CN110768703A

CN110768703A - Beamforming transmission method and communication device

Info

Publication number: CN110768703A
Application number: CN201810832057.6A
Authority: CN
Inventors: 孟鑫; 陈凯
Original assignee: Shanghai Huawei Technologies Co Ltd
Current assignee: Shanghai Huawei Technologies Co Ltd
Priority date: 2018-07-26
Filing date: 2018-07-26
Publication date: 2020-02-07
Anticipated expiration: 2038-07-26
Also published as: CN110768703B

Abstract

The application provides a beamforming transmission method and a communication device, which can flexibly adjust a beamforming weight of a channel and are beneficial to improving the system performance. The method comprises the following steps: the network equipment determines a beam forming weight of a target channel according to the received noise power of the terminal equipment, the sending power of the target channel and the beam weight of a downlink demodulation reference signal, wherein the downlink demodulation reference signal is used for the terminal equipment to demodulate the target channel; and the network equipment sends the target channel to the terminal equipment according to the beam forming weight of the target channel.

Description

Beamforming transmission method and communication device

Technical Field

The present application relates to the field of communications, and in particular, to a beamforming transmission method and a communication apparatus. .

Background

In current wireless communication systems, in order to guarantee coverage of all users in a cell, a cell-specific reference signal (CRS) must be transmitted using a wide beam at a cell level. In order to match the beam used by the CRS, a channel for CRS-assisted demodulation, for example, a Physical Downlink Control Channel (PDCCH) resource, needs to be weighted using the same wide beam as the CRS. This method of transmitting CRS-assisted demodulation-based channels using fixed beams is not flexible.

Disclosure of Invention

The application provides a beamforming transmission method and a communication device, which can flexibly adjust a beamforming weight of a channel and are beneficial to improving the system performance.

In a first aspect, a network device determines a beamforming weight of a target channel according to a received noise power of a terminal device, a transmission power of the target channel, and a beam weight of a downlink demodulation reference signal, where the downlink demodulation reference signal is used by the terminal device to demodulate the target channel; and the network equipment sends the target channel to the terminal equipment according to the beam forming weight of the target channel.

In this application, the downlink demodulation reference signal may be a CRS, but this is not limited in this embodiment of the application.

It is understood that the beam weight values of the downlink demodulation reference signals can be autonomously determined by the network device. And, the network device may send the downlink demodulation reference signal to the terminal device based on the determined beam weight of the downlink demodulation reference signal. After receiving the downlink demodulation reference signal sent by the network device, the terminal device may measure the channel quality according to the downlink demodulation reference signal to obtain a Channel Quality Indication (CQI). Further, the terminal device may report the obtained CQI to the network device.

Alternatively, the target channel may be a CRS demodulation-based channel, such as a Physical Downlink Control Channel (PDCCH) or a Physical Downlink Shared Channel (PDSCH).

In addition, as will be understood by those skilled in the art, the network device sending the target channel to the terminal device may also be understood as: the network device sends a signal to the terminal device, the network device sends a signal carried on a target channel to the terminal device, or the network device sends a signal carried on the target channel to the terminal device.

The beamforming transmission method of the embodiment of the application can flexibly adjust the BF weight of the target channel according to the received noise power of the terminal equipment, the transmitting power of the target channel and the beam weight of the downlink demodulation reference signal, thereby being beneficial to improving the system performance. For example, when a signal-to-noise ratio (SNR) (transmission power of a target channel/reception noise power of a terminal device) is low, the BF weight of the target channel may be adjusted to obtain a narrower transmission beam, so as to obtain a higher beam gain and system capacity. Under the condition of higher SNR, the BF weight of the target channel can be adjusted to obtain wider transmission beams so as to obtain smaller channel mismatch.

In a possible implementation manner, the determining, by the network device, a beamforming weight of a target channel according to a received noise power of a terminal device, a transmission power of the target channel, and a beamforming weight of a downlink demodulation reference signal includes:

the network equipment determines the beam forming weight of the target channel according to the following formula:

wherein, W_tRepresenting the beamforming weight of the target channel, R representing the statistical covariance matrix of the channel, σ²Representing the received noise power, P, of said terminal device_tRepresents the transmission power, W, of the target channel_rA beam weight value representing the downlink demodulation reference signal (·)^-1Representing the inverse of the matrix, I_MThe method includes the steps of representing an M × M identity matrix, wherein M represents the number of antennas of the network device, M is an integer greater than or equal to 1, a statistical covariance matrix of a channel is determined according to a channel matrix or a precoding matrix, the channel matrix is determined based on an uplink sounding reference signal sent by the terminal device, and the precoding matrix is determined based on a precoding matrix indicator PMI sent by the terminal device.

From the above equation, at high SNR, σ²/P_t→ 0, the above formula becomes W_t＝R^-1*RW_r＝W_rI.e. the BF weight is degenerated to the beam weight W of the downlink demodulation reference signal_rAt this time, althoughThe beam gain is not available, but the phase mismatch is not available, and the robustness is higher; at low SNR, i.e. σ²/P_t→ infinity, the above equation becomes W_t＝RW_rThat is, the BF weight is the beam weight W of the downlink demodulation reference signal_rA large beam gain can be obtained in spite of the phase mismatch when projected on the statistical covariance matrix R of the channel. In summary, according to the BF transmission method of the embodiment of the present application, a better performance tradeoff between beam gain and channel mismatch can be achieved.

In a possible manner, the received noise power of the terminal device is determined according to a statistical covariance matrix of a channel, a CQI reported by the terminal device, a beam weight of a downlink measurement reference signal, and a transmission power of the downlink measurement reference signal. The statistical covariance matrix of the channel is determined according to a channel matrix or a precoding matrix, the channel matrix is determined based on an uplink Sounding Reference Signal (SRS) sent by the terminal device, and the precoding matrix is determined based on a Precoding Matrix Indicator (PMI) sent by the terminal device. The downlink measurement reference signal is used for the terminal equipment to perform channel measurement.

In this application, the downlink measurement reference signal may be a CRS or a channel state information reference signal (CSI-RS), or may also be another signal used for the terminal device to perform channel measurement, which is not limited in this embodiment of the present application.

It should be understood that the terminal device may measure the channel quality according to the downlink measurement reference signal, and may report the obtained CQI to the network device. For example, in TM4 transmission mode, the terminal device may measure the channel quality and obtain the CQI according to the CRS sent by the network device. In the TM9 transmission mode, the terminal device may measure the channel quality and obtain the CQI according to the CSI-RS sent by the network device.

In one possible approach, the received noise power of the terminal device is determined according to the following formula:

wherein σ²Representing the received noise power of said terminal device, R representing the statistical covariance matrix of said channel, P_mRepresents the transmission power, W, of the downlink sounding reference signal_mRepresents the beam weight of the downlink measurement reference signal, tr (-) represents the trace of the calculation matrix, and gamma represents the linear value corresponding to the CQI, (.)^HRepresenting the conjugate transpose of the matrix.

It should be understood that if the downlink demodulation reference signal and the downlink measurement reference signal are the same, W is_m＝W_r。

It should be noted that the statistical covariance matrix of the channel in the present application may also be referred to as a long-term statistical channel covariance matrix of the terminal device, and the specific name of the statistical covariance matrix of the channel in the embodiment of the present application is not limited thereto. In addition, the present application also does not limit how to determine the statistical covariance matrix R of the channel, for example, the network device may determine the statistical covariance matrix R of the channel by the manner provided in the prior art based on the channel matrix or the precoding matrix.

For example, in an implementation manner, after receiving an uplink SRS transmitted by a terminal on multiple subbands, a network device estimates an uplink channel state to obtain a channel matrix h corresponding to the multiple subbands one to one. Then, the network device calculates h x h corresponding to the sub-bands one by one respectively^HAnd comparing the obtained h x h^HAnd averaging to obtain a full-band covariance matrix. Then, the network device performs temporal averaging or filtering on the full-band covariance matrix at different times, and then performs transposition operation on the averaged or filtered matrix to finally obtain the statistical covariance matrix R of the channel.

For example, in another implementation manner, the terminal device may obtain PMIs corresponding to multiple subbands in a one-to-one manner according to CRS or CSI-RS measurements received on the multiple subbands, and then report the obtained PMIs to the network device. The network equipment obtains one-to-one correspondence with the PMIs according to the plurality of PMI table look-up reported by the terminal equipmentAnd calculating p x p corresponding to each of the precoding matrices p^H. Then, the network device pair obtains a plurality of p^HAnd averaging to obtain a full-band covariance matrix. Or, the terminal device may obtain a corresponding PMI according to the CRS or CSI-RS received over the full bandwidth, and then report the obtained PMI to the network device. The network equipment obtains a corresponding precoding matrix p according to the PMI table lookup reported by the terminal equipment, and calculates p^H. At this time, the network device may obtain p^HAs a full band covariance matrix. After the full-band covariance matrix is obtained, the network device performs time averaging or filtering on the full-band covariance matrix at different moments to finally obtain a statistical covariance matrix R of the channel.

It should be understood that the channel matrix h may also be referred to as a channel gain matrix. R may also be referred to as a long-term statistical channel covariance matrix of the terminal device, and the name of R is not specifically limited in the embodiments of the present application.

In a second aspect, a communication device is provided that includes means for performing the method of the first aspect or any one of its possible implementations. The communication device comprises units that can be implemented by software and/or hardware.

In a third aspect, a communication device is provided, which includes a processor and a memory, the memory is used for storing a computer program, and the processor is used for calling the computer program from the memory and running the computer program, so that the apparatus executes the method in any one of the first aspect to the possible implementation manner of the first aspect.

Optionally, the number of the processors is one or more, and the number of the memories is one or more.

Alternatively, the memory may be integral to the processor or provided separately from the processor.

Optionally, the communication device further comprises a transmitter (or a transmitter) and a receiver (or a receiver).

In a fourth aspect, the present application provides a computer-readable storage medium. The computer readable storage medium has stored therein program code for execution by the communication device. The program code comprises instructions for performing the method of the first aspect as such or any one of the possible implementations of the first aspect as such.

In a fifth aspect, the present application provides a computer program product containing instructions. The computer program product, when run on a communication device, causes the communication device to perform the instructions of the first aspect as such or any one of the possible implementations of the first aspect as such.

In a sixth aspect, the present application provides a system chip, where the system chip includes an input/output interface and at least one processor, and the at least one processor is configured to call instructions in a memory to perform the operations of the first aspect or the method in any one of the possible implementations of the first aspect.

Optionally, the system-on-chip may further include at least one memory for storing instructions for execution by the processor and a bus.

Drawings

Fig. 1 is a schematic diagram of a communication system suitable for a beamforming transmission method according to an embodiment of the present application.

Fig. 2 is a schematic flow chart of a beamforming transmission method provided in the present application.

Fig. 3 is a schematic flow chart of a beamforming transmission method according to an embodiment of the present application.

Fig. 4 is a schematic flow chart of a beamforming transmission method according to another embodiment of the present application.

Fig. 5 is a schematic block diagram of a communication device provided herein.

Fig. 6 is a schematic structural diagram of a network device provided in the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: a global system for mobile communications (GSM) system, a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (WCDMA) system, a General Packet Radio Service (GPRS), a long term evolution (long term evolution, LTE) system, a LTE Frequency Division Duplex (FDD) system, a LTE Time Division Duplex (TDD), a universal mobile telecommunications system (universal mobile telecommunications system, UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication system, a fifth generation (5G) system or a new radio system (UMTS), a future wireless communication system, and the like.

A terminal device in this embodiment may refer to a User Equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user equipment. The terminal device may also be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication function, 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), and the like, which is not limited in this embodiment.

The network device in this embodiment may be a device for communicating with a terminal device, where the network device may be a Base Transceiver Station (BTS) in a global system for mobile communications (GSM) system or a Code Division Multiple Access (CDMA) system, may also be a base station (NodeB) in a Wideband Code Division Multiple Access (WCDMA) system, may also be an evolved NodeB (eNB) or eNodeB) in an LTE system, may also be a wireless controller in a Cloud Radio Access Network (CRAN) scenario, or may be a relay station, an access point, a vehicle-mounted device, a wearable device, a network device in a future 5G network, or a network device in a future evolved PLMN network, and the like, and the present embodiment is not limited.

In the embodiment of the application, the terminal device or the network device includes a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer includes hardware such as a Central Processing Unit (CPU), a Memory Management Unit (MMU), and a memory (also referred to as a main memory). The operating system may be any one or more computer operating systems that implement business processing through processes (processes), such as a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a windows operating system. The application layer comprises applications such as a browser, an address list, word processing software, instant messaging software and the like. Furthermore, the embodiment of the present application does not particularly limit the specific structure of the execution subject of the method provided by the embodiment of the present application, as long as the program recorded with the code of the method provided by the embodiment of the present application can be executed to perform communication according to the method provided by the embodiment of the present application, for example, the execution subject of the method provided by the embodiment of the present application may be a network device, or a functional module capable of calling a program and executing the program in the network device.

In addition, various aspects or features of the present application may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, etc.), optical disks (e.g., Compact Disk (CD), Digital Versatile Disk (DVD), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROM), card, stick, or key drive, etc.). In addition, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" can include, without being limited to, wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data.

For the convenience of understanding the embodiments of the present application, a communication system applicable to the embodiments of the present application will be first described in detail by taking the communication system shown in fig. 1 as an example. Fig. 1 shows a schematic diagram of a communication system suitable for the beamforming transmission method according to the embodiment of the present application. As shown in fig. 1, the communication system 100 may include at least one network device (e.g., network device 102) and at least one (e.g., terminal device 104), the network device 102 may communicate with the terminal device 104. Optionally, the communication system 100 may further include more network devices and/or more terminal devices, which is not limited in this application.

Hereinafter, the beamforming transmission method of the present application will be described in detail. It should be understood that the wireless communication system shown in fig. 1 should not limit the applicable scenarios of the beamforming transmission method provided in the present application.

Fig. 2 is a schematic flow chart of a beamforming transmission method provided in an embodiment of the present application, which is shown from the perspective of device interaction. As shown, the method shown in fig. 2 may include S210 and S220. The method is described in detail below with reference to fig. 2.

S210, the network equipment receives the noise power sigma according to the terminal equipment²The transmission power P of the target channel_tAnd the wave beam weight W of the downlink demodulation reference signal_rDetermining the BF weight W of the target channel_t。

The downlink demodulation reference signal is used for the terminal equipment to demodulate the target channel. For example, the downlink demodulation reference signal may be a CRS, but the downlink demodulation reference signal is not limited in this embodiment.

It can be understood that the beam weight W of the downlink demodulation reference signal_rMay be determined autonomously by the network device. And, the network device may determine the beam weight value W of the downlink demodulation reference signal based on the determined beam weight value W_rAnd sending the downlink demodulation reference signal to the terminal equipment.After receiving the downlink demodulation reference signal sent by the network device, the terminal device may measure the channel quality according to the downlink demodulation reference signal to obtain the CQI. Further, the terminal device may report the obtained CQI to the network device.

S220, the network equipment is according to the BF weight W of the target channel_tAnd sending the target channel to the terminal equipment. Accordingly, the terminal device receives the target channel.

Specifically, the target channel is a channel to be transmitted, and before transmitting the target channel, the network device may first transmit the target channel according to the received noise power σ of the terminal device²The transmission power P of the target channel to be used_tAnd the beam weight W of the downlink reference signal_rDetermining the BF weight W of the target channel_t. Then, the network device uses the BF weight W of the target channel_tAnd after BF, the target channel is sent.

After receiving the target channel, the terminal device may demodulate the target channel based on the downlink demodulation reference signal. For how the terminal device demodulates the target channel, reference may be made to the prior art, which is not described herein again.

Alternatively, the target channel may be a CRS demodulation based channel, such as PDCCH or PDSCH.

Those skilled in the art will understand that the network device sending the target channel to the terminal device can also be understood as: the network device sends a signal to the terminal device, the network device sends a signal carried on a target channel to the terminal device, or the network device sends a signal carried on the target channel to the terminal device.

Optionally, in S210, the network device may further determine the BF weight W of the target channel with reference to the statistical covariance matrix R of the channel_t。

For example, the network device may determine the BF weight W of the target channel according to the following formula (1)_t：

In formula (1), R represents a statistical covariance matrix of a channel, which is an M × M matrix, M represents the number of antennas of a network device, M is an integer greater than or equal to 1, and each element in R is a complex number. (.)^-1Representing the inverse of the matrix, I_MRepresenting an M × M identity matrix. W_rIs an M multiplied by N matrix, N represents the port number of the downlink demodulation reference signal, N is an integer greater than or equal to 1, W_rEach element in (1) is a complex number.

From the above equation, at high SNR, σ²/P_t→ 0, the above formula becomes W_t＝R^-1*RW_r＝W_rI.e. the BF weight is degenerated to the beam weight W of the downlink demodulation reference signal_rAt this time, although there is no beam gain, there is no phase mismatch, and the robustness is high; at low SNR, i.e. σ²/P_t→ infinity, the above equation becomes W_t＝RW_rThat is, the BF weight is the beam weight W of the downlink demodulation reference signal_rA large beam gain can be obtained in spite of the phase mismatch when projected on the statistical covariance matrix R of the channel. In summary, according to the BF transmission method of the embodiment of the present application, a better performance tradeoff between beam gain and channel mismatch can be achieved.

In the present application, the statistical covariance matrix R of the channel may be determined according to a channel matrix or a precoding matrix. The channel matrix may be determined based on an uplink SRS transmitted by the terminal device, and the precoding matrix may be determined based on a PMI transmitted by the terminal device. The embodiment of the present application does not limit how to determine the statistical covariance matrix R of the channel, for example, the network device may determine the statistical covariance matrix R of the channel by using a method provided in the prior art based on the channel matrix or the precoding matrix.

For example, in another implementation manner, the terminal device may obtain PMIs corresponding to multiple subbands in a one-to-one manner according to CRS or CSI-RS measurements received on the multiple subbands, and then report the obtained PMIs to the network device. The network equipment obtains a plurality of precoding matrixes p corresponding to the PMIs one by one according to a plurality of PMI table look-up reported by the terminal equipment, and calculates p corresponding to the precoding matrixes p respectively^H. Then, the network device pair obtains a plurality of p^HAnd averaging to obtain a full-band covariance matrix. Or, the terminal device may obtain a corresponding PMI according to the CRS or CSI-RS received over the full bandwidth, and then report the obtained PMI to the network device. The network equipment obtains a corresponding precoding matrix p according to the PMI table lookup reported by the terminal equipment, and calculates p^H. At this time, the network device may obtain p^HAs a full band covariance matrix. After the full-band covariance matrix is obtained, the network device performs time averaging or filtering on the full-band covariance matrix at different moments to finally obtain a statistical covariance matrix R of the channel.

Optionally, as an embodiment of the present application, the received noise power σ of the terminal device²According to the statistical covariance matrix R of the channel, the channel quality information CQI reported by the terminal equipment and the beam weight W of the downlink measurement reference signal_mAnd the transmission power P of the downlink measurement reference signal_mAnd (4) determining.

For example, the received noise power σ of the terminal device²Can be determined according to the following equation (2):

wherein tr (·) represents the trace of the calculation matrix, γ represents the linear value corresponding to the CQI, (·)^HRepresenting the conjugate transpose of the matrix.

It should be understood that if the downlink demodulation reference signal and the downlink measurement reference signal in the present application are the same, then W_m＝W_r。

It should also be understood that the above equation (1) is merely an exemplary illustration, and the present application is not limited to determining the reception noise power σ of the terminal device²E.g. received noise power σ of the terminal equipment²It can also be obtained by other methods of determining the received noise power of the terminal device in the prior art.

In order to make those skilled in the art better understand the present application, the target channel is taken as PDCCH as an example, and the present application is described in detail with reference to the specific embodiments shown in fig. 3 and fig. 4.

Fig. 3 shows a specific embodiment of the beamforming transmission method of the present application. It should be understood that fig. 3 shows steps or operations of the beamforming transmission method, but these steps or operations are only examples, and other operations or variations of the operations in fig. 3 may also be performed by the embodiments of the present application. Moreover, the various steps in FIG. 3 may be performed in a different order presented in FIG. 3, and it is possible that not all of the operations in FIG. 3 may be performed.

S301, the terminal device sends the uplink SRS to the network device. Accordingly, the network device receives the uplink SRS transmitted by the terminal device.

And S302, the network equipment estimates the uplink channel state according to the uplink SRS to obtain a channel matrix h.

The terminal device may send the uplink SRS on the plurality of subbands, and the network device may estimate the channel matrix h corresponding to each subband according to the uplink SRS on the plurality of subbands.

And S303, the network equipment determines a statistical covariance matrix R of the channel according to the channel matrix h.

Specifically, the network device may calculate corresponding h × h according to channel matrices h corresponding to the multiple subbands respectively^HThen, for the obtained h x h^HAnd finally, averaging to obtain a full-band covariance matrix. After the full-band covariance matrix is obtained, the network device performs time averaging or filtering on the full-band covariance matrix at different moments, and then performs transposition operation on the averaged or filtered matrix to finally obtain a statistical covariance matrix R of the channel.

S304, the network equipment sends CRS (or CSI-RS) to the terminal equipment. Accordingly, the terminal device receives the CRS (or CSI-RS) transmitted by the network device.

S305, the terminal equipment measures the channel quality based on the received CRS (or CSI-RS) to obtain CQI.

S306, the terminal device sends the obtained CQI to the network device. Accordingly, the network device receives the CQI transmitted by the terminal device.

It should be understood that the execution order of S301 and S304 is not limited in the embodiments of the present application. Accordingly, the present application also does not limit the execution order of S303 and S306.

S307, the network equipment determines the receiving noise power sigma of the terminal equipment²。

Specifically, the network device may determine the beam weight W according to CRS (or CSI-RS)_mCRS (or CSI-RS) transmission power P_mThe CQI obtained in S306 and the statistical covariance matrix R of the channel obtained in S303 are determinedReception noise power σ of terminal device². For example, the network device may calculate the received noise power σ of the terminal device according to the foregoing formula (2)²。

S308, the network equipment determines the BF weight W of the PDCCH_t。

Specifically, the network device may be based on the received noise power σ of the terminal device obtained in the statistical covariance matrix R, S307 of the obtained channel in S303²CRS beam weight W_rAnd transmission power P of PDCCH_tCalculating BF weight W of PDCCH according to the above formula (1)_t。

It should be understood that if the network device transmits the CSI-RS to the terminal device in step S304, the network device may or may not perform the operation of transmitting the CRS to the terminal device before step S308. However, when the network device does not perform the operation of transmitting the CRS to the terminal device, it needs to determine the beam weight W of the CRS before or during S308_r。

S309, the network equipment determines the BF weight W of the PDCCH_tAnd sending the PDCCH to the terminal equipment.

Specifically, the network device may determine the BF weight W according to the PDCCH_tAnd after BF, sending the PDCCH to the terminal equipment.

Fig. 4 shows a specific embodiment of the beamforming transmission method of the present application. It should be understood that fig. 4 shows steps or operations of the beamforming transmission method, but these steps or operations are merely examples, and other operations or variations of the operations in fig. 4 may also be performed by the embodiments of the present application. Moreover, the various steps in FIG. 4 may be performed in a different order presented in FIG. 4, and it is possible that not all of the operations in FIG. 4 may be performed.

S401, the network equipment sends CRS (or CSI-RS) to the terminal equipment. Accordingly, the terminal device receives the CRS (or CSI-RS) transmitted by the network device.

The network device may transmit the CRS over the full bandwidth, and may also transmit the CSI-RS over the full bandwidth or over multiple subbands.

S402, the terminal device carries out channel measurement based on the received CRS (or CSI-RS) to obtain PMI and CQI.

The terminal device may obtain the corresponding PMI and CQI based on the CRS or CSI-RS transmitted by the network device over the full bandwidth. Or, the terminal device may obtain PMIs and CQIs corresponding to the multiple subbands one to one based on CSI-RSs respectively transmitted by the network device on the multiple subbands.

S403, the terminal device reports the obtained PMI and CQI to the network device. Correspondingly, the network equipment receives the PMI and the CQI reported by the terminal equipment.

S404, the network equipment determines a precoding matrix p according to the PMI reported by the terminal equipment.

If the terminal device reports the PMI corresponding to the full bandwidth, the network device may determine the precoding matrix p corresponding to the full bandwidth. If the terminal device reports PMIs corresponding to a plurality of sub-bands, the network device may determine precoding matrices p corresponding to the plurality of sub-bands.

S405, the network equipment determines a statistical covariance matrix R of the channel according to the precoding matrix p.

Specifically, if the network device determines that the precoding matrix p corresponding to the full bandwidth is determined in step S404, the network device directly sends p × p^HAs a full band covariance matrix. If the network device determines that the precoding matrices p respectively corresponding to the multiple sub-bands in step S404, the network device respectively corresponds p × p to different sub-bands^HAnd averaging to obtain a full-band covariance matrix. Then, the network device performs time averaging or filtering on the full-band covariance matrix at different times to finally obtain a statistical covariance matrix R of the channel.

S406, the network equipment determines the receiving noise power sigma of the terminal equipment²。

Specifically, the network device may determine the beam weight W according to CRS (or CSI-RS)_mCRS (or CSI-RS) transmission power P_mDetermining the reception noise power σ of the terminal device by the CQI obtained in S403 and the statistical covariance matrix R of the channel obtained in S405². For example, the network device may calculate the received noise power σ of the terminal device according to the foregoing formula (2)²。

S407, the network device determines the BF weight W of the PDCCH_t。

Specifically, the network device may base the received noise power σ of the terminal device obtained in the statistical covariance matrix R, S406 of the obtained channel in S405 on²CRS beam weight W_rAnd transmission power P of PDCCH_tCalculating BF weight W of PDCCH according to the above formula (1)_t。

It should be understood that if the network device transmits the CSI-RS to the terminal device in step S401, the network device may or may not perform the operation of transmitting the CRS to the terminal device before step S407. However, when the network device does not perform the operation of transmitting the CRS to the terminal device, it needs to determine the beam weight W of the CRS at or before performing S407_r。

Fig. 5 shows a schematic structural diagram of a communication device provided in the present application, where the communication device 500 includes: a processing unit 510 and a transceiving unit 520.

A processing unit 510, configured to determine a beamforming weight of a target channel according to a received noise power of a terminal device, a transmission power of the target channel, and a beam weight of a downlink demodulation reference signal, where the downlink demodulation reference signal is used by the terminal device to demodulate the target channel;

a sending unit 520, configured to send the target channel to the terminal device according to the beamforming weight of the target channel.

The communication device 500 may be a communication device or a chip in the communication device. When the communication device is a communication device, the processing unit may be a processor and the transceiving unit may be a transceiver. The communication device may further comprise a storage unit, which may be a memory. The storage unit is used for storing instructions, and the processing unit executes the instructions stored by the storage unit so as to enable the communication equipment to execute the method. When the communication device is a chip in a communication device, the processing unit may be a processor, and the transceiving unit may be an input/output interface, a pin, a circuit, or the like; the processing unit executes instructions stored in a storage unit (e.g., a register, a cache memory, etc.) within the chip or located outside the chip within the communication device (e.g., a read-only memory, a random access memory, etc.) to cause the communication device to perform the operations performed by the network device in the above-described method

It is clear to those skilled in the art that, when the steps performed by the communication apparatus 500 and the corresponding advantages are described in the foregoing description of the network device in the method, the description is omitted here for brevity.

It should be understood that the above division of the units is only a functional division, and other division methods may be possible in actual implementation.

The network device may be a chip, and the processing unit may be implemented by hardware or software, and when implemented by hardware, the processing unit may be a logic circuit, an integrated circuit, or the like; when implemented in software, the processing unit may be a general-purpose processor implemented by reading software code stored in a memory unit, which may be integrated in the processor or located external to the processor, separately.

Fig. 6 is a schematic structural diagram of a network device provided in the present application, where the network device may be a base station, for example. As shown in fig. 6, the base station may be applied in the communication system shown in fig. 1, and performs the functions of the network device in the above method embodiments. The base station 20 may include one or more radio frequency units, such as a Remote Radio Unit (RRU) 201 and one or more baseband units (BBUs) (which may also be referred to as Digital Units (DUs)) 202. The RRU 201 may be referred to as a transceiver unit, transceiver circuit, or transceiver, etc., which may include at least one antenna 2011 and a radio unit 2012. The RRU 201 is mainly used for transceiving radio frequency signals and converting the radio frequency signals and baseband signals, for example, for transmitting the PDCCH and/or PDSCH in the above method embodiment. The BBU 202 is mainly used for performing baseband processing, controlling a base station, and the like. The RRU 201 and the BBU 202 may be physically disposed together or may be physically disposed separately, that is, distributed base stations.

The BBU 202 is a control center of a base station, and may also be referred to as a processing unit, and is mainly used for performing baseband processing functions, such as channel coding, multiplexing, modulation, spreading, and the like. For example, the BBU (processing unit) 202 can be used to control the base station to execute the operation flow related to the network device in the above method embodiment.

In an embodiment, the BBU 202 may be formed by one or more boards, and the boards may jointly support a radio access network (e.g., an LTE network) with a single access indication, or may respectively support radio access networks with different access schemes (e.g., an LTE network, a 5G network, or other networks). The BBU 202 also includes a memory 2021 and a processor 2022, the memory 2021 for storing the necessary instructions and data. The processor 2022 is configured to control the base station to perform necessary actions, for example, to control the base station to perform the operation procedures related to the network device in the above method embodiments. The memory 2021 and the processor 2022 may serve one or more boards. That is, the memory and processor may be provided separately on each board. Multiple boards may share the same memory and processor. In addition, each single board can be provided with necessary circuits.

The present application also provides a communication system comprising one or more of the aforementioned network devices, and one or more of the terminal devices.

It should be noted that the processor in the embodiments of the present application may be an integrated circuit chip having signal processing capability. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The processor may be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic device, or discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

It will be appreciated that the memory in the embodiments of the subject application can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), double data rate SDRAM, enhanced SDRAM, SLDRAM, Synchronous Link DRAM (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

The present application also provides a computer-readable medium having stored thereon a computer program which, when executed by a computer, performs the functions of any of the method embodiments described above.

The present application also provides a computer program product which, when executed by a computer, implements the functionality of any of the above-described method embodiments.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A beamforming transmission method, comprising:

the network equipment determines a beam forming weight of a target channel according to the received noise power of the terminal equipment, the sending power of the target channel and the beam weight of a downlink demodulation reference signal, wherein the downlink demodulation reference signal is used for the terminal equipment to demodulate the target channel

And the network equipment sends the target channel to the terminal equipment according to the beam forming weight of the target channel.

2. The method of claim 1, wherein the network device determines the beamforming weight of the target channel according to the received noise power of the terminal device, the transmission power of the target channel, and the beamforming weight of the downlink demodulation reference signal, and includes:

wherein, W_tRepresenting the target messageThe beamforming weights of the channels, R representing the statistical covariance matrix of the channel, σ²Representing the received noise power, P, of said terminal device_tRepresents the transmission power, W, of the target channel_rA beam weight value representing the downlink demodulation reference signal (·)^-1Representing the inverse of the matrix, I_MThe method includes the steps of representing an M × M identity matrix, wherein M represents the number of antennas of the network device, M is an integer greater than or equal to 1, a statistical covariance matrix of a channel is determined according to a channel matrix or a precoding matrix, the channel matrix is determined based on an uplink sounding reference signal sent by the terminal device, and the precoding matrix is determined based on a precoding matrix indicator PMI sent by the terminal device.

3. The method of claim 1 or 2, wherein the received noise power of the terminal device is determined according to a statistical covariance matrix of a channel, Channel Quality Information (CQI) reported by the terminal device, a beam weight of a downlink measurement reference signal, and a transmission power of the downlink measurement reference signal,

the statistical covariance matrix of the channel is determined according to a channel matrix or a precoding matrix, the channel matrix is determined based on an uplink sounding reference signal sent by the terminal device, the precoding matrix is determined based on a Precoding Matrix Indicator (PMI) sent by the terminal device, and the downlink measurement reference signal is used for the terminal device to perform channel measurement.

4. The method of claim 3, wherein the received noise power of the terminal device is determined according to the following equation:

wherein σ²Representing the received noise power of said terminal device, R representing the statistical covariance matrix of said channel, P_mRepresenting said downlink measurement reference signalTransmission power, W_mRepresents the beam weight of the downlink measurement reference signal, tr (-) represents the trace of the calculation matrix, and gamma represents the linear value corresponding to the CQI, (.)^HRepresenting the conjugate transpose of the matrix.

5. The method of any one of claims 1 to 4, wherein the target channel is a cell-specific reference signal (CRS) -assisted demodulation-based channel.

6. The method of claim 5, wherein the target channel is a physical downlink control channel.

7. A communications apparatus, comprising:

the processing unit is used for determining a beam forming weight of a target channel according to the received noise power of terminal equipment, the transmitting power of the target channel and a beam weight of a downlink demodulation reference signal, wherein the downlink demodulation reference signal is used for the terminal equipment to demodulate the target channel;

and the sending unit is used for sending the target channel to the terminal equipment according to the beam forming weight of the target channel.

8. The communications device of claim 7, wherein the processing unit is specifically configured to:

determining the beam forming weight of the target channel according to the following formula:

wherein, W_tRepresenting the beamforming weight of the target channel, R representing the statistical covariance matrix of the channel, σ²Representing the received noise power, P, of said terminal device_tRepresents the transmission power, W, of the target channel_rA beam weight value representing the downlink demodulation reference signal (·)^-1Representing the inverse of the matrix，I_MThe method comprises the steps of representing an M multiplied by M identity matrix, wherein M represents the number of antennas of the communication device, a statistical covariance matrix of the channel is determined according to a channel matrix or a precoding matrix, the channel matrix is determined based on an uplink sounding reference signal sent by the terminal equipment, and the precoding matrix is determined based on a Precoding Matrix Indicator (PMI) sent by the terminal equipment.

9. The communication apparatus according to claim 7 or 8, wherein the received noise power of the terminal device is determined according to a statistical covariance matrix of a channel, a channel quality information CQI reported by the terminal device, a beam weight of a downlink measurement reference signal, and a transmission power of the downlink measurement reference signal,

10. The communications apparatus of claim 9, wherein the received noise power of the terminal device is determined according to the following equation:

11. The communication apparatus according to any of claims 7 to 10, wherein the target channel is a channel based on cell-specific reference signal, CRS, assisted demodulation.

12. The communications apparatus of claim 11, wherein the target channel is a physical downlink control channel.

13. A communication device, comprising:

a memory for storing a computer program;

a processor for executing a computer program stored in the memory to cause the apparatus to perform the method of any of claims 1 to 6.

14. A processor configured to perform the method of any one of claims 1 to 6.

15. A chip system, comprising:

a memory for storing a computer program;

a processor for calling and running the computer program from the memory so that a device on which the system-on-chip is installed performs the method of any one of claims 1 to 6.

16. A computer-readable storage medium comprising a computer program which, when run on a computer, causes the computer to perform the method of any one of claims 1 to 6.

17. A computer program product comprising a computer program which, when executed, performs the method of any of claims 1 to 6.