates a protocol stack in an LTE eNB and an LAA node in accordance with one of the exemplary embodiments of the present invention. HARQ utilizes a combination of high rate forward error correction coding and ARQ error control, and each UE has one HARQ entity, and each HARQ entity has N stop-and-wait processes (ie, N HARQ- LAA process). The downlink HARQ-LAA process is presented to the LAA service. According to 3GPP TS 36.321, transmissions can be considered as "new transmissions" or "retransmissions". LTE coordinator 301 can belong to higher level functions. For example, the LTE coordinator 301 can be deployed in a media access control (MAC) scheduler. The functions of the LTE coordinator 301 may include (1) synchronization functions, such as timing alignment between the LTE eNB and the LAA node, subframe frame alignment, and (2) analyzing the reason for the HARQ NACK from the UE according to the occupancy notification, so that The LTE eNB corrects erroneous data (such as retransmission) due to poor channel quality or erroneous data (such as new transmission) due to occupation failure, and (3) data transmission when receiving HARQ NACK from the UE due to occupation failure, Further (3a) to prevent "retransmission" on the pre-scheduled sub-frame as much as possible and (3b) to mark the agreed data unit as "new transmission" when the occupation is successful, and (4) cross-carrier scheduling and Cross sub-frame scheduling. After multiplexing and HARQ, the LTE eNB may store the transport block or subframe in the LTE buffer 302. The LTE eNB may then deliver the transport block or subframe through the X2-LAA interface to the LAA buffer 303 at the LAA node via the backhaul link. One or two transport blocks (eg, downlink space multiplex) are expected for each subframe.

In one of the exemplary embodiments, LTE buffer 302 may contain transport blocks for assembling the contents of each subframe of the LAA node. A transport block in LTE buffer 302 is a collection of one or more pieces of material produced by one or more HARQ processes. The LTE eNB may place the transport block and associated scheduling information in the LTE PHY so that the LTE PHY can assemble the subframe content of the corresponding LAA node. The LTE PHY can send the assembled subframe content to the corresponding LAA node. The LAA node then stores the subframe content in the LAA buffer 303 and transmits the subframe content based on the configuration information provided by the LTE node.

In one of the exemplary embodiments, the LTE buffer 302 may include scheduling information for each of the transmission block and the LAA node. A transport block in LTE buffer 302 is a collection of one or more pieces of material produced by multiple HARQ processes. The LTE eNB may place the transport block and associated scheduling information in the LTE PHY and store the replica in the LTE buffer 302. The LTE PHY can transmit the transport block and associated scheduling information to the corresponding LTE node. The LAA node may assemble the subframe content according to the transmission block and associated scheduling information, and the LAA node may then transmit the subframe content according to the configuration information provided by the LTE node.

New data received from the LTE eNB (eg, subframe content, transport blocks, and/or scheduling information) may cover the data in the LAA buffer 303 of the LAA node. The LAA node may discard the data of the corresponding LAA subframe during the occupation failure. The LAA Coordinator 304 can perform functions including synchronization and subframe boundary alignment by taking into account the delay caused by the connection between the LTE eNB and the LAA node.

4A illustrates the subframe content in the LAA buffer 303 of the LTE buffer 302 or LAA node of the LTE eNB based on the cross-carrier scheduling. If the PDCCH 401 in the control region for scheduling the radio resources 402 of the LAA cells is not included in the LAA subframe content, the cross-carrier scheduling may be used only for scheduling the radio resources of the LAA cells.

4B illustrates the subframe content in the LAA buffer 303 of the LTE buffer 302 or LAA node of the LTE eNB based on the same carrier schedule. For the same carrier scheduling, control signaling is included in the control region of the LAA subframe content (eg, in the PDCCH or ePDCCH 411) to indicate the radio used to receive the UE Resource 412.

Propose the following scheduling concept. If the LAA node dynamically or sporadically occupies an unlicensed band if the backhaul link delay between the LTE eNB and the LAA node is longer than the critical value of the effective radio resource configuration (eg, the threshold for the instant carrier aggregation radio resource schedule) Then the LTE eNB may not be able to schedule radio resources to the UE in the unlicensed frequency band via the LAA node in time. To improve radio resource utilization, the LAA node may perform a channel occupancy mechanism based on the timing of the LTE eNB to occupy radio resources. In other words, the LAA node can be aligned with the timing of the LTE eNB by performing synchronization with the LTE eNB. For example, for each successful occupation of the operating frequency, the LAA node utilizes radio resources of the operating frequency occupied by at least 1 ms (this may correspond to 1 subframe), and the LAA node may utilize at least after successfully occupying the radio resources. A sub-frame. In such a scenario, the mechanism for improving LAA radio resource utilization may further include (1) pre-scheduling before the LTE eNB receives the occupancy notification from the LAA node; (2) for each subframe or crossover The mechanism of frame scheduling. Cross-branch scheduling refers to scheduling N consecutive sub-frames in an unlicensed band, such as N=4 in Japan or N=10 in parts of Europe. The scheduling performed by the LTE eNB may be implemented by DCI (length field), configuration index, or bit in the bitmap; (3) LTE eNB based on LTE eNB configuration (TDD or FDD) The occupancy mode of the configuration (ie, coordination between the LTE eNB and the LAA node). A blank LAA subframe can be configured to meet the requirements (ie, CCA, or random backoff). The occupancy mode and the blank LAA subframe can be part of a predefined period or a predefined pattern.

The occupancy mode based LAA node may perform after the LTE eNB receives the occupancy mode, or after an indication from the LTE eNB is initiated to begin performing the occupancy mechanism (eg, it may be sent after the UE completes the connection with the LAA node) Authorized frequency band operation frequency occupancy mechanism. The LAA node can transmit a reserved signal (eg, any signal, or a specific signal) for occupying an unlicensed frequency. The LTE eNB may pre-allocate the LAA radio resources after the UE completes the connection with the LAA node (eg, in response to the UE transmitting a message to the LTE eNB completing the connection with the LAA node). Similarly, if there is no data for transmission in the LAA buffer, the LAA node can release the unused frequency occupied. After the LTE eNB sends an indication that the LAA node stops performing the occupancy mechanism, or if there is no data for transmission for a predefined time or period in the LAA buffer, the LAA node may stop performing the occupancy mechanism. For example, the LTE eNB can coordinate synchronization and occupancy modes with the LAA node. The LAA node can then perform the occupancy mechanism upon receiving the occupancy mode. The LAA node may transmit a reserved signal for occupying an unlicensed band, or may release the occupied unlicensed band if there is no material for transmission in the LAA buffer. After the UE completes the connection with the LAA node, the LTE eNB may schedule the LAA radio resource and send a data segment (eg, subframe content, or a transmission block with scheduling information) that can be assembled to the LAA subframe content to LAA node. Based on the pre-scheduled configuration of the LTE eNB, the LAA node can transmit data to the UE when its unlicensed operating frequency occupancy is successful. The LAA node may stop performing the occupancy mechanism upon receiving an indication from the LTE eNB to stop using the unlicensed band, or if there is no data in the LAA buffer for a predefined time period.

5A through 5D are used to illustrate various aspects of the radio resource scheduling concept in the above unlicensed frequency bands. It is assumed that the network settings of Figures 5A through 5D are similar to Figure 1A. In step S501, before the LTE eNB receives the occupancy notification, the LTE eNB transmits the pre-scheduled information destined for the LAA node via the backhaul link (eg, the X2-LAA backhaul link), and the occupancy notification indicates whether the radio resource of the unlicensed band is Was successfully occupied. The pre-scheduled information may include schedule information for occupying a set of sub-frames 511. It is assumed that the one-way backhaul link delay between the LTE eNB and the LAA node is 5 ms. In response to receiving the occupancy mode from the LTE eNB, the LAA node attempts to occupy radio resources suitable for the occupancy mode in the unlicensed frequency band. In step S502, it is assumed that the LAA node has successfully occupied the radio resources in the unlicensed band. In step S503, the LTE eNB node may transmit the user profile to the UE through the scheduling information in the DCI. In step S504, the LAA node transmits an occupancy notification to the LTE eNB to inform the LTE eNB whether the unlicensed band is successfully occupied.

Figure 5B shows occupancy mode 521 as 4 consecutive pre-arranged sub-frames in the unlicensed band followed by a blank sub-frame. These pre-scheduled subframes (e.g., 511) may be followed by blank sub-frames 512 for meeting requirements such as clear channel assessment (CCA) or random backoff. Assuming that the LAA node has successfully occupied the reserved subframe in step S522, the LAA transmits the same occupancy notification as the embodiment shown in Fig. 5A in step S504.

Figure 5C further explains the embodiment of Figures 5A and 5B in more detail. It is assumed that the LTE eNB operates in FDD mode. The LAA node and the UE are synchronized to the LTE eNB. The LTE eNB can configure the occupation time 511 of the LAA node (for example, 4ms or 4) LAA subframes, occupancy mode 511+512 (eg, every 5ms or every 5 LAA subframes), and blank subframe 512 (eg, a LAA subframe after 4 LAA subframes). In addition, the LTE eNB can estimate the backhaul link delay between the LTE eNB and the LAA node. Therefore, the LTE eNB can calculate or predict/predict the point in time at which the LAA occupies an unlicensed frequency and the occupancy time of the LAA node. The LTE eNB is also able to estimate how long the LAA node is transmitting data to the UE via the occupied unlicensed frequency. Due to the backhaul link delay, it is assumed that a delay of 4 ms can be estimated between the LTE eNB and the LAA node in this case (this can correspond to 4 LAA subframes) because 4 ms can be sent to the LTE eNB for the LAA node The time required for the "occupation notification" (ie, the time required between step S502 and step S504) or the time required for the LTE eNB to send data to the LAA node. The pre-scheduled LAA subframe can be defined as the LAA subframe after the LAA node sends an "occupation notification" in step S504 or/and before the LAA node receives the "configured schedule" (FIG. 6A). The "configured schedule" may be related to occupancy time or/and occupancy mode.

For the present exemplary embodiment, the four LAA subframes immediately after the "occupation notification" is sent in step S504 are defined as pre-scheduled LAA subframes. Pre-scheduling is performed to pre-send data from the LTE eNB to the LAA node to occupy radio resources/frequency before receiving the occupancy notification. The LAA node then transmits the data to the UE when the LAA node has successfully occupied the unlicensed radio resources/frequency/channel. The LAA node may also transmit data to multiple UEs as soon as the LAA node occupies unlicensed radio resources/frequency. The data transmitted to different UEs can be transmitted via Orthogonal Frequency Division Multiple Access (OFDMA) technology. Do multiplex. The LTE eNB configured for the LAA node can predict/calculate the point in time at which the LAA node occupies the unlicensed radio resources/frequency and begins transmitting to the UE the data that has been provided by the LTE eNB to the LAA node. Based on the prediction/computation, the corresponding occupancy mode and the occupied radio resources/frequency exchanged between the LTE eNB and the LAA node, and the pre-scheduling of the LAA subframe, the LTE eNB transmits the PDCCH via the LTE eNB in step S531. The DCI is sent to one or more UEs configured by the LTE eNB and scheduled to receive downlink data from the LAA node.

In step S532, the UE sends a HARQ ACK or HARQ NACK to the LTE eNB to indicate whether the data is successfully received from the LAA node. The occupancy notification from the LAA node to the LTE eNB may include the result of the LAA node performing the occupancy mechanism by indicating whether the occupation has been occupied or failed. Therefore, the LTE eNB can discern the reason for the HARQ NACK from the UE depending on whether the cause of the failure is a poor channel quality or a failure. For example, assume that the LTE eNB has received both HARQ NACKs from UEs scheduled to receive downlink data from the LAA node, and occupancy notifications from the LAA nodes indicating that the unauthorized operating frequency occupation failed. Based on these two facts, the LTE eNB can conclude that the HARQ NACK from the UE is due to the failure of the LAA operating frequency occupancy rather than the poor signal quality. Furthermore, if the UE is capable of performing CRS probing, the UE may send an indication along with the HARQ NACK or new message based on the CRS measurement of the LAA cell to indicate whether the unlicensed band is successfully occupied. The retransmission of data in the HARQ buffer that was not successfully transmitted to the UE may be indicated as "retransmission" or "new transmission" [3GPP TS 36.321].

The LAA node can be configured to occupy 4ms before the border of the subframe. Radio resources in the right band. If the LAA node occupies the unlicensed frequency before the LAA subframe boundary, for example, by prematurely transmitting the scheduled or pre-scheduled data, the LAA node may transmit the reserved signal to occupy the unbefore the LAA subframe boundary is reached. Authorization frequency. According to an exemplary embodiment, control signaling may be sent from the LAA node to the UE instead of transmitting control signaling from the LTE eNB to the UE. When the LAA node has successfully occupied the radio resources in the unlicensed band, the LAA node can immediately transmit the data to the UE. When the LAA node occupies radio resources in the unlicensed band, the LAA node can then immediately transmit the data to the UE.

For the scenario of FIG. 5D, step S501 is the same as the previous embodiment: the LTE eNB transmits pre-scheduled information including the occupancy mode and the pre-scheduled user profile to the LAA. The occupancy mode may include a continuous subframe 511 and a blank subframe. However, in step S541, the LAA has decided that it has not successfully occupied the required radio resources in the unlicensed band, and then transmits an occupancy notification in step S504 to inform the LTE eNB of the occupation failure. In response to the occupancy failure in step S541, the LAA node does not transmit data to the UE via the unlicensed band. In step S531, in response to the fact that the data is not correctly received from the LAA node, if the subframe information cannot be correctly received, the UE transmits a continuous HARQ NACK for each of the four subframes in step S542.

The LTE eNB needs to identify the reason for the HARQ NACK from the UE. For example, the reason for the HARQ NACK is poor channel quality (wrong data with errors) or occupation failure (insignificant data), because HARQ with soft combination is no longer discarded. Poor data received (with incorrect data). Poor error The data (due to poor channel quality) will be combined with the next transmitted data, which can be a "retransmission" on the pre-scheduled sub-frame. Insignificant material (due to occupancy failure) should not be combined with the data transmitted next. The "new transmission" should be scheduled in a pre-scheduled subframe (for example, 511) or a configured subframe (for example, 602).

6A through 6H are for explaining the concept of another exemplary embodiment. In FIG. 6A, it is assumed that the LTE eNB operates in FDD mode, and the LAA node and the UE are synchronized to the LTE eNB. Furthermore, it is assumed that there is an estimated delay of 3 ms between the LTE eNB and the LAA node. In step S611, the LAA node transmits an occupancy notification to the LTE eNB. The pre-scheduling can be performed on the six LAA subframes (601), so the number of pre-scheduled LAA subframes can be referred to as the round-trip delay between the LTE eNB and the LAA node. In step S613, the LTE eNB may send the DCI to the at least one UE via the LTE PDCCH (eg, each subframe or cross subframe). In response to the LTE eNB confirming that the LAA node has successfully occupied the configured unauthorized operating frequency and the LTE eNB can schedule the downlink data to be timely transmitted by the LAA node via the confirmed successfully occupied unlicensed operating band to For a specific UE, the LAA receives the packet data from the LTE eNB via the configured scheduling message in step S612. The four LAA subframes (602) after the LAA node receives the configured schedule from the LTE eNB are defined as configured subframes. After the LTE eNB has decided that the LAA node has successfully occupied the radio resource/frequency, the LTE eNB may schedule the configured subframe via the configured scheduling message as in step S612. In step S614, the LTE eNB transmits the DCI to the UE by transmitting the DCI for the configured subframe 604 via the LTE PDCCH. material. The data corresponding to the HARQ NACK caused by the occupancy failure can be scheduled in the configured subframe and indicated as "new transmission". The LAA node may transmit data to the UE when it has successfully occupied unlicensed radio resources. The LAA node can also transmit data to multiple UEs as soon as the LAA node occupies unlicensed radio resources/frequency. Radio resources allocated to multiple UEs can be multiplexed through OFDMA technology.

Since the LAA node is controlled by the LTE eNB, the LTE eNB can configure the LAA node to occupy the radio resource by transmitting the occupancy mode and the blank LAA subframe, and configure the LAA node to transmit the data to the LAA node through the pre-scheduling and the DCI in the LTE PDCCH. Which UEs. The data transmission may be scheduled on the pre-scheduled subframe or the configured subframe, and the configured subframe may be pre-determined by the prediction of the LTE eNB or may be occupied by the LTE eNB. Configured after notifying and sending the configured schedule. The LTE eNB may utilize the occupancy notification from the LAA node to analyze the cause of the HARQ NACK from the UE. If it has been decided that HARQ NACK is caused by poor channel quality, it needs to be retransmitted on the pre-scheduled subframe. If the HARQ NACK is caused by an occupation failure, a new transmission needs to be performed on the configured subframe. If the user profile is retransmitted on the pre-scheduled subframe when the LAA node fails to occupy the radio resources in the unlicensed band, the UE may receive a meaningless signal and may perform a soft combining process, the soft The combination process combines meaningless signals with other parts of the data stored in the soft buffer.

FIG. 6B illustrates an exemplary embodiment that is different from FIG. 6A. In this exemplary embodiment, the LTE eNB can operate in FDD mode or TDD mode, and the LAA section The point and UE are synchronized to the LTE eNB to align the subframe boundaries. The backhaul link delay is 5ms. In step S615, the LTE eNB transmits the pre-scheduling information to configure the occupancy mode and occupation time of the LAA node. In this illustration, the occupancy time is 4ms or 4 LAA subframes. Once it is determined in step S623 that the occupation is successful, the LAA node may transmit an occupancy notification to the LTE eNB in step S616. In step S621, the LTE eNB may send mapping information to the UE plus DCI for pre-scheduling via the LTE PDCCH before the LAA node starts data transmission or before the LAA node performs the occupancy mechanism. The DCI for pre-scheduling via the LTE PDCCH may be applied after i LAA subframes, where i is a non-zero integer. In this illustration, i=5. Alternatively, the LTE eNB may also deliver mapping information independently of step S621, for example, via RRC (Radio Resource Control) message (RRCConnectionReconfiguration).

The mapping information informs the UE which subframe to monitor or informs the UE to receive signaling from the LAA node. The mapping information may be a one-to-one subframe mapping or a one-to-man subframe mapping, and may be different from the occupancy mode. The mapping information may be a data structure or a data format that enables the UE to look up the configuration to know when or how to apply the received PDCCH for pre-scheduling, thereby making the UE aware of receiving data from the LAA node. The mapping information can be for a specific UE such that mapping information can be applied only to unique UEs. In FIG. 6B, the UE knows to receive data from the LAA node for the interval 622 of the five subframes between step S621 and step S623.

6C illustrates an exemplary embodiment, which is the same as FIG. 6B, except that in this exemplary embodiment, the LTE eNB may start data transmission at the LAA node. The mapping information is previously transmitted in step S621, and the LTE eNB transmits DCI to one or more UEs via the LTE PDCCH (eg, each subframe or cross subframe) in step S651, which corresponds to the LAA node starting data transmission. The timing or LAA node performs an occupancy mechanism to occupy the timing before the unauthorized running frequency following the occupancy mode.

6D illustrates an exemplary embodiment, which is the same as FIG. 6B, except that in this exemplary embodiment, the LTE eNB may transmit mapping information in step S621 before the LAA node starts data transmission, and in step S651 The LAA node, instead of the LTE eNB, may send DCI to one or more UEs via an LTE PDCCH (eg, each subframe or cross subframe), which corresponds to the timing at which the LAA node initiates data transmission or the LAA node performs an occupancy mechanism. The timing before the unauthorized running frequency following the occupancy mode is occupied.

If the LAA node is operating in the licensed band, no occupancy mode and/or occupancy notification may be required. For example, an LTE eNB may be a large eNB. The LAA node may be a small node on the licensed band, such as a simplified Pico cell eNB, which may only include LTE PHY modules operating on the licensed band while being fully controlled by the large eNB. Instead of using the X2-LAA interface, the X2 interface can be used to enable the LTE eNB to communicate with the LAA node. However, for the X2 interface, the backhaul link delay may not be negligible.

Figure 6E is used to illustrate the use of mapping information in more detail. In this exemplary embodiment, it is assumed that the LTE eNB operates in FDD mode. In step S621, the LTE eNB transmits mapping information to the UE. For each UE, the mapping information can include "the presence bit (Existence bit), the "presence bit" can be delivered by broadcasting a PDCCH or a dedicated RRC message (RRCConnectionReconfiguration) from an LTE eNB. The LTE eNB may set the presence bit to 1 to inform the UE whether the UE will deliver the scheduled data to the UE after N subframes. N is not part of the mapping information, but can be calculated based on a given occupancy pattern. In addition, the LTE eNB may multiplex the DCI with the scheduled data to the UE. Upon receiving the "presence bit", in step S622, the UE decodes the DCI transmitted by the LAA node and the scheduled data. Conversely, when the presence bit is 0, the UE does not monitor the unlicensed band until the next available subframe occurs according to the given occupancy mode.

In FIG. 6E, the LTE eNB delivers a presence bit of 1 in mapping information #1~4 661 662 663 664. When the UE successfully receives the mapping information #661, the UE will stop receiving the subsequent mapping information #2~4 662 663 664 to save the battery power of the UE. In addition, even when the UE fails to successfully decode the mapping information #1 661, the UE can still learn the LAA scheduling message by receiving the mapping information #2~4 662 663 664. Therefore, the repeated transmission of the mapping information #1~4 661 662 663 664 can increase the probability that the UE successfully receives the LAA scheduling data. It is worth noting that the LTE eNB can provide mapping information to multiple UEs by providing multiple "presence bits" in the PDCCH or providing multiple RRC messages (RRCConnectionReconfiguration) to many UEs.

FIG. 6F illustrates an exemplary embodiment that is similar to FIG. 6E. In the exemplary embodiment of FIG. 6F, for each UE, the mapping information includes a set of presence bits 671 and a Reservation Duration 672 that are sent to the scheduled UE. By receiving the presence bit 671, the UE will know whether the LAA node is The scheduled data will be delivered to the UE after N subframes because N can be calculated according to a given occupancy pattern. However, when the presence bit is 0, the UE will not monitor the unlicensed band until the next available subframe occurs according to the given occupancy mode. In addition, by receiving the reserved interval 672, the UE knows how many consecutive subframes the UE will need to receive once the UE begins to receive the subframe based on the given occupancy mode.

In FIG. 6G, an illustration of a reserved interval is illustrated, by way of example, two bits may be used to indicate the length of time that a UE may need to receive downlink data from a LAA node or how many LAA subframes are scheduled. The UE is sent to receive downlink data. According to Fig. 6G, when the reserved interval is '11', it means that the UE needs to receive consecutive subframes #1 to #4 starting from the next available LAA subframe determined by the occupancy mode. If the reserved interval is '00', it means that the UE only needs to receive the subframe #1 in the next available LAA subframe determined by the occupancy mode, and the UE will not receive the subframes #2~4 to save Battery Life.

In the exemplary embodiment of FIG. 6F, the LTE eNB may deliver the presence bit 671 and the reserved interval 672 to the UE via a broadcast PDCCH or a dedicated RRC message (RRCConnectionReconfiguration). Moreover, the LTE eNB transmits the PDCCH to the UE along with the scheduled data, so after receiving the presence bit 671, the UE may need to decode the PDCCH transmitted by the LAA node to decode the scheduled data. In FIG. 6F, the LTE eNB delivers the same presence bit 672 and reserved interval 672 in mapping information #1~4. When the UE successfully receives the mapping information #1, the UE does not need to receive the subsequent mapping information #2~4 to save the UE battery power. If the UE fails to decode the mapping information #1, the UE then receives one of the mapping information #2~4. Learn about the LAA schedule message.

Similarly, the LTE eNB may deliver the presence bit 671 and the reserved interval 672 to multiple UEs via a broadcast PDCCH or a dedicated RRC message (RRCConnectionReconfiguration). Moreover, the LTE eNB multiplexes the PDCCH with the scheduled data to the UEs in the scheduled data. Therefore, after receiving the "presence bit" 671, the UE needs to decode the PDCCH transmitted by the LAA node to decode the scheduled data. In FIG. 6F, the LTE eNB may also deliver the same presence bit 671 and the reserved interval 672 in the mapping information #1~4. If a UE successfully receives the mapping information #1, it will not receive the subsequent mapping information #2~4 to conserve battery power. If the UE fails to decode the mapping information #1, the UE may then learn the LAA scheduling information by receiving the mapping information #2~4.

In the exemplary embodiment of FIG. 6H, it is assumed that the LTE eNB operates in FDD mode. In step S611, the LTE eNB may deliver a configuration such as an occupancy mode to the UE and the LAA node. The LAA node and the UE will know that the LAA node is attempting to access the unauthorized operating frequency. After the LTE eNB delivers the mapping information to the LAA node in the PDCCH transmitted with the scheduled data, the LAA node then delivers the PDCCH along with the mapping information and the scheduled data to the UE. As shown in FIG. 6H, in step S681, the LAA node delivers the scheduled data corresponding to the mapping information #1 to the subframe 1 of the UE. In step S682, the LAA node delivers the scheduled data corresponding to the mapping information #2 to the subframe 2 of the UE. In step S683, the LAA node delivers the scheduled data corresponding to the mapping information #3 to the subframe 3 of the UE. In step S684, the LAA node will deliver the scheduled data corresponding to the mapping information #4. Send to subframe 4 of the UE. After receiving the mapping information #1 presence bit and reserved interval, the UE starts to receive M consecutive subframes, where M is determined by the reserved interval as shown in FIG. 6G. For the UE, when the presence bit and the reserved interval are set to 1 and 01, respectively, the scheduled data will be given only in a part of the subframes #1 to 4. In this case, the UE receives subframes #1~2 based only on a given occupancy mode. It should be noted that even if the UE may not be able to decode PDCCH #1, the UE may still know scheduling information and mapping information by receiving one of the subsequent PDCCHs #2~4. Repeated transmission of PDCCH#1~4 can increase the probability that the UE successfully receives the LAA schedule information.

In an embodiment similar to the exemplary embodiment shown in FIG. 6H, it is assumed that the LTE eNB operates in FDD mode. The LTE eNB may deliver configurations such as occupancy mode to the UE and the LAA node. The LAA node and the UE will thus know that the LAA node is attempting to access the unauthorized operating frequency. In FIG. 6H, the LTE eNB delivers mapping information by providing (presentation bits, reserved intervals) in the PDCCH, and the PDCCH is multiplexed with the scheduled data to the LAA node. Therefore, the LAA node delivers the PDCCH to the UE along with the mapping information and the scheduled data. By receiving (presentation bit, reserved interval) in the mapping information #1, the UE starts to receive M consecutive subframes, where M is determined by the reserved interval as shown in FIG. 6G. For the UE, the scheduled data will only be given in a part of subframes #1~4, ie (existing bit, reserved interval) is set to (1, 01). In this case, the UE receives subframes #1~2 based only on a given occupancy mode. It should be noted that even if the UE may not be able to decode PDCCH #1, the UE may still know scheduling information and mapping information by receiving one of the subsequent PDCCHs #2~4. Repeated transmission of PDCCH#1~4 can increase the probability that the UE successfully receives the LAA schedule information.

Regarding the scheduling process in the TDD mode, the LTE PDCCH may be transmitted from the LTE eNB to the UE in a downlink (D) subframe or a dedicated (S) subframe. 7 illustrates that an LTE eNB selects a subframe configured as D or S based on a LAA node occupancy mode or based on a backhaul link delay between an LTE eNB and a LAA node to transmit pre-scheduled information to enable the UE to receive a downlink from the LAA node. An exemplary embodiment of a road material. 8 illustrates that if an LTE eNB selects a subframe configured as U (uplink) based on a LAA node occupancy mode or based on a backhaul link delay between an LTE eNB and a LAA node to transmit pre-scheduled information, the UE If the LAA node receives the downlink data, the LTE eNB may reselect the subframe configured as D or S to transmit the pre-scheduled information (eg, DCI in the PDCCH) to the UE in preference to the selected subframe. Sexual embodiment. Each of these two figures will be explained in more detail below.

Figure 7 illustrates an embodiment of an LTE eNB operating in TDD mode. It is assumed that the LAA node and the UE have been synchronized to the LTE eNB. In step S701, the LAA node determines to transmit the occupancy announcement after the occupancy is successful in step S702. In step S703, the LTE eNB may configure an occupation time of the LAA node (for example, 4 ms or 4 LAA subframes), an occupancy mode (for example, every 5 ms or every 5 LAA subframes), and a blank LAA subframe. (For example, a LAA subframe after 4 LAA subframes). For example, a delay of 4 ms can be estimated as shown in FIG. The occupancy mode can be configured according to the uplink/downlink configuration of the LTE cells of the LTE eNB [3GPP TS 36.300]. In this exemplary embodiment, LTE subframe #9/0/1/2 and subframe #4/5/6/7 can be configured with the LAA node to occupy unauthorized radio resources and transmit Time alignment of the data to be sent. LTE subframe #3 and LTE subframe #8 may be time aligned with the LAA subframe configured as a blank subframe. For each dedicated (S) subframe or/and downlink (D) subframe, the LTE eNB may send the DCI to at least one UE via an LTE PDCCH (eg, LTE PDCCH/each subframe). If the LAA node successfully occupies the unauthorized running frequency (ie, subframe #4 and subframe #9), the LTE eNB may access the LTE in the first LTE subframe that is aligned with the time of the first LAA subframe. The PDCCH (eg, a cross subframe) transmits the DCI to at least one UE.

8 is an embodiment in which an LTE eNB operates in a TDD mode. It is assumed that the LAA node and the UE have been synchronized to the LTE eNB. In this embodiment, only one 4 ms occupation time is shown. For example, a delay of 4 ms can be estimated in FIG. In step S801, the LTE eNB transmits the pre-scheduled DCI to the LAA node and the UE to transmit the data on a set of subframes 804. In response to determining that the occupation is successful in step S802, the LAA node transmits an occupancy notification to the LTE eNB in step S803. When the first LAA subframe is aligned with the uplink subframe of the LTE cell of the LTE eNB, scheduled by the LTE eNB for the first LAA subframe or for the continuous LAA subframe or the cross subframe The DCI for at least one UE is given in the previous downlink (D) subframe or the special (S) subframe, in this exemplary embodiment, the previous downlink (D) subframe The box or special (S) sub-frame is subframe #1.

Figure 9 illustrates the application of mapping information in the TDD mode. In this exemplary embodiment, it is assumed that the LAA node and the UE are synchronized to the LTE eNB. In step S901, the LTE eNB may send the DCI to the LTE PDCCH (eg, a cross subframe) One or more UEs, and an occupancy notification may be sent from the LAA node to the eNB in step S902. If the LAA node has successfully occupied the unauthorized running frequency at the pre-configured time of performing the occupancy mechanism (ie, the start time of LAA subframe #1), the LAA node can place the continuous LAA subframe (ie, the LAA subframe) #1~LAA subframe #4) is used for the configured occupation time (for example, 4ms or 4 LAA subframes as shown in FIG. 9). If the LAA node fails to occupy the nth LAA subframe, the LAA node may perform the occupancy mechanism at the beginning of the LAA subframe #(n+1), and if the occupancy is successful, the LAA subframe #(N+) 1) ~LAA sub-frame (occupied time). For example, assume that in step S903, the LAA node fails to occupy the radio resources of the LAA subframe #1 and the LAA subframe #2, and in step S904, the LAA subframe #3 and the LAA subframe are successfully occupied. For the radio resource of block #4, the LAA node can use LAA subframe #3 and LAA subframe #4. Therefore, the LAA node will transmit data for these two successfully occupied radio resources (ie 2ms). In step S905, the UE sends a HARQ NACK to the LTE eNB for the first two subframes (ie, LAA subframe #1 and LAA subframe #2), and for LAA subframe #3 and LAA in step S906. Subframe #4 sends a HARQ ACK. The LTE eNB will know the cause of the HARQ NACK by causing the ACK/NACK result reported by the UE to accompany the occupancy notification.

Referring to the embodiment shown in FIG. 9, the LTE eNB may assume that the LAA node performs an occupancy mechanism on the unauthorized operating frequency in the following manner: If the LAA node occupation fails (eg, the possible LAA subframe #n occupation fails), the LAA The node will perform occupancy at the beginning of the next possible LAA subframe (eg, LAA subframe #(n+1)). The occupancy mode may not be configured in the LAA node or coordinated with the LAA node. LTE The eNB may send the DCI to the at least one UE via the PDCCH for each subframe (ie, each subframe). Once the required radio resources are occupied, the LAA node can send the data; otherwise, the LAA node can discard the data of the specific subframe (such as the subframe content or the transmission block with scheduling information) and thus the UE to the LTE The eNB transmits a HARQ NACK.

FIG. 10 illustrates a process in which an LTE eNB classifies a deployment environment of an LAA node. The LTE eNB may classify the deployment environment of the LAA node based on the following criteria: (1) HARQ ACK/NACK from the UE, (2) occupancy notification from the LAA node, (3) UE indication regarding the occupancy result of the LAA node, and ( 4) Measurement report from the UE. The above criteria may also help the LTE eNB to select the UE to use the LAA cells of the LAA node. In step S1001, the eNB determines whether the LAA node is operating in a fully planned state based on whether or not the ACK/NACK condition reported by the UE does not exceed the ACK/NACK threshold. If the case where there is no ACK is greater than or equal to the ACK threshold, then in step S1002, the eNB determines that the LAA node can operate in a fully planned state, suffers from low interference, and can generally successfully occupy radio resources in the unlicensed band. Similarly, if there is no case where the NACK reported by the UE is greater than the NACK threshold, then in step S1003, the eNB may decide that the LAA node may be operating in a fully planned state, subject to low interference, and typically may successfully occupy unauthorized Radio resources in the band.

Various embodiments of occupancy patterns according to different TDD configurations are illustrated in Figures 11-23. These embodiments illustrate where the LTE eNB has a 3ms or 4ms occupation time with the configuration (ie, 3 or 4 available LAA subframes per successful occupancy) The LAA nodes are coordinated with various TDD configurations.

In the present invention, keywords or phrases such as "3GPP" are merely used as an illustration of the inventive concept according to the present invention; however, the same concepts provided in the present invention can also be applied to, for example, IEEE by those skilled in the art. Any other system such as 802.11, IEEE 802.16, WiMAX. No element, act, or instruction used in the Detailed Description of the invention should be construed as essential or essential to the invention.

In summary, the present invention is applicable to wireless communication systems and is capable of minimizing the impact of backhaul link delays to enable the base station to properly schedule radio resources in unlicensed frequency bands.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

Steps S211, S212, S213, S214‧‧

Claims (25)

A method for scheduling radio resources in an unlicensed frequency band, suitable for a base station, the method comprising: transmitting a node control information before receiving an occupancy notification, the node control information including a radio resource of the unlicensed frequency band An occupancy mode, the occupancy mode is a base station-based uplink or downlink configuration; before receiving the occupancy notification, transmitting a device control information, where the device control information includes the unlicensed frequency band The occupancy mode of the radio resource; transmitting, by the radio resource of the unlicensed band, a packet data before receiving the occupancy notification; and receiving the occupancy notification, the occupancy notification notifying the Availability of the radio resources in the licensed band. The method of claim 1, wherein the method further comprises: pre-arranging the packet data to be transmitted on the radio resource of the unlicensed frequency band, according to the The occupancy mode determines a start subframe; and according to a delay and the occupancy mode, the packet data is transmitted to an authorized auxiliary access node before the start subframe. The method of claim 2, wherein the transmitting the packet data to the authorized auxiliary access node further comprises: Downlink control information destined for the user equipment is transmitted via a physical downlink control channel for the same subframe scheduling or cross subframe scheduling. The method of claim 2, wherein the occupancy mode comprises: a continuous period, the continuous period is limited by a regional maximum occupancy period; and a blank period, the blank period is used for an idle channel Evaluation or a random backoff period. The method of claim 4, wherein the transmitting the device control information further comprises: transmitting a first mapping information corresponding to a first subframe of each successive subframe in the device control information, The first mapping information includes: a presence bit, the presence bit indicates whether the authorized auxiliary access node will deliver the packet data; and a reserved interval, the reserved interval indicating the continuous subframe The interval of the box. The method of claim 1, wherein the method further comprises: initializing a channel occupancy mechanism of the radio resource of the unlicensed band by transmitting at least one of: transmitting a first indicator Starting the channel occupancy mechanism; transmitting the occupancy mode; and transmitting the packet data. The method of claim 6, wherein the method further comprises: stopping the channel occupancy mechanism of the radio resource of the unlicensed band by transmitting at least one of: transmitting a second indication a character to stop the channel occupancy mechanism; and not to transmit the packet data. The method of claim 4, wherein the method further comprises: receiving an ACK signal or a NACK signal for each subframe in the continuous period; and based on the NACK signal and the Occupation notification to determine a reason for failure. The method of claim 8, wherein the method further comprises: determining, according to the received NACK signal, if the occupancy notification indicates that the radio resource of the unlicensed band is unavailable, then determining The failure cause is an occupation failure, and the packet data is determined as a new transmission due to the occupation failure; and, in response to the received NACK signal, if the occupancy notification indicates the unlicensed frequency band If the radio resource is available, the failure cause is determined as a non-occupation related failure, and the packet data is determined to be a retransmission due to the non-occupation related failure. The method of claim 1, wherein the method further comprises Included: the packet data is transmitted via the configured schedule message to schedule another consecutive subframes in response to receiving the occupancy notification indicating that the radio resource representing the unlicensed band is available. The method of claim 1, wherein the node control information further comprises at least one of the following or a combination thereof: delay, synchronization information, transmission power, number of channels, and about starting or stopping execution of channel occupancy Instructions. The method of claim 1, wherein the device control information further comprises at least one or a combination of the following: a frequency band, a number of channels, an authorized auxiliary access cell index or an identification code (ID), and a delay. . The method of claim 1, wherein the occupancy mode is determined according to one of a frequency domain duplex (FDD) configuration or a plurality of time domain duplex configurations (TDD). A method for scheduling radio resources, suitable for an Authorized Auxiliary Access (LAA) node, the method comprising: receiving a node control information before transmitting an occupancy notification, the node control information including the unlicensed frequency band a radio resource occupancy mode, the occupancy mode being a base station-based uplink or downlink configuration; before transmitting the occupancy notification, receiving a packet data, the packet data using the unlicensed frequency band The radio resource; determining the availability of the radio resource of the unlicensed band; and transmitting the occupancy notification to inform the radio resource of the unlicensed band The availability of the source. The method of claim 14, wherein the method further comprises: if the radio resource of the unlicensed band is determined to be available, transmitting the packet data; and if the unlicensed band If the radio resource is determined to be unavailable, the packet data is discarded. The method of claim 15, wherein the method further comprises: receiving a downlink destined for the user equipment via a physical downlink control channel for the same subframe scheduling or cross subframe scheduling Link control information. The method of claim 15, wherein the occupancy mode comprises: a continuous period, the continuous period is limited by a regional maximum estimation period; and a blank period, the blank period is used for an idle period Channel evaluation or a random backoff period. The method of claim 17, wherein the device control information is further received, and the device control information includes a first mapping information corresponding to a first subframe of each successive subframe. The first mapping information includes: a presence bit, the presence bit indicating whether the authorized auxiliary access node will deliver the packet data; a reserved interval, the reserved interval representing an interval of the consecutive subframes. The method of claim 14, wherein the method further comprises: performing a channel occupancy mechanism of the radio resource of the unlicensed band in response to at least one of: receiving a first indication Initiating the channel occupancy mechanism; receiving the occupancy mode; and receiving the packet data. The method of claim 19, wherein the method further comprises: stopping the channel occupancy mechanism of the radio resource of the unlicensed band in response to at least one of: receiving a second An indicator to stop the channel occupancy mechanism; and not receiving the packet data. The method of claim 14, wherein the method further comprises: receiving the packet via the configured scheduling signaling in response to transmitting the occupancy notification indicating that the radio resource representing the unlicensed band is available The data is scheduled for another consecutive sub-frame. The method of claim 14, wherein the method further comprises: prior to setting a transmission time of the packet data, in response to the occupied The radio resource of the unlicensed band transmits a reserved signal to reserve the radio resource of the unlicensed band. The method of claim 14, wherein the node control information further comprises at least one of the following or a combination thereof: delay, synchronization information, transmission power, number of channels, and about starting or stopping execution of channel occupancy Instructions. A base station comprising: a transmitter; a receiver; and a processor coupled to the transmitter and the receiver, and configured at least to transmit via the transmitter prior to receiving an occupancy notification a node control information, the node control information including an occupation mode of a radio resource of an unlicensed frequency band, the occupancy mode being a configuration of a base station based uplink link or a downlink; receiving the occupancy notification Previously, transmitting, by the transmitter, a device control information, the device control information including the occupancy mode of the radio resource of the unlicensed frequency band; utilizing the unlicensed frequency band before receiving the occupancy notification The radio resource transmits a packet material via the transmitter; and the occupancy notification is received via the receiver, the occupancy notification notifying the availability of the radio resource of the unlicensed band. An authorized auxiliary access node comprising: a first transceiver; and a processor coupled to the first transceiver and configured to be at least via the first transceiver prior to transmitting an occupancy notification Receiving a node control information, the node control information including an occupation mode of a radio resource of an unlicensed frequency band, the occupancy mode being a configuration of a base station based uplink link or a downlink; before transmitting the occupancy notification, Receiving, via the first transceiver, a packet material, the packet data using the radio resource of the unlicensed band; determining availability of the radio resource of the unlicensed band; and via the first transceiver The occupancy notification is transmitted to inform the availability of the radio resource of the unlicensed band.