CN115549738A

CN115549738A - Communication method and device

Info

Publication number: CN115549738A
Application number: CN202110732937.8A
Authority: CN
Inventors: 高翔; 董昶钊; 刘鹍鹏; 郭志恒
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-06-29
Filing date: 2021-06-29
Publication date: 2022-12-30

Abstract

The embodiment of the invention discloses a communication method and a communication device.A network device indicates a pre-coding matrix of a part of frequency domain units in N frequency domain units to a terminal device, and the terminal device determines the pre-coding matrix of each frequency domain unit in the N frequency domain units according to the pre-coding matrix of the part of frequency domain units in the N frequency domain units. The performance and the channel estimation precision of the MIMO system are improved.

Description

Communication method and device

Technical Field

The embodiment of the invention relates to the technical field of communication, in particular to a communication method and a communication device.

Background

For Multiple Input and Multiple Output (MIMO) -Orthogonal Frequency Division Multiplexing (OFDM) systems, the channel has frequency selective fading in the frequency domain. The channel can be considered to be substantially flat when the bandwidth is within the coherence bandwidth, and will no longer be flat when the bandwidth exceeds the coherence bandwidth, with the channel response varying with frequency. Therefore, precoding also needs to be adaptively adjusted as the frequency domain changes in order to best adapt to the channel frequency selective fading characteristics.

For a channel environment with severe frequency selective fading, a smaller pre-coding frequency domain granularity is beneficial to optimally adapting to channel variation, and the inter-stream interference and the inter-user interference are overcome to the maximum extent, so that the performance of the MIMO system can be improved. However, for the channel estimation of the receiving end, the larger pre-coding frequency domain granularity can ensure the continuity of the channel in the larger frequency domain granularity, so that the channel estimation can be better performed by combining with a larger bandwidth, a better noise reduction effect is obtained, and the channel estimation precision is improved. Therefore, how to implement precoding with small frequency domain granularity and ensure the capability of receiving end channel estimation, so as to improve the performance of the MIMO system and the accuracy of channel estimation has become a technical problem to be solved urgently.

Disclosure of Invention

The embodiment of the invention discloses a communication method and a communication device, which are used for improving the performance of an MIMO system and the channel estimation precision.

The first aspect discloses a communication method, which may be applied to a terminal device and may also be applied to a module (e.g., a chip) in the terminal device, and is described below by taking the application to the terminal device as an example. The communication method may include: receiving first indication information from a network device, where the first indication information is used to indicate M precoding matrices, where the M precoding matrices are precoding matrices corresponding to M frequency domain units in N frequency domain units, the N frequency domain units are frequency domain units used for uplink data transmission, M is an integer greater than 1, and N is an integer greater than M; and determining N pre-coding matrixes corresponding to the N frequency domain units according to the M pre-coding matrixes.

In the embodiment of the invention, the precoding with smaller frequency domain granularity (namely frequency domain units) is introduced in the uplink transmission, the precoding matrixes corresponding to different frequency domain units are different, and the equivalent channels corresponding to the frequency domain units for uplink data transmission are continuously changed in amplitude and phase, so that the precoding with small frequency domain granularity can be realized, the channel estimation capability of a receiving end is ensured, and the performance and the channel estimation precision of the MIMO system can be improved. In addition, since the network device only needs to indicate the precoding matrix corresponding to a part of the frequency domain units in the frequency domain unit for uplink data transmission, the indication overhead can be reduced, and the transmission resources can be saved. Further, the terminal device may restore precoding matrices corresponding to all frequency domain units for uplink data transmission according to a precoding matrix corresponding to a part of the frequency domain units indicated by the network device for uplink data transmission, so that continuity of amplitude and phase of the equivalent channel may be ensured.

As a possible implementation manner, the determining, according to the M precoding matrices, N precoding matrices corresponding to the N frequency domain units includes: and determining N pre-coding matrixes corresponding to the N frequency domain units according to the M pre-coding matrixes and the frequency domain positions of the M frequency domain units.

In the embodiment of the invention, the terminal equipment can accurately recover the pre-coding matrixes corresponding to all the frequency domain units for the uplink data transmission according to the pre-coding matrixes corresponding to part of the frequency domain units and the frequency domain positions of the part of the frequency domain units, which are indicated by the network equipment and used for the uplink data transmission, so that the uplink pre-coding with smaller frequency domain granularity is beneficial to adapting to the channel frequency selection characteristic, and the overall performance of the MIMO system is improved.

As a possible implementation manner, the determining, according to the M precoding matrices and the frequency domain positions of the M frequency domain units, N precoding matrices corresponding to the N frequency domain units includes: and determining the values of the ith row and the jth column in the precoding matrix corresponding to each frequency domain unit in the N frequency domain units according to the values of the ith row and the jth column in each precoding matrix in the M precoding matrices and the frequency domain positions of the M frequency domain units.

As a possible implementation manner, the first indication information is used to indicate M precoding matrices and includes: the first indication information is used for indicating the quantization amplitude and the quantization phase of part of or all of the elements in the M precoding matrices.

In the embodiment of the invention, the network equipment can indicate the quantized amplitude and the quantized phase of the precoding matrix instead of the unquantized amplitude and phase, so that the information amount of the network equipment for indicating the precoding matrix can be reduced, and the transmission resource can be saved. Meanwhile, compared with the existing indication mode of a fixed codebook, the indication precision of the uplink precoding matrix is improved by indicating the quantization amplitude and the quantization phase of the precoding matrix elements, the quantization loss of the precoding matrix is reduced, the data transmission rate can be obviously enhanced, and the overall performance of the MIMO system is improved.

As a possible implementation, the communication method may further include: receiving second indication information from the network device, the second indication information indicating frequency domain locations of the M frequency domain units.

In the embodiment of the invention, the frequency domain positions of the M frequency domain units can be determined by the network equipment and indicated to the terminal equipment, so that the processing process of the terminal equipment can be reduced, and the power consumption of the terminal equipment can be reduced.

As a possible implementation manner, the second indication information includes N bits, and the N bits are in one-to-one correspondence with the N frequency domain units.

In the embodiment of the invention, the network equipment can indicate the frequency domain positions corresponding to the M frequency domain units in a bitmap mode, the method can be issued to the terminal equipment when the network equipment determines the uplink scheduling bandwidth of the terminal equipment, the terminal equipment can know the M frequency domain positions in advance, the recovery coefficients of the N frequency domain positions can be calculated in advance, the processing speed of the terminal equipment can be improved, and the processing time delay of the terminal equipment can be reduced.

As a possible implementation, the second indication information is used to indicate indexes of the M frequency domain units in the N frequency domain units.

As a possible implementation, the communication method may further include: receiving resource configuration information of a reference signal from a network device, wherein the frequency domain positions of the M frequency domain units are determined based on the resource configuration information.

In the embodiment of the invention, the network equipment can indicate the frequency domain positions of the M frequency domain units to the terminal equipment through the resource configuration information of the reference signal without special indication of additional information, so that the transmitted information can be reduced, and the transmission resource can be saved.

As a possible implementation, the determining, based on the resource configuration information, the frequency domain positions of the M frequency domain units includes:

the frequency domain locations of the M frequency domain units are determined based on an index of resources of the reference signal; or alternatively

Frequency domain locations of the M frequency domain units are determined based on frequency domain locations of resources of the reference signal; or

The frequency domain locations of the M frequency domain units are determined based on the frequency domain locations of the resources of the reference signal and the offsets.

As a possible implementation, the frequency domain locations of the M frequency domain units are determined according to the values of N and M.

In the embodiment of the invention, after the values of N and M are obtained, the frequency domain positions of M frequency domain units can be rapidly and accurately determined according to the values of N and M. The frequency domain positions of the M frequency domain units are determined through the preset rule, so that the air interface signaling overhead can be reduced. Meanwhile, the processing complexity of the network equipment and the terminal equipment can be reduced, and the overall performance of the system is improved.

As a possible implementation, the frequency domain positions of the M frequency domain units are determined according to the formula of the values of N and M as follows:

wherein k denotes an index of a first frequency domain unit of the M frequency domain units, X _k Indicating an index of the first frequency domain unit of the N frequency domain units, N indicating a number of frequency domain units used for uplink data transmission, M indicating a number of precoding matrices indicated by the first indication information,

which means that the rounding is made up,

represents rounding down, the first frequency domain unit being a frequency domain unit of the M frequency domain units.

As a possible implementation, the frequency domain positions of the M frequency domain units are based on the values of N and M, and P _S Determining, the formula is expressed as follows:

wherein k denotes an index of a first frequency domain unit of the M frequency domain units, yk denotes an index of the first frequency domain unit in a full bandwidth, N denotes a number of frequency domain units used for uplink data transmission, M denotes a number of precoding matrices indicated by the first indication information, and P denotes _S An index representing a starting frequency-domain position of the N frequency-domain units in the full bandwidth,

which means that the rounding is made up,

As a possible implementation, the frequency domain positions of the M frequency domain units are based on the value of M, P _S And P _e Determining, the formula is expressed as follows:

wherein k denotes an index of a first frequency domain unit of the M frequency domain units, yk denotes an index of the first frequency domain unit in a full bandwidth, M denotes a number of precoding matrices indicated by the first indication information, P denotes _S An index, P, representing a starting frequency-domain position of the N frequency-domain units in the full bandwidth _e Represents the N numbersAn index of an end frequency-domain position of a frequency-domain unit in the full bandwidth,

which means that the rounding is made up,

representing a rounding-down, the first frequency-domain unit is a frequency-domain unit of the M frequency-domain units.

The second aspect discloses a communication method, which may be applied to a network device, and may also be applied to a module (e.g., a chip) in the network device, and the following description will be given by taking the application to the network device as an example. The communication method may include: receiving a reference signal from a terminal device; determining M precoding matrixes according to the reference signal, wherein the M precoding matrixes are precoding matrixes corresponding to M frequency domain units in N frequency domain units, the N frequency domain units are frequency domain units used for uplink data transmission, M is an integer larger than 1, and N is an integer larger than M; and sending first indication information to the terminal equipment, wherein the first indication information is used for indicating the M precoding matrixes.

It should be understood that the detailed description of the second aspect corresponds to the description of the first aspect, and the corresponding features and advantages of the second aspect can be referred to the description of the first aspect, and the detailed description is omitted here where appropriate to avoid redundancy.

As a possible implementation, the indicating information for indicating M precoding matrices includes: the first indication information is used for indicating the quantization amplitude and the quantization phase of part of or all elements in the M precoding matrixes.

As a possible implementation, the communication method may further include: and sending second indication information to the terminal equipment, wherein the second indication information is used for indicating the frequency domain positions of the M frequency domain units.

As a possible implementation, the second indication information includes N bits, and the N bits are in one-to-one correspondence with the N frequency domain units.

As a possible implementation manner, the second indication information is used for indicating indexes of the M frequency domain units in the N frequency domain units.

As a possible implementation, the communication method may further include: and sending the resource configuration information of the reference signal to the terminal equipment.

which means that the rounding is made up,

where k represents the index of the first of the M frequency domain units, Y _k Indicating an index of the first frequency-domain unit in full bandwidth, N indicating an index for upstream dataThe number of frequency domain units to be transmitted, M represents the number of precoding matrices indicated by the first indication information, P _s An index representing a starting frequency-domain position of the N frequency-domain units in the full bandwidth,

which means that the rounding is made up,

wherein k denotes an index of a first frequency domain unit of the M frequency domain units, yk denotes an index of the first frequency domain unit in a full bandwidth, M denotes a number of precoding matrices indicated by the first indication information, P denotes _S An index, P, representing a starting frequency-domain position of the N frequency-domain units in the full bandwidth _e An index representing an ending frequency-domain position of the N frequency-domain units in the full bandwidth,

which means that the rounding is made up,

The third aspect discloses a communication method, which may be applied to a terminal device and may also be applied to a module (e.g., a chip) in the terminal device, and is described below by taking the application to the terminal device as an example. The communication method may include: receiving seventh indication information from the network device, wherein the seventh indication information is used for indicating the M merging coefficients; receiving eighth indication information from the network device, where the eighth indication information is used to indicate indexes of M basis vectors, the M combining coefficients are in one-to-one correspondence with the M basis vectors, the M basis vectors are M basis vectors corresponding to M frequency domain units in N frequency domain units, the N frequency domain units are frequency domain units used for uplink data transmission, M is an integer greater than 1, and N is an integer greater than M; and determining N precoding matrixes corresponding to the N frequency domain units according to the M merging coefficients and the indexes of the M base vectors.

In the embodiment of the invention, the precoding with smaller frequency domain granularity (namely frequency domain units) is introduced in the uplink transmission, the precoding matrixes corresponding to different frequency domain units are different, and the equivalent channels corresponding to the frequency domain units for uplink data transmission are continuously changed in amplitude and phase, so that the precoding with small frequency domain granularity can be realized, the channel estimation capability of a receiving end is ensured, and the performance and the channel estimation precision of the MIMO system can be improved. In addition, since the network device only needs to indicate information of precoding matrices corresponding to a part of frequency domain units in the frequency domain units for uplink data transmission, the indication overhead can be reduced, and transmission resources can be saved. Further, the terminal device may recover the precoding matrices corresponding to all the frequency domain units for uplink data transmission according to the precoding matrices corresponding to a part of the frequency domain units indicated by the network device for uplink data transmission, so as to ensure the continuity of the amplitude and the phase of the equivalent channel.

As a possible implementation manner, the seventh indication information for indicating the M combining coefficients includes: the seventh indication information is used to indicate the quantization amplitude and quantization phase of some or all of the elements in the M combined coefficients.

A fourth aspect discloses a communication method, which may be applied to a network device and may also be applied to a module (e.g., a chip) in the network device, and is described below by taking the application to the network device as an example. The communication method may include: receiving a reference signal from a terminal device; determining indexes of M merging coefficients and M basis vectors according to the reference signal, wherein the M merging coefficients correspond to the M basis vectors one by one, the M basis vectors are M basis vectors corresponding to M frequency domain units in N frequency domain units, the N frequency domain units are frequency domain units used for uplink data transmission, M is an integer greater than 1, and N is an integer greater than M; and sending seventh indication information and eighth indication information to the terminal device, wherein the seventh indication information is used for indicating the M merging coefficients, and the eighth indication information is used for indicating indexes of the M basis vectors.

It should be understood that the detailed description of the fourth aspect corresponds to that of the third aspect, and the corresponding features and advantages of the fourth aspect can be referred to the description of the third aspect, and the detailed description is omitted here as appropriate to avoid redundancy.

As a possible implementation manner, the seventh indication information for indicating the M combining coefficients includes: the seventh indication information is used to indicate quantization amplitudes and quantization phases of some or all of the elements in the M combined coefficients.

A fifth aspect discloses a communication method, which may be applied to a terminal device and may also be applied to a module (e.g., a chip) in the terminal device, and is described below by taking the application to the terminal device as an example. The communication method may include: receiving third indication information from the network device, where the third indication information is used to indicate M values, where the M values are changes of N channel characteristic parameters in the first channel characteristic parameter set, M is a positive integer, and N is an integer greater than or equal to M; and performing channel estimation according to a second channel characteristic parameter set and the M values, wherein the second channel characteristic parameter set comprises one or more channel characteristic parameters in the N channel characteristic parameters.

In the embodiment of the present invention, the terminal device may receive the variation of the channel characteristic parameter value indicated by the network device, may compensate the channel characteristic parameter value used for channel estimation, and may compensate the channel estimation performance loss caused by using the smaller frequency domain granularity precoding technology. Therefore, the overall performance of the MIMO system can be improved under the condition of not only realizing the pre-coding of small frequency domain granularity, but also ensuring the channel estimation capability of a receiving end.

As a possible implementation manner, the first value is a difference value between a second value of a first channel characteristic parameter and a third value of the first channel characteristic parameter, the first channel characteristic parameter is one of the N channel characteristic parameters, the first value is a value corresponding to the first channel characteristic parameter in the M values, and a precoding matrix corresponding to the second value is different from a precoding matrix corresponding to the third value.

As a possible implementation manner, the first value is a ratio of a second value of a first channel characteristic parameter to a third value of the first channel characteristic parameter, the first channel characteristic parameter is one of the N channel characteristic parameters, the first value is a value corresponding to the first channel characteristic parameter in the M values, and a precoding matrix corresponding to the second value is different from a precoding matrix corresponding to the third value.

In the embodiment of the invention, the network equipment indicates the value change quantity of the channel characteristic parameter through the quantized ratio, thereby not only meeting the requirement of the channel estimation parameter of the terminal equipment on the value accuracy of the channel characteristic parameter, but also reducing the notification overhead, and further reducing the complexity of the network and the terminal equipment.

As a possible implementation, the N channel characteristic parameters include at least one of maximum delay, average delay, delay spread, doppler shift, and doppler spread.

As a possible implementation, the third indication information includes N identifiers of the N channel characteristic parameters, the M values, and a correspondence between the N identifiers and the M values.

In the embodiment of the invention, the network equipment can indicate the variation quantity which needs to be compensated by the terminal equipment and also can indicate the channel characteristic parameter which needs to be compensated by the terminal equipment, so that the terminal equipment can accurately compensate according to the indication of the network equipment, and the accuracy of channel estimation can be further improved.

As a possible implementation, the communication method may further include: receiving fourth indication information from the network equipment, wherein the fourth indication information is used for indicating the same channel characteristic parameters corresponding to the first reference signal and the second reference signal; determining the second channel characteristic parameter set according to the fourth indication information and the first reference signal, or determining the second channel characteristic parameter according to the fourth indication information and the second reference signal.

In the embodiment of the present invention, the network device may indicate which channel characteristic parameters between different reference signals of the terminal device may be shared when performing channel estimation, so that when the terminal device receives the reference signal for performing channel estimation, the network device may determine the channel characteristic parameters for performing channel estimation according to the reference signal and the indication.

As a possible implementation, the communication method may further include: receiving a third reference signal from the network device; the performing channel estimation according to the second channel characteristic parameter set and the M values includes: and performing channel estimation according to the second channel characteristic parameter set, the M values and the third reference signal.

In the embodiment of the present invention, the channel estimation of the terminal device may be performed according to a reference signal used for channel estimation after the terminal device receives the reference signal from the network device.

A sixth aspect discloses a communication method, which may be applied to a network device and may also be applied to a module (e.g., a chip) in the network device, and the following description will be given by taking the application to the network device as an example. The communication method may include: determining M values, wherein the M values are the variation of N channel characteristic parameters in the first channel characteristic parameter set, M is a positive integer, and N is an integer greater than or equal to M; and sending third indication information to the terminal equipment, wherein the third indication information is used for indicating the M values.

It should be understood that the detailed description of the sixth aspect corresponds to that of the fifth aspect, and the corresponding features and advantages of the sixth aspect can be referred to the description of the fifth aspect, and the detailed description is omitted here as appropriate to avoid redundancy.

As a possible implementation, the communication method may further include: receiving a fourth reference signal from the terminal equipment; performing channel measurement according to the fourth reference signal to obtain a channel matrix corresponding to each frequency domain unit in all frequency domain units for uplink data transmission; determining a precoding matrix according to the channel matrix; and determining third indication information according to the precoding matrix.

In the embodiment of the invention, the change quantity of the channel characteristic parameter can be determined by the network equipment through the result of the uplink channel measurement, so that the accuracy of the change quantity can be ensured.

As a possible implementation manner, the first value is a difference value between a second value of a first channel characteristic parameter and a third value of the first channel characteristic parameter, the first channel characteristic parameter is one of the N channel characteristic parameters, the first value is a value corresponding to the first channel characteristic parameter among the M values, and a precoding matrix corresponding to the second value is different from a precoding matrix corresponding to the third value.

As a possible implementation manner, the first value is a ratio of a second value of a first channel characteristic parameter to a third value of the first channel characteristic parameter, the first channel characteristic parameter is one of the N channel characteristic parameters, the first value is a value corresponding to the first channel characteristic parameter among the M values, and a precoding matrix corresponding to the second value is different from a precoding matrix corresponding to the third value.

As a possible implementation manner, the third indication information includes N identifiers of the N channel characteristic parameters, the M values, and a correspondence between the N identifiers and the M values.

As a possible implementation, the communication method may further include: and sending fourth indication information to the terminal equipment, wherein the fourth indication information is used for indicating the same channel characteristic parameters corresponding to the first reference signal and the second reference signal.

As a possible implementation, the communication method may further include: and sending a third reference signal to the terminal equipment.

A seventh aspect discloses a communication method, which may be applied to a terminal device and may also be applied to a module (e.g., a chip) in the terminal device, and is described below by taking the application to the terminal device as an example. The communication method may include: receiving third indication information from the network device, where the third indication information is used to indicate M values, where the M values are changes of M channel characteristic parameters in a first channel characteristic parameter set, the M values are in one-to-one correspondence with the M channel characteristic parameters, and M is a positive integer; and performing channel estimation according to a second channel characteristic parameter set and the M values, wherein the second channel characteristic parameter set comprises one or more channel characteristic parameters in the N channel characteristic parameters.

In the embodiment of the invention, the terminal equipment can receive the variation of the channel characteristic parameters indicated by the network equipment, can compensate the value of the channel characteristic parameters for channel estimation in advance, and can compensate the loss of the channel estimation caused by using the precoding smoothing technology, thereby improving the accuracy of the channel estimation under the condition of not only realizing the precoding with small frequency domain granularity, but also ensuring the channel estimation capability of a receiving end.

It should be understood that the detailed description of the seventh aspect corresponds to the description of the fifth aspect, and the corresponding features and advantages of the seventh aspect can be referred to the description of the fifth aspect, and the detailed description is omitted here appropriately to avoid redundancy.

As a possible implementation manner, the first value is a difference value between a second value of a first channel characteristic parameter and a third value of the first channel characteristic parameter, the first channel characteristic parameter is one of the M channel characteristic parameters, the first value is a value corresponding to the first channel characteristic parameter among the M values, and a precoding matrix corresponding to the second value is different from a precoding matrix corresponding to the third value.

As a possible implementation manner, the first value is a ratio of a second value of a first channel characteristic parameter to a third value of the first channel characteristic parameter, the first channel characteristic parameter is one of the M channel characteristic parameters, the first value is a value corresponding to the first channel characteristic parameter among the M values, and a precoding matrix corresponding to the second value is different from a precoding matrix corresponding to the third value.

As a possible implementation, the M channel characteristic parameters include at least one of maximum delay, average delay, delay spread, doppler shift, and doppler spread.

As a possible implementation, the third indication information includes M identifiers of the M channel characteristic parameters, the M values, and a correspondence between the M identifiers and the M values.

As a possible implementation, the communication method may further include: receiving fourth indication information from the network device, where the fourth indication information is used to indicate the same channel characteristic parameters corresponding to the first reference signal and the second reference signal; and determining the second channel characteristic parameter set according to the fourth indication information and the first reference signal, or determining the second channel characteristic parameter according to the fourth indication information and the second reference signal.

An eighth aspect discloses a communication method, which may be applied to a network device, and may also be applied to a module (e.g., a chip) in the network device, and the following description will be given by taking the application to the network device as an example. The communication method may include: determining M values, wherein the M values are the variation of M channel characteristic parameters in a first channel characteristic parameter set, the M values are in one-to-one correspondence with the M channel characteristic parameters, and M is a positive integer; and sending third indication information to the terminal equipment, wherein the third indication information is used for indicating the M values.

It should be understood that the detailed description of the eighth aspect corresponds to that of the sixth aspect, and the corresponding features and advantages of the eighth aspect can be referred to the description of the sixth aspect, and the detailed description is omitted here as appropriate to avoid repetition.

As a possible implementation manner, the first value is a ratio of a second value of a first channel characteristic parameter to a third value of the first channel characteristic parameter, the first channel characteristic parameter is one of the M channel characteristic parameters, the first value is a value corresponding to the first channel characteristic parameter in the M values, and a precoding matrix corresponding to the second value is different from a precoding matrix corresponding to the third value.

A ninth aspect discloses a communication apparatus, which may be a terminal device or a module (e.g., a chip) in the terminal device.

The beneficial effects can be seen from the description of the first aspect, and are not described in detail herein. The communication device has the functionality to implement the actions in the method instance of the first aspect described above. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

As a possible implementation, the communication device may include:

a receiving unit, configured to receive first indication information from a network device, where the first indication information is used to indicate M precoding matrices, where the M precoding matrices are precoding matrices corresponding to M frequency domain units in N frequency domain units, the N frequency domain units are frequency domain units used for uplink data transmission, M is an integer greater than 1, and N is an integer greater than M;

and the determining unit is used for determining N precoding matrixes corresponding to the N frequency domain units according to the M precoding matrixes.

As a possible implementation manner, the determining unit is specifically configured to determine, according to the M precoding matrices and the frequency domain positions of the M frequency domain units, N precoding matrices corresponding to the N frequency domain units.

As a possible implementation manner, the determining unit is specifically configured to determine, according to values of an ith row and a jth column in each precoding matrix of the M precoding matrices and frequency domain positions of the M frequency domain units, values of an ith row and a jth column in the precoding matrix corresponding to each frequency domain unit of the N frequency domain units.

As a possible implementation manner, the receiving unit is further configured to receive second indication information from the network device, where the second indication information is used to indicate frequency domain positions of the M frequency domain units.

As a possible implementation manner, the receiving unit is further configured to receive resource configuration information of a reference signal from a network device, and the frequency domain positions of the M frequency domain units are determined based on the resource configuration information.

The frequency domain locations of the M frequency domain units are determined based on the frequency domain locations of the resources of the reference signal; or

The frequency domain locations of the M frequency domain units are determined based on the frequency domain locations of the resources of the reference signal and an offset.

As a possible implementation, the frequency domain positions of the M frequency domain units are determined according to the values of N and M by the following formula:

where k represents an index of a first frequency domain unit of the M frequency domain units, X _k Indicating an index of the first frequency domain unit of the N frequency domain units, N indicating a number of frequency domain units used for uplink data transmission, M indicating a number of precoding matrices indicated by the first indication information,

which means that the rounding-up is performed,

wherein k denotes an index of a first frequency domain unit of the M frequency domain units, Y _k Indicating an index of the first frequency domain unit in a full bandwidth, N indicating a number of frequency domain units used for uplink data transmission, M indicating a number of precoding matrices indicated by the first indication information, P _S An index representing a starting frequency-domain position of the N frequency-domain units in the full bandwidth,

which means that the rounding is made up,

which means that the rounding is made up,

A tenth aspect discloses a communication apparatus, which may be a network device or a module (e.g., a chip) in the network device.

The beneficial effects can be seen from the description of the second aspect, which is not repeated herein. The communication device has the functionality to implement the actions in the method example of the second aspect described above. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions.

As a possible implementation, the communication device may include:

a receiving unit, configured to receive a reference signal from a terminal device;

a determining unit, configured to determine M precoding matrices according to the reference signal, where the M precoding matrices are precoding matrices corresponding to M frequency domain units in N frequency domain units, the N frequency domain units are frequency domain units used for uplink data transmission, M is an integer greater than 1, and N is an integer greater than M;

a sending unit, configured to send first indication information to the terminal device, where the first indication information is used to indicate the M precoding matrices.

As a possible implementation manner, the sending unit is further configured to send second indication information to the terminal device, where the second indication information is used to indicate frequency domain positions of the M frequency domain units.

As a possible implementation manner, the sending unit is further configured to send resource configuration information of the reference signal to the terminal device.

which means that the rounding is made up,

where k represents the index of the first of the M frequency domain units, Y _k Indicating an index of the first frequency domain unit in a full bandwidth, N indicating a number of frequency domain units used for uplink data transmission, M indicating a number of precoding matrices indicated by the first indication information, P _S An index representing a starting frequency-domain position of the N frequency-domain units in the full bandwidth,

which means that the rounding-up is performed,

wherein k denotes an index of a first frequency domain unit of the M frequency domain units, Y _k Indicating an index of the first frequency domain unit in a full bandwidth, M indicating the number of precoding matrices indicated by the first indication information, P _S An index, P, representing a starting frequency-domain position of the N frequency-domain units in the full bandwidth _e An index representing an ending frequency-domain position of the N frequency-domain units in the full bandwidth,

which means that the rounding is made up,

An eleventh aspect discloses a communication apparatus, which may be a terminal device or a module (e.g., a chip) in the terminal device.

The beneficial effects can be seen from the description of the third aspect, which is not described herein again. The communication device has the functionality to implement the actions in the method instance of the third aspect described above. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions.

As a possible implementation, the communication device may include:

a receiving unit, configured to receive seventh indication information from a network device, where the seventh indication information is used to indicate the M merging coefficients;

the receiving unit is further configured to receive eighth indication information from the network device, where the eighth indication information is used to indicate indexes of M basis vectors, the M combining coefficients are in one-to-one correspondence with the M basis vectors, the M basis vectors are M basis vectors corresponding to M frequency domain units in N frequency domain units, the N frequency domain units are frequency domain units used for uplink data transmission, M is an integer greater than 1, and N is an integer greater than M;

a determining unit, configured to determine, according to the M combining coefficients and the indexes of the M basis vectors, N precoding matrices corresponding to the N frequency domain units.

A twelfth aspect discloses a communication apparatus, which may be a network device or a module (e.g., a chip) in the network device.

The beneficial effects can be seen from the description of the fourth aspect, which is not repeated herein. The communication device has the functionality to implement the actions in the method instance of the fourth aspect described above. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

As a possible implementation, the communication device may include:

a determining unit, configured to determine, according to the reference signal, M merging coefficients and indexes of M basis vectors, where the M merging coefficients correspond to the M basis vectors in a one-to-one manner, the M basis vectors are M basis vectors corresponding to M frequency domain units in N frequency domain units, the N frequency domain units are frequency domain units used for uplink data transmission, M is an integer greater than 1, and N is an integer greater than M;

a sending unit, configured to send seventh indication information and eighth indication information to the terminal device, where the seventh indication information is used to indicate the M merging coefficients, and the eighth indication information is used to indicate indexes of the M basis vectors.

As a possible implementation manner, the seventh indication information is used to indicate that the M combining coefficients include: the seventh indication information is used to indicate quantization amplitudes and quantization phases of some or all of the elements in the M combined coefficients.

A thirteenth aspect discloses a communication apparatus, which may be a terminal device or a module (e.g., a chip) in the terminal device.

The beneficial effects can be seen from the description of the fifth aspect, which is not described herein again. The communication device has the functionality to implement the actions in the method example of the fifth aspect described above. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions.

As a possible implementation, the communication device may include:

a receiving unit, configured to receive third indication information from the network device, where the third indication information is used to indicate M values, where the M values are changes of N channel characteristic parameters in a first channel characteristic parameter set, M is a positive integer, and N is an integer greater than or equal to M;

a channel estimation unit, configured to perform channel estimation according to a second channel characteristic parameter set and the M values, where the second channel characteristic parameter set includes one or more channel characteristic parameters of the N channel characteristic parameters.

As a possible implementation manner, the receiving unit is further configured to receive fourth indication information from the network device, where the fourth indication information is used to indicate that the first reference signal and the second reference signal correspond to the same channel characteristic parameter;

the communication apparatus may further include:

a determining unit, configured to determine the second channel characteristic parameter set according to the fourth indication information and the first reference signal, or determine the second channel characteristic parameter set according to the fourth indication information and the second reference signal.

As a possible implementation manner, the receiving unit is further configured to receive a third reference signal from the network device;

the channel estimation unit is specifically configured to perform channel estimation according to the second channel characteristic parameter set, the M values, and the third reference signal.

A fourteenth aspect discloses a communication apparatus, which may be a network device or a module (e.g., a chip) in the network device.

The beneficial effects can be seen from the description of the sixth aspect, which is not described herein again. The communication apparatus has a function of realizing the behavior in the method example of the sixth aspect described above. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions.

As a possible implementation, the communication device may include:

a determining unit, configured to determine M values, where M values are changes of N channel characteristic parameters in a first channel characteristic parameter set, M is a positive integer, and N is an integer greater than or equal to M;

a sending unit, configured to send third indication information to a terminal device, where the third indication information is used to indicate the M values.

As a possible implementation, the communication device may further include:

a receiving unit, configured to receive a fourth reference signal from the terminal device;

a channel measurement unit, configured to perform channel measurement according to the fourth reference signal, to obtain a channel matrix corresponding to each frequency domain unit in all frequency domain units used for uplink data transmission;

a determining unit, configured to determine a precoding matrix according to the channel matrix;

the determining unit is further configured to determine third indication information according to the precoding matrix.

As a possible implementation manner, the sending unit is further configured to send fourth indication information to the terminal device, where the fourth indication information is used to indicate the same channel characteristic parameter corresponding to the first reference signal and the second reference signal.

As a possible implementation manner, the sending unit is further configured to send a third reference signal to the terminal device.

A fifteenth aspect discloses a communication apparatus, which may be a terminal device or a module (e.g., a chip) in the terminal device.

Beneficial effects can be seen from the description of the seventh aspect, which is not described herein again. The communication device has the functionality to implement the actions in the method instance of the seventh aspect described above. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions.

As a possible implementation, the communication device may include:

a receiving unit, configured to receive third indication information from the network device, where the third indication information is used to indicate M values, where the M values are changes of M channel characteristic parameters in a first channel characteristic parameter set, the M values are in one-to-one correspondence with the M channel characteristic parameters, and M is a positive integer;

As a possible implementation manner, the first value is a difference value between a second value of a first channel characteristic parameter and a third value of the first channel characteristic parameter, the first channel characteristic parameter is one of the M channel characteristic parameters, the first value is a value corresponding to the first channel characteristic parameter in the M values, and a precoding matrix corresponding to the second value is different from a precoding matrix corresponding to the third value.

As a possible implementation manner, the third indication information includes M identifiers of the M channel characteristic parameters, the M values, and a correspondence between the M identifiers and the M values.

the communication apparatus may further include:

the channel estimation unit is specifically configured to perform channel estimation according to the second set of channel characteristic parameters, the M values, and the third reference signal.

A sixteenth aspect discloses a communication apparatus, which may be a network device or a module (e.g., a chip) in the network device.

The beneficial effects can be seen from the description of the eighth aspect, and are not described in detail here. The communication apparatus has a function of realizing the behavior in the method example of the eighth aspect described above. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

As a possible implementation, the communication device may include:

a determining unit, configured to determine M values, where the M values are changes of M channel characteristic parameters in a first channel characteristic parameter set, the M values are in one-to-one correspondence with the M channel characteristic parameters, and M is a positive integer;

As a possible implementation, the communication device method may further include:

a channel measurement unit, configured to perform channel measurement according to the fourth reference signal to obtain a channel matrix corresponding to each frequency domain unit in all frequency domain units used for uplink data transmission;

A seventeenth aspect discloses a communication apparatus, which may be a terminal device or a module (e.g., a chip) within the terminal device. The communication device may include a processor, a memory, an input interface, and an output interface, the input interface being configured to receive information from a communication device other than the communication device, and the output interface being configured to output information to the communication device other than the communication device, and when the processor executes a computer program stored in the memory, the processor is caused to execute a communication method disclosed in the first aspect or any one of the embodiments of the first aspect, or a communication method disclosed in the third aspect or any one of the embodiments of the third aspect, or a communication method disclosed in any one of the fifth aspect or the fifth aspect, or a communication method disclosed in any one of the seventh aspect or the seventh aspect.

An eighteenth aspect discloses a communication apparatus, which may be a network device or a module (e.g., a chip) within a network device. The communication device may comprise a processor, a memory, an input interface for receiving information from a communication device other than the communication device, and an output interface for outputting information to the communication device other than the communication device, the processor being caused to execute the communication method disclosed in the second aspect or any embodiment of the second aspect, or the communication method disclosed in the fourth aspect or any embodiment of the fourth aspect, or the communication method disclosed in the sixth aspect or any embodiment of the sixth aspect, or the communication method disclosed in any embodiment of the eighth aspect, when the processor executes a computer program stored in the memory.

A nineteenth aspect discloses a communication system comprising at least one communication device of the seventeenth aspect and at least one communication device of the eighteenth aspect.

A twentieth aspect discloses a computer readable storage medium having stored thereon a computer program or computer instructions which, when run, implements a communication method as disclosed in any of the embodiments of the first aspect or the first aspect, the second aspect or the second aspect, the third aspect or the third aspect, the fourth aspect or the fourth aspect, the fifth aspect or the fifth aspect, the sixth aspect or the sixth aspect, the seventh aspect or the seventh aspect, the eighth aspect or the eighth aspect, as described above.

A twenty-first aspect discloses a chip comprising a processor for executing a program stored in a memory, which program, when executed, causes the chip to perform the method disclosed by any of the embodiments of the first or first aspect, the second or second aspect, the third or third aspect, the fourth or fourth aspect, the fifth or fifth aspect, the sixth or sixth aspect, the seventh or seventh aspect, the eighth or eighth aspect.

As a possible implementation, the memory is located off-chip.

A twenty-second aspect discloses a computer program product comprising computer program code which, when run, causes the communication method of any of the first aspect or any of the embodiments of the first aspect, the second aspect or any of the second aspects, the third aspect or any of the third aspects, the fourth aspect or any of the fourth aspects, the fifth aspect or any of the fifth aspects, the sixth aspect or any of the sixth aspects, the seventh aspect or any of the seventh aspects, the eighth aspect or any of the eighth aspects described above to be performed.

Drawings

FIG. 1 is a schematic diagram of a network architecture according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a pre-coding frequency domain granularity according to an embodiment of the present invention;

fig. 3 is a flow chart of a communication method according to an embodiment of the present invention;

FIG. 4 is a diagram illustrating values of N and M according to an embodiment of the present invention;

fig. 5 is a flow chart illustrating another communication method disclosed in the embodiment of the present invention;

FIG. 6 is a flow chart illustrating another communication method disclosed in the embodiments of the present invention;

FIG. 7 is a diagram illustrating a precoding smoothing technique according to an embodiment of the present invention;

fig. 8 is a schematic diagram of channel delay spread under different precoding modes according to an embodiment of the present invention;

fig. 9 is a flow chart of another communication method disclosed in the embodiment of the invention;

fig. 10 is a schematic structural diagram of a communication device according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of another communication device disclosed in the embodiment of the present invention;

fig. 12 is a schematic structural diagram of another communication device disclosed in the embodiment of the present invention;

fig. 13 is a schematic structural diagram of another communication device disclosed in the embodiment of the present invention;

fig. 14 is a schematic structural diagram of another communication device according to the embodiment of the present disclosure;

fig. 15 is a schematic structural diagram of another communication device according to an embodiment of the present invention.

Detailed Description

The embodiment of the invention discloses a communication method and a communication device, which are used for improving the performance of an MIMO system and the channel estimation precision. The following are detailed below.

In order to better understand a communication method and apparatus disclosed in the embodiments of the present invention, a network architecture used in the embodiments of the present invention is described below. Referring to fig. 1, fig. 1 is a schematic diagram of a network architecture according to an embodiment of the present invention. As shown in fig. 1, the network architecture may include one or more terminal devices 1 (one is illustrated in fig. 1) and one or more network devices 2 (one is illustrated in fig. 1), and the terminal devices 1 and the network devices 2 form a Multiple Input and Multiple Output (MIMO) system.

The communication between the terminal device 1 and the network device 2 may include an upstream communication (i.e., terminal device 1 to network device 2 communication) and a downstream communication (i.e., network device 2 to terminal device 1 communication). In the uplink communication, the terminal device 1 is configured to send an uplink signal to the network device 2; and the network equipment 2 is used for receiving the uplink signal from the terminal equipment 1. In the downlink communication, the network device 2 is configured to send a downlink signal to the terminal device 1; the terminal device 1 is configured to receive a downlink signal from the network device 2.

A terminal device 1, which may also be referred to as a User Equipment (UE), a Mobile Station (MS), a Mobile Terminal (MT), etc., is a device that provides voice and/or data connectivity to a user. The terminal device may be a handheld terminal, a Customer Premises Equipment (CPE) notebook, a subscriber unit (subscriber unit), a cellular phone, a smart phone, a wireless data card, a Personal Digital Assistant (PDA) computer, a tablet, a wireless modem (modem), a handheld device (hand), a laptop computer (laptop computer), a Session Initiation Protocol (SIP) phone, a cordless phone (cordless phone) or a Wireless Local Loop (WLL) station, a Machine Type Communication (MTC) terminal, a wearable device (e.g., a smart watch, smart bracelet, pedometer, etc.), in-vehicle devices (e.g., cars, bicycles, electric vehicles, airplanes, ships, trains, high-speed rails, etc.), virtual Reality (VR) devices, augmented Reality (AR) devices, wireless terminals in industrial control (industrial control), smart home devices (e.g., refrigerators, televisions, air conditioners, electric meters, etc.), smart robots, plant room devices, wireless terminals in self driving (self driving), wireless terminals in remote surgery (remote medical supply), wireless terminals in smart grid (smart grid), wireless terminals in transportation safety (transportation safety), wireless terminals in smart city (smart city), or wireless terminals in smart home (smart home), A flying device (e.g., a smart robot, a hot air balloon, a drone, an airplane, etc.) or other device that may access a network.

The network device 2 is a device capable of communicating with the terminal device 1, and may be a base station, a relay station, or an access point. The base station may be a Base Transceiver Station (BTS) in a global system for mobile communications (GSM) or Code Division Multiple Access (CDMA) network, a base station Node (NB) in a Wideband Code Division Multiple Access (WCDMA), an evolved Node (NB) in a Long Term Evolution (LTE) (eNB or eNodeB), a radio controller in a Cloud Radio Access Network (CRAN) scenario, a base station device in a 5G network or a network device in a future evolved PLMN network, or a wearable device or a vehicle-mounted device.

It should be noted that the system architecture shown in fig. 1 is not limited to include only the network device and the terminal device shown in the figure, and may also include other network devices or terminal devices that are not shown in the figure, and specific embodiments of the present invention are not listed here.

For a better understanding of the embodiments of the present invention, the following description will be made of the related art of the embodiments of the present invention.

The MIMO technology is a core technology of Long Term Evolution (LTE) system and New Radio (NR) of fifth generation (5 th generation,5 g). In order to greatly improve the channel capacity, in the MIMO technology, a plurality of antennas are used for both the transmitting end and the receiving end, and an antenna system of a plurality of channels is configured between the transmitting end and the receiving end. For uplink transmission, when the terminal device is configured with a multi-antenna transmission radio frequency channel, the terminal device may perform uplink MIMO transmission through multiple antennas. A plurality of terminal devices transmit simultaneously on the same time-frequency resource, and may also form a virtual MIMO system, i.e., uplink multi-user MIMO (UL MU-MIMO). Currently, the NR protocol supports 2 uplink MIMO transmission modes of codebook (codebook) -based transmission and non-codebook (non-codebook) transmission. For codebook transmission, the precoding matrix may be selected from a quantized codebook by the network device, the terminal device may determine the precoding matrix for uplink transmission based on a fixed codebook, and the specific uplink transmission flow may be as follows:

1) The terminal device may send a Sounding Reference Signal (SRS) to the network device.

2) The network device may perform uplink channel measurement according to the SRS sent by the terminal device, and may determine the precoding matrix.

3) The network device may notify the terminal device of the precoding matrix through a Transmit Precoding Matrix Indicator (TPMI).

4) The terminal device may precode uplink data based on the precoding matrix indicated by the network device, and may further send the uplink data to the network device through a Physical Uplink Shared Channel (PUSCH).

For non-codebook transmissions. Different from codebook transmission, in non-codebook transmission, a precoding matrix is not limited to a preset codebook any more, the precoding matrix can be calculated by terminal equipment, and the overhead of indicating the precoding matrix by network equipment can be saved. In addition, the loss of the quantization of the precoding matrix is avoided, and the transmission performance can be further improved. The uplink transmission flow of non-codebook transmission may be as follows:

1) The terminal device may perform channel measurement through the downlink reference signal to obtain an uplink candidate precoding matrix, may precode the SRS based on the uplink candidate precoding matrix, and may then transmit the precoded SRS to the network device.

2) The network device may perform channel estimation based on the SRS sent by the terminal device, may select one precoding matrix from the uplink candidate precoding matrices as an uplink precoding matrix based on a result of the channel estimation, and may then indicate the precoding matrix to the terminal device.

3) The terminal device may perform precoding on the uplink data according to the precoding matrix indicated by the network device, and may further send the uplink data to the network device through the PUSCH.

However, since the frequency domain granularity of precoding for codebook transmission and non-codebook transmission is all scheduling bandwidths, small granularity precoding cannot be realized.

It should be understood that for common terminal equipment and network equipment configurations, reference signals are typically sent by the terminal equipment and received by the network equipment for channel measurement. For Time Division Duplexing (TDD), due to the reciprocity of uplink and downlink channels, after a network device obtains an uplink channel matrix through reference signal measurement, the network device may perform conjugate transposition on the uplink channel to obtain a corresponding downlink channel matrix, and may further determine a downlink precoding matrix. Therefore, for the TDD system, the uplink precoding matrix and the downlink precoding matrix can be determined through one channel measurement.

For a MIMO-Orthogonal Frequency Division Multiplexing (OFDM) system, the channel has frequency selective fading in the frequency domain. Within the coherence bandwidth, the channel can be considered to be substantially flat, and after the bandwidth exceeds the coherence bandwidth, the channel is no longer flat and there is a variation in the channel response with frequency. In order to best adapt to the frequency selective fading characteristics of the channel, the precoding matrix also needs to be adaptively adjusted as the channel changes in the frequency domain. Under the theoretical optimal design, each frequency domain unit corresponds to one frequency domain channel response, and correspondingly, each frequency domain unit corresponds to one optimal precoding matrix. For the kth frequency domain element, the precoding matrix W _k Equivalently changes the channel response H _k Form an equivalent channel matrix

However, for the receiving end, different precoding matrixes Wk of the frequency domain units can result in equivalent channel matrixes

Hopping in the frequency domain. This may cause that the receiving end cannot perform joint channel estimation by combining multiple frequency domain units when performing channel estimation, thereby reducing the accuracy of channel estimation.

In order to reduce the processing complexity and consider the performance of the channel estimation at the receiving end in an actual system, the same precoding matrix may be used for one frequency domain resource. The size of the frequency domain resources with the same precoding may be referred to as a precoding frequency domain granularity. The pre-coding frequency domain granularity is one or more frequency domain units. The frequency domain unit may be a subcarrier, a subband, a Resource Block (RB), or a frequency domain resource of other sizes.

Taking frequency domain units as RBs as an example, consecutive RBs with the same precoding matrix may be referred to as precoding resource block groups (PRGs). For example, if the size of one PRG includes 2 RBs, the precoding matrices within the 2 RBs included in one PRG are the same. Referring to fig. 2, fig. 2 is a schematic diagram of a precoding frequency domain granularity according to an embodiment of the present invention. In fig. 2, the size of PRG is 2RB. Because the amplitude and the phase of the frequency domain channel are continuously changed in each frequency domain granularity, the receiving end can carry out joint channel estimation on a plurality of frequency domain units, and the channel estimation performance of the receiving end is ensured. Within a pre-coding frequency domain granularity, the amplitude and phase of the frequency domain channel are continuously changed, and joint channel estimation can be carried out. When the pre-coding frequency domain granularity is larger, the receiving end can carry out joint channel estimation, so that more frequency domain resources are available, and the channel estimation is more accurate; when the granularity of the pre-coding frequency domain is small, the pre-coding precision is high, the channel change can be better adapted, however, the frequency domain resources which can be used by the receiving end for joint channel estimation are less, so that the requirement on the channel estimation capability is high. Therefore, for resisting channel frequency selective fading, the pre-coding frequency domain granularity needs to be compromised between improving the performance of the MIMO system and the receiving end channel estimation performance.

In order to implement precoding with small frequency domain granularity, precoding with small frequency domain granularity may be introduced in codebook transmission and non-codebook transmission in uplink transmission. However, for codebook transmission, the network device needs to indicate the precoding matrices corresponding to all frequency domain units for uplink data transmission to the terminal device, so that more information needs to be transmitted, resulting in waste of transmission resources; for non-codebook transmission, the terminal device needs to send different precoding matrices on all uplink transmission frequency domain units to the network device, and this transmission scheme may cause the network device to be unable to perform uplink channel estimation and may cause transmission information waste at the same time. Therefore, the two existing uplink transmission modes are difficult to support sub-band-level high-precision uplink precoding in an uplink MIMO scene.

Referring to fig. 3, fig. 3 is a schematic flow chart of a communication method according to an embodiment of the present invention. The communication method may be applied to an uplink MIMO scenario, and may also be applied to other scenarios, which are similar, and is not limited herein. As shown in fig. 3, the communication method may include the following steps.

301. The terminal equipment sends a reference signal to the network equipment. Accordingly, the network device receives the reference signal from the terminal device.

Before the terminal device sends uplink data to the network device, a reference signal may be sent to the network device. The reference signal may be an SRS, or may be another reference signal, which is not limited herein.

302. And the network equipment determines M pre-coding matrixes according to the reference signal.

The M precoding matrixes are precoding matrixes corresponding to the M frequency domain units in the N frequency domain units. The M precoding matrices are in one-to-one correspondence with the M frequency domain units, namely, one frequency domain unit uniquely corresponds to one precoding matrix. Here, the precoding matrix is an uplink precoding matrix. The N frequency domain units are frequency domain units used for uplink data transmission, and may be understood as frequency domain units scheduled by the network device for the terminal device, and may also be understood as frequency domain units scheduled by the network device for the terminal device for uplink data transmission. M is an integer greater than 1, and N is an integer greater than M.

In an optional manner, after receiving the reference signal from the terminal device, the network device may first perform uplink channel measurement according to the reference signal in 301 to obtain a channel matrix, and then may determine the precoding matrix according to the channel matrix. For example, the network device may decompose the channel matrix to obtain a precoding matrix. Alternatively, the network device may also decompose the channel matrix to obtain a decomposed matrix, and then may use Eigenvector Zero Forcing (EZF) to the decomposed matrix to obtain the precoding matrix.

Corresponding to the above two determination methods of the precoding matrix, an exemplary determination process is as follows. Suppose the number of antennas of the terminal device is N _R The number of the antennas of the network equipment is N _T The total number of K terminal devices performs uplink multi-user (MU) -MIMO transmission, and the number of uplink transmission streams corresponding to each terminal device is L _k If the total number L of uplink transmission streams of the K terminal devices is equal to

The number of uplink transmission streams corresponding to each terminal device may be the same or different. Lk is an integer greater than or equal to 1. The channel matrix obtained by the network device performing channel measurement on the kth terminal device is H _k Can be paired with H _k Singular Value Decomposition (SVD) or eigenvalue decomposition (EVD) is performed to obtain an eigenvector V _k And a characteristic value. Each H _k Corresponding maximum L in corresponding eigenvalues _k The feature vector corresponding to each feature value is

Namely satisfy

Wherein H _k Is N _T ×N _R Matrix of V _k Is N _R ×N _R The matrix of (a) is,

is N _R ×L _k Matrix of (U) _k Is N of _T ×N _T Unitary matrix, D _k For half positive determination of N _T ×N _R The order-diagonal matrix is then used,

is a V _k The conjugate transpose of (c).

Using EZF on the decomposed matrix, the linear precoding matrix W can be represented as W = V (V) ^H V+δI) ^-1 。

Corresponding from K terminal devices

Spliced into a matrix of N _R A matrix of x L. W is also N _R A matrix of x L. According to the splicing, the corresponding of the k terminal equipment can be determined

The column vector in the corresponding W is taken as W _k That is, the zf precoding weight of the kth terminal device is the precoding matrix. δ is the noise figure. And I is an identity matrix.

Corresponding to the two pre-coding matrix determining modes, the terminal equipment can adopt the largest L when carrying out Single User (SU) -MIMO transmission _k Feature vector corresponding to each feature value

As the uplink precoding matrix of the terminal device. When the terminal equipment performs MU-MIMO transmission, the corresponding W after EZF algorithm can be adopted _k As the uplink precoding matrix of the terminal device.

When the network device performs uplink channel measurement according to the reference signal in step 301, the network device may perform channel measurement only on the reference signals corresponding to the M frequency domain units, may determine channel matrices corresponding to the M frequency domain units based on the reference signals corresponding to the M frequency domain units, and then may determine the M precoding matrices according to the channel matrices corresponding to the M frequency domain units. Since the network device does not need to perform channel measurement on all frequency domain units for uplink data transmission, the processing procedure of the network device can be reduced, so that the channel measurement efficiency can be improved and the power consumption of the network device can be reduced.

The M frequency domain units may be any M frequency domain units selected by the network device from the N frequency domain units. The M frequency domain units may also be M frequency domain units selected from the N frequency domain units by the network device according to a certain rule. For example, the network device may select one frequency domain unit from N frequency domain units at an interval of one frequency domain unit, may also select one frequency domain unit from N frequency domain units at an interval of two frequency domain units, may also select two frequency domain units from N frequency domain units at an interval of one frequency domain unit, may also select the first M frequency domain units or the last M frequency domain units from N frequency domain units, and may also be in other selection manners, which are not limited herein. The M frequency domain units may also be M frequency domain units selected by the network device from the N frequency domain units according to the indication of the terminal device. For example, the terminal device may transmit indication information indicating the M frequency domain units to the network device. The indication information may be sent to the network device by the terminal device in advance, or may be sent to the network device together with the reference signal. The M frequency domain units may also be frequency domain units of a reference signal configured by the network device for the terminal device, or determined by frequency domain units corresponding to the reference signal and frequency domain unit offset.

When the network device performs uplink channel measurement, it may also perform channel measurement on all frequency domain units used for uplink data transmission, that is, perform channel measurement on the N frequency domain units to obtain channel matrices corresponding to the N frequency domain units. The network device may first determine the precoding matrices corresponding to the N frequency domain units according to the channel matrices corresponding to the N frequency domain units, and then may select M precoding matrices from the N precoding matrices. The network device may also select M channel matrices from the N channel matrices first, and then determine M precoding matrices according to the M channel matrices. The selection method may refer to the above description, or may be selected according to interference noise (i.e. interference plus noise) obtained by channel measurement. For example, M frequency domain units with smaller interference noise may be selected.

The M precoding matrices may be quantized precoding matrices or non-quantized precoding matrices.

303. The network equipment sends the first indication information to the terminal equipment. Accordingly, the terminal device receives the first indication information from the network device.

In an optional implementation manner, the first indication information may indicate the M precoding matrices by indicating quantization amplitudes and quantization phases of some or all of the elements in the M precoding matrices. Quantized amplitude is understood to mean quantized amplitude. Quantized phase is understood to mean quantized phase.

Regarding the first indication information, the quantization amplitude and quantization phase of the M precoding matrix part elements may be indicated, and optionally, the first indication information may indicate the quantization amplitude and quantization phase of non-zero precoding matrices. For example, the first indication information may indicate non-zero quantized amplitude and quantized phase of the M precoding matrices. The network device needs to quantize the amplitude and phase of the unquantized M precoding matrices. Before quantizing the M unquantized precoding matrices, the network device may normalize the M precoding matrices, that is, divide the first precoding matrix by the maximum value in the first precoding matrix to make the maximum value in the first precoding matrix 1, and then quantize the M normalized precoding matrices. The first precoding matrix is any one of unquantized M precoding matrices. The network device may quantize the amplitude and phase of the unquantized precoding matrix using a plurality of bits. The larger the number of bits used, the finer the quantization, and the less performance loss due to quantization. For example, the network device may quantize the amplitude and phase of the unquantized precoding matrix by using 3 bits, and the corresponding relationship between the quantized bits and the quantized amplitude and quantized phase may be as shown in table 1:

TABLE 1 quantization bits and quantization amplitude and quantization phase

It should be understood that table 1 is merely an exemplary illustration of the correspondence relationship of the quantization bits to the quantization amplitude and the quantization phase, and does not limit the correspondence relationship of the quantization bits to the quantization amplitude and the quantization phase. For example, the network device may quantize the amplitude and phase of the unquantized precoding matrix with 4 bits.

Regarding the first indication information, the first indication information may indicate quantization amplitudes and quantization phases of all elements of the M precoding matrices, and the first indication information may include quantization bits corresponding to the quantization amplitudes and quantization phases included in each of the M precoding matrices. The quantization bit may be 2 bits, 3 bits, 4 bits, 5 bits, or other bit values, which is not limited herein.

When the M frequency domain units are determined by the network device, the network device may indicate the frequency domain positions of the M frequency domain units to the terminal device according to the second indication information.

In one case, the second indication information indicates, in a bitmap manner, frequency domain positions of M frequency domain units, the second indication information includes N bits, the N bits correspond to the N frequency domain units one by one, that is, each of the N bits corresponds to one frequency domain unit for uplink data transmission, an nth bit of the N bits corresponds to an nth frequency domain unit of the N frequency domain units, and two state values of each of the N bits respectively indicate whether the network device indicates a precoding matrix of the bit corresponding to the frequency domain unit, for example, when a value of one bit is 1, the one bit may indicate that the network device indicates a precoding matrix of the bit corresponding to the frequency domain unit, and when the value of the one bit is 0, the one bit may indicate that the network device does not indicate a precoding matrix of the bit corresponding to the frequency domain unit.

For example, assuming that N =9, the 9 bits included in the second indication information are 010010010, the 9 bits from left to right correspond to frequency domain units 1 to 9, a bit value of 0 indicates that no precoding matrix is reported in the frequency domain unit, and a bit value of 1 indicates that a precoding matrix is reported in the frequency domain unit.

In another case, the second indication information may be indexes of M frequency domain units, for example, the second indication information includes M first bit fields in one-to-one correspondence with the M frequency domain units, and a state value of each bit field is an index of a corresponding frequency domain unit.

It should be understood that the second indication information may be sent together with the first indication information or separately, and the present invention is not limited thereto.

When the M frequency domain units are reported to the network device by the terminal device, or the M frequency domain units are M predefined frequency domain units in the N frequency domain units, the network device may not send the second indication information to the terminal device, that is, the network device sends the second indication information is an optional step.

The frequency domain locations of the M frequency domain elements may be determined based only on the values of N and M. For example, equation (1) shows an example in which the frequency domain locations of M frequency domain cells are determined according to the values of N and M.

Where k denotes the index of the frequency domain unit in M frequency domain units, X _k Indicates indexes of the frequency domain units in N frequency domain units, N indicates the number of the frequency domain units used for uplink data transmission, M indicates the number of precoding matrices indicated by the first indication information or the number of precoding matrices prescribed by a protocol,

which means that the rounding is made up,

meaning rounding down.

For example, please refer to fig. 4, wherein fig. 4 is a schematic diagram of values of N and M according to an embodiment of the present invention. As shown in fig. 4, the N frequency domain units are 9 subbands, and the network device indicates 3 precoding matrices to the terminal device. The indexes of the 3 pre-coding matrixes corresponding to the 3 sub-bands are respectively 0, 1 and 2, and the indexes of the three sub-bands in the 9 sub-bands can be calculated to be respectively 1, 4 and 7 according to the formula.

It should be understood that the above formula is only an exemplary illustration of determining the frequency domain locations of the M frequency domain units according to the values of N and M, and is not a limitation thereof. For example, in the above formula

Can be replaced by

In the above formula

Can be replaced by

As another example, in the above formula

Can be replaced by

As another example, in the above formula

Can be replaced by

The frequency domain locations of the M frequency domain elements may also be determined based on the values of N and M, as well as other one or more parameters. For example, formula (2) shows an example that the frequency domain locations of the M frequency domain units can also be determined according to the values of N and M, and other one or more parameters.

Wherein, Y _k Denotes the index of the first frequency-domain unit in the full bandwidth, P _s An index representing the starting frequency-domain position of the N frequency-domain units in the full bandwidth. It can be seen that the N frequency domain units can be consecutive N frequency domain units in the full bandwidth. The index of the starting frequency-domain position of the N frequency-domain units in the full bandwidth may be understood as the index of the frequency-domain position of the first frequency-domain unit of the N frequency-domain units in the full bandwidth.

The frequency domain locations of the M frequency domain elements may also be determined based on the value of M and one or more other parameters. Equation (3) shows an example that the frequency domain locations of the M frequency domain units can also be determined according to the value of M and other one or more parameters.

Wherein, P _e An index representing the ending frequency-domain position of the N frequency-domain units in the full bandwidth. The index of the end frequency domain position of the N frequency domain units in the full bandwidth may be understood as an index of the frequency domain position of the nth frequency domain unit of the N frequency domain units in the full bandwidth.

304. And the terminal equipment determines N pre-coding matrixes corresponding to the N frequency domain units according to the M pre-coding matrixes.

The terminal device may determine N precoding matrices from the M precoding matrices. In an optional manner, the terminal device may determine, according to the M precoding matrices and the frequency domain positions of the M frequency domain units, N precoding matrices corresponding to the N frequency domain units. In yet another optional manner, the terminal device may determine, according to values of an ith row and a jth column in each precoding matrix of the M precoding matrices and frequency domain positions of the M frequency domain units, values of an ith row and a jth column in the precoding matrix corresponding to each frequency domain unit of the N frequency domain units. For example, the terminal device may determine a variation trend of the values of the ith row and the jth column in the precoding matrix along with the frequency domain positions according to the values of the ith row and the jth column in each precoding matrix of the M precoding matrices and the frequency domain positions of the M frequency domain units, and then may determine the precoding matrix corresponding to each frequency domain unit of the N frequency domain units according to the variation trend of the values of the ith row and the jth column along with the frequency domain positions and the frequency domain position corresponding to each frequency domain unit of the N frequency domain units. The obtaining mode of the variation trend can be a frequency domain flat push algorithm, a linear interpolation algorithm, a transform domain interpolation algorithm and the like. It can be seen that the element values of the same position in the pre-coding matrix corresponding to the non-indicated frequency domain position are determined according to the value of the same element position in the pre-coding matrix corresponding to the indicated frequency domain position. The following takes a Discrete Cosine Transform (DCT) algorithm as an example to specifically describe a process of obtaining N precoding matrices from M precoding matrices.

The following describes a process of determining N precoding matrices by M precoding matrices by using a DCT transform domain interpolation algorithm in a terminal device. Suppose M precoding matrices received by the terminal device are W _m A precoding matrix W _m Is N _R ×L _m Matrix of N _R Number of antennas for terminal equipment, L _m And the number of the uplink transmission streams corresponding to the terminal equipment. The elements in the ith row and the jth column of the M precoding matrices may be column-spliced to obtain V (i, j) = [ W ₁ (i，j)W ₂ (i，j)...W _M (i，j)] ^T And V (i, j) is an M × 1 matrix. V (i, j) may be subjected to a Discrete Cosine Transform (DCT) transform, i.e., a left-multiplication of transform matrix Ti, resulting in a column vector V = d (i, j). The V = d (i, j) may be subjected to Inverse Discrete Cosine Transform (IDCT) transform, i.e., a left-multiplication transform matrix Td, to obtain a column vector W _d (i，j)。W _d (i, j) is an N × 1 matrix. Can be formed by _d And (i, j) determining each element in (i, j) as the element in the ith row and the jth column in the N precoding matrices, namely recovering the N precoding matrices.

The transformation matrix Ti belongs to C ^M×M And Td ∈ C ^M×M May be expressed as the following formula (4) and formula (5), respectively.

The terminal device may perform coding modulation on the uplink data to be transmitted according to the MCS, and then may perform precoding on the uplink data to be transmitted after the coding modulation according to the precoding matrices corresponding to the N frequency domain units, so as to transmit the precoded uplink data to be transmitted to the network device.

Referring to fig. 5, fig. 5 is a schematic flow chart of another communication method according to the embodiment of the present invention. The communication method may be applied to UL MU-MIMO scenarios, and may also be applied to other similar scenarios, which is not limited herein. As shown in fig. 5, the communication method may include the following steps.

501. And the network equipment sends the sixth indication information to the terminal equipment, and correspondingly, the terminal equipment receives the sixth indication information from the network equipment.

The sixth indication information is used to indicate M frequency domain units of the N frequency domain units, where the N frequency domain units are frequency domain units used for uplink data transmission, and may be understood as frequency domain units scheduled by the network device for the terminal device, and may also be understood as frequency domain units scheduled by the network device for the terminal device for uplink data transmission. M is an integer greater than 1, and N is an integer greater than or equal to M. Alternatively, the sixth indication information may be resource configuration information of the reference signal.

In one case, the sixth indication information may include or indicate indexes of the M frequency domain units, and the terminal device may determine the M frequency domain units according to the indexes of the M frequency domain units. In another case, the sixth indication information may include or indicate frequency domain positions of the M frequency domain units, and the terminal device may determine the M frequency domain units according to the frequency domain positions of the M frequency domain units or according to the frequency domain positions of the M frequency domain units and a predefined offset. In still another case, the sixth indication information may include or indicate the frequency domain positions and offsets of the M frequency domain units, and the terminal device may determine the M frequency domain units according to the frequency domain positions and offsets of the M frequency domain units.

502. The terminal device sends the reference signal to the network device through the M frequency domain units, and accordingly, the network device can receive the reference signal from the terminal device through the M frequency domain units.

503. The network equipment determines M pre-coding matrixes according to the M reference signals.

The M precoding matrices correspond one-to-one to the M frequency domain units. Here, the precoding matrix is an uplink precoding matrix.

In an optional manner, after receiving M reference signals from the terminal device, the network device may first perform uplink channel measurement on the M frequency domain units according to the reference signals to obtain M channel matrices, and then may determine M precoding matrices according to the M channel matrices. For example, the network device may decompose the M channel matrices to obtain M precoding matrices. For another example, the network device may decompose M channel matrices first, and then may perform eigenvector zero forcing on the M decomposed channel matrices to obtain M precoding matrices. The process of obtaining M precoding matrices from M channel matrices may be eigenvalue decomposition or eigenvector zero forcing in step 302.

504. The network equipment sends the first indication information to the terminal equipment, and accordingly, the terminal equipment receives the first indication information from the network equipment.

Specifically, the first indication information is used to indicate M precoding matrices. That is, the network device determines M precoding matrices of M frequency domain units according to the reference signal sent by the terminal device on the M frequency domain units.

505. And the terminal equipment determines N pre-coding matrixes corresponding to the N frequency domain units according to the M pre-coding matrixes.

After receiving the first indication information from the network device, the terminal device may determine, according to the M precoding matrices, N precoding matrices corresponding to the N frequency domain units.

The terminal device may determine the frequency domain locations of the M frequency domain units selected in step 501 as the frequency domain locations of the M frequency domain resources. The terminal device may determine N precoding matrices corresponding to the N frequency domain units according to the M precoding matrices and the frequency domain positions of the M frequency domain units. The detailed description may refer to step 304.

Referring to fig. 6 based on the above network architecture, fig. 6 is a schematic flowchart of another communication method according to an embodiment of the present invention. The communication method may be applied to UL MU-MIMO scenarios, and may also be applied to other similar scenarios, which is not limited herein. As shown in fig. 6, the communication method may include the following steps.

601. The terminal equipment sends the reference signal to the network equipment, and accordingly the network equipment receives the reference signal from the terminal equipment.

For a detailed description of step 601, reference may be made to step 301.

602. The network device determines the M combining coefficients and the indexes of the M basis vectors according to the reference signal.

The network device may determine the M combining coefficients and the indices of the M basis vectors from the reference signal. The M combining coefficients correspond to the M basis vectors one-to-one. The M basis vectors are M basis vectors corresponding to M frequency domain units in the N frequency domain units, the N frequency domain units are frequency domain units used for uplink data transmission, M is an integer larger than 1, and N is an integer larger than M.

The network device may obtain the precoding matrix W of the uplink MIMO according to the reference signal and the precoding matrix calculation method in step 302 _n 。W _n Is N _R ×L _k A matrix of (c). n is the index n epsilon (1, N) of the frequency domain position of the frequency domain unit corresponding to the precoding matrix, L _k Number of upstream transmission streams, N, for kth terminal equipment _R The number of antennas of the terminal device. After obtaining the precoding matrix, the network device may send the lth information to the kth terminal device _k And carrying out transform domain operation on the precoding matrixes corresponding to the N frequency domain positions of the N frequency domain units of the uplink transmission stream, and extracting the strongest M merging coefficients and the corresponding M basis vectors by using the sparse characteristics of the transform domain. The transform domain operation may be a discrete fourier transform, a discrete cosine transform, etc., and is not limited herein. According to the above steps, precoding matrix W _n Can be represented as W _n ＝W _n，m ×W _m，k 。W _n，m For the strongest M coefficients of the transform domain, i.e. the combined coefficients, N _R A matrix of xm; w _m，k For transform domain basis vectors, an M × N matrix.

The following describes in detail a process of obtaining, by a network device, M combining coefficients and indexes of M basis vectors by taking Discrete Fourier Transform (DFT) as an example. The network device obtains W _n Then, the precoding matrix of each uplink transmission stream can be subjected to column splicing at N frequency domain positions to obtain a precoding matrix of each uplink transmission streamW _l Is N of _R A matrix of x N; then can be paired with W _l Performing inverse DFT transform, i.e. right-by-N dimensional IDFT matrix

Obtaining a transform domain matrix w _l Is N of _R A matrix of x N; the transform domain matrix w may then be aligned _l Select M magnitude and maximum column vectors at N _R Dimension is averaged, and then the averaged value is quantized to obtain M merging coefficients of the transform domain, namely W _n，m 。W _n，m Corresponding M IDFT matrices

Is W _m，k . The index of M basis vectors is w _l M magnitudes and the index of the largest column vector.

603. And the network equipment sends the seventh indication information and the eighth indication information to the terminal equipment, and correspondingly, the terminal equipment receives the seventh indication information and the eighth indication information from the network equipment.

The network device may transmit the seventh indication information and the eighth indication information to the terminal device. The seventh indication information may indicate the M combining coefficients. The eighth indication information may indicate indexes of the M basis vectors. The seventh indication information may indicate quantized amplitude and quantized phase values of the M combined coefficients, which may be W _n，m Quantized amplitude and quantized phase. The eighth indication information may be an index of the M basis vectors.

604. And the terminal equipment determines N precoding matrixes corresponding to the N frequency domain units according to the seventh indication information and the eighth indication information.

The terminal device may determine precoding matrices of the N frequency domain units according to the seventh indication information and the eighth indication information. Taking DFT as an example, a detailed description is given below to a terminal device for obtaining a precoding matrix W of each frequency domain unit on N frequency domain units according to the seventh indication information and the eighth indication information _n The process of (2).

The terminal device may determine W according to the seventh indication information _n，m May be according to the eighth fingerIndicating information determination W _n，m Indices of the corresponding M basis vectors. Corresponding N-dimensional DFT matrix D _N From D, possibly according to the indices of the M basis vectors _N Selecting M rows to obtain D _M Then, the quantized precoding matrix for each uplink transmission stream is right-multiplied by D _M Obtaining the pre-coding matrix W on the N frequency domain positions corresponding to the N frequency domain units corresponding to each uplink transmission stream _n I.e. W _n ＝W _n，m ×D _M 。

In a frequency domain resource, the same precoding matrix is adopted, the amplitude and the phase of the equivalent channel matrix are continuous, and the joint channel estimation can be carried out on the reference signals in the frequency domain resource. The precoding smoothing technology can realize that different precoding matrixes are adopted in one frequency domain resource under the condition of ensuring that the amplitude and/or the phase of the equivalent channel are kept continuous in the frequency domain.

Taking the domain transform based precoding smoothing technique as an example, one frequency domain unit may employ the same precoding matrix. Referring to fig. 7, fig. 7 is a schematic diagram illustrating a precoding smoothing technique according to an embodiment of the present invention. As shown in fig. 7, I =3 frequency domain units, each of which may contain K =8 subcarriers, may calculate a precoding matrix for each frequency domain unit, and calculate I =3 precoding matrices W ₁ 、W ₂ 、W ₃ . The elements of the ith row and jth column of each of the three precoding matrices form a vector

For vector W _ij Performing DCT to obtain vector C _ij ＝D _N W _ij 。D _N Denotes the DCT transform matrix of I = 3. Then for vector C _ij Performing IDCT transformation to obtain vector P _ij ＝E _M D _N W _ii 。E _M IDCT transform matrix with dimension J × I, J = I × K =24 is represented. At this time, the obtained vector P _ij Contains 24 elements, corresponding to J =24 subcarriers of I =3 frequency domain units, respectively.

Therefore, the precoding with small frequency domain granularity can be realized by the precoding smoothing technology. In addition, because the amplitude and the phase of the equivalent channel are smoothly changed along with the frequency in a plurality of frequency domain units, the receiving end can perform joint channel estimation on the plurality of frequency domain units.

However, the precoding smoothing technique may change some channel characteristic parameters of the channel, such as Delay Spread (DS), while ensuring the precoding with small frequency domain granularity smoothing. For the traditional precoding method, one frequency domain resource adopts the same precoding matrix, so that the trend of the equivalent channel changing along with the frequency is the same as the trend of the channel changing along with the frequency. The precoding smoothing technology enables a refined precoding matrix, and the trend of the equivalent channel changing along with the frequency and the trend of the channel changing along with the frequency are caused to change. Referring to fig. 8, fig. 8 is a schematic diagram of channel delay spread under different precoding manners according to an embodiment of the present invention. As shown in fig. 8, in the conventional method, a frequency domain resource uses the same precoding matrix, and the normalized delay spread corresponding to the equivalent channel matrix and the channel matrix is close. However, for small granularity precoding of the smoothing technique, the normalized delay spread corresponding to the equivalent channel matrix is significantly larger than the normalized delay spread corresponding to the channel matrix.

The receiving end needs to perform accurate channel estimation, and often needs to acquire channel characteristic parameters such as delay spread corresponding to a relatively accurate equivalent channel matrix. However, for precoding based on the precoding smoothing technique, the accuracy of channel estimation is reduced because accurate channel characteristic parameters such as delay spread cannot be obtained.

Based on the network architecture, please refer to fig. 9, fig. 9 is a flowchart illustrating another communication method according to an embodiment of the present invention. The communication method can be applied to a downlink MIMO scene. As shown in fig. 9, the communication method may include the following steps.

901. The network device determines M values.

The network device may determine M values. The M values are the variation of N channel characteristic parameters in the first channel characteristic parameter set, M is a positive integer, and N is an integer greater than or equal to M. The N channel characteristic parameters may include one or more of maximum delay, average delay, delay spread, doppler shift, doppler spread, and the like. Each of the N channel characteristic parameters may be maximum delay, average delay, delay spread, doppler shift, or doppler spread, but two channel characteristic parameters may not be maximum delay, average delay, delay spread, doppler shift, or doppler spread at the same time. For example, when N is 1, the N channel characteristic parameters may be maximum delay, average delay, delay spread, doppler shift, and doppler spread; when N is 2, the N channel characteristic parameters may be maximum delay and average delay, maximum delay and delay spread, average delay and delay spread, maximum delay and doppler shift, maximum delay and doppler spread, average delay and doppler shift, doppler shift and doppler spread, delay spread and doppler shift, and delay spread and doppler spread. N is other values and is not described in detail herein.

The first value may be a difference value between the second value of the first channel characteristic parameter and the third value of the first channel characteristic parameter. The first channel characteristic parameter may be one of N channel characteristic parameters, that is, any one of the N channel characteristic parameters. The first value is a value corresponding to a first channel characteristic parameter among the M values. The difference between the second value and the third value may be the second value minus the third value, or may be the third value minus the second value. The difference value can be positive or negative. In one case, the second value may be a value of the first channel characteristic parameter obtained by using a smooth difference algorithm, and the third value may be a value of the first channel characteristic parameter obtained without using the smooth difference algorithm. In another case, the second value may be a value of the first channel characteristic parameter obtained without using the smooth difference algorithm, and the third value may be a value of the first channel characteristic parameter obtained using the smooth difference algorithm. The precoding matrix corresponding to the second value is different from the precoding matrix corresponding to the third value, and it can be understood that, when channel estimation is performed, if a first channel characteristic parameter exists in used channel characteristic parameters, under the assumption that values of other channel characteristic parameters except the first channel characteristic parameter are all kept unchanged, the second value of the first channel characteristic parameter is used for performing channel estimation to obtain the first precoding matrix, and the channel estimation is different from the second precoding matrix obtained by using the third value of the first channel characteristic parameter for performing channel estimation.

The first value may also be a ratio of the second value of the first channel characteristic parameter to a third value of the first channel characteristic parameter. The ratio is a number greater than 0. The ratio may be an integer or a non-integer.

The first value may also be a dB value of the second value of the first channel characteristic parameter and the third value of the first channel characteristic parameter. For example, the second value is a, the third value is B, a =10logB.

Next, both N and M are 1. For example, when the first value is a difference value between the second value of the first channel characteristic parameter and the third value of the first channel characteristic parameter, the third indication information may indicate the difference value by 2 bits, the third indication information may be an index of the difference value, and the difference value between the third indication information and the indicated difference value may be as shown in table 2:

third indication information	Difference value
		00	-0.1
01	-0.2
		10	-0.3
11	-0.4

Table 2 the correspondence relationship between the third indication information and the first value is as shown in table 2, and the third indication information is different and the indicated first value is different. For another example, when the first value is a ratio of the second value of the first channel characteristic parameter to the third value of the first channel characteristic parameter, the third indication information may indicate the ratio by 2 bits, the third indication information may be an index of the ratio, and the ratio between the third indication information and the indication may be as shown in table 3:

third indication information	Ratio of
		00	0.5x
01	1x
		10	2x
11	3x

TABLE 3 correspondence between third indication information and ratio

Where x may represent a second value. As shown in table 3.

It should be understood that tables 2-3 are exemplary illustrations of the third indication information, and the third indication information is not limited thereto. For example, the third indication information may indicate the difference value or the ratio value by 3 bits or other methods. As another example, a difference value of +0.5 (i.e., increased by 0.5) may correspond to 00 in Table 2, and a difference value of-0.5 (i.e., decreased by 0.5) may correspond to 10 in Table 2.

The terminal device may transmit the fourth reference signal to the network device. The network device may receive a fourth reference signal from the terminal device, perform channel measurement according to the fourth reference signal, obtain a channel matrix corresponding to each frequency domain unit in all frequency domain units used for uplink data transmission, determine a precoding matrix according to the channel matrix corresponding to each frequency domain unit, and then determine third indication information according to the precoding matrix. The fourth reference signal may be an SRS signal or another reference signal, and is not limited herein.

The network device may first determine, according to the reciprocity of uplink and downlink channels, a channel matrix corresponding to each frequency domain unit in all frequency domain units used for uplink data transmission, and then may determine, according to a channel matrix corresponding to each frequency domain unit in all frequency domain units used for downlink data transmission, a precoding matrix corresponding to each frequency domain unit used for downlink data transmission. The network device may determine an equivalent channel matrix corresponding to each frequency domain unit, and then may determine, according to the equivalent channel matrix, a value of the first channel characteristic parameter that is obtained without using a smoothing difference algorithm for the first channel characteristic parameter. And the network device may use a smooth difference algorithm for the precoding matrix corresponding to each frequency domain unit used for downlink data transmission, and then may determine the value of the first channel characteristic parameter obtained by using the smooth difference algorithm for the channel characteristic parameter according to the equivalent channel matrix obtained by using the smooth difference algorithm.

902. And the network equipment sends the third indication information to the terminal equipment, and correspondingly, the terminal equipment receives the third indication information from the network equipment.

The network device may send the third indication information to the terminal device. The third indication information is used for indicating the M values.

The network device may further indicate to the terminal device a correspondence between the M values and the N channel characteristic parameters. In one case, the network device may transmit the fifth indication information to the terminal device. The fifth indication information is used for indicating the corresponding relation between the M values and the N channel characteristic parameters. The third indication information and the fifth indication information may be transmitted simultaneously or separately. Each of the M values may correspond to one or more of the N channel characteristics. Each of the N channel characterizing parameters corresponds to one of the M values, and the values corresponding to different channel characterizing parameters may be the same. When M is 1 and N is greater than 1, the fifth indication information may indicate N channel characteristic parameters, indicating that the change amounts of the N channel characteristic parameters are the same value. When M and N are both greater than 1, the fifth indication information may be as shown in tables 4 to 6:

identification of channel characteristic parameters	Index of value
		Channel characteristic parameter 1	00
Channel characteristic parameter 2	10
		Channel characteristic parameter 3	11
Channel characteristic parameter 4	01

TABLE 4 fifth indicating information

Identification of channel characteristic parameters	Index of value
		Channel characteristic parameter 1	00
Channel characteristic parameter 2	00
		Channel characteristic parameter 3	11
Channel characteristic parameter 4	01

TABLE 5 fifth indicating information

Index of value	Identification of channel characteristic parameters
		00	Channel characteristic parameter 1, channel characteristic parameter 2
11	Channel characteristic parameter 3
		01	Channel characteristic parameter 4

TABLE 6 fifth instruction information

It should be understood that tables 4-6 are illustrated with four channel characterization parameters as examples. Tables 4 to 6 are exemplary illustrations of the fifth indication information, and do not limit the fifth indication information.

In another case, the third indication information may include N identifiers of the N channel characteristic parameters, M values, and a correspondence between the N identifiers and the M values. For example, the third indication information may be as in tables 4 to 6. For another example, the third indication information may be two bit sequences, where one or more consecutive bits in one bit sequence may be an identifier of the channel characteristic parameter, and one or more consecutive bits in the other bit sequence may be an index of the change amount of the channel characteristic parameter. For example, the first bit sequence is 00011110, the second bit sequence is 11101100, and the first bit sequence is assumed to be a sequence formed by the identifier of the channel characteristic parameter, and the second bit sequence is a sequence formed by the index of the change amount of the channel characteristic parameter, which may be that the first two bits 00 in the first bit sequence correspond to the first two bits 11 in the second bit sequence, the third and fourth bits 01 in the first bit sequence correspond to the third and fourth bits 10 in the second bit sequence, the fifth and sixth bits 11 in the first bit sequence correspond to the fifth and sixth bits 11 in the second bit sequence, and the last two bits 10 in the first bit sequence correspond to the last two bits 00 in the second bit sequence.

903. And the terminal equipment carries out channel estimation according to the second channel characteristic parameter set and the M values.

The terminal device may perform channel estimation according to the second set of channel characteristic parameters and the M values. The second set of channel characteristic parameters comprises one or more of the N channel characteristic parameters.

The terminal device may first determine the second channel characteristic parameter set and an initial value of each channel characteristic parameter in the second channel characteristic parameter set, then may determine one or more channel characteristic parameters of the N channel characteristic parameters included in the second channel characteristic parameter set, that is, determine an intersection between the first channel characteristic parameter set and the second channel characteristic parameter set, and may further adjust the one or more channel characteristic parameters from the initial values to final values according to a value corresponding to each channel characteristic parameter of the one or more channel characteristic parameters of the M values. The network device may then perform channel estimation based on the second set of channel characteristics parameters and the final value of each channel characteristic parameter in the second set of channel characteristics parameters. When a channel characteristic parameter does not correspond to one of the M values, the initial value and the final value of the channel characteristic parameter are the same.

When the first value is a difference value between the second value of the first channel characteristic parameter and the third value of the first channel characteristic parameter, the final value of the first channel characteristic parameter may be a sum of the initial value of the first channel characteristic parameter and a value corresponding to the first channel characteristic parameter, or a difference between the initial value of the first channel characteristic parameter and the value corresponding to the first channel characteristic parameter. When the first value is a ratio of the second value of the first channel characteristic parameter to the third value of the first channel characteristic parameter, the final value of the first channel characteristic parameter may be a product of the initial value of the first channel characteristic parameter and a value corresponding to the first channel characteristic parameter, or may be a value obtained by dividing the initial value of the first channel characteristic parameter by the value corresponding to the first channel characteristic parameter.

In one case, the terminal device may store a channel characteristic parameter set for performing channel estimation and an initial value of each channel characteristic parameter in the channel characteristic parameter set, and the terminal device may determine the stored channel characteristic parameter set and the initial value of each channel characteristic parameter in the channel characteristic parameter set as the second channel characteristic parameter set and the initial value of each channel characteristic parameter in the second channel characteristic parameter set. In another case, there are a default set of channel characteristic parameters for channel estimation and an initial value of each channel characteristic parameter in the set of channel characteristic parameters, and the terminal device may determine the default set of channel characteristic parameters and the initial value of each channel characteristic parameter in the set of channel characteristic parameters as the second set of channel characteristic parameters and the initial value of each channel characteristic parameter in the second set of channel characteristic parameters. In another case, the network device may send, to the terminal device, fourth indication information, where the fourth indication information is used to indicate the same channel characteristic parameters corresponding to the first reference signal and the second reference signal, and optionally, the fourth indication information may be a quasi co-location (QCL) bonding relationship between the first reference signal and the second reference signal, that is, a channel characteristic parameter that can be shared by the two reference signals. The terminal device may determine the second channel characteristic parameter set and the initial value of each channel characteristic parameter in the second channel characteristic parameter set according to the fourth indication information and the first reference signal, and may also determine the second channel characteristic parameter set and the initial value of each channel characteristic parameter in the second channel characteristic parameter set according to the fourth indication information and the second reference signal. The network device may further send the first reference signal or the second reference signal to the terminal device, and the terminal device may further receive the first reference signal or the second reference signal from the network device. For example, when a demodulation reference signal (DMRS) is indicated by a QCL Type (Type) a onto a Tracking Reference Signal (TRS), i.e., the network device may assume the DMRS using the measured QCLTypeA channel-related parameters of the TRS. At this time, if the channel delay spread measured by the TRS is 200ns, and the equivalent channel delay spread corresponding to the change of the smooth precoding technique is 400ns due to the use of the precoding smoothing algorithm by the network device, it may indicate, by "10" in table 3, that the offset of the delay spread due to the precoding change of the network device is caused, and the terminal device may assume that the delay spread change of the equivalent channel is 400ns, and perform DMRS channel estimation according to the parameter. At this time, if the network device correspondingly adopts the precoding smoothing technique, the offset of the specific delay spread channel parameter with respect to the QCL measurement result may be indicated through signaling. Similarly, the terminal device may also assume this QCL binding relationship, and assume a binding relationship between a channel state information reference signal (CSI-RS) and a DMRS.

Optionally, the network device may transmit a third reference signal to the terminal device. After receiving the third reference signal, the terminal device may perform channel estimation according to the second channel characteristic parameter set, the M values, and the third reference signal. The third reference signal is a reference signal for channel estimation.

It should be understood that the third reference signal may be the same as the first reference signal, may be the same as the second reference signal, and may be different from both the first reference signal and the second reference signal.

The equivalent channel matrix can be obtained by channel estimation, and then after the terminal device receives the downlink data from the network device, the downlink data can be demodulated according to the equivalent channel matrix.

In another embodiment, the N channel characteristics parameters may be replaced by M channel characteristics parameters, and in this case, the M values correspond to the M channel characteristics parameters one to one. There may be the same value in the M values. Other relevant descriptions may refer to the corresponding embodiment of fig. 7.

The frequency domain location of the frequency domain unit may be an index of the frequency domain unit.

It should be understood that the functions performed by the network device in the above-described communication method may also be performed by a module (e.g., a chip) in the network device, and the functions performed by the terminal device may also be performed by a module (e.g., a chip) in the terminal device.

It should be understood that the related information (i.e., the same information or similar information) in the different embodiments described above may be referred to each other.

Referring to fig. 10, fig. 10 is a schematic structural diagram of a communication device according to an embodiment of the present invention. As shown in fig. 10, the communication apparatus may include:

a receiving unit 1001, configured to receive first indication information from a network device, where the first indication information is used to indicate M precoding matrices, where the M precoding matrices are precoding matrices corresponding to M frequency domain units in N frequency domain units, the N frequency domain units are frequency domain units used for uplink data transmission, M is an integer greater than 1, and N is an integer greater than M;

a determining unit 1002, configured to determine N precoding matrices corresponding to the N frequency domain units according to the M precoding matrices.

In an embodiment, the determining unit 1002 is specifically configured to determine, according to the M precoding matrices and the frequency domain positions of the M frequency domain units, N precoding matrices corresponding to the N frequency domain units.

In an embodiment, the determining unit 1002 is specifically configured to determine, according to values of an ith row and a jth column in each of the M precoding matrices and frequency domain positions of the M frequency domain units, values of an ith row and a jth column in the precoding matrix corresponding to each of the N frequency domain units.

In one embodiment, the first indication information is used for indicating M precoding matrices and includes: the first indication information is used for indicating the quantization amplitude and the quantization phase of part of or all of the elements in the M precoding matrices.

In one embodiment, the receiving unit 1001 is further configured to receive second indication information from the network device, where the second indication information is used to indicate frequency domain positions of the M frequency domain units.

In one embodiment, the second indication information includes N bits, and the N bits correspond to the N frequency domain units one to one.

In one embodiment, the second indication information is used to indicate an index of the M frequency-domain cells among the N frequency-domain cells.

In an embodiment, the receiving unit 1001 is further configured to receive resource configuration information of a reference signal from a network device, and the frequency domain positions of the M frequency domain units are determined based on the resource configuration information of the reference signal.

In one embodiment, the determining of the frequency domain locations of the M frequency domain units based on the resource configuration information of the reference signal comprises:

the frequency domain positions of the M frequency domain units are determined based on the index of the resource of the reference signal; or alternatively

In one embodiment, the frequency domain locations of the M frequency domain units are determined based on the values of N and M.

In one embodiment, the frequency domain locations of the M frequency domain elements are represented by the following formula determined by the values of N and M:

where k denotes the index of the first of the M frequency-domain units, x _k Indicating an index of a first frequency domain unit of the N frequency domain units, N indicating the number of frequency domain units used for uplink data transmission, M indicating the number of precoding matrices indicated by the first indication information,

which means that the rounding is made up,

representing a rounding-down, the first frequency domain unit is a frequency domain unit of the M frequency domain units.

In one embodiment, the frequency domain locations of the M frequency domain units are based on the values of N and M, and P _S Determining, the formula is expressed as follows:

wherein k denotes an index of a first frequency domain unit in the M frequency domain units, yk denotes an index of the first frequency domain unit in the full bandwidth, N denotes the number of frequency domain units used for uplink data transmission, M denotes the number of precoding matrices indicated by the first indication information, P denotes _S Representing N frequency-domain units in the full bandwidthThe index of the starting frequency-domain position,

which means that the rounding-up is performed,

representing a rounding down, the first frequency domain unit is a frequency domain unit of the M frequency domain units.

In one embodiment, the frequency domain locations of the M frequency domain units are based on the value of M, P _S And P _e Determining, the formula is expressed as follows:

where k denotes an index of a first frequency domain unit of the M frequency domain units, Y _k Denotes an index of the first frequency domain unit in the full bandwidth, M denotes the number of precoding matrices indicated by the first indication information, P _S Index, P, representing the starting frequency-domain position of N frequency-domain units in the full bandwidth _e An index indicating the ending frequency-domain position of the N frequency-domain units in the full bandwidth,

which means that the rounding is made up,

More detailed descriptions about the receiving unit 1001 and the determining unit 1002 can be directly obtained by referring to the related descriptions of the terminal device in the method embodiment shown in fig. 3, which are not repeated herein.

Referring to fig. 11, fig. 11 is a schematic structural diagram of another communication device according to an embodiment of the present invention. As shown in fig. 11, the communication apparatus may include:

a receiving unit 1101 configured to receive a reference signal from a terminal device;

a determining unit 1102, configured to determine M precoding matrices according to the reference signal, where the M precoding matrices are precoding matrices corresponding to M frequency domain units in N frequency domain units, the N frequency domain units are frequency domain units used for uplink data transmission, M is an integer greater than 1, and N is an integer greater than M;

a sending unit 1103, configured to send first indication information to the terminal device, where the first indication information is used to indicate the M precoding matrices.

In one embodiment, the first indication information for indicating M precoding matrices includes: the first indication information is used for indicating the quantization amplitude and the quantization phase of part of or all of the elements in the M precoding matrices.

In an embodiment, the sending unit 1103 is further configured to send, to the terminal device, second indication information, where the second indication information is used to indicate frequency domain positions of the M frequency domain units.

In one embodiment, the second indication information includes N bits, and the N bits correspond one-to-one to the N frequency domain units.

In an embodiment, the sending unit 1103 is further configured to send resource configuration information of the reference signal to the terminal device.

where k denotes the index of the first of the M frequency domain units, X _k Indicating an index of a first frequency domain unit of the N frequency domain units, N indicating the number of frequency domain units used for uplink data transmission, M indicating the number of precoding matrices indicated by the first indication information,

which means that the rounding is made up,

wherein k denotes an index of a first frequency domain unit in the M frequency domain units, yk denotes an index of the first frequency domain unit in the full bandwidth, N denotes the number of frequency domain units used for uplink data transmission, M denotes the number of precoding matrices indicated by the first indication information, P denotes _S An index representing the starting frequency-domain position of the N frequency-domain units in the full bandwidth,

which means that the rounding is made up,

wherein k denotes an index of a first frequency domain unit of the M frequency domain units, yk denotes an index of the first frequency domain unit in the full bandwidth, M denotes the number of precoding matrices indicated by the first indication information, P denotes _s Index representing starting frequency domain position of N frequency domain units in full bandwidth，P _e An index indicating the ending frequency-domain position of the N frequency-domain units in the full bandwidth,

which means that the rounding-up is performed,

More detailed descriptions about the receiving unit 1101, the determining unit 1102 and the sending unit 1103 can be directly obtained by referring to the related descriptions of the network device in the embodiment of the method shown in fig. 3, which are not repeated herein.

Referring to fig. 12, fig. 12 is a schematic structural diagram of another communication device according to an embodiment of the present invention. The communication device may be a terminal device. As shown in fig. 12, the communication apparatus may include a receiving unit 1201, a channel estimation unit 1202, and a determination unit 1203.

In one case, wherein:

a receiving unit 1201, configured to receive third indication information from a network device, where the third indication information is used to indicate M values, where the M values are changes of N channel characteristic parameters in a first channel characteristic parameter set, M is a positive integer, and N is an integer greater than or equal to M;

a channel estimation unit 1202, configured to perform channel estimation according to a second channel characteristic parameter set and M values, where the second channel characteristic parameter set includes one or more channel characteristic parameters of the N channel characteristic parameters.

In one embodiment, the first value is a difference value between a second value of the first channel characteristic parameter and a third value of the first channel characteristic parameter, the first channel characteristic parameter is one of N channel characteristic parameters, the first value is a value corresponding to the first channel characteristic parameter among M values, and a precoding matrix corresponding to the second value is different from a precoding matrix corresponding to the third value.

In one embodiment, the first value is a ratio of a second value of the first channel characteristic parameter to a third value of the first channel characteristic parameter, the first channel characteristic parameter is one of N channel characteristic parameters, the first value is a value corresponding to the first channel characteristic parameter among M values, and a precoding matrix corresponding to the second value is different from a precoding matrix corresponding to the third value.

In one embodiment, the N channel characteristic parameters include at least one of maximum delay, average delay, delay spread, doppler shift, and doppler spread.

In one embodiment, the third indication information includes N identifiers of the N channel characteristic parameters, and each of the N identifiers identifies a value or information of a value of the corresponding M values.

In an embodiment, the receiving unit 1201 is further configured to receive fourth indication information from the network device, where the fourth indication information is used to indicate that the first reference signal and the second reference signal correspond to the same channel characteristic parameter;

a determining unit 1203 is configured to determine a second channel characteristic parameter set according to the fourth indication information and the first reference signal, or determine the second channel characteristic parameter set according to the fourth indication information and the second reference signal.

In an embodiment, the receiving unit 1201 is further configured to receive a third reference signal from the network device;

the channel estimation unit 1202 is specifically configured to perform channel estimation according to the second set of channel characteristic parameters, the M values, and the third reference signal.

The more detailed description about the receiving unit 1201, the channel estimating unit 1202, and the determining unit 1203 may be obtained directly by referring to the related description of the terminal device in the embodiment of the method shown in fig. 9, which is not repeated herein.

In another instance, wherein:

a receiving unit 1201, configured to receive third indication information from a network device, where the third indication information is used to indicate M values, where the M values are changes of M channel characteristic parameters in a first channel characteristic parameter set, the M values are in one-to-one correspondence with the M channel characteristic parameters, and M is a positive integer;

In one embodiment, the first value is a difference value between a second value of the first channel characteristic parameter and a third value of the first channel characteristic parameter, the first channel characteristic parameter is one of M channel characteristic parameters, the first value is a value corresponding to the first channel characteristic parameter among the M values, and a precoding matrix corresponding to the second value is different from a precoding matrix corresponding to the third value.

In one embodiment, the first value is a ratio of a second value of the first channel characteristic parameter to a third value of the first channel characteristic parameter, the first channel characteristic parameter is one of M channel characteristic parameters, the first value is a value corresponding to the first channel characteristic parameter among the M values, and a precoding matrix corresponding to the second value is different from a precoding matrix corresponding to the third value.

In one embodiment, the M channel characteristic parameters include at least one of maximum delay, average delay, delay spread, doppler shift, and doppler spread.

In one embodiment, the third indication information includes M identifiers of the M channel characteristic parameters, and each of the M identifiers identifies a value or information of a value of the corresponding M values.

More detailed descriptions about the receiving unit 1201, the channel estimating unit 1202, and the determining unit 1203 can be directly obtained by referring to the related descriptions of the terminal device in the other embodiment, which are not repeated herein.

Referring to fig. 13 based on the network architecture, fig. 13 is a schematic structural diagram of another communication device according to an embodiment of the present invention. The communication device may be a terminal device. As shown in fig. 13, the communication apparatus may include a transmitting unit 1301, a receiving unit 1302, a channel measuring unit 1303, and a determining unit 1304.

In one case, wherein:

a determining unit 1304, configured to determine M values, where M values are changes of N channel characteristic parameters in the first channel characteristic parameter set, M is a positive integer, and N is an integer greater than or equal to M;

a sending unit 1301, configured to send third indication information to the terminal device, where the third indication information is used to indicate the M values.

In one embodiment, the receiving unit 1302 is configured to receive a fourth reference signal from the terminal device;

a channel measuring unit 1303, configured to perform channel measurement according to the fourth reference signal, so as to obtain a channel matrix corresponding to each frequency domain unit in all frequency domain units for uplink data transmission;

a determining unit 1304, configured to determine a precoding matrix according to the channel matrix;

the determining unit 1304 is further configured to determine third indication information according to the precoding matrix.

In an embodiment, the sending unit 1301 is further configured to send fourth indication information to the terminal device, where the fourth indication information is used to indicate the same channel characteristic parameter corresponding to the first reference signal and the second reference signal.

In an embodiment, the sending unit 1301 is further configured to send a third reference signal to the terminal device.

More detailed descriptions about the sending unit 1301, the receiving unit 1302, the channel measuring unit 1303, and the determining unit 1304 may be directly obtained by referring to the description about the network device in the embodiment of the method shown in fig. 9, which is not described herein again.

In another case, wherein:

a determining unit 1304, configured to determine M values, where the M values are the variation amounts of M channel characteristic parameters in the first channel characteristic parameter set, the M values are in one-to-one correspondence with the M channel characteristic parameters, and M is a positive integer;

The more detailed descriptions of the sending unit 1301, the receiving unit 1302, the channel measuring unit 1303, and the determining unit 1304 may be directly obtained by referring to the related descriptions of the network device in the above another embodiment, which is not described herein again.

Referring to fig. 14, fig. 14 is a schematic structural diagram of another communication device according to an embodiment of the present invention. As shown in fig. 14, the communication apparatus may include a processor 1401, a memory 1402, an input interface 1403, an output interface 1404, and a bus 1405. Memory 1402 may be self-contained and may be coupled to processor 1401 by bus 1405. Memory 1402 may also be integrated with processor 1401. Bus 1405 is used, among other things, to enable connections between these components.

In one embodiment, the communication apparatus may be a terminal device or a module (e.g., a chip) in the terminal device, when the computer program instructions stored in the memory 1402 are executed, the processor 1401 is configured to control the receiving unit 1001 to perform the operations performed in the above embodiments, the processor 1401 is further configured to perform the operations performed by the determining unit 1002, the input interface 1403 is configured to perform the operations performed by the receiving unit 1001 in the above embodiments, and the output interface 1404 is configured to transmit information to other communication apparatuses. The terminal device or the module in the terminal device may also be configured to execute various methods executed by the terminal device in the embodiment of the method in fig. 3, which is not described again.

In one embodiment, the communication apparatus may be a network device or a module (e.g., a chip) in the network device, when computer program instructions stored in the memory 1402 are executed, the processor 1401 is configured to control the receiving unit 1101 and the sending unit 1103 to perform operations performed in the foregoing embodiments, the processor 1401 is further configured to perform operations performed by the determining unit 1102, the input interface 1403 is configured to perform operations performed by the receiving unit 1101 in the foregoing embodiments, and the output interface 1404 is configured to perform operations performed by the sending unit 1103 in the foregoing embodiments. The network device or the module in the network device may also be configured to execute various methods executed by the network device in the embodiment of the method in fig. 3, which is not described again.

In one embodiment, the communication apparatus may be a terminal device or a module (e.g., a chip) in the terminal device, when computer program instructions stored in the memory 1402 are executed, the processor 1401 is configured to control the receiving unit 1201 to perform the operations performed in the above embodiments, the processor 1401 is further configured to perform the operations performed by the channel estimation unit 1202 and the determination unit 1203, the input interface 1403 is configured to perform the operations performed by the receiving unit 1201 in the above embodiments, and the output interface 1404 is configured to transmit information to other communication apparatuses. The terminal device or the module in the terminal device may also be configured to execute various methods executed by the terminal device in the embodiment of the method in fig. 9, which is not described again.

In one embodiment, the communication apparatus may be a network device or a module (e.g., a chip) in the network device, when the computer program instructions stored in the memory 1402 are executed, the processor 1401 is configured to control the receiving unit 1302 and the sending unit 1301 to perform the operations performed in the foregoing embodiments, the processor 1401 is further configured to perform the operations performed by the channel measuring unit 1303 and the determining unit 1304, the input interface 1403 is configured to perform the operations performed by the receiving unit 1302 in the foregoing embodiments, and the output interface 1404 is configured to perform the operations performed by the sending unit 1301 in the foregoing embodiments. The network device or the module in the network device may also be configured to execute various methods executed by the network device in the embodiment of the method in fig. 9, which is not described again.

Referring to fig. 15, fig. 15 is a schematic structural diagram of another communication device according to an embodiment of the present invention. As shown in fig. 15, the communication apparatus may include an input interface 1501, a logic circuit 1502, and an output interface 1503. The input interface 1501 is connected to the output interface 1503 via a logic circuit 1502. The input interface 1501 is used for receiving information from other communication devices, and the output interface 1503 is used for outputting, scheduling or transmitting information to other communication devices. The logic circuit 1502 is configured to perform operations other than the operations of the input interface 1501 and the output interface 1503, for example, to realize the functions realized by the processor 1401 in the above-described embodiments. The communication device may be a terminal device or a module in the terminal device, or may also be a network device or a module in the network device. The more detailed descriptions of the input interface 1501, the logic circuit 1502, and the output interface 1503 can be directly obtained by referring to the related descriptions of the terminal device or the network device in the foregoing method embodiments, which are not described herein again.

The embodiment of the invention also discloses a computer readable storage medium, wherein the computer readable storage medium is stored with instructions, and the instructions are executed to execute the method in the embodiment of the method.

Embodiments of the present invention also disclose a computer program product comprising instructions that, when executed, perform the method in the above method embodiments.

The embodiment of the present invention further discloses a communication system, which may include a terminal device, a network device, and the like, and specifically describes the communication method shown in fig. 3, fig. 5, fig. 6, and fig. 9.

The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made on the basis of the technical solutions of the present invention should be included in the scope of the present invention.

Claims

1. A method of communication, comprising:

receiving first indication information from a network device, where the first indication information is used to indicate M precoding matrices, where the M precoding matrices are precoding matrices corresponding to M frequency domain units in N frequency domain units, the N frequency domain units are frequency domain units used for uplink data transmission, M is an integer greater than 1, and N is an integer greater than M;

and determining N pre-coding matrixes corresponding to the N frequency domain units according to the M pre-coding matrixes.

2. The method according to claim 1, wherein said determining N precoding matrices corresponding to the N frequency domain units according to the M precoding matrices comprises:

and determining N pre-coding matrixes corresponding to the N frequency domain units according to the M pre-coding matrixes and the frequency domain positions of the M frequency domain units.

3. The method of claim 2, wherein the determining N precoding matrices corresponding to the N frequency domain elements according to the M precoding matrices and the frequency domain positions of the M frequency domain elements comprises:

and determining the values of the ith row and the jth column in the precoding matrix corresponding to each frequency domain unit in the N frequency domain units according to the values of the ith row and the jth column in each precoding matrix in the M precoding matrices and the frequency domain positions of the M frequency domain units.

4. The method according to any of claims 1-3, wherein the first indication information is used for indicating M precoding matrices, and comprises: the first indication information is used for indicating the quantization amplitude and the quantization phase of part of or all elements in the M precoding matrixes.

5. The method according to any one of claims 2-4, further comprising:

receiving second indication information from the network device, the second indication information indicating frequency domain locations of the M frequency domain units.

6. The method of claim 5, wherein the second indication information comprises N bits, and wherein the N bits correspond to the N frequency domain units one to one.

7. The method according to any one of claims 1-4, further comprising:

receiving resource configuration information of a reference signal from a network device, the frequency domain locations of the M frequency domain units being determined based on the resource configuration information.

8. The method according to any of claims 1-4, wherein the frequency domain locations of the M frequency domain units are determined according to the values of N and M.

9. A method of communication, comprising:

receiving a reference signal from a terminal device;

determining M precoding matrixes according to the reference signal, wherein the M precoding matrixes are precoding matrixes corresponding to M frequency domain units in N frequency domain units, the N frequency domain units are frequency domain units used for uplink data transmission, M is an integer larger than 1, and N is an integer larger than M;

and sending first indication information to the terminal equipment, wherein the first indication information is used for indicating the M precoding matrixes.

10. The method of claim 9, wherein the first indication information is used for indicating M precoding matrices, and comprises: the first indication information is used for indicating the quantization amplitude and the quantization phase of part of or all of the elements in the M precoding matrices.

11. The method according to claim 9 or 10, characterized in that the method further comprises:

and sending second indication information to the terminal equipment, wherein the second indication information is used for indicating the frequency domain positions of the M frequency domain units.

12. The method of claim 11, wherein the second indication information comprises N bits, and wherein the N bits correspond to the N frequency domain units one to one.

13. The method of claim 9 or 10, wherein the frequency domain locations of the M frequency domain units are determined according to the values of N and M.

14. A communications apparatus, comprising:

a determining unit, configured to determine, according to the M precoding matrices, N precoding matrices corresponding to the N frequency domain units.

15. The apparatus according to claim 14, wherein the determining unit is specifically configured to determine, according to the M precoding matrices and frequency domain positions of the M frequency domain units, N precoding matrices corresponding to the N frequency domain units.

16. The apparatus according to claim 15, wherein the determining unit is specifically configured to determine, according to values of an ith row and a jth column in each of the M precoding matrices and frequency domain positions of the M frequency domain units, values of an ith row and a jth column in the precoding matrix corresponding to each of the N frequency domain units.

17. The apparatus according to any of claims 14-16, wherein the first indication information is used for indicating M precoding matrices, and comprises: the first indication information is used for indicating the quantization amplitude and the quantization phase of part of or all of the elements in the M precoding matrices.

18. The apparatus according to any of claims 15-17, wherein said receiving unit is further configured to receive second indication information from the network device, the second indication information being used to indicate frequency domain locations of the M frequency domain units.

19. The apparatus of claim 18, wherein the second indication information comprises N bits, and wherein the N bits correspond to the N frequency domain units one to one.

20. The apparatus according to any of claims 14-17, wherein the receiving unit is further configured to receive resource configuration information of a reference signal from a network device, and the frequency domain locations of the M frequency domain units are determined based on the resource configuration information.

21. The apparatus of any of claims 14-17, wherein the frequency domain locations of the M frequency domain units are determined based on a combination of N and M.

22. A communications apparatus, comprising:

23. The apparatus of claim 22, wherein the first indication information is used for indicating M precoding matrices and comprises: the first indication information is used for indicating the quantization amplitude and the quantization phase of part of or all elements in the M precoding matrixes.

24. The apparatus according to claim 22 or 23, wherein the sending unit is further configured to send second indication information to the terminal device, where the second indication information is used to indicate frequency domain positions of the M frequency domain units.

25. The apparatus of claim 24, wherein the second indication information comprises N bits, and wherein the N bits correspond to the N frequency domain units one to one.

26. The apparatus of claim 22 or 23 wherein the frequency domain locations of the M frequency domain units are determined according to the values of N and M.

27. A communications device comprising a processor, a memory, an input interface for receiving information from a communications device other than the communications device, and an output interface for outputting information to the communications device other than the communications device, the processor invoking a computer program stored in the memory to implement the method of any one of claims 1-8 or 9-13.

28. A computer-readable storage medium, in which a computer program or computer instructions are stored which, when executed, implement the method according to any one of claims 1 to 13.