Disclosure of Invention
The embodiment of the invention provides a method and equipment for feeding back channel state information, which are used for reducing system overhead.
The embodiment of the invention provides the following specific technical scheme:
in a first aspect, a method for feeding back channel state information includes:
the non-reference terminal equipment receives channel state information sent by one or more reference terminal equipment in a device-to-device D2D mode;
the non-reference terminal equipment carries out channel measurement according to a first downlink pilot frequency sent by a network side to obtain self channel state information;
selecting a reference terminal device by the non-reference terminal device;
the non-reference terminal device reports one or all of the following two kinds of information to the network side: the difference between the self channel state information and the channel state information of the selected reference terminal equipment, and the identifier of the selected reference terminal equipment.
With reference to the first aspect, in a first possible implementation manner, before the non-reference terminal device receives the channel state information sent by the reference terminal device, the method further includes: and the non-reference terminal equipment determines the type of the terminal as the non-reference terminal equipment.
With reference to the first possible implementation manner of the first aspect, in a second possible implementation manner, the determining, by the non-reference terminal device, that the terminal type of the non-reference terminal device is a non-reference terminal device is one or more of the following manners:
the non-reference terminal equipment determines the type of the terminal as non-reference terminal equipment according to the indication information issued by the network side in the process of accessing the system;
or,
the non-reference terminal equipment determines the type of the terminal as non-reference terminal equipment according to the indication information issued by the network side after accessing the system;
or,
and the non-reference terminal equipment determines the non-reference terminal equipment according to the identification of the non-reference terminal equipment.
With reference to the first aspect or any one of the foregoing possible implementation manners of the first aspect, in a third possible implementation manner, if there are multiple reference terminal devices, the selecting, by the non-reference terminal device, one reference terminal device includes:
the non-reference terminal equipment respectively calculates the similarity between the channel state information of the non-reference terminal equipment and the channel state information of the plurality of reference terminal equipment;
and the non-reference terminal equipment selects one reference terminal equipment with high similarity.
With reference to the third possible implementation manner of the first aspect, in a fourth possible implementation manner, the selecting, by the non-reference terminal device, a reference terminal device with a high similarity includes:
and the non-reference terminal equipment selects the reference terminal equipment with the highest similarity.
With reference to the first aspect or any one of the foregoing possible implementation manners of the first aspect, in a fifth possible implementation manner, if there is one reference terminal device, the selecting, by the non-reference terminal device, one reference terminal device includes:
the non-reference terminal equipment directly selects the reference terminal equipment
With reference to the first aspect or any one of the foregoing possible implementation manners of the first aspect, in a sixth possible implementation manner, the non-reference terminal device reports one or all of the following two types of information to the network side: the difference between the channel state information of the reference terminal device and the channel state information of the selected reference terminal device, and the identifier of the selected reference terminal device include:
and the non-reference terminal equipment judges whether the difference value between the self channel state information and the selected channel state information of the reference terminal equipment is zero or not, and reports the difference value between the self channel state information and the selected channel state information of the reference terminal equipment and the identifier of the reference terminal equipment to the network side when the difference value is not zero.
With reference to the first aspect or any one of the foregoing possible implementation manners of the first aspect, in a seventh possible implementation manner, the non-reference terminal device reports one or all of the following two types of information to the network side: the difference between the channel state information of the terminal device and the channel state information of the selected reference terminal device, and the identifier of the selected reference terminal device include:
and the non-reference terminal equipment judges whether the difference value between the self channel state information and the channel state information of the selected reference terminal equipment is zero, and reports the identifier of the selected reference terminal equipment to the network side when the difference value is determined to be zero.
With reference to the first aspect or any one of the foregoing possible implementation manners of the first aspect, in an eighth possible implementation manner, the method further includes:
the non-reference terminal equipment determines that the non-reference terminal equipment is converted into the reference terminal equipment according to the indication information sent by the network side, performs channel measurement according to the second downlink pilot frequency sent by the network side to obtain the channel state information of the non-reference terminal equipment, reports the obtained channel state information to the network side, and sends the channel state information to the peripheral terminal equipment in a D2D mode.
With reference to the first aspect or any one of the foregoing possible implementation manners of the first aspect, in a ninth possible implementation manner, the channel state information at least includes channel quality information CQI; or, the channel state information at least includes CQI and precoding matrix indicator PMI.
In a second aspect, a method for feeding back channel state information includes:
the reference terminal equipment carries out channel measurement according to a third downlink pilot frequency sent by a network side to obtain self channel state information;
the reference terminal device reports the obtained channel state information to the network side and sends the channel state information to the peripheral terminal devices in a device-to-device D2D mode.
With reference to the second aspect, in a first possible implementation manner, before the reference terminal device performs channel measurement according to a third downlink pilot frequency sent by a network side to obtain channel state information of the reference terminal device itself, the method further includes;
and the reference terminal equipment determines the terminal type of the reference terminal equipment as the reference terminal equipment.
With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner, the reference terminal device determines that the terminal type of the reference terminal device is one or more of the following manners:
the reference terminal equipment determines the type of the terminal as the reference terminal equipment according to the indication information issued by the network side in the process of accessing the system;
or,
the reference terminal equipment determines the type of the terminal as the reference terminal equipment according to the indication information issued by the network side after accessing the system;
or,
and the reference terminal equipment determines that the reference terminal equipment is the reference terminal equipment according to the identification of the reference terminal equipment.
With reference to the second aspect or any one of the foregoing possible implementation manners of the second aspect, in a third possible implementation manner, the method further includes:
when the reference terminal equipment determines that the reference terminal equipment is converted into non-reference terminal equipment according to the indication information sent by the network side, the reference terminal equipment receives channel state information sent by one or more reference terminal equipment in a D2D mode, performs channel measurement according to a fourth downlink pilot frequency sent by the network side to obtain the channel state information of the equipment, selects one reference terminal equipment, and reports one or all of the following two kinds of information to the network side: the difference between the channel state information of the device and the channel state information of the selected reference terminal device, and the identifier of the selected reference terminal device.
With reference to the third possible implementation manner of the second aspect, in a fourth possible implementation manner, the channel state information at least includes channel quality information CQI; or, the channel state information at least includes CQI and precoding matrix indicator PMI.
In a third aspect, an apparatus for feeding back channel state information includes:
a receiver, configured to receive channel state information sent by one or more reference terminal devices in a device-to-device D2D manner;
the processor is used for carrying out channel measurement according to the first downlink pilot frequency sent by the network side to obtain the channel state information of the equipment and selecting a reference terminal equipment;
the sender is used for reporting one or all of the following two kinds of information to the network side: the difference between the channel state information of the device and the channel state information of the selected reference terminal device, and the identifier of the selected reference terminal device.
With reference to the third aspect, in a first possible implementation manner, before the receiver receives the channel state information sent by the reference terminal device, the processor is further configured to: determining that the terminal type of the device is a non-reference terminal device.
With reference to the first possible implementation manner of the third aspect, in a second possible implementation manner, the processor determines that the terminal type of the device is a non-reference terminal device, and the determination is one or more of the following manners:
determining the terminal type of the equipment as non-reference terminal equipment according to indication information issued by a network side in a system access process;
or,
determining the terminal type of the equipment as non-reference terminal equipment according to indication information issued by a network side after accessing a system;
or,
determining that the device is a non-reference terminal device according to the identity of the device.
With reference to the third aspect or any one of the foregoing possible implementation manners of the third aspect, in a third possible implementation manner, if there are multiple reference terminal devices, the selecting, by the processor, one reference terminal device includes:
the processor respectively calculates the similarity between the channel state information of the equipment and the channel state information of the plurality of reference terminal equipment;
the processor selects a reference terminal device with high similarity.
With reference to the third possible implementation manner of the third aspect, in a fourth possible implementation manner, the selecting, by the processor, one reference terminal device with a high similarity includes:
the processor selects a reference terminal device with the highest similarity.
With reference to the third aspect or any one of the foregoing possible implementation manners of the third aspect, in a fifth possible implementation manner, if there is one reference terminal device, the selecting, by the processor, one reference terminal device includes:
the processor directly selects the reference terminal equipment
With reference to the third aspect or any one of the foregoing possible implementation manners of the third aspect, in a sixth possible implementation manner, the transmitter reports one or all of the following two kinds of information to the network side: the difference between the channel state information of the device and the channel state information of the selected reference terminal device, and the identifier of the selected reference terminal device include:
and the processor judges whether the difference value between the channel state information of the equipment and the channel state information of the selected reference terminal equipment is zero or not, and when the difference value is not zero, the transmitter reports the difference value between the channel state information of the equipment and the channel state information of the selected reference terminal equipment and the identifier of the selected reference terminal equipment to the network side.
With reference to the third aspect or any one of the foregoing possible implementation manners of the third aspect, in a seventh possible implementation manner, the transmitter reports one or all of the following two kinds of information to the network side: the difference between the channel state information of the device and the channel state information of the selected reference terminal device, and the identifier of the selected terminal device include:
and the processor judges whether the difference value between the channel state information of the equipment and the channel state information of the selected terminal equipment is zero, and when the difference value is determined to be zero, the transmitter reports the identifier of the selected reference terminal equipment to the network side.
With reference to the third aspect or any one of the foregoing possible implementations of the third aspect, in an eighth possible implementation, the processor is further configured to:
determining that the equipment is converted from non-reference terminal equipment to reference terminal equipment according to the indication information sent by the network side, and performing channel measurement according to a second downlink pilot frequency sent by the network side to obtain channel state information of the equipment;
the transmitter is further configured to:
and reporting the obtained channel state information to a network side and sending the channel state information to peripheral terminal equipment by adopting a D2D mode.
With reference to the third aspect or any one of the foregoing possible implementation manners of the third aspect, in a ninth possible implementation manner, the channel state information at least includes channel quality information CQI; or, the channel state information at least includes CQI and precoding matrix indicator PMI.
In a fourth aspect, an apparatus for feeding back channel state information includes:
the processor is used for carrying out channel measurement according to a third downlink pilot frequency sent by a network side to obtain channel state information of the equipment;
and the transmitter is used for reporting the obtained channel state information to a network side and transmitting the obtained channel state information to the peripheral terminal equipment in a device-to-device D2D mode.
With reference to the fourth aspect, in a first possible implementation manner, before the processor performs channel measurement according to a third downlink pilot frequency sent by a network side to obtain channel state information of the processor, the processor is further configured to;
the processor determines that the terminal type of the device is a reference terminal device.
With reference to the first possible implementation manner of the fourth aspect, in a second possible implementation manner, the processor determines that the terminal type of the device is one or more of the following manners with reference to the terminal device:
the processor determines the terminal type of the equipment as reference terminal equipment according to the indication information issued by the network side in the process of accessing the system;
or,
the processor determines the terminal type of the equipment as reference terminal equipment according to the indication information issued by the network side after accessing the system;
or,
the processor determines that the device is a reference terminal device according to the identity of the device.
With reference to the fourth aspect or any one of the foregoing possible implementation manners of the fourth aspect, in a third possible implementation manner, the method further includes:
the receiver is used for receiving the channel state information sent by one or more reference terminal devices in a D2D mode when the device is determined to be converted from the reference terminal device to the non-reference terminal device according to the indication information sent by the network side;
the processor is further configured to:
performing channel measurement according to a fourth downlink pilot frequency sent by a network side to obtain channel state information of the equipment, and selecting a reference terminal equipment;
the transmitter is further configured to:
reporting one or all of the following two kinds of information to a network side: the difference between the channel state information of the device and the channel state information of the selected reference terminal device, and the identifier of the selected reference terminal device.
With reference to the third possible implementation manner of the fourth aspect, in a fourth possible implementation manner, the channel state information at least includes channel quality information CQI; or, the channel state information at least includes CQI and precoding matrix indicator PMI.
To sum up, in the embodiment of the present invention, when the terminal device determines that it is the reference terminal device, the terminal device reports the channel state information to the network side according to the channel state information of itself and sends the channel state information to the peripheral terminal device in a D2D manner, and when the terminal device determines that it is the non-reference terminal device, the terminal device receives the channel state information sent by the peripheral reference terminal device, selects one reference terminal device, and reports one or all of the following two types of information to the network side: the difference between the self channel state information and the channel state information of the selected reference terminal equipment, and the identifier of the selected reference terminal equipment. In this way, only the reference terminal device reports the complete channel state information, and the non-reference terminal device reports only the difference, and in the application scene where the terminal devices are dense, the difference of the channel state information between the adjacent terminal devices is not large, so that the feedback amount can be greatly reduced by feeding back the channel state information in a difference mode between different terminal devices, thereby effectively reducing the system overhead and improving the system performance.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In order to solve the problem that the overhead of uplink feedback of the system increases with the increase of the number of terminal devices, referring to fig. 1, in the embodiment of the present invention, all terminal devices are divided into two types: a reference terminal device and a non-reference terminal device. The classification of the terminal equipment can be judged by network equipment designation or the terminal equipment according to the self identification, and the reference terminal equipment and the non-reference terminal equipment respectively adopt different modes to report the channel state information. The reference terminal device can send the channel state information to the network side according to the existing protocol, and the reference terminal device means that the channel state information of the reference terminal device can be used as a reference of the non-reference terminal device; and the non-reference terminal device means that the reporting of the channel state information of the non-reference terminal device needs to be based on the channel state information of the reference terminal device.
The Network device may be a device for communicating with a terminal device, and the Network device may be a Base Transceiver Station (BTS) in Global System for Mobile communications (GSM) or Code Division Multiple Access (CDMA), a Base Station (NodeB, NB) in Wideband Code Division Multiple Access (WCDMA), an eNB or evolved Node B (eNodeB) or Access point in Long Term Evolution (Long Term Evolution, LTE), or a vehicle-mounted device, a Network-side device in a future 5G Network, or a Network device in a future evolved Public Land Mobile Network (PLMN).
Terminal Equipment (including reference terminal Equipment and non-reference terminal Equipment of the present application) may also be referred to as User Equipment (UE), User Equipment, access terminal, subscriber unit, subscriber station, mobile station, remote terminal, mobile device, User terminal, wireless communication device, User agent, or User Equipment. An access terminal may be a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with Wireless communication capabilities, a computing device or other processing device connected to a Wireless modem, a vehicle mounted device, a wearable device, a terminal device in a future 5G Network, or a terminal device in a future evolved Public Land Mobile Network (PLMN) Network.
Referring to fig. 2A, in the embodiment of the present invention, a flow of the non-reference terminal device performing channel state information feedback is as follows:
step 2100: the non-reference terminal device receives the channel state information sent by one or more reference terminal devices through the D2D mode.
In this embodiment of the present invention, before step 2100 is executed, the non-reference terminal device determines that its terminal type is a non-reference terminal device, specifically, the non-reference terminal device determines that its terminal type is a non-reference terminal device in one or more of the following manners:
the non-reference terminal equipment determines the type of the terminal as non-reference terminal equipment according to the indication information issued by the network side in the process of accessing the system;
or,
the non-reference terminal equipment determines the type of the terminal as non-reference terminal equipment according to the indication information issued by the network side after accessing the system;
or,
and the non-reference terminal equipment determines the non-reference terminal equipment according to the identification of the non-reference terminal equipment.
Step 2101: and the non-reference terminal equipment carries out channel measurement according to the first downlink pilot frequency sent by the network side to obtain the self channel state information.
Step 2102: the non-reference terminal device selects a reference terminal device.
Specifically, the following two cases are classified:
the first case is: if there are multiple reference terminal devices, then in step 2102, the non-reference terminal devices respectively calculate similarities between their own channel state information and the channel state information of the multiple reference terminal devices, and select one reference terminal device with a high similarity; preferably, the non-reference terminal device may select a reference terminal device with the highest similarity.
In the embodiment of the present invention, the similarity may have many calculation manners, and preferably, the similarity between two pieces of channel state information may be calculated by using a difference manner, that is, the difference between two pieces of channel state information is calculated, and the greater the difference is, the lower the similarity is, of course, other manners for calculating the similarity are available, which are not described herein again.
On the other hand, in the embodiment of the present invention, the high similarity means that the value of the similarity is within the prepaid value range, and taking the difference as an example, the difference that does not exceed the set value range can be regarded as high similarity.
The second case is: and if the reference terminal equipment is one, the non-reference terminal equipment directly selects the reference terminal equipment.
Step 2103: the non-reference terminal device reports one or all of the following two kinds of information to the network side: the difference between the self channel state information and the channel state information of the selected reference terminal equipment, and the identifier of the selected reference terminal equipment.
Specifically, when step 2103 is executed, the non-reference terminal may adopt, but is not limited to, the following two ways:
the first mode is as follows: and the non-reference terminal equipment judges whether the difference value between the self channel state information and the selected channel state information of the reference terminal equipment is zero or not, and reports the difference value between the self channel state information and the selected channel state information of the reference terminal equipment and the identifier of the reference terminal equipment to the network side when the difference value is not zero.
The second way is: and the non-reference terminal equipment judges whether the difference value between the self channel state information and the channel state information of the selected reference terminal equipment is zero, and reports the identifier of the selected reference terminal equipment to the network side when the difference value is determined to be zero.
Based on steps 2100 to 2103, in the working process, if the non-reference terminal device determines that the non-reference terminal device is converted into the reference terminal device according to the indication information sent by the network side, the channel measurement is performed according to the second downlink pilot frequency sent by the network side to obtain the channel state information of the non-reference terminal device, and the obtained channel state information is reported to the network side and sent to the peripheral terminal device by adopting a D2D mode, wherein the first downlink pilot frequency is the same as the second downlink pilot frequency, only the sending time is different, and certainly, the first downlink pilot frequency may be different from the second downlink pilot frequency. Other parts of the specification are explained similarly and are not repeated.
The channel state information mentioned in the above flow includes at least CQI; alternatively, the channel state information includes at least CQI and PMI.
Referring to fig. 2B, in the embodiment of the present invention, a process of feeding back channel state information by reference to a terminal device is as follows:
step 2200: and the reference terminal equipment performs channel measurement according to the third downlink pilot frequency sent by the network side to obtain the self channel state information.
Before executing step 2200, the reference terminal device needs to determine its terminal type as the reference terminal device, and specifically may adopt one or more of the following manners:
the reference terminal equipment determines the type of the terminal as the reference terminal equipment according to the indication information issued by the network side in the process of accessing the system;
or,
the reference terminal equipment determines the type of the terminal as the reference terminal equipment according to the indication information issued by the network side after accessing the system;
or,
and the reference terminal equipment determines that the reference terminal equipment is the reference terminal equipment according to the identification of the reference terminal equipment.
Step 2201: the reference terminal device reports the obtained channel state information to the network side and sends the channel state information to the peripheral terminal devices in a device-to-device D2D mode.
Based on steps 2201-2202. In the working process, if the reference terminal equipment determines that the reference terminal equipment is converted into non-reference terminal equipment according to the indication information sent by the network side, the reference terminal equipment receives channel state information sent by one or more reference terminal equipment in a D2D mode, performs channel measurement according to a fourth downlink pilot frequency sent by the network side to obtain the channel state information of the equipment, selects one reference terminal equipment, and reports one or all of the following two kinds of information to the network side: the difference value of the channel state information of the equipment and the channel state information of the selected reference terminal equipment, and the identification of the selected reference terminal equipment; the fourth downlink pilot frequency can be the same as the third downlink pilot frequency, and only the sending time is different; of course, the fourth downlink pilot and the third downlink pilot may be different. Other parts of the specification are explained similarly and are not repeated.
Similarly, the channel state information at least comprises CQI; alternatively, the channel state information includes at least CQI and PMI.
Based on the above embodiment, referring to fig. 2C, a detailed flow of the terminal device performing channel information feedback is as follows:
step 200: the terminal equipment judges whether the terminal equipment is reference terminal equipment or non-reference terminal equipment; if the reference terminal device is the reference terminal device, executing step 210; if the reference terminal device is not the reference terminal device, step 230 is executed.
Specifically, the terminal device may determine whether the terminal device is a reference terminal device or a non-reference terminal device according to the indication information of the network device when or after accessing the system, or may determine whether the terminal device is a reference terminal device or a non-reference terminal device according to the identifier of the terminal device.
Step 210: the terminal device sends its own Information State Information (CSI) to the peripheral terminal devices in a D2D manner.
Specifically, the terminal device may perform downlink channel measurement according to a downlink pilot frequency periodically sent by the network side, so as to obtain CSI of a downlink channel.
Step 220: and the terminal equipment reports the CSI of the terminal equipment to the network side.
And step 230, the terminal equipment receives CSI sent by other peripheral reference terminal equipment and selects one reference terminal equipment.
Specifically, the CSI may include at least CQI measured by the terminal device, or at least CQI and PMI measured by the terminal device.
Step 240: and the terminal equipment calculates the CSI of the terminal equipment and the difference value of the CSI of the terminal equipment and the CSI of the selected reference terminal equipment.
Specifically, the difference refers to a difference between each parameter in the CSI calculated by the terminal device and a corresponding parameter in the CSI of the selected reference terminal device.
Step 250: and the terminal equipment reports the difference value of the CSI of the terminal equipment and the CSI of the selected reference terminal equipment and the ID of the selected reference terminal equipment to the network side.
Obviously, in the embodiment of the present invention, when the terminal device determines that the terminal device itself is a non-reference terminal device, after receiving the CSI sent by the peripheral reference terminal device, the terminal device selects one reference terminal device, calculates the difference between the CSI of the terminal device itself and the CSI of the selected reference terminal device, and reports the difference and the identifier of the selected reference terminal device to the network side. Specifically, before reporting, the terminal device first determines whether a difference between the CSI of the terminal device and the CSI of the selected reference terminal device is zero, and reports the difference between the CSI of the terminal device and the CSI of the selected reference terminal device and the identifier of the selected reference terminal device to the network side when determining that the difference is not zero, so that only the difference is reported, thereby reducing the system overhead; when the determination is zero, only the identifier of the selected reference terminal device is reported to the network side, so that the system overhead can be further reduced.
The above embodiments are further described in detail with reference to specific application scenarios.
A first scenario: taking cell a as an example, assume that 200 terminal devices exist in cell a at the same time. When each terminal device accesses the system, the network device specifies the terminal class of the terminal device through the indication message. In the cell a, it is assumed that the network device designates 50 terminal devices as reference terminal devices, and the remaining 150 terminal devices are non-reference terminal devices, and the network device periodically sends downlink pilot frequency at set time intervals, so that each terminal device performs downlink channel measurement.
If the terminal equipment is reference terminal equipment, the reference terminal equipment measures a downlink channel through downlink pilot frequency, calculates CQI of the downlink channel and takes the obtained CQI as channel state information; then, the reference terminal device transmits the calculated CQI periodically to the peripheral terminal devices by means of D2D, and the reference terminal device also feeds back the calculated CQI to the network device via the uplink channel.
If the terminal equipment is non-reference terminal equipment, the non-reference terminal equipment measures a downlink channel through downlink pilot frequency, calculates CQI of the downlink channel and takes the obtained CQI as channel state information; then, the non-reference terminal device receives the CQIs sent by the surrounding reference terminal devices through a D2D method, and selects one reference terminal device with a CQI value having a high similarity to its own CQI value. Preferably, a reference terminal device with the highest similarity may be selected, and a CQI value corresponding to the selected reference terminal device may be used as the reference CQI. And the non-reference terminal equipment calculates the difference value between the CQI of the non-reference terminal equipment and the reference CQI, and feeds back the difference value and the ID of the selected reference terminal equipment to the network equipment, wherein if the difference value is zero, only the ID of the reference terminal equipment is fed back.
A second scenario: taking cell a as an example, assume that 200 terminal devices exist in cell a at the same time. When each terminal device accesses the system, the network device specifies the terminal class of the terminal device through the indication message. In the cell a, it is assumed that the network device designates 50 terminal devices as reference terminal devices, and the remaining 150 terminal devices are non-reference terminal devices, and the network device periodically sends downlink pilot frequency at set time intervals, so that each terminal device performs downlink channel measurement.
If the terminal equipment is reference terminal equipment, the reference terminal equipment measures a downlink channel through downlink pilot frequency, calculates CQI and PMI of the downlink channel, and takes the obtained CQI and PMI as channel state information; then, the reference terminal device periodically transmits the calculated CQI and PMI to peripheral terminal devices by a D2D method, and simultaneously, the reference terminal device also feeds back the calculated CQI and PMI to the network device through an uplink channel.
If the terminal equipment is non-reference terminal equipment, the non-reference terminal equipment measures a downlink channel through a downlink pilot frequency, calculates CQI and PMI of the downlink channel, and takes the obtained CQI and PMI as channel state information; and then, the non-reference terminal equipment receives the CQI and the PMI sent by the peripheral reference terminal equipment in a D2D mode, and selects one reference terminal equipment with a CQI value and a PMI value which have high similarity with the CQI value and the PMI value of the non-reference terminal equipment. Preferably, a reference terminal device with the highest similarity may be selected, and the CQI value and the PMI value corresponding to the selected reference terminal device may be respectively used as the reference CQI and the reference PMI. And the non-reference terminal equipment calculates the difference value between the CQI of the non-reference terminal equipment and the reference CQI and the difference value between the PMI of the non-reference terminal equipment and the reference PMI of the non-reference terminal equipment, and feeds back the two difference values and the ID of the selected reference terminal equipment to the network equipment, wherein if the difference value is zero, only the ID of the reference terminal equipment is fed back.
A third scenario: the network equipment periodically sends down-link pilot frequency in set time interval for terminal equipment to measure down-link channel. Each terminal device judges whether the terminal device is a reference terminal device or a non-reference terminal device according to the self identification. For example, taking an LTE system as an example, the terminal device may determine according to a Cell Radio Network Temporary Identifier (C-RNTI), and if mod (C-RNTI,4) is zero, the terminal device is a reference terminal device; if mod (C-RNTI,4) is non-zero, then the terminal device is a non-reference terminal device.
If the terminal equipment is reference terminal equipment, the reference terminal equipment measures a downlink channel through downlink pilot frequency, calculates CQI of the downlink channel and takes the obtained CQI as channel state information; then, the reference terminal device transmits the calculated CQI periodically to the peripheral terminal devices by means of D2D, and the reference terminal device also feeds back the calculated CQI to the network device via the uplink channel.
If the terminal equipment is non-reference terminal equipment, the non-reference terminal equipment measures a downlink channel through downlink pilot frequency, calculates CQI of the downlink channel and takes the obtained CQI as channel state information; then, the non-reference terminal device receives the CQIs sent by the surrounding reference terminal devices through a D2D method, and selects one reference terminal device with a CQI value having a high similarity to its own CQI value, preferably, selects one reference terminal device with a CQI value having a highest similarity to its own CQI value, and uses the CQI value corresponding to the selected reference terminal device as a reference CQI. And the non-reference terminal equipment calculates the difference value between the CQI of the non-reference terminal equipment and the reference CQI, and feeds back the difference value and the ID of the selected reference terminal equipment to the network equipment, wherein if the difference value is zero, only the ID of the reference terminal equipment is fed back.
Of course, in practical applications, the identifier of the reference terminal device may be other parameters, and the ID herein is merely an example.
A fourth scenario: taking cell a as an example, assume that 200 terminal devices exist in cell a at the same time. The network equipment periodically sends down-link pilot frequency in set time interval for each terminal equipment to measure down-link channel.
In the embodiment of the present invention, the terminal device determines whether itself is a reference terminal device or a non-reference terminal device according to the indication information sent by the network device, and specifically, the following two methods may be adopted, but not limited to:
the first mode is as follows: the terminal device is started and then accesses the system, network attachment is completed in the access process, that is, the terminal device and the network device negotiate initial communication parameters, and the network device issues the type information of the terminal device to each terminal device through an RRC instruction (for example, RRConnectionReconfiguration), so that the terminal device can obtain the initial terminal device type parameters (refer to the terminal device or non-refer to the terminal device);
the second way is: after the terminal device accesses the system, the network device may adaptively adjust the type information of the terminal device according to the current network state, that is, in the working process, according to the fluctuation of the network state, the reference terminal device may be converted into a non-reference terminal device, and the non-reference terminal device may also be converted into a reference terminal device.
If the terminal equipment is reference terminal equipment, the reference terminal equipment measures a downlink channel through downlink pilot frequency, calculates CQI of the downlink channel and takes the obtained CQI as channel state information; then, the reference terminal device transmits the calculated CQI periodically to the peripheral terminal devices by means of D2D, and the reference terminal device also feeds back the calculated CQI to the network device via the uplink channel.
If the terminal equipment is non-reference terminal equipment, the non-reference terminal equipment measures a downlink channel through downlink pilot frequency, calculates CQI of the downlink channel and takes the obtained CQI as channel state information; then, the non-reference terminal device receives the CQIs sent by the peripheral reference terminal devices through a D2D method, selects one reference terminal device with a CQI value having a high similarity (preferably highest) with the CQI value of itself as a reference terminal device, uses the CQI value corresponding to the reference terminal device as a reference CQI, calculates a difference between the CQI of itself and the reference CQI, and feeds back the difference and the ID of the reference terminal device to the network device, wherein if the difference is zero, only the ID of the reference terminal device is fed back.
The scheme provided by the embodiment of the invention is mainly applied to an FDD scene of a Large Scale MIMO system, and can be used for other systems after adaptive adjustment, and is not described again.
Based on the above embodiments, referring to fig. 3, in an embodiment of the present invention, an apparatus for feeding back channel state information (as a non-reference terminal apparatus) includes a receiver 30, a processor 31 and a transmitter 32, wherein,
a receiver 30, configured to receive channel state information sent by one or more reference terminal devices by means of D2D;
the processor 31 is configured to perform channel measurement according to a first downlink pilot frequency sent by a network side to obtain channel state information of the device, and select a reference terminal device;
a sender 32, configured to report one or all of the following two types of information to a network side: the difference between the channel state information of the device and the channel state information of the selected reference terminal device, and the identifier of the selected reference terminal device.
Preferably, before the receiver 30 receives the channel state information sent by the reference terminal device, the processor 31 is further configured to: determining that the terminal type of the device is a non-reference terminal device.
Preferably, the processor 31 determines that the terminal type of the device is a non-reference terminal device in one or more of the following ways:
determining the terminal type of the equipment as non-reference terminal equipment according to indication information issued by a network side in a system access process;
or,
determining the terminal type of the equipment as non-reference terminal equipment according to indication information issued by a network side after accessing a system;
or,
determining that the device is a non-reference terminal device according to the identity of the device.
Preferably, if there are a plurality of reference terminal devices, the processor 21 selects one reference terminal device, including:
the processor 31 calculates the similarity between the channel state information of the device and the channel state information of the plurality of reference terminal devices respectively;
the processor 31 selects a reference terminal device with a high similarity.
Preferably, the processor 31 selects a reference terminal device with high similarity, which includes:
the processor 31 selects the reference terminal device with the highest similarity.
Preferably, if there is one reference terminal device, the processor 31 selects one reference terminal device, including:
the processor 31 directly selects the one reference terminal device
Preferably, the sender 32 reports one or all of the following two information to the network side: the difference between the channel state information of the device and the channel state information of the selected reference terminal device, and the identifier of the selected reference terminal device include:
the processor 31 determines whether the difference between the channel state information of the device and the channel state information of the selected reference terminal device is zero, and if it is determined that the difference is not zero, the transmitter 32 reports the difference between the channel state information of the device and the channel state information of the selected reference terminal device, and the identifier of the selected reference terminal device to the network side.
Preferably, the sender 32 reports one or all of the following two information to the network side: the difference between the channel state information of the device and the channel state information of the selected reference terminal device, and the identifier of the selected terminal device include:
the processor 31 determines whether the difference between the channel state information of the device and the channel state information of the selected terminal device is zero, and if the difference is zero, the transmitter 32 reports the identifier of the selected reference terminal device to the network side.
Preferably, the processor 31 is further configured to:
determining that the equipment is converted from non-reference terminal equipment to reference terminal equipment according to the indication information sent by the network side, and performing channel measurement according to a second downlink pilot frequency sent by the network side to obtain channel state information of the equipment;
the transmitter 32 is further configured to:
and reporting the obtained channel state information to a network side and sending the channel state information to peripheral terminal equipment by adopting a D2D mode.
The channel state information comprises at least a CQI; or, the channel state information at least includes CQI and PMI.
Referring to fig. 4, in an embodiment of the present invention, an apparatus (serving as a reference terminal apparatus) for feeding back channel state information includes a processor 41 and a transmitter 42:
a processor 41, configured to perform channel measurement according to a third downlink pilot sent by the network side to obtain channel state information of the device;
and the transmitter 42 is configured to report the obtained channel state information to the network side and transmit the obtained channel state information to the peripheral terminal device in a D2D manner.
Preferably, the processor 41 is further configured to perform channel measurement according to a third downlink pilot frequency sent by the network side before obtaining channel state information of itself;
the processor 41 determines the terminal type of the device as a reference terminal device.
Preferably, the processor 41 determines that the terminal type of the device is one or more of the following with reference to the terminal device:
the processor 41 determines the terminal type of the device as a reference terminal device according to the indication information issued by the network side in the process of accessing the system;
or,
the processor 41 determines the terminal type of the device as a reference terminal device according to the indication information issued by the network side after accessing the system;
or,
processor 41 determines from the identity of the device that the device is a reference terminal device.
Further comprising:
the receiver 40 is configured to receive channel state information sent by one or more reference terminal devices in a D2D manner when determining that the device is converted from a reference terminal device to a non-reference terminal device according to the indication information sent by the network side;
processor 41 is further configured to:
performing channel measurement according to a fourth downlink pilot frequency sent by a network side to obtain channel state information of the equipment, and selecting a reference terminal equipment;
the transmitter 42 is further configured to:
reporting one or all of the following two kinds of information to a network side: the difference between the channel state information of the device and the channel state information of the selected reference terminal device, and the identifier of the selected reference terminal device.
Preferably, the channel state information at least comprises CQI; or, the channel state information at least includes CQI and PMI.
To sum up, in the embodiment of the present invention, when the terminal device determines that it is the reference terminal device, the terminal device reports the channel state information to the network side according to the channel state information of itself and sends the channel state information to the peripheral terminal device in a D2D manner, and when the terminal device determines that it is the non-reference terminal device, the terminal device receives the channel state information sent by the peripheral reference terminal device, selects one reference terminal device, and reports one or all of the following two types of information to the network side: the difference between the self channel state information and the channel state information of the selected reference terminal equipment, and the identifier of the selected reference terminal equipment. In this way, only the reference terminal device reports the complete channel state information, and the non-reference terminal device reports only the difference, and in the application scene where the terminal devices are dense, the difference of the channel state information between the adjacent terminal devices is not large, so that the feedback amount can be greatly reduced by feeding back the channel state information in a difference mode between different terminal devices, thereby effectively reducing the system overhead and improving the system performance.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments of the present invention without departing from the spirit or scope of the embodiments of the invention. Thus, if such modifications and variations of the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to encompass such modifications and variations.