CN113906696B

CN113906696B - Data transmission method and device

Info

Publication number: CN113906696B
Application number: CN201980097036.7A
Authority: CN
Inventors: 阮卫
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-06-11
Filing date: 2019-06-11
Publication date: 2022-11-25
Anticipated expiration: 2039-06-11
Also published as: WO2020248108A1; CN113906696A

Abstract

The embodiment of the application provides a data transmission method and a device, wherein detection signals are received through M receiving antennas; the detection signal is sent by a sending end through N sending antennas; m and N are both greater than or equal to 2; calculating a channel matrix according to the detection signal; performing Singular Value Decomposition (SVD) on the channel matrix to obtain a first matrix; wherein the first matrix comprises: the front NSS column of the first unitary matrix, wherein the NSS is the smaller value of M and N; the first unitary matrix is: performing SVD on the channel matrix to obtain an N-N matrix; performing unitary transformation on the first matrix to obtain a second matrix; the second matrix is used for the sending end to carry out weight assignment on the N sending antennas; sending the second matrix to the sending end; the transmitting end may assign values to the multiple transmitting antennas by using the second matrix to improve the quality of the received signal at the receiving end.

Description

Data transmission method and device

Technical Field

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

Background

With the development of network technology, a transmit beamforming (TxBF) technology is introduced into a Wireless Local Area Network (WLAN), in the application of TxBF, a plurality of antennas are weighted at a transmitting end of a multiple-input multiple-output (MIMO) system, and a directional beam is formed in a space by changing a weight of each antenna, so as to improve the quality of a received signal at a receiving end.

In the prior art, when a plurality of antennas of a transmitting end are weighted, the transmitting end transmits a channel estimation frame (sounding) to a receiving end, after the receiving end receives the channel estimation frame, the receiving end transforms the channel estimation frame to a frequency domain through Fast Fourier Transform (FFT), extracts a signal on each subcarrier, performs channel estimation on each subcarrier to obtain a channel matrix H, performs Singular Value Decomposition (SVD) on H, that is, H = USVH, where U and V are unitary matrices, S is a diagonal matrix, the receiving end transmits V as a weight feedback matrix to the transmitting end, and the transmitting end uses the V matrix to perform weighted transmission on a transmission signal.

However, the prior art has a single way of weighting the antennas at the transmitting end, so that the weighting of the antennas at the transmitting end is not flexible.

Disclosure of Invention

The embodiment of the application provides a data transmission method and device, and provides a substitute scheme for determining a sending end assignment matrix for improving the quality of a received signal of a receiving end.

In a first aspect, an embodiment of the present application provides a data transmission method, including:

receiving detection signals through M receiving antennas; the detection signal is sent by a sending end through N sending antennas; m and N are both greater than or equal to 2; calculating a channel matrix according to the detection signal; acquiring a first matrix according to the channel matrix; wherein the first matrix comprises: the front NSS column of the first unitary matrix, wherein the NSS is the smaller value of M and N; the first unitary matrix is: carrying out Singular Value Decomposition (SVD) on the channel matrix to obtain an N x N matrix; performing unitary transformation on the first matrix to obtain a second matrix; and sending the second matrix to the sending end to indicate the sending end to use the second matrix to carry out weight assignment on the N sending antennas.

In the method, an alternative scheme for determining the assignment matrix of the sending end is provided, specifically, detection signals are received through M receiving antennas; the detection signal is sent by a sending end through N sending antennas; m and N are both greater than or equal to 2; then, calculating a channel matrix according to the detection signal; performing Singular Value Decomposition (SVD) on the channel matrix to obtain a first matrix; wherein the first matrix comprises: the front NSS column of the first unitary matrix, wherein NSS is the smaller value of M and N; the first unitary matrix is: performing SVD on the channel matrix to obtain an N-N matrix; performing unitary transformation on the first matrix to obtain a second matrix; the second matrix is used for the sending end to carry out weight assignment on the N sending antennas; sending the second matrix to the sending end; the transmitting end may assign values to the multiple transmitting antennas by using the second matrix to improve the quality of the received signal at the receiving end.

Optionally, the unitary transformation is performed on the first matrix to obtain a second matrix, where the unitary transformation includes:

multiplying the first matrix by a preset matrix to obtain a third matrix; and replacing the first NSS row of the first unitary matrix with the third matrix to obtain a second matrix.

Optionally, the preset matrix includes: a normalized discrete fourier transform, DFT, matrix.

Optionally, in the DFT matrix:

wherein, DFT (k, l) represents the elements of the k row and l column of the DFT matrix; k is an integer of 0 to NSS-1; l is an integer of 0 to NSS-1; pi is the circumferential ratio.

Optionally, the preset matrix includes: givens transforms Givens matrices.

Optionally, the Givens matrix includes a plurality of transformation matrices Gi, wherein,

wherein i is an integer of 0 to Np-1; n = i; m = Nss-2 × (n + 1); in the case that Nss is an even number greater than 2, np = Nss/2; in the case that Nss is an odd number greater than 2, np = (Nss-1)/2; i is _n，n Unit matrix representing n rows and n columns, I _m，m A unit array representing m rows and m columns; 0 _m，1 A 0 matrix representing m rows and 1 columns;

S _i to S _Nss-1 Is the singular value of the channel matrix; wherein S is _i+1 Greater than or equal to S _i 。

Optionally, performing unitary transformation on the first matrix to obtain a second matrix includes: performing unitary transformation on the first matrix to obtain a second matrix under the condition that the channel state meets at least one of a first preset condition, a second preset condition and a third preset condition; wherein, the first preset condition comprises: the received signal strength indication RSSI of the M receiving antennas is larger than a first threshold and smaller than a second threshold; the second preset condition includes: a maximum condition number of the channel matrix is greater than a third threshold and less than a fourth threshold, wherein the condition number is used for identifying correlation between spatial streams of the N transmit antennas and the M receive antennas; the third preset condition includes: the maximum difference value of the signal-to-noise ratios is larger than a fifth threshold; the maximum signal-to-noise ratio difference value is the maximum signal-to-noise ratio difference value between the spatial streams formed after the sending end performs weight assignment through the first unitary matrix.

In the method, whether unitary transformation is carried out on the first matrix is determined according to the specific situation of the channel state, so that the signal quality can be further improved.

Optionally, the method further includes:

determining the output signal-to-noise ratio of each spatial stream formed by the sending end after carrying out weight assignment by using the second matrix according to the fourth matrix; the fourth matrix includes: the front Nss row and the front Nss column of the diagonal matrix are: carrying out SVD on the channel matrix to obtain a singular value matrix; and sending the output signal-to-noise ratio of each spatial stream to the sending end.

Optionally, determining, according to the fourth matrix, an output signal-to-noise ratio of each spatial stream formed by the sending end performing weight assignment by using the second matrix includes: determining the output signal-to-noise ratio of each spatial stream formed after the weight assignment is performed on the second matrix by the sending end according to the fourth matrix under the condition that the channel state meets at least one of a first preset condition, a second preset condition and a third preset condition; wherein, the first preset condition comprises: the received signal strength indication RSSI of the M receiving antennas is larger than a first threshold and smaller than a second threshold; the second preset condition includes: a maximum condition number of the channel matrix is greater than a third threshold and less than a fourth threshold, wherein the condition number is used for identifying correlation between spatial streams of the N transmit antennas and the M receive antennas; the third preset condition includes: the maximum difference of the signal-to-noise ratios is larger than a fifth threshold; the maximum signal-to-noise ratio difference value is the maximum signal-to-noise ratio difference value between the spatial streams formed after the sending end performs weight assignment through the first unitary matrix.

In the method, whether the output signal-to-noise ratio of each spatial stream formed after the sending end uses the second matrix for weight assignment is determined according to the specific condition of the channel state is determined, and the occupation of the output signal-to-noise ratio of each spatial stream formed after the sending end uses the second matrix for weight assignment and the calculation resource are prevented from being determined blindly.

Optionally, determining, according to the fourth matrix, an output signal-to-noise ratio of each spatial stream formed by the sending end performing weight assignment by using the second matrix includes:

and determining the output signal-to-noise ratio of each spatial stream as:

wherein S is the fourth matrix, S ^-1 Representing the inversion of S; DFT _Nss×Nss S ^-1 Is the inverse of S multiplied right by the DFT matrix; (DFT) _Nss×Nss S ^-1 ) _{1 X Nss} Is to take DFT _Nss×Nss S ^-1 Line 1 of (a); | | (DFT) _Nss×Nss S ^-1 ) _{1 X Nss} || ² Is for DFT _Nss×Nss S ^-1 Line 1 of (1) calculates the norm, σ ² Is the average of the noise variance of the M receive antennas.

In the method, the output signal-to-noise ratios of any two spatial streams of the MIMO system are the same, so that the MIMO system can process and balance the signals of the spatial streams, thereby solving the corner effect to a greater extent and reducing the packet error rate between the sending end and the receiving end.

Optionally, determining, according to a fourth matrix, an output signal-to-noise ratio of each spatial stream formed by the sending end performing weight assignment by using the second matrix, includes:

and determining the output signal-to-noise ratio of each spatial stream formed after the sending end uses the second matrix to carry out weight assignment according to the fourth matrix as follows:

wherein postSNR _i To postSNR _Nss-1 An output SNR for an ith spatial stream to an Nss-1 th spatial stream in the MIMO system; si to SNss-1 are singular values in the fourth matrix; wherein S is _i+1 Is greater than or equal to S _i 。

In the method, the second matrix is obtained by performing givens transformation on the first matrix, so that when a transmitting end of the MIMO system performs weight assignment through the second matrix, the maximum difference between the output signal-to-noise ratios of any two spatial streams is lower than the maximum difference between the output signal-to-noise ratios of any two spatial streams in the prior art, and therefore, signal processing of each spatial stream by the MIMO system is more balanced compared with the prior art, the corner effect can be solved to a greater extent, and the packet error rate between the transmitting end and the receiving end is reduced.

Optionally, the condition number CN of the channel matrix is calculated by the following formula:

wherein S is _a And S _b Are singular values of the channel matrix, a and b are integers not less than 0, and a is less than b.

Optionally, obtaining the first matrix according to the channel matrix includes: SVD is carried out on the channel matrix to obtain the first unitary matrix; selecting the first NSS row of the first unitary matrix to obtain the first matrix.

In a second aspect, an embodiment of the present application provides a data transmission apparatus, including:

the detection signal receiving module is used for receiving detection signals through the M receiving antennas; the detection signal is sent by a sending end through N sending antennas; m and N are both greater than or equal to 2.

And the channel matrix calculation module is used for calculating a channel matrix according to the detection signal.

A matrix obtaining module, configured to obtain a first matrix according to the channel matrix; wherein the first matrix comprises: the front NSS column of the first unitary matrix, wherein NSS is the smaller value of M and N; the first unitary matrix is: and carrying out Singular Value Decomposition (SVD) on the channel matrix to obtain an N-N matrix.

The unitary transformation module is used for carrying out unitary transformation on the first matrix to obtain a second matrix;

and the matrix sending module is used for sending the second matrix to the sending end so as to indicate the sending end to use the second matrix to carry out weight assignment on the N sending antennas.

In the device, firstly, detection signals are received through M receiving antennas; the detection signal is sent by a sending end through N sending antennas; m and N are both greater than or equal to 2; then, calculating a channel matrix according to the detection signal; performing Singular Value Decomposition (SVD) on the channel matrix to obtain a first matrix; wherein the first matrix comprises: the front NSS column of the first unitary matrix, wherein NSS is the smaller value of M and N; the first unitary matrix is: performing SVD on the channel matrix to obtain an N-N matrix; performing unitary transformation on the first matrix to obtain a second matrix; the second matrix is used for the sending end to carry out weight assignment on the N sending antennas; sending the second matrix to the sending end; the transmitting end may assign values to the multiple transmitting antennas by using the second matrix, so as to improve the quality of the received signal at the receiving end.

Optionally, the unitary transform module includes:

the first unitary transformation submodule is used for right-multiplying the first matrix by a preset matrix to obtain a third matrix; and replacing the front NSS row of the first unitary matrix with the third matrix to obtain a second matrix.

Optionally, in the DFT matrix:

Optionally, the preset matrix includes: givens transforms Givens matrices.

wherein i is an integer of 0 to Np-1; n = i; m = Nss-2 × (n + 1); in the case that Nss is an even number greater than 2, np = Nss/2; in the case that Nss is an odd number greater than 2, np = (Nss-1)/2; i is _n，n Unit matrix representing n rows and n columns, I _m，m A unit array representing m rows and m columns; 0 _m，1 A 0 matrix representing m rows and 1 column;

S _i to S _Nss-1 Is the singular value of the channel matrix; wherein S is _i+1 Is greater than or equal to S _i 。

Optionally, the unitary transform module includes: the second unitary transformation submodule is used for performing unitary transformation on the first matrix under the condition that the channel state meets at least one of a first preset condition, a second preset condition and a third preset condition to obtain a second matrix; wherein, the first preset condition comprises: the received signal strength indication RSSI of the M receiving antennas is larger than a first threshold and smaller than a second threshold; the second preset condition includes: a maximum condition number of the channel matrix is greater than a third threshold and less than a fourth threshold, wherein the condition number is used for identifying correlation between spatial streams of the N transmit antennas and the M receive antennas; the third preset condition includes: the maximum difference value of the signal-to-noise ratios is larger than a fifth threshold; the maximum difference value of the signal-to-noise ratios is the maximum difference value of the signal-to-noise ratios between the spatial streams formed by the sending end after the sending end carries out weight assignment through the first unitary matrix.

In the device, whether unitary transformation is carried out on the first matrix is determined according to the specific situation of the channel state, so that the signal quality can be further improved.

Optionally, the apparatus further comprises:

the output signal-to-noise ratio determining module is used for determining the output signal-to-noise ratio of each spatial stream formed by the sending end after the sending end uses the second matrix to carry out weight assignment according to the fourth matrix; the fourth matrix includes: the front Nss row and front Nss column of the diagonal matrix, which is: and carrying out SVD on the channel matrix to obtain a singular value matrix.

And the output signal-to-noise ratio sending module is used for sending the output signal-to-noise ratio of each spatial stream to the sending end.

Optionally, the output snr determining module includes: a first output signal-to-noise ratio determining submodule, configured to determine, according to the fourth matrix, an output signal-to-noise ratio of each spatial stream formed after the sending end performs weight assignment using the second matrix, when the channel state satisfies at least one of a first preset condition, a second preset condition, and a third preset condition; wherein, the first preset condition comprises: the received signal strength indication RSSI of the M receiving antennas is larger than a first threshold and smaller than a second threshold; the second preset condition includes: a maximum condition number of the channel matrix is greater than a third threshold and less than a fourth threshold, wherein the condition number is used for identifying correlation between spatial streams of the N transmit antennas and the M receive antennas; the third preset condition includes: the maximum difference of the signal-to-noise ratios is larger than a fifth threshold; the maximum difference value of the signal-to-noise ratios is the maximum difference value of the signal-to-noise ratios between the spatial streams formed by the sending end after the sending end carries out weight assignment through the first unitary matrix.

In the device, whether the output signal-to-noise ratio of each spatial stream formed after the sending end uses the second matrix for weight assignment is determined according to the specific condition of the channel state is determined, and the occupation of the output signal-to-noise ratio of each spatial stream formed after the sending end uses the second matrix for weight assignment and calculation resources is avoided.

and determining the output signal-to-noise ratio of each spatial stream as:

In the device, the output signal-to-noise ratios of any two spatial streams of the MIMO system are the same, so that the MIMO system can perform balanced signal processing on each spatial stream, thereby solving the corner effect to a greater extent and reducing the packet error rate between a sending end and a receiving end.

Optionally, the output snr determining module includes: a second output signal-to-noise ratio determining submodule, configured to determine, according to the fourth matrix, that the output signal-to-noise ratio of each spatial stream formed after the sending end performs weight assignment using the second matrix is:

wherein postSNR _i To postSNR _Nss-1 Output SNR for the ith through NSS-1 spatial streams in the MIMO system; si to SNss-1 are singular values in the fourth matrix; wherein S is _i+1 Greater than or equal to S _i 。

In the device, a second matrix is obtained by performing givens transformation on a first matrix, so that when a transmitting end of the MIMO system of the embodiment of the application performs weight assignment through the second matrix, the maximum difference between the output signal-to-noise ratios of any two spatial streams is lower than the maximum difference between the output signal-to-noise ratios of any two spatial streams in the prior art, therefore, the signal processing of the MIMO system to each spatial stream is more balanced compared with the prior art, the corner effect can be solved to a greater extent, and the packet error rate between the transmitting end and the receiving end is reduced.

Optionally, the matrix obtaining module includes: a matrix obtaining submodule, configured to perform SVD on the channel matrix to obtain the first unitary matrix; selecting the first NSS row of the first unitary matrix to obtain the first matrix.

In a third aspect, an embodiment of the present application provides a communication apparatus, including: a processor, and a transceiver coupled to the processor.

The transceiver is used for receiving detection signals through M receiving antennas; the detection signal is sent by a sending end through N sending antennas; m and N are both greater than or equal to 2.

The processor is configured to calculate a channel matrix according to the detection signal.

The processor is configured to obtain a first matrix according to the channel matrix; wherein the first matrix comprises: the front NSS column of the first unitary matrix, wherein the NSS is the smaller value of M and N; the first unitary matrix is: and carrying out Singular Value Decomposition (SVD) on the channel matrix to obtain an N-N matrix.

The processor is used for carrying out unitary transformation on the first matrix to obtain a second matrix;

the transceiver is configured to send the second matrix to the sending end to instruct the sending end to perform weight assignment on the N sending antennas by using the second matrix.

In the device, firstly, detection signals are received through M receiving antennas; the detection signal is sent by a sending end through N sending antennas; m and N are both greater than or equal to 2; then, calculating a channel matrix according to the detection signal; performing Singular Value Decomposition (SVD) on the channel matrix to obtain a first matrix; wherein the first matrix comprises: the front NSS column of the first unitary matrix, wherein the NSS is the smaller value of M and N; the first unitary matrix is: performing SVD on the channel matrix to obtain an N-N matrix; performing unitary transformation on the first matrix to obtain a second matrix; the second matrix is used for the sending end to carry out weight assignment on the N sending antennas; sending the second matrix to the sending end; the transmitting end may assign values to the multiple transmitting antennas by using the second matrix to improve the quality of the received signal at the receiving end.

Optionally, the processor is configured to right-multiply the first matrix by a preset matrix to obtain a third matrix; and replacing the first NSS row of the first unitary matrix with the third matrix to obtain a second matrix.

Optionally, in the DFT matrix:

wherein, DFT (k, l) represents the elements of the k row and l column of the DFT matrix; k is an integer of 0 to NSS-1; l is an integer of 0 to NSS-1; pi is the circumference ratio.

Optionally, the preset matrix includes: givens transforms Givens matrices.

Optionally, the processor is configured to perform unitary transformation on the first matrix to obtain the second matrix when the channel state satisfies at least one of a first preset condition, a second preset condition, and a third preset condition; wherein, the first preset condition comprises: the received signal strength indication RSSI of the M receiving antennas is larger than a first threshold and smaller than a second threshold; the second preset condition includes: a maximum condition number of the channel matrix is greater than a third threshold and less than a fourth threshold, wherein the condition number is used for identifying correlation between spatial streams of the N transmit antennas and the M receive antennas; the third preset condition includes: the maximum difference value of the signal-to-noise ratios is larger than a fifth threshold; the maximum difference value of the signal-to-noise ratios is the maximum difference value of the signal-to-noise ratios between the spatial streams formed by the sending end after the sending end carries out weight assignment through the first unitary matrix.

Optionally, the processor is configured to determine, according to the fourth matrix, an output signal-to-noise ratio of each spatial stream that is formed after the sending end performs weight assignment using the second matrix; the fourth matrix includes: the front Nss row and front Nss column of the diagonal matrix, which is: and carrying out SVD on the channel matrix to obtain a singular value matrix.

The transceiver is configured to send the output snr of each spatial stream to the sending end.

Optionally, the processor is configured to determine, according to the fourth matrix, an output signal-to-noise ratio of each spatial stream formed by the sending end after performing weight assignment using the second matrix when the channel state meets at least one of a first preset condition, a second preset condition, and a third preset condition; wherein, the first preset condition comprises: the received signal strength indication RSSI of the M receiving antennas is larger than a first threshold and smaller than a second threshold; the second preset condition includes: a maximum condition number of the channel matrix is greater than a third threshold and less than a fourth threshold, wherein the condition number is used for identifying correlation between spatial streams of the N transmit antennas and the M receive antennas; the third preset condition includes: the maximum difference of the signal-to-noise ratios is larger than a fifth threshold; the maximum difference value of the signal-to-noise ratios is the maximum difference value of the signal-to-noise ratios between the spatial streams formed by the sending end after the sending end carries out weight assignment through the first unitary matrix.

Optionally, the processor is configured to:

and determining the output signal-to-noise ratio of each spatial stream according to the fourth matrix as follows:

wherein S is the fourth matrix, S ^-1 Representing the inversion of S; DFT _Nss×Nss S ^-1 Is the inverse of S multiplied right by the DFT matrix; (DFT) _Nss×Nss S ^-1 ) _{1 X Nss} Is to take DFT _Nss×Nss S ^-1 Line 1 of (a); | (DFT) _Nss×Nss S ^-1 ) _{1 X Nss} || ² Is for DFT _Nss×Nss S ^-1 Line 1 of (1) calculates the norm, σ ² Is the average of the noise variance of the M receive antennas.

Optionally, the processor is configured to determine, according to the fourth matrix, that an output signal-to-noise ratio of each spatial stream formed by the sending end after performing weight assignment by using the second matrix is:

In the device, the second matrix is obtained by performing givens transformation on the first matrix, so that when the sending end of the MIMO system of the embodiment of the application performs weight assignment through the second matrix, the maximum difference between the output signal-to-noise ratios of any two spatial streams is lower than the maximum difference between the output signal-to-noise ratios of any two spatial streams in the prior art, therefore, the signal processing of the MIMO system to each spatial stream is more balanced compared with the prior art, the corner effect can be solved to a greater extent, and the packet error rate between the sending end and the receiving end is reduced.

Optionally, the processor is configured to perform SVD on the channel matrix to obtain the first unitary matrix; and selecting the front NSS row of the first unitary matrix to obtain the first matrix.

In a fourth aspect, an embodiment of the present application provides an apparatus, including: a processor and a memory; wherein the memory is used for storing program instructions; the processor is configured to call and execute program instructions stored in the memory to implement the method according to any one of the first aspect.

In a fifth aspect, an embodiment of the present application provides a communication system, including a receiving end and a transmitting end, where the receiving end is configured to perform the method according to any one of the first aspect, and the transmitting end is configured to perform weight assignment on the N transmit antennas by using the second matrix.

In a sixth aspect, embodiments of the present application provide a computer-readable storage medium storing instructions that, when executed, cause a computer to perform the method according to any one of the first aspect of the present application.

In a seventh aspect, the present application provides a computer program product, which includes instructions that, when executed, cause a computer to perform the method according to any one of the first aspect of the present application.

To sum up, the data transmission method and apparatus of the embodiment of the present application provide an alternative scheme for determining an assignment matrix at a sending end, and specifically, receive a detection signal through M receiving antennas first; the detection signal is sent by a sending end through N sending antennas; m and N are both greater than or equal to 2; then, calculating a channel matrix according to the detection signal; performing Singular Value Decomposition (SVD) on the channel matrix to obtain a first matrix; wherein the first matrix comprises: the front NSS column of the first unitary matrix, wherein NSS is the smaller value of M and N; the first unitary matrix is: performing SVD on the channel matrix to obtain an N-N matrix; performing unitary transformation on the first matrix to obtain a second matrix; the second matrix is used for the sending end to carry out weight assignment on the N sending antennas; sending the second matrix to the sending end; the transmitting end may assign values to the multiple transmitting antennas by using the second matrix, so as to improve the quality of the received signal at the receiving end.

Drawings

Fig. 1 is a schematic diagram of channels of an antenna array of a MIMO system according to an embodiment of the present application;

fig. 2 is an architecture diagram of a MIMO system applied in an embodiment of the present application;

fig. 3 is a schematic flowchart of a data transmission method according to an embodiment of the present application;

fig. 4 is another schematic flow chart of a data transmission method according to an embodiment of the present application

Fig. 5 is a functional structure diagram of an apparatus according to an embodiment of the present disclosure;

fig. 6 is a schematic structural diagram of an apparatus according to an embodiment of the present application.

Detailed Description

The data transmission method and device provided by the embodiment of the application can be applied to an MIMO system, and the MIMO system can specifically mean that a plurality of transmitting antennas and receiving antennas are respectively used at a transmitting end and a receiving end, so that signals are transmitted and received through the plurality of antennas of the transmitting end and the receiving end.

For example, fig. 1 is a schematic diagram of a channel of an antenna array of a MIMO system, as shown in fig. 1, a transmitting end may have N transmitting antennas, a receiving end may have M receiving antennas, and data transmission may be performed between the N transmitting antennas and the M receiving antennas. The values of M and N may be the same or different, and when M and N are different, M may be greater than N or less than N, which is not limited in the present application.

In a specific implementation, when data transmission is performed between N transmitting antennas and M receiving antennas, an Orthogonal Frequency Division Multiplexing (OFDM) technique may be adopted, where OFDM is one of multi-carrier modulation (MCM), and the main idea of OFDM is: the channel is divided into a plurality of orthogonal sub-channels, a high-speed data signal is converted into parallel low-speed sub-data streams, the parallel low-speed sub-data streams are modulated to each sub-channel for transmission, the orthogonal signals can be separated by adopting a correlation technique at a receiving end, so that the mutual interference between the sub-channels can be reduced, and the signal bandwidth on each sub-channel is smaller than the correlation bandwidth of the channel, so that each sub-channel can be regarded as flat fading, so that the intersymbol interference can be eliminated, and because the bandwidth of each sub-channel is only a small part of the bandwidth of the original channel, the channel equalization becomes relatively easy.

Fig. 2 is an architecture diagram of a MIMO system applied in the embodiment of the present application. The MIMO system may specifically comprise a base station 110 and a terminal device 120. Uplink and/or downlink connections may be established between the base station 110 and the terminal devices 120 for transmitting data from the terminal devices 120 to the base station 110 and vice versa. The data transmitted over the uplink/downlink connection may include data transmitted between terminal devices 120, and the like. It is understood that in practical applications, there may be a plurality of terminal devices 120, and in consideration of the similarity of the communication process between each terminal device 120 and the base station 110, the process of communication between any terminal device 120 and the base station 110 is taken as an example in the embodiments of the present application for description.

The base station related to the embodiment of the present application may also be referred to as a Radio Access Network (RAN) device. The base station 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 evolved node B (eNB or eNodeB) in Long Term Evolution (LTE), a relay station or an access point, or a base station in a future 5G network, and the like, which are not limited herein. Herein, the base station in the 5G network may also be referred to as a gNB.

The terminal device related to the embodiment of the application can be a wired terminal or a wireless terminal. The wireless terminal may be a device with a wireless transceiving function. The terminal equipment related to the embodiment of the application can be deployed on land, and comprises indoor or outdoor, handheld or vehicle-mounted equipment; can also be deployed on the water surface (such as a ship and the like); and may also be deployed in the air (e.g., airplanes, balloons, satellites, etc.). The terminal device related to the embodiment of the present application may be a User Equipment (UE), where the UE includes a handheld device, a vehicle-mounted device, a wearable device, or a computing device having a wireless communication function. Illustratively, the UE may be a mobile phone (mobile phone), a tablet computer, or a computer with wireless transceiving function. The terminal device may also be a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in unmanned driving, a wireless terminal in telemedicine, a wireless terminal in smart grid, a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), and so on. In the embodiment of the present application, the apparatus for implementing the function of the terminal may be the terminal, or may be an apparatus for supporting the terminal to implement the function.

The terminal device or the base station according to the embodiment of the present application may include 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 processes 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.

Of course, the data transmission method and apparatus provided in the embodiment of the present application may also be applied to other scenarios, and the embodiment of the present application is not limited thereto.

In the embodiment of the present application, a device for executing the terminal device (or referred to as terminal) side method may be a terminal device, or may be a device in the terminal device. For example, the apparatus in the terminal device may be a chip system, a circuit or a module, and the like, and the application is not limited thereto. It can be understood that, in this embodiment, the sending end may be a device that executes the terminal device side method.

In the embodiment of the present application, the apparatus for executing the base station side method may be a base station, or may be an apparatus in the base station. For example, the apparatus in the base station may be a chip system, a circuit or a module, and the like, and the application is not limited thereto. It can be understood that, in the embodiment of the present application, the receiving end may be a device that executes the base station side method.

Fig. 3 is a schematic flowchart of a data transmission method according to an embodiment of the present application; as shown in fig. 3, the method provided by the embodiment of the present application may include the following steps:

step S201: and the sending end sends detection signals to M receiving antennas of the receiving end through the N sending antennas.

In the embodiment of the present application, the detection signal may be used for signal detection between the transmitting end and the receiving end. The detection signal may specifically be a channel estimation frame (sounding), a Sounding Reference Signal (SRS), or another signal, which is not limited in this embodiment of the present invention.

Step S202: the receiving end calculates a channel matrix according to the detection signal.

In this embodiment of the application, after a sending end sends a detection signal to M receiving antennas of a receiving end through N sending antennas, and after the receiving end receives the detection signal, the receiving end may transform the detection signal to a frequency domain through Fast Fourier Transformation (FFT) to obtain a plurality of subcarriers, then extract a signal on each subcarrier, perform channel estimation on each subcarrier, and obtain a channel matrix H.

For example, if 2 receiving antennas are located at the receiving end and 4 transmitting antennas are located at the transmitting end, H is a 2 × 4 matrix.

Wherein h00, h01, h02, h03, h10, h11, h12, and h13 are channel responses on the respective channels of the receiving end and the transmitting end.

Step S203: the receiving end acquires a first matrix according to the channel matrix; wherein the first matrix comprises: the front NSS column of the first unitary matrix, wherein the NSS is the smaller value of M and N; the first unitary matrix is: and carrying out Singular Value Decomposition (SVD) on the channel matrix to obtain an N-N matrix.

In an implementation manner, a receiving end may perform SVD decomposition on a channel matrix to obtain three matrices U, V, and S, where U is a unitary matrix of M × M, V is a unitary matrix of N × N, and S is a diagonal matrix of M × N, and SVD decomposition of the matrix is performed to the prior art, which is not described herein again, and then the first unitary matrix in this embodiment is a V matrix, and the first matrix may be a matrix composed of front Nss rows in the V matrix. In a specific application, after the V matrix is obtained, the front Nss column is selected from the V matrix to obtain the first matrix.

In another implementation manner of the embodiment of the present application, other operations may be performed on the channel matrix to directly obtain the first matrix, so that the content of the first matrix is the Nss column of the V matrix.

Step S204: and the receiving end carries out unitary transformation on the first matrix to obtain a second matrix.

In the embodiment of the present application, unitary transformation (unitary transformation) refers to equal-metric transformation of a unitary space. Specifically, the unitary transform may be a normalized Discrete Fourier Transform (DFT) or a Givens transform, and the embodiment of the present application does not specifically limit the unitary transform.

In an alternative embodiment, the receiving end performs unitary transformation on the first matrix, and the obtained second matrix may be:

In the embodiment of the present application, the preset matrix may be a DFT matrix or a Givens matrix, and the preset matrix is not specifically limited in the embodiment of the present application. And right multiplying the first matrix by a preset matrix to obtain a third matrix, wherein the third matrix is an N-Nss matrix, and replacing the first Nss column of the first matrix with the third matrix to obtain a second matrix.

In another alternative embodiment, the receiving end performs unitary transformation on the first matrix, and the obtained second matrix may be: and under the condition that the channel state meets at least one of a first preset condition, a second preset condition and a third preset condition, performing unitary transformation on the first matrix to obtain the second matrix.

Wherein, the first preset condition comprises: the Received Signal Strength Indication (RSSI) of the M receiving antennas is greater than a first threshold and less than a second threshold; the second preset condition includes: a maximum condition number of the channel matrix is greater than a third threshold and less than a fourth threshold, wherein the condition number is used for identifying correlation between spatial streams of the N transmit antennas and the M receive antennas; the third preset condition includes: the maximum difference value of the signal-to-noise ratios is larger than a fifth threshold; the maximum difference value of the signal-to-noise ratios is the maximum difference value of the signal-to-noise ratios between the spatial streams formed by the sending end after the sending end carries out weight assignment through the first unitary matrix.

In consideration of the fact that, in some cases, performing unitary transformation on the first matrix has a poor effect on improving signal quality, in the embodiment of the present application, in a case where the channel state satisfies at least one of the first preset condition, the second preset condition, and the third preset condition, the unitary transformation is performed on the first matrix to obtain the second matrix.

In a specific application, the first preset condition is a condition related to a signal strength indicator RSSI, and in the first preset condition, the RSSI is greater than a first threshold and less than a second threshold. The value of the first threshold is determined by the lowest demodulated signal strength of multiple spatial streams in an MIMO system composed of M receiving antennas and N transmitting antennas, and specifically, the value of the first threshold is to ensure that the number of spatial streams transmitted by a transmitting end is greater than or equal to 2, because the signal strength is too small, the transmitting end may transmit signals with a single spatial stream, but the method of the embodiment of the present application may generate a negative benefit when the single spatial stream occurs; the second threshold is selected according to a maximum signal strength value of a linear working area of a signal-to-noise ratio of the receiving end, specifically, when the signal strength is small, the signal-to-noise ratio of the receiving end linearly increases along with the signal strength, and when the signal strength exceeds a certain value, due to the influence of a radio frequency device (such as a low noise amplifier), the signal-to-noise ratio does not increase along with the increase of the signal strength. Illustratively, the first threshold may take a value between-100 and 10dBm, such as-70 dBm, and the second threshold may take a value between-100 and 10dBm, such as-30 dBm.

In a specific application, the second predetermined condition is a condition related to a maximum condition number of the channel matrix, and in the second predetermined condition, the maximum condition number of the channel matrix is greater than the third threshold and less than the fourth threshold. The value of the third threshold is related to the error correction capability of channel decoding of the receiving end, and can be determined in practical application through simulation, for example, about 9dB is taken in WiFi, and when the condition number is smaller than the value, the unitary matrix transformation of the application is not needed to be adopted in consideration of the compatibility of single stream; the scheduling algorithm of the value-taking transmitting end of the fourth threshold is related, and can be given through testing in practical application, specifically, when the condition number is considered to be larger than a certain value, the probability that the transmitting end transmits a single spatial stream is relatively large, and for example, the fourth threshold can be selected to be about 30 dB. Specifically, the condition number is used to identify correlation between spatial streams in a MIMO system formed by M receiving antennas and N transmitting antennas, where the correlation between the spatial streams may be orthogonality of the spatial streams, and the embodiment of the present application is not limited in this respect. In practical application, the condition number CN of the channel matrix is calculated by the following formula:

wherein S is _a And S _b Are singular values of the channel matrix, a and b are integers not less than 0, and a is less than b. Adaptive, the logarithm of the condition number can be defined as

The unit is dB.

In a specific application, the third preset condition is a condition related to a maximum difference of signal-to-noise ratios, and in the third preset condition, the maximum difference of signal-to-noise ratios of the spatial streams is greater than a fifth threshold. The value of the fifth threshold is related to the error correction capability of channel decoding at the receiving end, and may be determined in practical application through simulation, for example, about 9dB is taken in Wireless Fidelity (WiFi), and when the maximum difference of the signal-to-noise ratio is smaller than this value, it is not necessary to adopt unitary matrix transformation of the present application in consideration of single stream compatibility.

In the embodiment of the application, whether unitary transformation is performed on the first matrix is determined according to the specific condition of the channel state, so that the signal quality can be further improved.

Step S205: and the receiving end sends the second matrix to the sending end to indicate the sending end to use the second matrix to carry out weight assignment on the N sending antennas.

In the embodiment of the present application, the second matrix is used as an assignment matrix of the sending end. In specific application, the receiving end may further compress the second matrix into two angle vectors phi and psi, and then send the two angle vectors phi and psi to the sending end, which is not specifically limited in this embodiment of the present application.

Optionally, after the sending end receives the second matrix, the method may include step S206: and the transmitting end weights the N transmitting antennas according to the second matrix.

In the embodiment of the application, the sending end can perform weighted sending on the sending signal according to the second matrix in subsequent data packet sending, so that the quality of the receiving signal is improved. It can be understood that, if the sending end receives the compressed second matrix, the second matrix may be recovered by decompressing according to a method defined by a compression protocol of the second matrix, which is not specifically limited in this embodiment of the application.

As an optional implementation manner of the embodiment of the present application, the receiving end may further determine, according to the fourth matrix, an output signal-to-noise ratio of each spatial stream formed after the sending end performs weight assignment using the second matrix; the fourth matrix includes: the front Nss row and the front Nss column of the diagonal matrix are: carrying out SVD on the channel matrix to obtain a singular value matrix; and sending the output signal-to-noise ratio of each spatial stream to the sending end.

In general, the larger the difference between the output signal-to-noise ratios of the spatial streams in the MIMO system is, the more unbalanced the signal processing of the spatial streams in practical application is, and further, a phenomenon that the spatial streams with smaller output signal-to-noise ratios cannot be decoded correctly may occur.

In specific application, the output signal-to-noise ratios of the spatial streams formed after the sending end performs the weight assignment by using the second matrix can be determined according to singular values included in a diagonal matrix obtained by performing SVD on a channel matrix, and the output signal-to-noise ratios of the spatial streams may be consistent or inconsistent.

As an optional implementation manner of the embodiment of the present application, determining, according to a fourth matrix, an output signal-to-noise ratio of each spatial stream formed after the sending end performs weight assignment by using the second matrix includes:

determining the output signal-to-noise ratio of each spatial stream formed after the weight assignment is performed on the second matrix by the sending end according to the fourth matrix under the condition that the channel state meets at least one of a first preset condition, a second preset condition and a third preset condition; wherein, the first preset condition comprises: the received signal strength indication RSSI of the M receiving antennas is larger than a first threshold and smaller than a second threshold; the second preset condition includes: a maximum condition number of the channel matrix is greater than a third threshold and less than a fourth threshold, wherein the condition number is used for identifying correlation between spatial streams of the N transmit antennas and the M receive antennas; the third preset condition includes: the maximum difference of the signal-to-noise ratios is larger than a fifth threshold; the maximum signal-to-noise ratio difference value is the maximum signal-to-noise ratio difference value between the spatial streams formed after the sending end performs weight assignment through the first unitary matrix.

In the embodiment of the application, whether the output signal-to-noise ratio of each spatial stream formed after the sending end uses the second matrix for weight assignment is determined according to the specific condition of the channel state is determined, so that the occupation of the output signal-to-noise ratio of each spatial stream formed after the sending end uses the second matrix for weight assignment and the calculation resource are avoided being determined blindly.

Specifically, the detailed description of the first preset condition, the second preset condition and the third preset condition refers to the detailed description of the description part in step S204, and is not repeated herein.

To sum up, in the embodiment of the present application, the receiving end performs unitary transformation on the first unitary matrix to obtain the second matrix, so that the transmitting end can perform weighted transmission on the transmission signal of the transmitting antenna according to the second matrix, whereas in the prior art, the transmitting end performs weighted transmission on the transmission signal of the transmitting antenna through the V matrix in the SVD, and therefore, the embodiment of the present application provides an alternative scheme for weighting the transmitting antenna.

In practice, through a great deal of research, the inventor of the present application finds that, in a technical scheme in the prior art in which a transmitting end uses a V matrix to perform weighted transmission on a transmission signal, a situation that a packet error rate between the receiving end and the transmitting end is high often occurs, where the V matrix is obtained by performing SVD decomposition on a channel matrix at the receiving end, and the V matrix is a unitary matrix.

The inventor further finds that the reason that the packet error rate between the receiving end and the transmitting end is high is that a corner effect often occurs in practical application, and the corner effect specifically refers to: under the condition that the distance between the transmitting end and the receiving end is not changed, the relative position of the transmitting end and the receiving end is changed, for example, the placing direction of an antenna is changed, the throughput between the transmitting end and the receiving end is obviously changed, and the packet error rate is obviously increased; and the inventors have further found that the main causes of the corner effect are: after the relative positions of the transmitting end and the receiving end are changed, the difference of the output signal-to-noise ratios of the spatial streams of the MIMO is large, so that signal processing of the spatial streams is unbalanced, and the spatial streams with small output signal-to-noise ratios cannot be decoded correctly.

By way of example, in the prior artIn the operation, taking the number of transmitting antennas as 2 and the number of receiving antennas as 2 as an example, the output snr of two spatial streams is respectively

And

where s0 and s1 are singular values of the channel matrix, σ ² The average value of the noise variances of the M receiving antennas is an average value of the noise variances of the M receiving antennas, because s0 and s1 in the prior art are usually different greatly, specifically, s0 is much larger than s1, so that although the output signal-to-noise ratio of s0 can meet the demodulation requirement, s1 is too small, and the output signal-to-noise ratio corresponding to s1 is too small, so that the spatial stream corresponding to s1 cannot be demodulated, and the data packet demodulation fails.

Based on the findings, the inventors further studied and determined that, when the unitary transform is performed on the first matrix in embodiment one, the angle effect can be effectively improved and the packet error rate between the transmitting end and the receiving end can be reduced in the case of DFT transform or Givens transform.

A second embodiment of the present application provides a data transmission method, where in the second embodiment of the present application, a specific implementation of step S204 in the first embodiment of the present application is that unitary transformation is DFT transformation, a preset matrix is a normalized DFT matrix, and a receiving end obtains a third matrix by right-multiplying the first matrix by the DFT matrix.

Specifically, in the DFT matrix:

Further conversion of DFT (k, l) yields:

suitably, the determining, according to the fourth matrix, the output signal-to-noise ratio of each spatial stream formed after the sending end performs weight assignment by using the second matrix in the first embodiment of the present application includes:

and determining the output signal-to-noise ratio of each spatial stream as:

For example, taking the number of transmit antennas as 2 and the number of receive antennas as 2, there may be two spatial streams between the receive antennas and the transmit antennas.

The fourth matrix S may be:

the DFT matrix may be:

the second matrix Vnew may be:

output signal-to-noise ratio postSNR of spatial streams ₀ And postSNR ₁ All are as follows:

other steps in the second embodiment of the present application are the same as those in the first embodiment of the present application, and specific reference is made to the first embodiment of the present application, which is not described herein again.

In the embodiment of the application, the output signal-to-noise ratios of any two spatial streams of the MIMO system are the same, so that the MIMO system processes signals of the spatial streams uniformly, thereby solving the corner effect to a greater extent and reducing the packet error rate between the transmitting end and the receiving end.

A third embodiment of the present application provides a data transmission method, where the third embodiment of the present application is another specific implementation of step S204 in the foregoing embodiments, in particular, in the third embodiment of the present application, unitary transformation is Givens transformation, a preset matrix is a Givens matrix, and a receiving end obtains a third matrix by right-multiplying the first matrix by the Givens matrix.

In particular, the Givens matrix includes a plurality of transformation matrices Gi.

Wherein i is an integer of 0 to Np-1; n = i; m = Nss-2 × (n + 1); in the case that Nss is an even number greater than 2, np = Nss/2; in the case where Nss is an odd number greater than 2, np = (Nss-1)/2 is defined; I.C. A _n，n Unit array representing n rows and n columns, I _m，m A unit array representing m rows and m columns; 0 _m，1 A 0 matrix representing m rows and 1 columns;

The third matrix is the first matrix right-multiplied by G1 to GNp, i.e., P = V1 × G1.

and determining that the output signal-to-noise ratio of each spatial stream formed by the sending end after carrying out weight assignment by using the second matrix is as follows according to the fourth matrix:

For example, taking the number of receiving antennas as 2, the number of transmitting antennas as no less than 2, and Nss as 2, there may be two spatial streams between the receiving antennas and the transmitting antennas.

The third matrix P is the first matrix V1 multiplied right by G1.

Wherein the content of the first and second substances,

for example, taking the number of receiving antennas as 4, the number of transmitting antennas as no less than 4 as an example, nss is 4, and there may be four spatial streams between the receiving antennas and the transmitting antennas.

The third matrix P is the first matrix V1 multiplied right by G1 and then by G2, i.e. P = V1 × G2.

Wherein G1 is:

wherein the content of the first and second substances,

g2 is:

wherein the content of the first and second substances,

for example, taking the number of receiving antennas as Nrx and the number of transmitting antennas as Ntx, nss is the smaller of Nrx and Ntx, and there may be Nss spatial streams between the receiving antennas and the transmitting antennas. In the case where Nss is an even number greater than 2, np = Nss/2.

The third matrix P is the first matrix V1 multiplied right by G1 to GNp, i.e. P = V1G 2 \8230. G1 G2., GNp is an extended Givens matrix.

Wherein m = Np-2,I is the unit array, I _m，m A unit matrix of m rows and m columns is shown. 0 _m，1 Representing a 0 matrix of m rows and 1 column.

Wherein m = Np-4.

Wherein n = i-1, m = np-2 n.

It is understood that, in the case where Nss is an odd number greater than 2, np = (Nss-1)/2, and other calculation manners are the same as those in the case where Nss is an even number greater than 2, and are not described herein again.

Other steps in the third embodiment of the present application are the same as those in the first embodiment of the present application, and specific reference is made to the first embodiment of the present application, which is not described herein again.

In the embodiment of the present application, the second matrix is obtained by performing givens transformation on the first matrix, so that when the transmitting end of the MIMO system of the embodiment of the present application performs weight assignment through the second matrix, the maximum difference between the output signal-to-noise ratios of any two spatial streams is lower than the maximum difference between the output signal-to-noise ratios of any two spatial streams in the prior art, therefore, the MIMO system is more balanced with respect to the prior art in terms of signal processing of each spatial stream, and further can solve the corner effect to a greater extent, and reduce the packet error rate between the transmitting end and the receiving end.

Fig. 4 shows a detailed flowchart of a data transmission method in the fifth embodiment of the present application. As shown in fig. 4, in practical applications, a receiving end may receive a signal of an antenna 1 sent by an antenna 1 and a signal of an antenna 2 sent by an antenna 2, and then perform fast fourier transform FFT on the signal of the antenna 1 and the signal of the antenna 2, respectively, to further obtain channel estimation of each channel, to obtain a channel matrix H, after performing singular value decomposition SVD on the channel matrix H, a first unitary matrix V may be obtained, and according to the channel estimation, a signal strength estimation that can be used to identify a channel state, a maximum condition number of the channel matrix, a noise estimation and a maximum difference of signal to noise ratio may also be obtained, where the signal strength estimation satisfies a first preset condition, and/or the maximum condition number of the channel matrix satisfies a second preset condition, and/or, in a case where the maximum difference of the channel matrix satisfies a third preset condition, the unitary transform of the embodiment of the present application may be performed according to the V matrix, to obtain a second matrix, and then the second matrix is compressed and then reported to a frame sending end through a report frame compression method, and the frame compression method may be directly reported to a frame without applying the signal strength estimation; and under the condition that the signal strength estimation meets a first preset condition, and/or the maximum condition number of the channel matrix meets a second preset condition, and/or the maximum signal-to-noise ratio difference value meets a third preset condition, combining a diagonal matrix obtained by performing Singular Value Decomposition (SVD) on the channel matrix H with noise variance calculation to obtain a new signal-to-noise ratio of each spatial stream formed after the sending end performs weight assignment according to the second matrix, and feeding the new signal-to-noise ratio of each spatial stream back to the sending end through a report frame.

For example, table 1 shows signal quality improvement gains of 2 transmitting antennas and 2 receiving antennas in a Quadrature Amplitude Modulation (QAM) scenario in the embodiment of the present application, as shown in table 1:

channel condition number	Modulation order	Channel coding rate	Gain (dB)
				20	256QAM	5/6	3
20	256QAM	3/4	2
				20	64QAM	5/6	4
20	64QAM	3/4	3
				20	64QAM	2/3	3
25	256QAM	5/6	10
				25	256QAM	3/4	6
25	64QAM	5/6	8
				25	64QAM	3/4	6
25	64QAM	2/3	4

TABLE 1

In summary, in the embodiment of the present application, the receiving end obtains the second matrix by performing unitary transformation on V, so that the transmitting end can perform weighted transmission on the transmission signals of the transmitting antennas according to the second matrix, whereas in the prior art, the transmitting end performs weighted transmission on the transmission signals of the transmitting antennas through the V matrix in the SVD, so that the embodiment of the present application provides an alternative scheme for weighting the transmitting antennas to improve signal quality.

Fig. 5 is a schematic functional structure diagram of a data processing apparatus according to an embodiment of the present invention, as shown in fig. 5, the apparatus includes:

a detection signal receiving module 51, configured to receive detection signals through M receiving antennas; the detection signal is sent by a sending end through N sending antennas; m and N are both greater than or equal to 2.

A channel matrix calculating module 52, configured to calculate a channel matrix according to the detection signal.

A matrix obtaining module 53, configured to obtain a first matrix according to the channel matrix; wherein the first matrix comprises: the front NSS column of the first unitary matrix, wherein the NSS is the smaller value of M and N; the first unitary matrix is: and carrying out Singular Value Decomposition (SVD) on the channel matrix to obtain an N-N matrix.

A unitary transformation module 54, configured to perform unitary transformation on the first matrix to obtain a second matrix;

a matrix sending module 55, configured to send the second matrix to the sending end, so as to instruct the sending end to perform weight assignment on the N sending antennas by using the second matrix.

In the device, firstly, detection signals are received through M receiving antennas; the detection signal is sent by a sending end through N sending antennas; m and N are both greater than or equal to 2; then, calculating a channel matrix according to the detection signal; performing Singular Value Decomposition (SVD) on the channel matrix to obtain a first matrix; wherein the first matrix comprises: the front NSS column of the first unitary matrix, wherein the NSS is the smaller value of M and N; the first unitary matrix is: performing SVD on the channel matrix to obtain an N-N matrix; performing unitary transformation on the first matrix to obtain a second matrix; the second matrix is used for the sending end to carry out weight assignment on the N sending antennas; sending the second matrix to the sending end; the transmitting end may assign values to the multiple transmitting antennas by using the second matrix, so as to improve the quality of the received signal at the receiving end.

Optionally, the unitary transform module includes:

the first unitary transformation submodule is used for right-multiplying the first matrix by a preset matrix to obtain a third matrix; and replacing the first NSS row of the first unitary matrix with the third matrix to obtain a second matrix.

Optionally, in the DFT matrix:

wherein, DFT (k, l) represents the elements of the k row and l column of the DFT matrix; k is an integer of 0 to NSS-1; l isAn integer of 0 to NSS-1; pi is the circumferential ratio.

Optionally, the preset matrix includes: givens transforms Givens matrices.

wherein i is an integer of 0 to Np-1; n = i; m = Nss-2 × (n + 1); in the case that Nss is an even number greater than 2, np = Nss/2; in the case that Nss is an odd number greater than 2, np = (Nss-1)/2; I.C. A _n，n Unit array representing n rows and n columns, I _m，m A unit array representing m rows and m columns; 0 _m，1 A 0 matrix representing m rows and 1 column;

Optionally, the unitary transform module includes: the second unitary transformation submodule is used for performing unitary transformation on the first matrix to obtain the second matrix under the condition that the channel state meets at least one of a first preset condition, a second preset condition and a third preset condition; wherein, the first preset condition comprises: the received signal strength indication RSSI of the M receiving antennas is larger than a first threshold and smaller than a second threshold; the second preset condition includes: a maximum condition number of the channel matrix is greater than a third threshold and less than a fourth threshold, wherein the condition number is used for identifying correlation between spatial streams of the N transmit antennas and the M receive antennas; the third preset condition includes: the maximum difference value of the signal-to-noise ratios is larger than a fifth threshold; the maximum signal-to-noise ratio difference value is the maximum signal-to-noise ratio difference value between the spatial streams formed after the sending end performs weight assignment through the first unitary matrix.

Optionally, the apparatus further comprises:

Optionally, the output snr determining module includes: a first output signal-to-noise ratio determining submodule, configured to determine, according to the fourth matrix, an output signal-to-noise ratio of each spatial stream formed by the sending end performing weight assignment using the second matrix when the channel state satisfies at least one of a first preset condition, a second preset condition, and a third preset condition; wherein, the first preset condition comprises: the received signal strength indication RSSI of the M receiving antennas is larger than a first threshold and smaller than a second threshold; the second preset condition includes: a maximum condition number of the channel matrix is greater than a third threshold and less than a fourth threshold, wherein the condition number is used for identifying correlation between spatial streams of the N transmit antennas and the M receive antennas; the third preset condition includes: the maximum difference of the signal-to-noise ratios is larger than a fifth threshold; the maximum difference value of the signal-to-noise ratios is the maximum difference value of the signal-to-noise ratios between the spatial streams formed by the sending end after the sending end carries out weight assignment through the first unitary matrix.

wherein S is the fourth matrix, S ^-1 Representing the S inversion; DFT _Nss×Nss S ^-1 Is the inverse of S multiplied right by the DFT matrix; (DFT) _Nss×Nss S ^-1 ) _{1 X Nss} Is to take DFT _Nss×Nss S ^-1 Line 1 of (a); | (DFT) _Nss×Nss S ^-1 ) _{1 X Nss} || ² Is for DFT _Nss×Nss S ^-1 Line 1 of (1) calculates the norm, σ ² Is the average of the noise variance of the M receive antennas.

In the device, the output signal-to-noise ratios of any two spatial streams of the MIMO system are the same, so that the MIMO system can process and balance the signals of the spatial streams, further can solve the corner effect to a greater extent, and reduce the packet error rate between the sending end and the receiving end.

wherein postSNR _i To postSNR _Nss-1 An output SNR for an ith spatial stream to an Nss-1 th spatial stream in the MIMO system; si to SNss-1 are singular values in the fourth matrix; wherein S is _i+1 Greater than or equal to S _i 。

Optionally, the matrix obtaining module includes: the matrix acquisition submodule is used for carrying out SVD on the channel matrix to obtain the first unitary matrix; and selecting the front NSS row of the first unitary matrix to obtain the first matrix.

Fig. 6 is a schematic structural diagram of a communication device according to an embodiment of the present invention, and as shown in fig. 6, the communication device includes: a processor 61, and a transceiver 63 coupled to the processor.

Optionally, in the DFT matrix:

Optionally, the preset matrix includes: givens transforms Givens matrices.

wherein i is an integer of 0 to Np-1; n = i; m = Nss-2 × (n + 1); in the case that Nss is an even number greater than 2, np = Nss/2; in the case that Nss is an odd number greater than 2, np = (Nss-1)/2; i is _n，n Unit array representing n rows and n columns, I _m，m Represents m rows and m columnsThe unit array of (2); 0 _m，1 A 0 matrix representing m rows and 1 columns;

Optionally, the processor is configured to perform unitary transformation on the first matrix to obtain the second matrix when the channel state satisfies at least one of a first preset condition, a second preset condition, and a third preset condition; wherein, the first preset condition comprises: the received signal strength indication RSSI of the M receiving antennas is larger than a first threshold and smaller than a second threshold; the second preset condition includes: a maximum condition number of the channel matrix is greater than a third threshold and less than a fourth threshold, wherein the condition number is used for identifying correlation between spatial streams of the N transmit antennas and the M receive antennas; the third preset condition includes: the maximum difference value of the signal-to-noise ratios is larger than a fifth threshold; the maximum signal-to-noise ratio difference value is the maximum signal-to-noise ratio difference value between the spatial streams formed after the sending end performs weight assignment through the first unitary matrix.

Optionally, the processor is configured to determine, according to a fourth matrix, an output signal-to-noise ratio of each spatial stream formed by the sending end performing weight assignment by using the second matrix; the fourth matrix includes: the front Nss row and the front Nss column of the diagonal matrix are: and carrying out SVD on the channel matrix to obtain a singular value matrix.

Optionally, the processor is configured to determine, according to the fourth matrix, an output signal-to-noise ratio of each spatial stream formed by the sending end after performing weight assignment using the second matrix when the channel state meets at least one of a first preset condition, a second preset condition, and a third preset condition; wherein, the first preset condition comprises: the received signal strength indication RSSI of the M receiving antennas is larger than a first threshold and smaller than a second threshold; the second preset condition includes: a maximum condition number of the channel matrix is greater than a third threshold and less than a fourth threshold, wherein the condition number is used for identifying correlation between spatial streams of the N transmit antennas and the M receive antennas; the third preset condition includes: the maximum difference of the signal-to-noise ratios is larger than a fifth threshold; the maximum signal-to-noise ratio difference value is the maximum signal-to-noise ratio difference value between the spatial streams formed after the sending end performs weight assignment through the first unitary matrix.

In the device, whether the output signal-to-noise ratio of each spatial stream formed after the sending end uses the second matrix for weight assignment is determined according to the specific condition of the channel state is determined, so that the blind determination of the occupation of the output signal-to-noise ratio of each spatial stream formed after the sending end uses the second matrix for weight assignment to calculate resources is avoided.

Optionally, the processor is configured to:

In the embodiments of the present application, the processor may be a general processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logic blocks disclosed in the embodiments of the present application. A general purpose processor may be a microprocessor or 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 processor, or implemented by a combination of hardware and software modules in a processor.

In the embodiment of the present application, the memory 62 may store a computer program, and the memory 62 may be a non-volatile memory, such as a Hard Disk Drive (HDD) or a solid-state drive (SSD), and may also be a volatile memory (RAM), such as a random-access memory (RAM), and may also be a circuit or any other device that can implement a storage function. The memory can also be, but is not limited to, any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.

The embodiment of the application also provides equipment, which comprises a processor and a memory; wherein the memory is used for storing program instructions; the processor is configured to call and execute the program instructions stored in the memory, so as to implement the function of the receiving end in the embodiment of the data transmission method described in the present application, and the implementation principle and the technical effect are similar, which are not described herein again.

An embodiment of the present application further provides a communication system, including a receiving end and a transmitting end, where the receiving end is configured to execute the method according to any of the foregoing data transmission method embodiments of the present application, and the transmitting end is configured to perform weight assignment on the N transmitting antennas by using the second matrix.

The embodiments of the present application further provide a computer program product including instructions, which when run on a computer, enables the computer to execute the technical solution in the above embodiments of the data transmission method of the present application, and the implementation principle and the technical effect are similar, and are not described herein again.

An embodiment of the present application further provides a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, and when the instructions are executed on a computer, the computer is enabled to execute the technical solution in the data transmission method embodiment of the present application, and implementation principles and technical effects of the technical solution are similar, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed 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 unit is only one logical functional 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 integrated unit may be implemented in the form of hardware, or in the form of hardware plus a software functional unit.

It should be understood by those of ordinary skill in the art that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of the processes should be determined by their functions and inherent logic, and should not limit the implementation process of the embodiments of the present application.

In the above embodiments, all or part of the implementation may be realized by software, hardware, firmware or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The procedures or functions described in accordance with the embodiments of the application are all or partially generated when the computer program instructions are loaded and executed on a computer. The computer may be a general purpose computer, a special purpose computer, a computer network, a network appliance, a terminal device or other programmable apparatus. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that includes one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid State Disk (SSD)), among others.

Claims

1. A data transmission method, applied to a MIMO system, the method comprising:

receiving detection signals through M receiving antennas; the detection signal is sent by a sending end through N sending antennas; m and N are both greater than or equal to 2;

calculating a channel matrix according to the detection signal;

acquiring a first matrix according to the channel matrix; wherein the first matrix comprises: the front NSS column of the first unitary matrix, wherein the NSS is the smaller value of M and N; the first unitary matrix is: performing Singular Value Decomposition (SVD) on the channel matrix to obtain an N-N matrix;

performing unitary transformation on the first matrix to obtain a second matrix;

and sending the second matrix to the sending end to indicate the sending end to use the second matrix to carry out weight assignment on the N sending antennas.

2. The method of claim 1, wherein performing a unitary transform on the first matrix to obtain a second matrix comprises:

right multiplying the first matrix by a preset matrix to obtain a third matrix;

and replacing the front NSS row of the first unitary matrix with the third matrix to obtain a second matrix.

3. The method of claim 2, wherein the predetermined matrix comprises: a normalized discrete fourier transform, DFT, matrix.

4. The method of claim 3, wherein in the DFT matrix:

wherein, DFT (k, l) represents the k row and l column elements of the DFT matrix; k is an integer of 0 to NSS-1; l is an integer of 0 to NSS-1; pi is the circumferential ratio.

5. The method of claim 2, wherein the predetermined matrix comprises: givens transforms Givens matrices.

6. The method of claim 5, wherein the Givens matrix comprises a plurality of transformation matrices Gi, wherein,

wherein i is an integer of 0 to Np-1; n = i; m = Nss-2 (n + 1); in the case that Nss is an even number greater than 2, np = Nss/2; in the case that Nss is an odd number greater than 2, np = (Nss-1)/2; i is _n,n Unit matrix representing n rows and n columns, I _m,m A unit array representing m rows and m columns; 0 _m,1 A 0 matrix representing m rows and 1 column;

S _i to S _Nss-1 Singular values of the channel matrix; wherein S is _i+1 Is greater than or equal to S _i 。

7. The method of any of claims 1-6, wherein performing a unitary transform on the first matrix to obtain a second matrix comprises:

performing unitary transformation on the first matrix to obtain a second matrix under the condition that the channel state meets at least one of a first preset condition, a second preset condition and a third preset condition;

wherein the first preset condition comprises: the RSSI of the received signal strength indication of the M receiving antennas is greater than a first threshold and less than a second threshold;

the second preset condition comprises: a maximum condition number of the channel matrix is greater than a third threshold and less than a fourth threshold, wherein the condition number is used for identifying correlation between spatial streams of the N transmit antennas and the M receive antennas;

the third preset condition includes: the maximum difference value of the signal-to-noise ratios is larger than a fifth threshold; the maximum difference value of the signal-to-noise ratios is the maximum difference value of the signal-to-noise ratios between the spatial streams formed by the sending end after the sending end carries out weight assignment through the first unitary matrix.

8. The method of any one of claims 1-6, further comprising:

determining the output signal-to-noise ratio of each spatial stream formed by the sending end after carrying out weight assignment by using the second matrix according to a fourth matrix; the fourth matrix includes: the front NSS row and the front NSS column of the diagonal matrix are as follows: carrying out SVD on the channel matrix to obtain a singular value matrix;

and sending the output signal-to-noise ratio of each spatial stream to the sending end.

9. The method of claim 8, wherein determining the output snr of each spatial stream formed by the transmitter performing weight assignment using the second matrix according to a fourth matrix comprises:

under the condition that the channel state meets at least one of a first preset condition, a second preset condition and a third preset condition, determining the output signal-to-noise ratio of each spatial stream formed by the sending end after carrying out weight assignment by using the second matrix according to the fourth matrix;

wherein the first preset condition comprises: the received signal strength indication RSSI of the M receiving antennas is greater than a first threshold and less than a second threshold;

the third preset condition comprises: the maximum difference value of the signal-to-noise ratios is larger than a fifth threshold; the maximum difference value of the signal-to-noise ratios is the maximum difference value of the signal-to-noise ratios between the spatial streams formed by the sending end after the sending end carries out weight assignment through the first unitary matrix.

10. The method of claim 8, wherein determining the output snr of each spatial stream formed by the transmitter performing weight assignment using the second matrix according to a fourth matrix comprises:

and determining the output signal-to-noise ratio of each spatial stream as:

wherein S isThe fourth matrix, S ^-1 Representing the S inversion; DFT _Nss×Nss S ^-1 Is the inverse right-times DFT matrix of S; (DFT) _Nss×Nss S ^-1 ) _1XNss Is to take DFT _Nss×Nss S ^-1 Line 1 of (a); | (DFT) _Nss×Nss S ^-1 ) _1XNss || ² Is to DFT _Nss×Nss S ^-1 Line 1 of (1) calculates the norm, σ ² Is the average of the noise variance of the M receive antennas.

11. The method of claim 8, wherein determining the output snr of each spatial stream formed by the transmitter performing weight assignment using the second matrix according to a fourth matrix comprises:

wherein postSNR _i To postSNR _Nss-1 Output SNR for the ith through NSS-1 spatial streams in said MIMO system; si to SNss-1 are singular values in the fourth matrix; wherein S is _i+1 Is greater than or equal to S _i 。

12. The method of claim 7,

the condition number CN of the channel matrix is calculated by the following formula:

13. The method of any of claims 1-6 and 9-12, wherein obtaining the first matrix from the channel matrix comprises:

SVD is carried out on the channel matrix to obtain the first unitary matrix;

and selecting the front NSS row of the first unitary matrix to obtain the first matrix.

14. A data transmission apparatus, comprising: a processor, and a transceiver coupled to the processor;

the transceiver is used for receiving detection signals through M receiving antennas; the detection signal is sent by a sending end through N sending antennas; m and N are both greater than or equal to 2;

the processor is used for calculating a channel matrix according to the detection signal;

the processor is further configured to obtain a first matrix according to the channel matrix; wherein the first matrix comprises: the front NSS column of the first unitary matrix, wherein the NSS is the smaller value of M and N; the first unitary matrix is: performing Singular Value Decomposition (SVD) on the channel matrix to obtain an N x N matrix;

the processor is further configured to perform unitary transformation on the first matrix to obtain a second matrix;

the transceiver is further configured to send the second matrix to the sending end to instruct the sending end to perform weight assignment on the N sending antennas by using the second matrix.

15. The apparatus of claim 14, wherein the processor is further configured to:

right multiplying the first matrix by a preset matrix to obtain a third matrix;

16. The apparatus of claim 15, wherein the predetermined matrix comprises: a normalized discrete fourier transform, DFT, matrix, or a Givens transform, givens, matrix.

17. The apparatus according to any one of claims 14 to 16,

the processor is further configured to determine, according to a fourth matrix, an output signal-to-noise ratio of each spatial stream formed by the sending end after performing weight assignment using the second matrix; the fourth matrix includes: the front NSS row and the front NSS column of the diagonal matrix are as follows: carrying out SVD on the channel matrix to obtain a singular value matrix;

the transceiver is further configured to send the output snr of each spatial stream to the sending end.

18. An electronic device comprising a processor and a memory;

wherein the memory is configured to store program instructions;

the processor, configured to call and execute program instructions stored in the memory, to implement the method according to any one of claims 1 to 13.

19. A communication system, comprising a receiving end and a transmitting end, wherein the receiving end is configured to perform the method according to any one of claims 1 to 13, and the transmitting end is configured to perform weight assignment on the N transmit antennas by using the second matrix.

20. A computer-readable storage medium storing instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 13.