Communication method and device

Abstract

The present application provides a communication method and apparatus, wherein the method includes: a terminal device receives a downlink reference signal from an access network device; the terminal device sends a first indication message to the access network device, the first indication message indicates at least one Doppler shift, the at least one Doppler shift is determined based on the downlink reference signal, and the at least one Doppler shift is associated with at least two frequency domain bases. According to the above method, at least one Doppler shift is indicated by the first indication message, so that it is not necessary to feed back all Doppler shifts determined based on the downlink reference signal, thereby reducing feedback overhead and improving feedback efficiency. When the access network device performs channel estimation, it can determine the time domain related information of the channel based on the Doppler shift indicated by the first indication message, and can use the channel at several past moments and the Doppler shift information to obtain a more accurate channel state, thereby overcoming the performance degradation problem caused by channel aging.

Description

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 1, 2022, with application number 202210915805.3 and application name “A Communication Method and Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a communication method and device. Background Art

[0003] To improve signal transmission quality or speed, a base station must perform channel estimation on the wireless channel before transmitting data to a terminal device. The base station uses the sounding reference signal (SRS) from the terminal device to perform channel estimation, obtaining uplink channel state information (CSI). This information is then used to determine downlink CSI based on the uplink and downlink reciprocity. The base station uses CSI to calculate the precoding used for data transmission, thereby improving signal transmission quality or speed.

[0004] In a time division duplexing (TDD) system, the uplink and downlink of wireless channels are different. Therefore, during the channel estimation process, the terminal device can feed back channel matrix related information to the base station, thereby improving the accuracy of the base station's channel estimation.

[0005] However, as the number of base station antennas increases, the feedback overhead for channel matrix-related information also increases accordingly. Reducing this feedback overhead for terminal devices is a pressing issue. Furthermore, due to the delay between the time the base station acquires the channel and the time the terminal device actually receives the downlink precoding service, if the terminal device moves, the channel may have changed dramatically during this time. This can lead to a mismatch between the precoding and the terminal device's channel at the corresponding moment, resulting in performance degradation, a problem known as "channel aging." Summary of the Invention

[0006] The present application provides a communication method and apparatus to solve the problem of how to reduce the feedback overhead of terminal equipment.

[0007] In a first aspect, the present application provides a communication method, which includes: a terminal device receives a downlink reference signal from an access network device; the terminal device determines at least one spatial domain vector and multiple frequency domain vectors based on the downlink reference signal, the at least one spatial domain vector and the multiple frequency domain vectors correspond to a first matrix, the first matrix includes multiple merging coefficients, each merging coefficient is a merging coefficient of a spatial domain vector and a frequency domain vector, and the position of the merging coefficient is represented by a spatial domain vector and a frequency domain vector; the terminal device sends first information to the access network device; the first information is used to indicate the position of at least one merging coefficient among the multiple merging coefficients; at least one merging coefficient satisfies any of the following conditions: at least one merging coefficient has an energy greater than or equal to that of the multiple merging coefficients The first energy is less than or equal to the merging coefficient of the second energy, and the second energy is less than the energy of the merging coefficient with the largest energy among the multiple merging coefficients; at least one merging coefficient is the Y2 merging coefficient with the smallest energy among the Y1 merging coefficients with energy greater than or equal to the first energy among the multiple merging coefficients, where Y2 is an integer less than Y1 and greater than 0; at least one merging coefficient is the Y4 merging coefficient with the smallest energy among the Y3 merging coefficients with the largest energy among the multiple merging coefficients, where Y4 is an integer less than Y3 and greater than 0; at least one merging coefficient is the merging coefficient with energy less than or equal to the second energy among the Y3 merging coefficients with the largest energy among the multiple merging coefficients, and the second energy is less than the energy of the merging coefficient with the largest energy among the multiple merging coefficients.

[0008] According to the above method, the embodiment of the present application indicates the position of at least one combining coefficient that meets the conditions among multiple combining coefficients through first information, thereby eliminating the need to feedback the positions of all combining coefficients, reducing feedback overhead, and improving feedback efficiency. Furthermore, by feeding back the first information to the access network device, the terminal device enables the access network device to determine the position of at least one combining coefficient indicated by the first information. When performing channel estimation, the access network device no longer treats the combining coefficient corresponding to the position indicated by the first information as noise / interference, and no longer sets the energy of the combining coefficient corresponding to the position indicated by the first information to zero. Instead, the energy of these combining coefficients is retained, thereby reducing noise / interference while improving the accuracy of channel estimation.

[0009] In a second aspect, the present application provides a communication method, which includes: an access network device sends a downlink reference signal to a terminal device; the access network device receives first information from the terminal device; wherein the first information is used to indicate the position of at least one merging coefficient among multiple merging coefficients included in the first matrix; the first matrix corresponds to at least one spatial domain vector and multiple frequency domain vectors, at least one spatial domain vector and multiple frequency domain vectors are determined according to the downlink reference signal, each merging coefficient is a merging coefficient of a spatial domain vector and a frequency domain vector, and the position of the merging coefficient is represented by a spatial domain vector and a frequency domain vector; at least one merging coefficient satisfies any of the following conditions: at least one merging coefficient is a merging coefficient having an energy greater than or equal to the first energy among multiple merging coefficients The energy of the merging coefficient is less than or equal to the second energy, and the second energy is less than the energy of the merging coefficient with the largest energy among the multiple merging coefficients; at least one merging coefficient is the Y2 merging coefficient with the smallest energy among the Y1 merging coefficients with energy greater than or equal to the first energy among the multiple merging coefficients, and Y2 is an integer less than Y1 and greater than 0; at least one merging coefficient is the Y4 merging coefficient with the smallest energy among the Y3 merging coefficients with the largest energy among the multiple merging coefficients, and Y4 is an integer less than Y3 and greater than 0; at least one merging coefficient is the merging coefficient with energy less than or equal to the second energy among the Y3 merging coefficients with the largest energy among the multiple merging coefficients, and the second energy is less than the energy of the merging coefficient with the largest energy among the multiple merging coefficients.

[0010] In combination with the first aspect or the second aspect, in a possible implementation method, the first energy is the product of the energy of the merging coefficient with the largest energy among multiple merging coefficients and the first coefficient, and the first coefficient is greater than 0 and less than 1; or, the first energy is the energy of the first merging coefficient; wherein, the sum of the energies of the merging coefficients among the multiple merging coefficients that are greater than or equal to the energy of the first merging coefficient is the first total energy, and the sum of the energies of the multiple merging coefficients is the second total energy; wherein, the ratio of the first total energy to the second total energy is equal to the first ratio.

[0011] In combination with the first aspect or the second aspect, in a possible implementation manner, the first energy is the energy of the first combining coefficient;

[0012] Among them, the sum of the energies of the merging coefficients among the multiple merging coefficients that are greater than or equal to the energy of the first merging coefficient is the first total energy, the sum of the energies of the multiple merging coefficients is the second total energy, and the sum of the energies of the merging coefficients among the multiple merging coefficients that are greater than or equal to the energy of the second merging coefficient is the third total energy; the energy of the first merging coefficient is greater than the energy of the second merging coefficient, and when the multiple merging coefficients are sorted from large to small according to energy, the first merging coefficient and the second merging coefficient are adjacent in sequence; wherein, the ratio of the first total energy to the second total energy is smaller than the first ratio, and the ratio of the third total energy to the second total energy is greater than the first ratio.

[0013] In combination with the first aspect or the second aspect, in a possible implementation manner, the first energy is the energy of the first combining coefficient;

[0014] Among them, the sum of the energies of the merging coefficients among multiple merging coefficients that are greater than or equal to the energy of the first merging coefficient is the first total energy, the sum of the energies of the multiple merging coefficients is the second total energy, and the sum of the energies of the merging coefficients among multiple merging coefficients that are greater than or equal to the energy of the third merging coefficient is the fourth total energy; the energy of the third merging coefficient is greater than the energy of the first merging coefficient, and when the multiple merging coefficients are sorted from large to small according to energy, the third merging coefficient and the first merging coefficient are adjacent in sequence; wherein, the ratio of the first total energy to the second total energy is greater than the first ratio, and the ratio of the fourth total energy to the second total energy is less than the first ratio.

[0015] In combination with the first aspect or the second aspect, in one possible implementation, the second energy is the product of the energy of the combining coefficient with the maximum energy among the multiple combining coefficients and the second coefficient, and the second coefficient is greater than 0 and less than 1; or, the second energy is the energy of the fourth combining coefficient in the first set; wherein the first set includes all combining coefficients whose energy is greater than or equal to the first energy among the multiple combining coefficients, or the first set includes Y3 combining coefficients with the maximum energy among the multiple combining coefficients;

[0016] The sum of the energies of the combining coefficients in the first set that are less than or equal to the energy of the fourth combining coefficient is the fifth total energy, and the sum of the energies of all the combining coefficients included in the first set is the sixth total energy; wherein the ratio of the fifth total energy to the sixth total energy is equal to the second ratio.

[0017] In combination with the first aspect or the second aspect, in a possible implementation, the second energy is the energy of the fourth combining coefficient in the first set; wherein the first set includes all combining coefficients whose energy is greater than or equal to the first energy among the multiple combining coefficients, or the first set includes Y3 combining coefficients with the largest energy among the multiple combining coefficients; the sum of the energies of the combining coefficients in the first set that are less than or equal to the energy of the fourth combining coefficient is a fifth total energy, the sum of the energies of all combining coefficients included in the first set is a sixth total energy, and the sum of the energies of the combining coefficients in the first set that are less than or equal to the energy of the fifth combining coefficient is a seventh total energy; the energy of the fourth combining coefficient is greater than the energy of the fifth combining coefficient, and when all the combining coefficients included in the first set are sorted from largest to smallest according to energy, the fourth combining coefficient and the fifth combining coefficient are adjacent in sequence;

[0018] The ratio of the fifth total energy to the sixth total energy is greater than the second ratio, and the ratio of the seventh total energy to the sixth total energy is less than the second ratio.

[0019] In combination with the first aspect or the second aspect, in a possible implementation, the second energy is the energy of the fourth combining coefficient in the first set; wherein the first set includes all combining coefficients whose energy is greater than or equal to the first energy among the multiple combining coefficients, or the first set includes Y3 combining coefficients with the largest energy among the multiple combining coefficients; the sum of the energies of the combining coefficients in the first set that are less than or equal to the energy of the fourth combining coefficient is a fifth total energy, the sum of the energies of all combining coefficients included in the first set is a sixth total energy, and the sum of the energies of the combining coefficients in the first set that are less than or equal to the energy of the sixth combining coefficient is an eighth total energy; the energy of the sixth combining coefficient is greater than the energy of the fourth combining coefficient, and when all the combining coefficients included in the first set are sorted from largest to smallest according to energy, the sixth combining coefficient is adjacent to the fourth combining coefficient in sequence;

[0020] The ratio of the fifth total energy to the sixth total energy is smaller than the second ratio, and the ratio of the eighth total energy to the sixth total energy is larger than the second ratio.

[0021] In combination with the first aspect or the second aspect, in a possible implementation, at least one merging coefficient is divided into K merging coefficient groups, where K is an integer greater than 0; each merging coefficient in the at least one merging coefficient is a merging coefficient of one spatial domain vector in X spatial domain vectors and one frequency domain vector in multiple frequency domain vectors, where the X spatial domain vectors are part or all of the spatial domain vectors in the at least one spatial domain vector, and X is an integer greater than 0; the X spatial domain vectors and the multiple frequency domain vectors correspond to a second matrix, the second matrix includes K sub-matrices, each sub-matrix corresponds to one or more spatial domain vectors in the X spatial domain vectors and one or more frequency domain vectors in the multiple frequency domain vectors; the K merging coefficient groups and the K sub-matrices correspond one-to-one, and each merging coefficient group in the K merging coefficient groups is located in a sub-matrix of the K sub-matrices.

[0022] In combination with the first aspect or the second aspect, in one possible implementation, the first information includes at least one of the following:

[0023] The position of the starting spatial vector corresponding to the submatrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0024] The number of spatial vectors corresponding to the submatrices corresponding to each of the K merging coefficient groups;

[0025] The position of the starting frequency domain vector corresponding to the submatrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0026] The number of frequency domain vectors corresponding to the submatrix corresponding to each merging coefficient group in the K merging coefficient groups.

[0027] In combination with the first aspect, in a possible implementation, the method also includes: the terminal device sends second information to the access network device; the second information is used to indicate a first position range, and the first position range is the position corresponding to M consecutive frequency domain vectors in multiple frequency domain vectors; the frequency domain vector corresponding to each merging coefficient in at least one merging coefficient is one of the M consecutive frequency domain vectors.

[0028] By this method, among the K merging coefficient groups, the number of bits occupied by the position of the starting frequency domain vector of the submatrix corresponding to each merging coefficient group is This can further reduce the feedback overhead of the terminal device.

[0029] In combination with the second aspect, in a possible implementation, the method also includes: the access network device receives second information from the terminal device; the second information is used to indicate a first position range, and the first position range is the position corresponding to M consecutive frequency domain vectors in multiple frequency domain vectors; the frequency domain vector corresponding to each merging coefficient in at least one merging coefficient is one of the M consecutive frequency domain vectors.

[0030] In combination with the first aspect or the second aspect, in a possible implementation, in the K merging coefficient groups, the number of bits occupied by the position of the starting frequency domain vector corresponding to the submatrix corresponding to each merging coefficient group is

[0031] In conjunction with the first aspect, in one possible implementation, the method further includes:

[0032] The terminal device sends third information to the access network device, where the third information includes at least one of the following:

[0033] The phase of the merging coefficient at the center of the submatrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0034] Among the K merging coefficient groups, the angular gradient of the submatrix corresponding to each merging coefficient group in the matrix row direction;

[0035] Among the K merging coefficient groups, the angular gradient of the submatrix corresponding to each merging coefficient group in the matrix column direction.

[0036] Through the above method, after obtaining the third information, the access network device can correct the phase of the combining coefficient at the position indicated by the first information, so that the channel estimation is more accurate.

[0037] In conjunction with the second aspect, in one possible implementation, the method further includes:

[0038] The access network device receives third information from the terminal device, where the third information includes at least one of the following:

[0039] The phase of the merging coefficient at the center of the submatrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0040] Among the K merging coefficient groups, the angular gradient of the submatrix corresponding to each merging coefficient group in the matrix row direction;

[0041] Among the K merging coefficient groups, the angular gradient of the submatrix corresponding to each merging coefficient group in the matrix column direction.

[0042] In combination with the first aspect, in a possible implementation, the method also includes: the terminal device sends fourth information to the access network device, the fourth information includes all coefficients of the autocorrelation matrix of each submatrix in the K submatrices, or the fourth information includes the first H1 eigenvalues of the autocorrelation matrix of each submatrix in the K submatrices and the eigenvectors corresponding to the first H1 eigenvalues, or the fourth information includes the first H2% eigenvalues of the autocorrelation matrix of each submatrix in the K submatrices and the eigenvectors corresponding to the first H2% eigenvalues, wherein H1 and H2 are preset values.

[0043] Through the above method, after acquiring the third information, the access network device can obtain the autocorrelation matrix of the merging coefficients of each sub-matrix, so the autocorrelation matrix can be used to perform noise reduction, making the channel estimation more accurate.

[0044] In conjunction with the second aspect, in one possible implementation, the method further includes:

[0045] The access network device receives fourth information from the terminal device, where the fourth information includes all coefficients of the autocorrelation matrix of each submatrix in the K submatrices, or the fourth information includes the first H1 eigenvalues of the autocorrelation matrix of each submatrix in the K submatrices and the eigenvectors corresponding to the first H1 eigenvalues, or the fourth information includes the first H2% eigenvalues of the autocorrelation matrix of each submatrix in the K submatrices and the eigenvectors corresponding to the first H2% eigenvalues, where H1 and H2 are preset values.

[0046] In a third aspect, the present application provides a communication method, which includes: a terminal device receives multiple downlink reference signals from an access network device; the terminal device determines at least one spatial domain vector, multiple frequency domain vectors, and multiple time domain vectors based on the multiple downlink reference signals, and the at least one spatial domain vector, multiple frequency domain vectors, and multiple time domain vectors correspond to a first three-dimensional matrix, and the first three-dimensional matrix includes multiple merging coefficients, each merging coefficient is a merging coefficient of a spatial domain vector, a frequency domain vector, and a time domain vector, and the position of the merging coefficient is represented by a spatial domain vector, a frequency domain vector, and a time domain vector; the terminal device sends first information to the access network device; the first information is used to indicate the position of at least one merging coefficient among the multiple merging coefficients; at least one merging coefficient satisfies any of the following conditions: at least One merging coefficient is a merging coefficient among multiple merging coefficients whose energy is greater than or equal to the first energy and less than or equal to the second energy, and the second energy is less than the energy of the merging coefficient with the largest energy among the multiple merging coefficients; at least one merging coefficient is the Y2 merging coefficient with the smallest energy among the Y1 merging coefficients among the multiple merging coefficients whose energy is greater than or equal to the first energy, and Y2 is an integer less than Y1 and greater than 0; at least one merging coefficient is the Y4 merging coefficient with the smallest energy among the Y3 merging coefficients among the multiple merging coefficients, and Y4 is an integer less than Y3 and greater than 0; at least one merging coefficient is the Y3 merging coefficient with the largest energy among the multiple merging coefficients, and the energy is less than the second energy, and the second energy is less than the energy of the merging coefficient with the largest energy among the multiple merging coefficients.

[0047] According to the above method, the embodiment of the present application indicates the position of at least one combining coefficient that meets the conditions among multiple combining coefficients through first information, thereby eliminating the need to feedback the positions of all combining coefficients, reducing feedback overhead, and improving feedback efficiency. Furthermore, by feeding back the first information to the access network device, the terminal device enables the access network device to determine the position of at least one combining coefficient indicated by the first information. When performing channel estimation, the access network device no longer treats the combining coefficient corresponding to the position indicated by the first information as noise / interference, and no longer sets the energy of the combining coefficient corresponding to the position indicated by the first information to zero. Instead, the energy of these combining coefficients is retained, thereby reducing noise / interference while improving the accuracy of channel estimation.

[0048] In a fourth aspect, the present application provides a communication method, the method comprising: an access network device sending multiple downlink reference signals to a terminal device; the access network device receiving first information from the terminal device; wherein the first information is used to indicate the position of at least one combining coefficient among multiple combining coefficients included in a first three-dimensional matrix; the first three-dimensional matrix corresponds to at least one spatial domain vector, multiple frequency domain vectors, and multiple time domain vectors, at least one spatial domain vector, multiple frequency domain vectors, and multiple time domain vectors are determined based on multiple downlink reference signals, each combining coefficient is a combining coefficient of a spatial domain vector, a frequency domain vector, and a time domain vector, and the position of the combining coefficient is represented by a spatial domain vector, a frequency domain vector, and a time domain vector; at least one combining coefficient satisfies any of the following conditions: at least one combining coefficient is a combining coefficient whose energy is greater than or equal to a first energy and less than or equal to a second energy among multiple combining coefficients, and the second energy is less than the energy of the combining coefficient with the largest energy among the multiple combining coefficients; at least one combining coefficient is Y2 combining coefficients with the smallest energy among Y1 combining coefficients whose energy is greater than or equal to the first energy among the multiple combining coefficients, and Y2 is an integer less than Y1 and greater than 0;

[0049] At least one merging coefficient is the Y4 merging coefficient with the smallest energy among the Y3 merging coefficients with the largest energy among the multiple merging coefficients, where Y4 is an integer less than Y3 and greater than 0; at least one merging coefficient is the Y3 merging coefficient with the largest energy among the multiple merging coefficients, where the energy is less than the second energy, and the second energy is less than the energy of the merging coefficient with the largest energy among the multiple merging coefficients.

[0050] In combination with the third aspect or the fourth aspect, in a possible implementation method, the first energy is the product of the energy of the merging coefficient with the largest energy among multiple merging coefficients and the first coefficient, and the first coefficient is greater than 0 and less than 1; or, the first energy is the energy of the first merging coefficient; wherein, the sum of the energies of the merging coefficients among the multiple merging coefficients that are greater than or equal to the energy of the first merging coefficient is the first total energy, and the sum of the energies of the multiple merging coefficients is the second total energy; wherein, the ratio of the first total energy to the second total energy is equal to the first ratio.

[0051] In combination with the third aspect or the fourth aspect, in a possible implementation method, the first energy is the energy of the first merging coefficient; wherein, the sum of the energies of the merging coefficients greater than or equal to the energy of the first merging coefficient among multiple merging coefficients is the first total energy, the sum of the energies of the multiple merging coefficients is the second total energy, and the sum of the energies of the merging coefficients greater than or equal to the energy of the second merging coefficient among multiple merging coefficients is the third total energy; the energy of the first merging coefficient is greater than the energy of the second merging coefficient, and when the multiple merging coefficients are sorted from large to small according to energy, the first merging coefficient and the second merging coefficient are adjacent in sequence; wherein, the ratio of the first total energy to the second total energy is less than the first ratio, and the ratio of the third total energy to the second total energy is greater than the first ratio.

[0052] In combination with the third aspect or the fourth aspect, in a possible implementation method, the first energy is the energy of the first merging coefficient; wherein, the sum of the energies of the merging coefficients greater than or equal to the energy of the first merging coefficient among multiple merging coefficients is the first total energy, the sum of the energies of the multiple merging coefficients is the second total energy, and the sum of the energies of the merging coefficients greater than or equal to the energy of the third merging coefficient among multiple merging coefficients is the fourth total energy; the energy of the third merging coefficient is greater than the energy of the first merging coefficient, and when the multiple merging coefficients are sorted from large to small according to energy, the third merging coefficient and the first merging coefficient are adjacent in sequence; wherein, the ratio of the first total energy to the second total energy is greater than the first ratio, and the ratio of the fourth total energy to the second total energy is less than the first ratio.

[0053] In combination with the third aspect or the fourth aspect, in one possible implementation, the second energy is a product of the energy of a combining coefficient with the largest energy among the multiple combining coefficients and the second coefficient, and the second coefficient is greater than 0 and less than 1;

[0054] Alternatively, the second energy is the energy of the fourth combining coefficient in the first set; wherein, the first set includes all combining coefficients whose energy is greater than or equal to the first energy among the multiple combining coefficients, or the first set includes Y3 combining coefficients with the largest energy among the multiple combining coefficients; the sum of the energies of the combining coefficients in the first set whose energy is less than or equal to the fourth combining coefficient is the fifth total energy, and the sum of the energies of all the combining coefficients included in the first set is the sixth total energy; wherein, the ratio of the fifth total energy to the sixth total energy is equal to the second ratio.

[0055] In combination with the third aspect or the fourth aspect, in a possible implementation, the second energy is the energy of the fourth combining coefficient in the first set; wherein, the first set includes all combining coefficients whose energy is greater than or equal to the first energy among multiple combining coefficients, or the first set includes Y3 combining coefficients with the largest energy among multiple combining coefficients; the sum of the energies of the combining coefficients in the first set whose energy is less than or equal to the fourth combining coefficient is the fifth total energy, the sum of the energies of all combining coefficients included in the first set is the sixth total energy, and the sum of the energies of the combining coefficients in the first set whose energy is less than or equal to the fifth combining coefficient is the seventh total energy; the energy of the fourth combining coefficient is greater than the energy of the fifth combining coefficient, and when all the combining coefficients included in the first set are sorted from large to small according to energy, the fourth combining coefficient and the fifth combining coefficient are adjacent in sequence; wherein, the ratio of the fifth total energy to the sixth total energy is greater than the second ratio, and the ratio of the seventh total energy to the sixth total energy is less than the second ratio.

[0056] In combination with the third aspect or the fourth aspect, in a possible implementation, the second energy is the energy of the fourth merging coefficient in the first set; wherein, the first set includes all merging coefficients whose energy is greater than or equal to the first energy among multiple merging coefficients, or the first set includes Y3 merging coefficients with the largest energy among multiple merging coefficients; the sum of the energies of the merging coefficients in the first set whose energy is less than or equal to the fourth merging coefficient is the fifth total energy, the sum of the energies of all merging coefficients included in the first set is the sixth total energy, and the sum of the energies of the merging coefficients in the first set whose energy is less than or equal to the sixth merging coefficient is the eighth total energy; the energy of the sixth merging coefficient is greater than the energy of the fourth merging coefficient, and when all the merging coefficients included in the first set are sorted from large to small according to energy, the sixth merging coefficient and the fourth merging coefficient are adjacent in sequence; wherein, the ratio of the fifth total energy to the sixth total energy is less than the second ratio, and the ratio of the eighth total energy to the sixth total energy is greater than the second ratio.

[0057] In combination with the third aspect or the fourth aspect, in a possible implementation method, at least one merging coefficient is divided into K merging coefficient groups, K is an integer greater than 0; each merging coefficient in the at least one merging coefficient is a merging coefficient of one spatial domain vector in Z1 spatial domain vectors, one frequency domain vector in multiple frequency domain vectors, and one time domain vector in Z2 time domain vectors, the Z1 spatial domain vector is part or all of the spatial domain vectors in at least one spatial domain vector, the Z2 time domain vector is part or all of the time domain vectors in multiple time domain vectors, Z1 and Z2 are integers greater than 0, the Z1 spatial domain vector, the multiple frequency domain vectors, and the Z2 time domain vector correspond to a second three-dimensional matrix; the second three-dimensional matrix includes K sub-three-dimensional matrices, each sub-three-dimensional matrix corresponds to at least one spatial domain vector in the Z1 spatial domain vectors, at least one frequency domain vector in multiple frequency domain vectors, and at least one time domain vector in the Z2 time domain vectors; the K merging coefficient groups correspond one-to-one to the K sub-three-dimensional matrices, and each merging coefficient group in the K merging coefficient groups is located in a sub-three-dimensional matrix in the K sub-three-dimensional matrices.

[0058] In combination with the third aspect or the fourth aspect, in a possible implementation method, the first information includes at least one of the following items: the position of the starting spatial domain vector of the sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups; the number of spatial domain vectors included in the sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups; the position of the starting frequency domain vector of the sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups; the number of frequency domain vectors included in the sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups; the position of the starting time domain vector of the sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups; the number of time domain vectors included in the sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups.

[0059] In combination with the third aspect, in a possible implementation, the method further includes: the terminal device sends second information to the access network device; the second information is used to indicate that the second position range includes positions corresponding to M1 consecutive frequency domain vectors in multiple frequency domain vectors, and positions corresponding to M2 consecutive time domain vectors in multiple time domain vectors, M1 and M2 are integers greater than 0; the frequency domain vector corresponding to each of the at least one merging coefficients is one of the M1 consecutive frequency domain vectors, and the time domain vector corresponding to each of the at least one merging coefficients is one of the M2 consecutive time domain vectors. Specifically, the second information can be used to indicate at least one of the following: the number M1 of frequency domain vectors corresponding to the second position range; the index of the first frequency domain vector or the index of the last frequency domain vector in the M1 frequency domain vectors in the second position range; the number M2 of time domain vectors corresponding to the second position range; the index of the first time domain vector or the index of the last time domain vector in the M2 time domain vectors in the second position range.

[0060] In combination with the third aspect, in a possible implementation manner, the method further includes: the terminal device sends third information to the access network device.

[0061] In combination with the fourth aspect, in a possible implementation manner, the method further includes: the access network device receives third information from the terminal device.

[0062] In combination with the third aspect or the fourth aspect, in a possible implementation manner, the third information includes at least one of the following: a phase of a merging coefficient at a center position of a sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0063] Among the K merging coefficient groups, the angular gradient of the sub-three-dimensional matrix corresponding to each merging coefficient group in the spatial domain dimension; among the K merging coefficient groups, the angular gradient of the sub-three-dimensional matrix corresponding to each merging coefficient group in the frequency domain dimension; among the K merging coefficient groups, the angular gradient of the sub-three-dimensional matrix corresponding to each merging coefficient group in the time domain dimension.

[0064] In combination with the third aspect, in a possible implementation manner, the method further includes: the terminal device sends fourth information to the access network device.

[0065] In combination with the fourth aspect, in a possible implementation manner, the method further includes: the access network device receives fourth information from the terminal device.

[0066] In combination with the third aspect or the fourth aspect, in a possible implementation method, the fourth information includes all coefficients of the autocorrelation matrix of each sub-three-dimensional matrix in the K sub-three-dimensional matrices, or the fourth information includes the first H1 eigenvalues of the autocorrelation matrix of each sub-three-dimensional matrix in the K sub-three-dimensional matrices and the eigenvectors corresponding to the first H1 eigenvalues, or the fourth information includes the first H2% eigenvalues of the autocorrelation matrix of each sub-three-dimensional matrix in the K sub-three-dimensional matrices and the eigenvectors corresponding to the first H2% eigenvalues, where H1 and H2 are preset values.

[0067] In a fifth aspect, the present application provides a communication method, which includes: a terminal device receives a downlink reference signal from an access network device; the terminal device sends a first indication information to the access network device, the first indication information indicating at least one Doppler shift, the at least one Doppler shift is determined based on the downlink reference signal, and the at least one Doppler shift is associated with at least two frequency domain bases.

[0068] In a sixth aspect, the present application provides a communication method, which includes: an access network device sends a downlink reference signal to a terminal device; the access network device receives first indication information from the terminal device, the first indication information is used to indicate at least one Doppler shift, the at least one Doppler shift is determined based on the downlink reference signal, and the at least one Doppler shift is associated with at least two frequency domain bases.

[0069] According to the above method, embodiments of the present application indicate at least one Doppler shift through first indication information, eliminating the need to feed back all Doppler shifts determined based on the downlink reference signal, thereby reducing feedback overhead and improving feedback efficiency. Furthermore, when performing channel estimation, the access network device can determine the time-domain related information of the channel based on the Doppler shift indicated by the first indication information. This allows the access network device to utilize the channel at the time of channel estimation, the channel at several past times, and Doppler shift information to obtain a more accurate channel state, enabling the access network device to perform channel prediction and overcome performance degradation caused by channel aging.

[0070] In combination with the fifth aspect or the sixth aspect, in a possible implementation, the first indication information is used to indicate at least one Doppler shift, including: the first indication information indicates the at least one Doppler shift by indicating the index of the Doppler basis corresponding to the Doppler shift, or the first indication information indicates the at least one Doppler shift by indicating the value of the Doppler shift.

[0071] In combination with the fifth aspect or the sixth aspect, in a possible implementation method, the at least one Doppler offset is one or more groups of Doppler offsets, each group of Doppler offsets in the one or more groups of Doppler offsets includes at least two Doppler offsets, and the at least two Doppler offsets are continuous, and the continuity is that the indexes of the Doppler bases corresponding to the Doppler offsets are continuous or the values of the Doppler offsets are equally spaced.

[0072] In combination with the fifth aspect or the sixth aspect, in a possible implementation method, for each group of the Doppler offsets, the first indication information indicates the indexes of two Doppler bases, and the indexes of the two Doppler bases are respectively the index with the largest value and the index with the smallest value among the indexes of the Doppler bases corresponding to a group of the Doppler offsets.

[0073] In combination with the fifth aspect or the sixth aspect, in a possible implementation, for each group of Doppler offsets, the first indication information indicates an index of a Doppler basis and an index length value, and the index of the Doppler basis and the index length value are used to determine each of the Doppler offsets in the group of Doppler offsets.

[0074] In combination with the fifth aspect or the sixth aspect, in a possible implementation manner, the index of the Doppler basis is an index with the largest value or an index with the smallest value among a group of indices of the Doppler basis corresponding to the Doppler shift.

[0075] In combination with the fifth aspect or the sixth aspect, in a possible implementation, for each group of Doppler offsets, the first indication information indicates an index length value of a Doppler basis, the index length value and the index of a Doppler basis are used to determine each of the Doppler offsets in the group of Doppler offsets, the index of the Doppler basis is predefined, or the index of the Doppler basis is indicated by fourth indication information.

[0076] In combination with the fifth aspect or the sixth aspect, in a possible implementation, for each group of Doppler offsets, the first indication information indicates two Doppler offset values, and the two Doppler offset values are respectively the maximum value and the minimum value of the Doppler offset in the group of Doppler offsets.

[0077] In combination with the fifth aspect or the sixth aspect, in a possible implementation, for each group of Doppler offsets, the first indication information indicates a value and a numerical span of a Doppler offset, and the value and the numerical span of the Doppler offset are used to determine each of the Doppler offsets in the group of Doppler offsets.

[0078] In combination with the fifth aspect or the sixth aspect, in a possible implementation manner, the value of the Doppler shift is a maximum value or a minimum value in a group of the Doppler shifts.

[0079] In combination with the fifth aspect or the sixth aspect, in a possible implementation, for each group of Doppler offsets, the first indication information indicates a numerical span of a Doppler offset, and the numerical span and the value of a Doppler offset are used to determine each of the Doppler offsets in the group of Doppler offsets, and the value of the Doppler offset is predefined, or the value of the Doppler offset is indicated by fourth indication information.

[0080] In combination with the fifth aspect or the sixth aspect, in a possible implementation method, for each group of Doppler offsets, the first indication information indicates the value of each Doppler offset in a group of Doppler offsets, or the first indication information indicates the index of the Doppler basis corresponding to each Doppler offset in a group of Doppler offsets.

[0081] In combination with the fifth aspect or the sixth aspect, in a possible implementation, the first indication information indicates the value of each of the at least one Doppler shift, or the first indication information indicates the index of the Doppler basis corresponding to each of the at least one Doppler shift.

[0082] In combination with the fifth aspect or the sixth aspect, in a possible implementation manner, the terminal device sends second indication information to the access network device, where the second indication information indicates the at least two frequency domain bases.

[0083] In combination with the fifth aspect or the sixth aspect, in a possible implementation method, the at least two frequency domain bases are one or more groups of frequency domain bases, each group of frequency domain bases in the one or more groups of frequency domain bases includes at least two frequency domain bases, and the at least two frequency domain bases are continuous, and the continuity is the continuity of the indexes of the frequency domain bases.

[0084] In combination with the fifth aspect or the sixth aspect, in a possible implementation method, for each group of the frequency domain bases, the second indication information indicates the indexes of two frequency domain bases, and the indexes of the two frequency domain bases are respectively the index with the largest value and the index with the smallest value in a group of indexes of the frequency domain bases.

[0085] In combination with the fifth aspect or the sixth aspect, in a possible implementation method, for each group of frequency domain bases, the second indication information indicates the index and index length value of a frequency domain base, and the index and index length of the frequency domain base are used to determine each of the frequency domain bases in the group of frequency domain bases.

[0086] In combination with the fifth aspect or the sixth aspect, in a possible implementation manner, the index of the frequency domain basis is an index with the largest value or an index with the smallest value among a group of indices of the frequency domain basis.

[0087] In combination with the fifth aspect or the sixth aspect, in a possible implementation method, for each group of the frequency domain bases, the second indication information indicates the index length value of a frequency domain base, the index length value and the index of a frequency domain base are used to determine each of the frequency domain bases in the group of frequency domain bases, the index of the frequency domain base is predefined, or the index of the frequency domain base is indicated by the fifth indication information.

[0088] In combination with the fifth aspect or the sixth aspect, in a possible implementation manner, for each group of the frequency domain bases, the second indication information indicates each of the frequency domain bases in a group of the frequency domain bases.

[0089] In combination with the fifth aspect or the sixth aspect, in a possible implementation manner, the second indication information indicates an index of each frequency domain basis in the at least two frequency domain basis.

[0090] In combination with the fifth or sixth aspect, in one possible implementation, the Doppler basis is a discrete Fourier transform (DFT) basis related to at least one of the number of downlink reference signals and the time interval of the downlink reference signals; or the Doppler basis is a Doppler value basis based on at least one bit quantization;

[0091] Alternatively, the Doppler basis is a basis constructed based on a first cyclic shift sequence.

[0092] In combination with the fifth or sixth aspect, in a possible implementation manner, the frequency domain basis is a DFT basis related to at least one of a bandwidth of the downlink reference signal and a frequency domain granularity of the downlink reference signal;

[0093] Alternatively, the predefined frequency domain basis is a delay value basis based on at least one bit quantization;

[0094] Alternatively, the predefined frequency domain basis is a basis constructed based on a second cyclic shift sequence.

[0095] In combination with the fifth aspect or the sixth aspect, in a possible implementation manner, the method further includes:

[0096] The terminal device sends third indication information to the access network device, where the third indication information is used to indicate one or more Doppler shift and frequency domain basis pairs, each of the Doppler shift and frequency domain basis pairs including a Doppler shift and a frequency domain basis; the Doppler shift included in each of the Doppler shift and frequency domain basis pairs belongs to at least one Doppler shift indicated by the first indication information, and the frequency domain basis included in each of the Doppler shift and frequency domain basis pairs belongs to the at least two frequency domain basis.

[0097] In combination with the fifth aspect or the sixth aspect, in a possible implementation, the method also includes: the at least one Doppler shift indicated by the first indication information and the at least two frequency domain bases constitute multiple Doppler shift and frequency domain base pairs; the energy corresponding to one or more Doppler shift and frequency domain base pairs indicated by the third indication information is greater than or equal to the energy corresponding to other Doppler shift and frequency domain base pairs in the multiple Doppler shift and frequency domain base pairs; or, the energy corresponding to one or more Doppler shift and frequency domain base pairs indicated by the third indication information is a Doppler shift and frequency domain base pair whose corresponding energy in the multiple Doppler shift and frequency domain base pairs is greater than or equal to the first energy.

[0098] In combination with the fifth aspect or the sixth aspect, in one possible implementation, the method further includes:

[0099] The number of the one or more Doppler shift and frequency domain basis pairs is indicated by or predefined in sixth indication information, or the first energy is indicated by or predefined in sixth indication information.

[0100] In the seventh aspect, the present application provides a communication device, which can be applied to a terminal device and has the function of implementing the method performed by the terminal device in the first aspect, the third aspect, or the fifth aspect. This function can be implemented by hardware, or it can be implemented by hardware executing the corresponding software. The hardware or software includes one or more units corresponding to the above functions. For example, it includes a transceiver unit and a processing unit. The transceiver unit can also be called a communication unit or a transceiver module. The transceiver unit can specifically include a receiving unit and a sending unit, and the processing unit can also be called a processing module.

[0101] In one design, the communication device is a communication chip, and the transceiver unit may be an input / output circuit or port, interface circuit, output circuit, input circuit, pin, or related circuit of the communication chip. The processing unit may be a processing circuit or logic circuit of the communication chip.

[0102] In an eighth aspect, the present application provides a communication device that can be applied to an access network device and has the function of implementing the method performed by the access network device in the second aspect, the fourth aspect, or the sixth aspect. This function can be implemented by hardware, or it can be implemented by hardware executing corresponding software. The hardware or software includes one or more units corresponding to the above functions. For example, it includes a transceiver unit and a processing unit. The transceiver unit can also be called a communication unit or a transceiver module. The transceiver unit can specifically include a receiving unit and a sending unit, and the processing unit can also be called a processing module.

[0103] In one design, the communication device is a communication chip, and the transceiver unit may be an input / output circuit or port, interface circuit, output circuit, input circuit, pin, or related circuit of the communication chip. The processing unit may be a processing circuit or logic circuit of the communication chip.

[0104] In a ninth aspect, the present application provides a communication device, comprising: a processor and a memory. The memory stores a computer program or computer instructions, and the processor is configured to call and execute the computer program or computer instructions stored in the memory, so that the processor implements any possible implementation of aspects 1 to 6.

[0105] Optionally, the communication device further includes an interface circuit, and the processor is used to control the interface circuit to send and receive signals and / or information and / or data, etc.

[0106] In a tenth aspect, the present application provides a communication device, comprising a processor, wherein the processor is configured to call a computer program or computer instruction stored therein, so that the processor implements any possible implementation of the first to sixth aspects.

[0107] Optionally, the communication device further includes an interface circuit, and the processor is used to control the interface circuit to send and receive signals and / or information and / or data, etc.

[0108] In an eleventh aspect, the present application further provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute any possible implementation of the first to sixth aspects.

[0109] In a twelfth aspect, the present application also provides a computer-readable storage medium comprising computer instructions, which, when executed on a computer, enable the computer to execute any possible implementation of aspects 1 to 6.

[0110] In a thirteenth aspect, the present application further provides a chip device, comprising a processor configured to call a computer program or computer instruction in the memory so as to cause the processor to execute any possible implementation of the aforementioned aspects 1 to 6. Optionally, the processor is coupled to the memory via an interface.

[0111] In the fourteenth aspect, an embodiment of the present application provides a communication system, which includes the communication device described in the fifth aspect (such as a terminal device) and the communication device described in the sixth aspect (such as an access network device).

[0112] These and other aspects of the present application will become more readily apparent from the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0113] Figure 1 A schematic diagram of a network architecture applicable to an embodiment of the present application;

[0114] Figure 2 An intention of combining coefficients provided in an embodiment of the present application;

[0115] Figure 3 A flow chart of a communication method provided in an embodiment of the present application;

[0116] Figures 4(a) to (g) are schematic diagrams of a merging coefficient provided in an embodiment of the present application;

[0117] FIG4(h) is a schematic diagram of a combined coefficient group provided in an embodiment of the present application;

[0118] Figure 5 A schematic diagram of the relationship between the two sub-matrices provided in an embodiment of the present application;

[0119] Figure 6 A schematic diagram of the relationship between the two sub-matrices provided in an embodiment of the present application;

[0120] Figure 7 A schematic diagram of the relationship between the two sub-matrices provided in an embodiment of the present application;

[0121] Figure 8 A schematic diagram of the relationship between the two sub-matrices provided in an embodiment of the present application;

[0122] Figure 9 A schematic diagram of multiple merging coefficient groups provided in an embodiment of the present application;

[0123] Figure 10 A schematic diagram of multiple merging coefficient groups provided in an embodiment of the present application;

[0124] Figure 11 A schematic diagram of multiple merging coefficient groups provided in an embodiment of the present application;

[0125] Figure 12 A flow chart of a communication method provided in an embodiment of the present application;

[0126] Figure 13 A flow chart of a communication method provided in an embodiment of the present application;

[0127] Figure 14 A schematic diagram of a frequency domain basis and Doppler shift provided in an embodiment of the present application;

[0128] Figure 15 A schematic diagram of a frequency domain basis and Doppler shift provided in an embodiment of the present application;

[0129] Figure 16 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0130] Figure 17 A schematic diagram of the structure of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0131] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0132] The communication method provided in the embodiments of the present application can be applied to fourth-generation (4G) communication systems, such as long-term evolution (LTE), and can also be applied to fifth-generation (5G) communication systems, such as 5G new radio (NR), or to various future communication systems, such as sixth-generation (6G) communication systems.

[0133] The methods and devices provided in the embodiments of the present application are based on the same or similar technical concepts. Since the principles of solving problems by the methods and devices are similar, the implementation of the devices and methods can refer to each other, and the repeated parts will not be repeated.

[0134] In the embodiment of the present application, the access network device can be any device with wireless transceiver functions. The device includes but is not limited to: an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., a home evolved NodeB, or homeNodeB, HNB), a base band unit (BBU), an access point (AP) in a wireless fidelity (WIFI) system, a wireless relay node, a wireless backhaul node, a transmission point (TP) or a transmission and reception point (TRP), etc. It can also be a gNB or a transmission point (TRP or TP) in a 5G (such as NR) system, or one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or a network node constituting a gNB or a transmission point, such as a baseband unit (BBU) or a distributed unit (DU), etc.

[0135] In some deployments, a gNB may include a centralized unit (CU) and a DU. The gNB may also include an active antenna unit (AAU). The CU implements some gNB functions, while the DU implements some gNB functions. For example, the CU is responsible for processing non-real-time protocols and services, and implementing the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. The DU is responsible for processing physical layer protocols and real-time services, and implementing the functions of the radio link control (RLC), medium access control (MAC), and physical (PHY) layers. The AAU implements some physical layer processing functions, RF processing, and active antenna-related functions. Because RRC layer information ultimately becomes PHY layer information, or is converted from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or by both the DU and the AAU. It is understood that an access network device can be a device that includes one or more of a CU node, a DU node, or an AAU node. In addition, the CU may be classified as an access network device in an access network (radio access network, RAN), or the CU may be classified as an access network device in a core network (core network, CN), which is not limited in this application.

[0136] The access network equipment provides services for the cell, and the terminal device communicates with the cell through the transmission resources (for example, frequency domain resources, or spectrum resources) allocated by the access network equipment. The cell can belong to a macro base station (for example, macro eNB or macro gNB, etc.) or a base station corresponding to a small cell. The small cells here can include: metro cells, micro cells, pico cells, femto cells, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services.

[0137] In an embodiment of the present application, the terminal device may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The terminal device in the embodiments of the present application can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a 5G network, or a terminal device in a future evolved public land mobile communication network (PLMN), etc.

[0138] Wearable devices, also known as wearable smart devices, are a general term for wearable devices that use wearable technology to intelligently design and develop wearable devices for daily wear, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not just hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. In a broad sense, wearable smart devices include those that are fully functional, large in size, and can achieve full or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0139] Furthermore, the terminal device can also be a terminal device in the Internet of Things (IoT) system. IoT is an important component of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network that interconnects people, machines, and things.

[0140] To facilitate understanding of the embodiments of the present application, the following is a brief introduction to the terms involved in the embodiments of the present application.

[0141] 1. Antenna port:

[0142] The antenna port can be simply referred to as a port. It can be understood as a transmitting antenna recognized by the receiving device, or a transmitting antenna that can be distinguished in space. An antenna port can be pre-configured for each virtual antenna, and each virtual antenna can be a weighted combination of multiple physical antennas. Each antenna port can correspond to a reference signal. Therefore, each antenna port can be called a reference signal port, for example, a sounding reference signal (SRS) port, etc. In an embodiment of the present application, the reference signal can be a non-precoded reference signal or a precoded reference signal, and this application does not limit this. When the reference signal is a precoded reference signal, the reference signal port can be a transmitting antenna port. The transmitting antenna port can refer to an independent transceiver unit (transceiverunit, TxRU).

[0143] 2. Spatial domain vector:

[0144] A spatial vector can also be called a spatial component vector, beam vector, spatial beam basis vector, or spatial basis vector. A spatial vector can correspond to a beam or a beam direction. A spatial vector can be one of the vectors used to construct a channel matrix. Each element in a spatial vector can represent the weight of each antenna port. Based on the weights of each antenna port represented by each element in the spatial vector, the signals from each antenna port are linearly superimposed to form an area with a strong signal in a certain spatial direction.

[0145] For the convenience of explanation below, it is assumed that the spatial vector is denoted as u. The length of the spatial vector u can be the number of transmitting antenna ports N in a polarization direction. s , N s ≥1 and is an integer. The spatial vector can be, for example, of length N s This application does not limit this.

[0146] In one implementation, the spatial domain vector is a discrete Fourier transform (DFT) vector. The DFT vector may refer to a vector in a DFT matrix.

[0147] In one implementation, the spatial domain vector is a conjugate transposed vector of the DFT vector. The DFT conjugate transposed vector may refer to a column vector in a conjugate transposed matrix of the DFT matrix.

[0148] In one implementation, the spatial domain vector is an oversampled DFT vector. The oversampled DFT vector may refer to a vector in an oversampled DFT matrix.

[0149] In one implementation, the spatial domain vector may be, for example, a two-dimensional (2D)-DFT vector v defined in the type II codebook in NR protocol 38.214 release 15 (R15). l,m In other words, the spatial domain vector can be a 2D-DFT vector or an oversampled 2D-DFT vector. For the sake of brevity, the detailed description of the 2D-DFT vector is omitted here.

[0150] 3. Frequency domain vector:

[0151] Frequency domain vectors, also known as frequency domain component vectors, frequency domain basis vectors, or frequency domain basis, are vectors that represent the frequency domain channel's variation patterns. A frequency domain vector corresponds to a delay path or a delay domain path. Each frequency domain vector can represent a specific variation pattern. As a signal travels through a wireless channel, it can travel through multiple paths from the transmitting antenna to the receiving antenna. Multipath delay causes frequency-selective fading, which is a frequency domain channel variation. Therefore, different frequency domain vectors can be used to represent the frequency domain channel variation patterns caused by delays on different transmission paths.

[0152] Frequency domain vector u f The length can be recorded as N f , N f is a positive integer, the frequency domain vector can be, for example, of length N fThe length of the frequency domain vector can be determined by the number of frequency domain units to be reported pre-configured in the reporting bandwidth, or by the length of the reporting bandwidth, or by a protocol predefined value. This application does not limit the length of the frequency domain vector. The reporting bandwidth may, for example, refer to the CSI reporting bandwidth (csi-ReportingBand) carried in the CSI reporting pre-configuration in the high-layer signaling (such as the radio resource control (RRC) message).

[0153] For example, the frequency domain vector or frequency domain basis can be a DFT basis related to at least one of the bandwidth of the downlink reference signal and the frequency domain granularity of the downlink reference signal, or a delay value basis based on M bits of quantization, or a basis based on cyclic shift (Cycling Shift). Each delay value basis in the M-bit quantized delay value basis corresponds to a delay path or a delay domain path, such as 10ns, which can be quantized into an M-bit delay value, i.e., a delay value basis, by predefinition or notification of the base station to the terminal device, or notification of the terminal device to the base station. The basis based on cyclic shift can be a basis composed of N cyclic shift sequences, each basis being a cyclic shift sequence, and each cyclic shift sequence corresponding to a cyclic shift mode of a delay path or a frequency domain basis.

[0154] After determining the frequency domain basis or frequency domain vector, the indexes corresponding to all frequency domain basis can be determined. Each frequency domain basis corresponds to an index, and each index can be used to determine a frequency domain basis. For example, if there are N frequency domain basis, one possible method is to index the frequency domain basis from 1 to N. Another possible method is to use the value of the frequency domain basis as the index. For example, if the frequency domain basis is the delay value basis, the index of the frequency domain basis corresponding to 10ns can be 10.

[0155] 4. Doppler shift and time domain vector:

[0156] Doppler shift, also known as Doppler frequency offset, represents the frequency shift caused by the movement of a terminal device or base station or other factors. Doppler shift can indicate the magnitude of the frequency offset or a pattern of channel time-domain variation. As signals travel through wireless channels at different times, multipath and the mobility of the transmitter or receiver cause time-selective fading, which is a variation in the time-domain channel. Each delay path of a channel may experience different mobility environments, so each delay path or frequency-domain basis corresponds to one or more Doppler shifts. This correspondence indicates that the energy or amplitude of the coefficient corresponding to the Doppler shift on the delay path or frequency-domain basis is greater than 0, indicating the specific time-domain channel variation experienced by the delay path. Accordingly, the Doppler shift can also be said to be associated with the delay path or frequency-domain basis. A delay path or frequency-domain basis and a corresponding Doppler shift, or a Doppler shift and an associated delay path or frequency-domain basis, constitute a Doppler shift and frequency-domain basis pair. This frequency-domain basis pair also corresponds to the coefficients described above.

[0157] Time domain vectors, also known as time domain component vectors, time domain basis vectors, or Doppler domain basis, are vectors that represent the channel's time domain variation. A time domain vector or Doppler basis corresponds to a Doppler path or Doppler shift. Each time domain vector can represent a specific variation. As signals travel through wireless channels at different times, multipath and the mobility of the transmitter or receiver cause time-selective fading, representing a change in the time domain channel. Therefore, different time domain vectors can be used to represent the channel's time domain variation.

[0158] Time domain vector u t The length can be recorded as N t , N t is a positive integer, the time domain vector can be, for example, of length N t The length of the time domain vector can be determined by the number of joint observation moments. For example, if we focus on the measurement results of S times CSI-RS, then N t =S; the time domain vector can be the DFT basis.

[0159] For example, the time domain vector or Doppler basis can be a DFT basis related to at least one of the number of downlink reference signals and the time interval of the downlink reference signals, or a Doppler value basis based on P-bit quantization, or a basis based on cyclic shift (Cycling Shift). Each Doppler value basis in the P-bit quantized Doppler value basis corresponds to a Doppler offset, such as 20Hz, which can be quantized into a P-bit Doppler offset, that is, a Doppler value basis, by predefinition or notification of the base station to the terminal device, or notification of the terminal device to the base station. The basis based on cyclic shift can be a basis composed of Q cyclic shift sequences, each basis is a cyclic shift sequence, and each cyclic shift sequence corresponds to a Doppler offset or time domain vector cyclic shift mode.

[0160] After the Doppler basis or time domain vector is determined, the indices corresponding to all Doppler bases can be determined. Each Doppler basis corresponds to an index, and each index can be used to determine a Doppler basis, and thus its corresponding Doppler shift. For example, when there are a total of Q Doppler bases, one possible approach is to number the Doppler bases from 1 to Q as indices. Another possible approach is to use the Doppler shift value corresponding to the Doppler basis as an index. For example, when the Doppler basis is a Doppler value basis, the index of the Doppler basis corresponding to 20 Hz can be 20.

[0161] 5. Space-frequency vector pair:

[0162] A space-frequency vector pair can also be called a space-frequency component vector. A space-domain vector and a frequency-domain vector can be combined to obtain a space-frequency vector pair. In other words, a space-frequency vector pair can include a space-domain vector and a frequency-domain vector. A space-frequency component matrix can be obtained from the space-domain vector and the frequency-domain vector in a space-frequency vector pair. For example, multiplying a space-domain vector by the conjugate transpose of a frequency-domain vector can obtain a space-frequency component matrix. The space-frequency component matrix described here is relative to the space-frequency matrix described below. Since a space-frequency matrix can be obtained by weighted summation of multiple space-frequency component matrices, each item used for weighting can be called a component of a space-frequency matrix, that is, the space-frequency component matrix mentioned here.

[0163] 6. Space-frequency-time vector group:

[0164] A space-frequency-time vector group can also be called a space-frequency-time component vector. A space-domain vector, a frequency-domain vector, and a time-domain vector can be combined to form a space-frequency-time vector group. In other words, a space-frequency-time vector group can include a space-domain vector, a frequency-domain vector, and a time-domain vector. A space-frequency-time component three-dimensional matrix can be obtained from the space-domain vector, the frequency-domain vector, and the time-domain vector in a space-frequency-time vector group. For example, by performing a tensor product multiplication on a space-domain vector, a frequency-domain vector, and a time-domain vector, a space-frequency-time component three-dimensional matrix can be obtained. The space-frequency-time component three-dimensional matrix described here is relative to the space-frequency-time three-dimensional matrix described below. Since a space-frequency-time three-dimensional matrix can be obtained by weighted summation of multiple space-frequency-time component three-dimensional matrices, each item used for weighting can be called a component of a space-frequency-time three-dimensional matrix, that is, the space-frequency-time component three-dimensional matrix mentioned here.

[0165] 7. Space-frequency matrix:

[0166] In the embodiments of the present application, the space-frequency matrix can be understood as an intermediate quantity used to determine the channel matrix corresponding to each frequency domain unit. For a terminal device, the space-frequency matrix can be determined by the channel matrix corresponding to each frequency domain unit. For an access network device, the space-frequency matrix can be obtained by taking the weighted sum of multiple space-frequency component matrices to recover the channel matrix.

[0167] For example, the space-frequency matrix can be denoted as H, Among them, w0 to Yes and N f The frequency domain units corresponding to N f column vectors, each column vector can be a channel vector or channel matrix corresponding to each frequency domain unit, and the length of each column vector can be N s The N f The column vectors correspond to N f The channel vector of frequency domain units. That is, the space-frequency matrix can be regarded as N f The joint matrix is composed of the channel vectors corresponding to the frequency domain units.

[0168] In one possible design, the space-frequency matrix can correspond to a receive antenna port. This corresponds to a receive antenna port because the terminal device can provide feedback on the frequency domain vector, space domain vector, and combining coefficients for each receive antenna port. The space-frequency matrix determined by the access network device based on the terminal device's feedback is the space-frequency matrix corresponding to the receive antenna port.

[0169] It should be understood that the space-frequency matrix is only a form of expression for determining the channel matrix and should not constitute any limitation to this application. For example, the column vectors in the space-frequency matrix can be connected in order from left to right, or arranged according to other predefined rules to obtain a length of N. s×N f The vector of , which can be called the space-frequency vector.

[0170] It should also be understood that the dimensions of the space-frequency matrix and space-frequency vector shown above are only examples and should not constitute any limitation to this application. For example, the space-frequency matrix can also be of dimension N f ×N s Each row vector may correspond to a frequency domain unit, so as to determine the channel vector of the corresponding frequency domain unit.

[0171] In addition, when the transmitting antenna is configured with multiple polarization directions, the dimension of the space-frequency matrix can be further expanded. For example, for a dual-polarization antenna, the dimension of the space-frequency matrix can be 2N s ×N f or N f ×2N s It should be understood that the present application does not limit the number of polarization directions of the transmitting antenna.

[0172] Furthermore, the space-frequency matrix corresponding to a receiving antenna port can also be expressed as

[0173] One or more spatial domain vectors may constitute a matrix W1, where each column vector in W1 corresponds to a spatial domain vector. One or more frequency domain vectors may constitute a matrix W3, where each column vector in W3 corresponds to a frequency domain vector.

[0174] When the number of receiving antenna ports is greater than 1, the spatial domain vectors used by each receiving antenna port may not be exactly the same, that is, each receiving antenna port uses an independent spatial domain vector; the spatial domain vectors used by each receiving antenna port may also be the same, that is, multiple receiving antenna ports share L spatial domain vectors.

[0175] When the number of receiving antenna ports is greater than 1, the frequency domain vectors used by each receiving antenna port may not be exactly the same, that is, each receiving antenna port uses an independent frequency domain vector; the frequency domain vectors used by each receiving antenna port may also be the same, that is, multiple receiving antenna ports share M frequency domain vectors.

[0176] In this case, the channel vector corresponding to each frequency domain unit on the i-th receiving antenna port can be based on the above L spatial domain vectors and M i The frequency domain vectors are constructed.

[0177] If a dual-polarization transmitting antenna is used, L spatial vectors can be selected for each polarization direction. Then, the dimension of W1 can be 2N s ×2L. In one possible implementation, the two polarization directions can use the same L spatial vectors At this time, W1 can be expressed as:

[0178]

[0179] in, Represents the i-th spatial domain vector among the selected L spatial domain vectors, i = 0, 1, ..., L-1.

[0180] For the i-th receiving antenna port, W3 H The dimension can be M i ×N f Each column vector in W3 can be a frequency domain vector. At this time, each spatial domain vector in W1 and each frequency domain vector in W3 can form a spatial frequency vector pair, and each spatial frequency vector pair can correspond to a merging coefficient, so there are 2L spatial domain vectors and M i 2L×M constructed by frequency domain vectors i Space-frequency vector pairs can be combined with 2L×M i The merging coefficients correspond one to one.

[0181] For the i-th receiving antenna port, It can be made of the above 2L×M i The merging coefficient matrix is composed of merging coefficients, and its dimension can be 2L×M i The combined coefficient matrix The lth row in may correspond to the lth spatial vector in the first polarization direction among the 2L spatial vectors. The merging coefficient matrix The L+lth row in the matrix can correspond to the lth spatial vector in the second polarization direction among the 2L spatial vectors. The mth (0≤m≤M i -1 and m is an integer) columns can correspond to M i The mth frequency domain vector among the frequency domain vectors.

[0182] The position of the space-frequency vector pair used to construct the space-frequency matrix specifically refers to the position of the spatial domain vector used to construct the space-frequency matrix within the spatial domain vector reported by the terminal device, and the position of the frequency domain vector used to construct the space-frequency matrix within the frequency domain vector reported by the terminal device. Since each space-frequency vector pair corresponds to a non-zero combining coefficient (referred to as a non-zero coefficient), the position of the space-frequency vector pair used to construct the space-frequency matrix is also the position of the non-zero coefficient.

[0183] 8. Space-frequency-time three-dimensional matrix:

[0184] In the embodiments of the present application, the space-frequency-time three-dimensional matrix can be understood as an intermediate quantity used to determine the channel vector or matrix corresponding to each frequency domain unit at a specific time. For a terminal device, the space-frequency-time three-dimensional matrix can be determined by the channel matrix corresponding to each frequency domain unit obtained from downlink reference signals at several different times. For an access network device, the space-frequency-time three-dimensional matrix can be obtained by taking the weighted sum of multiple space-frequency-time component three-dimensional matrices to recover the channel matrix.

[0185] In one possible design, the space-frequency-time three-dimensional matrix can correspond to the receiving antenna port, and each receiving port expands its corresponding space-frequency matrix to N in the time dimension. t Dimension, take the space-frequency matrix obtained by the corresponding downlink reference signal in each time dimension, and finally obtain the space-frequency three-dimensional matrix, whose dimension can be N s ×N f ×N t .

[0186] In addition, when the transmitting antenna is configured with multiple polarization directions, the dimension of the space-frequency-time three-dimensional matrix can be further expanded. For example, for a dual-polarization antenna, the dimension of the space-frequency-time three-dimensional matrix can be 2N s ×N f ×N t or N f ×2N s ×N t It should be understood that the present application does not limit the number of polarization directions of the transmitting antenna.

[0187] Furthermore, the space-frequency-time three-dimensional matrix corresponding to a receiving antenna port can also be expressed as:

[0188]

[0189] Among them, one or more vectors can form a matrix W1, and each column vector in W1 corresponds to a spatial domain vector. One or more frequency domain vectors can form a matrix W3, and each column vector in W3 corresponds to a frequency domain vector. One or more time domain vectors can form a matrix W4, and each column vector in W4 corresponds to a time domain vector.

[0190] Among them, for the N-dimensional matrix R, the dimensions are I1×I2×...×I N , operation⊙ n , n=1,2,...,N is defined as: for the two-dimensional matrix Q n , with dimensions of a×I n , n∈[1, 2, ..., N],

[0191] R new =Q n ⊙ nR, whose dimensions are I1×I2×...×I n-1 ×a×I n+1 ×...×I N .

[0192] in,

[0193] For the i-th receiving antenna port, It can be made of the above 2L×M i ×S merging coefficients constitute a three-dimensional matrix of merging coefficients, whose dimension can be 2L×M i ×S. The three-dimensional matrix of the combined coefficients The lth first dimension in the 2L spatial vectors may correspond to the lth spatial vector in the first polarization direction. The combined coefficient three-dimensional matrix The L+lth first dimension in the 2Lth spatial vector corresponds to the lth spatial vector in the second polarization direction. The mth (0≤m≤M i -1 and m is an integer) the second dimension can correspond to M i The mth frequency domain vector in the frequency domain vectors. The three-dimensional matrix of the combined coefficients The s-th (0≤s≤S-1 and s is an integer) third dimension in can correspond to the s-th time domain vector in the S time domain vectors.

[0194] The position of the space-frequency-time vector group used to construct the space-frequency-time three-dimensional matrix specifically refers to the position of the spatial domain vector used to construct the space-frequency-time three-dimensional matrix within the spatial domain vector reported by the terminal device, the position of the frequency domain vector used to construct the space-frequency-time three-dimensional matrix within the frequency domain vector reported by the terminal device, and the position of the time domain vector used to construct the space-frequency-time three-dimensional matrix within the frequency domain vector reported by the terminal device. Since each space-frequency-time vector group corresponds to a non-zero combining coefficient (referred to as a non-zero space-frequency-time coefficient), the position of the space-frequency-time vector group used to construct the space-frequency-time three-dimensional matrix is also the position of the non-zero space-frequency-time coefficient.

[0195] 9. Space-frequency combining coefficient:

[0196] The space-frequency combining coefficient can also be called combining coefficient, weighting coefficient, etc. Each combining coefficient can correspond to a space domain vector and a frequency domain vector, or in other words, each combining coefficient can correspond to a space-frequency vector pair. Each combining coefficient is a weighting coefficient of the space-frequency component matrix constructed by the space-frequency vector pair to which it corresponds. A combining coefficient corresponds to a space domain vector and a frequency domain vector. Specifically, the combining coefficient matrix The element in the i-th row and j-th column is the combining coefficient corresponding to the space-frequency vector pair composed of the i-th space vector and the j-th frequency vector. For dual-polarization antennas, the above i∈{1,2,…,2L}, the length of each space vector is 2N s .

[0197] Each combining coefficient includes amplitude and phase. For example, the combining coefficient can be expressed as ae jθ , a is the amplitude of the combining coefficient, and θ is the phase of the combining coefficient.

[0198] Some combining coefficients may have amplitudes of zero or close to zero, and their corresponding quantization values may be zero. Combining coefficients whose amplitudes are quantized using a quantization value of zero are referred to as combining coefficients with zero amplitudes. Correspondingly, some combining coefficients have larger amplitudes, and their corresponding quantization values are non-zero. Combining coefficients whose amplitudes are quantized using a non-zero quantization value are referred to as combining coefficients with amplitudes greater than zero.

[0199] 10, space-frequency time combining coefficient:

[0200] The space-frequency-time combining coefficient can also be called combining coefficient, space-frequency-time weighting coefficient, etc. Each space-frequency-time combining coefficient can correspond to a space domain vector, a frequency domain vector and a time domain vector. Each space-frequency-time combining coefficient is a weighting coefficient of the space-frequency-time component three-dimensional matrix constructed by the space-frequency-time vector group to which it corresponds. A space-frequency-time combining coefficient corresponds to a space domain vector, a frequency domain vector and a time domain vector. Specifically, the space-frequency-time combining coefficient three-dimensional matrix The (i, j, k) element in is the space-frequency-time combining coefficient corresponding to the space-frequency-time vector group of the i-th space-domain vector, the j-th frequency-domain vector, and the k-th time-domain vector.

[0201] Each space-frequency time combining coefficient includes amplitude and phase. For example, the space-frequency time combining coefficient can be expressed as ae jθ , a is the amplitude of the combining coefficient in the space-frequency period, and θ is the phase of the combining coefficient in the space-frequency period.

[0202] The amplitude value of some space-frequency combining coefficients may be zero, or close to zero, and the corresponding quantization value may be zero. The space-frequency combining coefficients whose amplitude is quantized by the quantization value zero may be called the space-frequency combining coefficients whose amplitude is zero. Correspondingly, the amplitude values of some space-frequency combining coefficients are large, and the corresponding quantization values are not zero. The space-frequency combining coefficients whose amplitude is quantized by the quantization value of non-zero may be called the space-frequency combining coefficients whose amplitude is greater than zero. To facilitate understanding of the embodiments of the present application, first combine Figure 1 The communication system applicable to the embodiment of the present application is described in detail. Figure 1 As shown, the communication system may include at least one access network device, such as Figure 1The communication system may also include at least one terminal device, such as Figure 1 The communication system may further include other network entities such as a network controller and a mobility management entity, which is not limited in the embodiments of the present application.

[0203] It should be understood that Figure 1 An access network device and a terminal device are shown as examples. The communication system may include multiple access network devices, and the signal coverage range of each access network device may include other number of terminal devices, which is not limited in this application.

[0204] In a TDD system, before transmitting data to a terminal device, the access network device can estimate the uplink channel based on the received uplink reference signal, and obtain the downlink channel based on the reciprocity of the uplink and downlink channels, thereby improving the downlink signal transmission quality or rate. However, the quality of the uplink reference signal received by the access network device is limited by the transmit power of the terminal device and the interference of other uplink signals, resulting in errors in the downlink channel obtained by the access network device, thereby affecting the transmission of the downlink signal. In this application, the uplink reference signal includes but is not limited to the SRS; the downlink reference signal includes but is not limited to the channel state information reference signal (CSI-RS).

[0205] In a frequency division duplexing (FDD) system, in order to improve the accuracy of the access network device in acquiring the downlink channel, the terminal device can estimate the downlink channel based on the received downlink reference signal and feed back the downlink channel information to the access network device. Since the downlink channel information fed back by the terminal device is used to assist the base station in channel estimation based on the uplink reference signal, the downlink channel information fed back by the terminal device can be part of the downlink channel information to reduce feedback overhead. For example, the access network device sends a downlink reference signal to the terminal device. The terminal device can determine the space-frequency matrix, at least one space domain vector and multiple frequency domain vectors corresponding to each receiving antenna port based on the downlink reference signal. For example, Figure 2 As shown, the terminal device can determine the channel matrix corresponding to each receive antenna port of the terminal device based on the downlink reference signal, and thus can determine the corresponding space-frequency matrix based on the channel matrix. The following is an example of the space-frequency matrix corresponding to a receive antenna port. The terminal device performs channel estimation based on the downlink reference signal received by the receive antenna port and can determine the corresponding space-frequency matrix. The space-frequency matrix H can be expressed as:

[0206] Among them, each column vector in W1 corresponds to a spatial domain vector, and each column vector in W3 corresponds to a frequency domain vector. is the merging coefficient matrix, the merging coefficient matrix The merging coefficient in the i-th row and j-th column corresponds to the i-th spatial domain vector in W1 and the j-th frequency domain vector in W3.

[0207] Figure 2 Each small square in the figure represents a merging coefficient, and each small square here only represents the position of a merging coefficient. In the horizontal axis direction, the merging coefficients located on the same horizontal axis correspond to the same spatial vector; in the vertical axis direction, the merging coefficients located on the same vertical axis correspond to the same frequency vector. The dotted box in the figure indicates that the merging coefficients on the same vertical axis correspond to the same frequency vector. For example, in the figure, merging coefficient 1 corresponds to spatial vector 1 and frequency vector 0; merging coefficient 2 corresponds to spatial vector 2 and frequency vector 4. The position of the merging coefficient can be represented by the index of the spatial vector and the frequency vector. For example, merging coefficient 1 can be identified as (1, 0), 1 represents the index of the spatial vector corresponding to merging coefficient 1, and 0 represents the index of the frequency vector corresponding to merging coefficient 1.

[0208] In light of the above description, in current FDD systems, for each receive antenna port, the terminal device feeds back to the access network the position of the combining coefficients whose quantized amplitudes are greater than zero, among all the combining coefficients corresponding to that receive antenna port. However, in FDD systems, the number of spatial and frequency domain vectors is relatively small, so the number of non-zero combining coefficients in the space-frequency matrix is relatively small, resulting in a relatively low feedback overhead for the terminal device.

[0209] In TDD systems, access network devices have a large number of antennas, which increases the number of spatial domain vectors. In TDD systems, the improved delay domain accuracy of channel estimation based on uplink reference signals also increases the number of frequency domain vectors. Consequently, the number of combining coefficients that terminal devices need to provide feedback also increases, resulting in significant feedback overhead.

[0210] This application provides a method that can reduce the feedback overhead of terminal devices and improve resource utilization.

[0211] In addition, due to the time delay between the time when the access network device acquires the channel and the time when the terminal device is actually served by the downlink precoding service, in the terminal device mobility scenario, the terminal device's channel may have undergone drastic changes during this time, resulting in a mismatch between the precoding and the terminal device's channel at the corresponding moment, causing performance degradation, which is also known as the "channel aging" problem. In one or another method provided in this application, the terminal device combines the downlink channel (CSI-RS, TRS, etc.) measurement information at multiple times and feeds back its Doppler-related information to the access network device, enabling the access network device to perform channel prediction and overcome the performance degradation caused by channel aging. This will be described in detail below.

[0212] It should also be understood that the methods provided in the embodiments of the present application are not limited to communications between access network devices and terminal devices, but can also be applied to communications between terminal devices, etc. This application does not limit the scenarios in which the methods are applied. The embodiments shown below are merely for ease of understanding and illustration, and the methods provided in the embodiments of the present application are described in detail using the interaction between an access network device and a terminal device as an example.

[0213] It should also be understood that the embodiments shown below do not specifically limit the specific structure of the execution subject of the method provided in the embodiments of the present application. As long as it is possible to communicate according to the method provided in the embodiments of the present application by running a program that records the code of the method provided in the embodiments of the present application, for example, the execution subject of the method provided in the embodiments of the present application can be a terminal device or an access network device, or a functional module in the terminal device or the access network device that can call and execute the program.

[0214] The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Ordinary technicians in this field will know that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0215] like Figure 3 FIG. 1 is a flow chart of a communication method provided in an embodiment of the present application. The method can be applied to a TDD system or an FDD system. The method includes:

[0216] S301: The access network device sends a downlink reference signal to the terminal device; correspondingly, the terminal device receives the downlink reference signal from the access network device.

[0217] The downlink reference signal is a channel state information reference signal (CSI-RS), and may also be other types of signals, which is not limited in this application.

[0218] In one implementation, the access network device may use one or more transmitting antenna ports to send a downlink reference signal, and the terminal device may use multiple or one or more receiving antenna ports to receive the downlink reference signal.

[0219] S302: The terminal device determines at least one spatial domain vector and multiple frequency domain vectors according to a downlink reference signal.

[0220] For each receiving antenna port of the terminal device, the terminal device performs channel estimation based on the downlink reference signal received through the receiving antenna port, and can determine the space-frequency matrix corresponding to the receiving antenna port. The detailed process of determining the space-frequency matrix is not limited in this application and will not be repeated here.

[0221] The space-frequency matrix corresponding to each receiving antenna port can be composed of a matrix W1 consisting of one or more space domain vectors, a matrix W3 consisting of multiple frequency domain vectors, and a merging coefficient matrix including multiple merging coefficients. Expressed as follows, the space-frequency matrix H can be expressed as:

[0222] Among them, Figure 3 In the process shown, the combining coefficient refers to the space-frequency combining coefficient. The specific meaning of the space-frequency combining coefficient can be referred to the previous description and will not be repeated here.

[0223] Among them, each column vector in W1 corresponds to a spatial domain vector, and each column vector in W3 corresponds to a frequency domain vector. is the combined coefficient matrix. Assuming that W1 includes L spatial domain vectors and W3 includes T frequency domain vectors, then The dimension is L×T. The merge coefficient matrix The i-th row in corresponds to the i-th spatial vector in L spatial vectors, and the combined coefficient matrix The jth column in corresponds to the jth frequency domain vector in the T frequency domain vectors, that is, the combined coefficient matrix The combining coefficient in the i-th row and j-th column in W1 corresponds to the i-th spatial domain vector in W1 and the j-th frequency domain vector in W3. L can be determined based on the number of transmit antenna ports of the access network device, and T can be determined by the number of frequency domain units to be reported preconfigured in the reporting bandwidth, or by the length of the reporting bandwidth, or by a protocol predefined value. The reporting bandwidth can refer to the value configured by the access network device through high-layer signaling (such as an RRC message).

[0224] A combining coefficient may be information about a delay path coefficient corresponding to a beam, and the information about the delay path coefficient may be the amplitude and phase of the path coefficient. The position of a combining coefficient in the combining coefficient matrix may be the position of a delay path corresponding to a beam, and the position of the delay path may be the relative position of the time domain path within the delay domain range, and the delay domain range may be determined by the frequency domain interval between two frequency domain units among the multiple frequency domain units corresponding to the reported bandwidth. The position of the delay path may also be an absolute delay (e.g., 300 ns).

[0225] In one implementation, in the present application, for each receiving antenna port, part of the spatial domain vectors can be extracted from the L spatial domain vectors, and the one or more rows of combining coefficients corresponding to the extracted part of the spatial domain vectors in the combining coefficient matrix (hereinafter referred to as the first matrix) are used as a matrix. In the following description, the matrix is referred to as the second matrix. For example, the access network device or the terminal device can select X spatial domain vectors from one or more spatial domain vectors corresponding to a receiving antenna port, where the X spatial domain vectors are part or all of the spatial domain vectors in at least one spatial domain vector, and X is an integer greater than 0. The value of X corresponding to different receiving antenna ports may be different. For any receiving antenna port of the terminal device, the matrix composed of the X rows of combining coefficients corresponding to the X spatial domain vectors in the first matrix corresponding to the receiving antenna port can be regarded as the second matrix, that is, the X spatial domain vectors and multiple frequency domain vectors corresponding to the receiving antenna port can correspond to the second matrix.

[0226] It can be seen from the above description that for each receiving antenna port of the terminal device, the terminal device can determine at least one spatial domain vector, multiple frequency domain vectors and a first matrix corresponding to each receiving antenna port based on the downlink reference signal received through each receiving antenna port, and the above-mentioned at least one spatial domain vector and multiple frequency domain vectors correspond to the first matrix. The first matrix includes multiple combining coefficients, and each combining coefficient included in the first matrix is a combining coefficient of a spatial domain vector and a frequency domain vector. Each combining coefficient included in the first matrix corresponds to a spatial domain vector and a frequency domain vector. Here, the at least one spatial domain vector and the multiple frequency domain vectors correspond to the first matrix, indicating that the spatial-frequency matrix corresponding to the receiving antenna port can be determined by the above-mentioned at least one spatial domain vector, the multiple frequency domain vectors and the first matrix.

[0227] In the present application, the position of each merging coefficient included in the first matrix is represented by a spatial domain vector and a frequency domain vector. For example, for a merging coefficient, the position of the merging coefficient can be indicated by the index of the spatial domain vector corresponding to the merging coefficient and the index of the frequency domain vector corresponding to the merging coefficient.

[0228] S303: The terminal device sends first information to the access network device, and correspondingly, the access network device receives the first information from the terminal device.

[0229] In this application, the first information is used to indicate the position of at least one merging coefficient among multiple merging coefficients, wherein the at least one merging coefficient satisfies any of the following conditions:

[0230] Condition 1: at least one combining coefficient is a combining coefficient whose energy is greater than or equal to a first energy and less than or equal to a second energy among the multiple combining coefficients, and the second energy is less than or equal to the energy of the combining coefficient with the largest energy among the multiple combining coefficients;

[0231] For example, as shown in Figure 4(a), assume that the energy of each of the multiple combining coefficients can be as shown in the figure, and the energy of the unmarked combining coefficients is 0. For example, the energy of the combining coefficient (1, 0) in the figure is 0, and the energy of the combining coefficient (1, 1) is 0.1. Where x in the combining coefficient (x, y) represents the index of the spatial domain vector corresponding to the combining coefficient, and y represents the index of the frequency domain vector corresponding to the combining coefficient.

[0232] In conjunction with Figure 4(a), assuming the first energy is 0.3 and the second energy is 0.5, then as shown in Figure 4(b), the merging coefficients that meet condition one are merging coefficient (1, 7), merging coefficient (1, 13), merging coefficient (1, 15), merging coefficient (2, 6), merging coefficient (2, 7), merging coefficient (2, 8), merging coefficient (2, 13), merging coefficient (2, 14), merging coefficient (3, 7), and merging coefficient (3, 8). The filled cells in the figure represent merging coefficients that meet condition one.

[0233] Condition 2: at least one combining coefficient is Y2 combining coefficients with the smallest energy among Y1 combining coefficients whose energy is greater than or equal to the first energy among the multiple combining coefficients, where Y2 is an integer less than Y1 and greater than 0;

[0234] In conjunction with Figure 4(a), the first energy is 0.3, the value of Y1 is 10, and the value of Y2 is 5. Then, as shown in Figure 4(c), the merging coefficients that meet condition 2 are merging coefficient (1, 7), merging coefficient (1, 15), merging coefficient (2, 6), merging coefficient (2, 8), and merging coefficient (3, 7). The filled cells in the figure represent merging coefficients that meet condition 2.

[0235] In one implementation, when selecting the Y2 merging coefficients with the smallest energy from the Y1 merging coefficients, the Y2 merging coefficients can be selected from the Y1 merging coefficients in order from the smallest to the largest energy of the Y1 merging coefficients. If, during the selection process, there are multiple merging coefficients with equal energy, when all of the multiple merging coefficients with equal energy are used as part of the Y2 merging coefficients, the number of selected merging coefficients is greater than Y2, then only a portion of the multiple merging coefficients with equal energy can be selected (for example, a portion can be randomly selected or selected in other ways), so that the number of finally selected merging coefficients is equal to Y2. Of course, all of the multiple merging coefficients with equal energy can also be used as part of the Y2 merging coefficients, and this application is not limited to this.

[0236] For example, in conjunction with Figure 4(a), the first energy is 0.3, the value of Y1 is 10, and if the value of Y2 is 4. At this time, the merging coefficients (1, 7), (1, 15), and (2, 6) are selected in sequence. Since the energies of the merging coefficients (2, 8) and (3, 7) are equal, if both of these merging coefficients are selected, the final number of merging coefficients will be greater than Y2. At this time, one of the merging coefficients can be randomly selected. Here, taking the merging coefficient (2, 8) as an example, the merging coefficients that meet condition 2 as shown in Figure 4(d) can be the merging coefficients (1, 7), (1, 15), (2, 6), and (2, 8). The small filled boxes in the figure represent the merging coefficients that meet condition 2.

[0237] Condition three: at least one of the merging coefficients is the Y4 merging coefficient with the smallest energy among the Y3 merging coefficients with the largest energy among the multiple merging coefficients, where Y4 is an integer less than Y3 and greater than 0;

[0238] In conjunction with Figure 4(a), if the value of Y3 is 5 and the value of Y4 is 2, then the two combining coefficients with the lowest energy are selected from the five combining coefficients with the highest energy. Then, as shown in Figure 4(e), the combining coefficients that meet condition three are (2, 15) and (3, 9). The filled cells in the figure represent combining coefficients that meet condition three.

[0239] Similarly, in one implementation, when selecting the Y4 merging coefficients with the smallest energy from the Y3 merging coefficients, the Y4 merging coefficients can be selected from the Y3 merging coefficients in order from the smallest to the largest energy of the Y3 merging coefficients. If, during the selection process, there are multiple merging coefficients with equal energy, when all of the multiple merging coefficients with equal energy are used as part of the Y4 merging coefficients, the number of selected merging coefficients is greater than Y4. Then, only a portion of the merging coefficients with equal energy can be selected (for example, a portion can be randomly selected or selected in other ways), so that the number of finally selected merging coefficients is equal to Y4. Of course, all of the multiple merging coefficients with equal energy can also be used as part of the Y4 merging coefficients, and this application is not limited to this.

[0240] Condition 4: At least one combining coefficient is a combining coefficient with an energy less than or equal to a second energy among the Y3 combining coefficients with the largest energy among the multiple combining coefficients, and the second energy is less than the energy of the combining coefficient with the largest energy among the multiple combining coefficients;

[0241] In conjunction with Figure 4(a), if the value of Y3 is 5 and the second energy is 0.7, then as shown in Figure 4(f), the merging coefficients that meet condition four are merging coefficient (1, 14), merging coefficient (2, 10), merging coefficient (2, 15), and merging coefficient (3, 9). The filled cells in the figure represent the merging coefficients that meet condition four.

[0242] Condition five: at least one combining coefficient is a combining coefficient whose energy is greater than or equal to the first energy among the multiple combining coefficients.

[0243] In conjunction with Figure 4(a), if the first energy is 0.7, then as shown in Figure 4(g), the merging coefficients that meet condition five are merging coefficients (1, 14), merging coefficients (2, 10), and merging coefficients (2, 11). The filled small boxes in the figure represent merging coefficients that meet condition five.

[0244] In the above conditions 1 to 5, the values of Y1, Y2, Y3 and Y4 can be configured by the access network device, determined by the terminal device, or be pre-agreed values, which is not limited in this application.

[0245] In the present application, the energy of each combining coefficient may be the modulus or the square of the modulus of the amplitude of the combining coefficient.

[0246] In the present application, after the access network device obtains the first information, it can improve the accuracy of channel estimation based on the first information. For example, the access network device can perform channel estimation based on the uplink reference signal from the terminal device, thereby obtaining a space-frequency matrix with noise / interference, hereinafter referred to as the third matrix. The access network device can calculate the energy distribution of each row of combining coefficients in the third matrix, and obtain a non-zero combining coefficient estimate based on the energy distribution. Due to the presence of noise / interference, the energy of some combining coefficients in the third matrix changes. For example, a combining coefficient has an energy of 0 in the absence of noise / interference, but due to noise / interference, the energy of the combining coefficient may be greater than 0. In this case, it is impossible to distinguish which combining coefficients have an energy determined based on noise / interference. In order to eliminate noise / interference, an energy threshold can be set, and combining coefficients greater than or equal to the energy threshold are regarded as non-zero combining coefficients, and combining coefficients less than the energy threshold are regarded as noise / interference. That is, the energy of combining coefficients less than the energy threshold is set to zero, thereby reducing noise / interference.

[0247] However, in the absence of noise / interference, the energy of some combining coefficients is very small. When there is noise / interference, the energy of these combining coefficients may be comparable to the energy of the combining coefficients corresponding to the noise / interference. If an energy threshold is set, these combining coefficients with smaller energy will be directly set to zero by the access network device as noise / interference, resulting in a decrease in the accuracy of space-frequency channel estimation. In this application, after the access network device obtains the first information, it can determine the position of at least one combining coefficient indicated by the first information. Even if the energy of the combining coefficient corresponding to the position indicated by the first information in the third matrix is less than the energy threshold, the access network device will no longer set the energy of these combining coefficients to 0, but will retain the energy of these combining coefficients, thereby reducing noise / interference while retaining the corresponding space-frequency vector pairs and improving the accuracy of channel estimation.

[0248] In this application, the first energy may be implemented in multiple ways. In one implementation, the first energy is the product of the energy of the largest combining coefficient among the multiple combining coefficients and the first coefficient, where the first coefficient is greater than 0 and less than 1.

[0249] In another implementation, the first energy is the energy of the first combining coefficient.

[0250] The first merging coefficient may satisfy any of the following conditions:

[0251] In case 1, the sum of the merging coefficients whose energy is greater than or equal to the energy of the first merging coefficient among the multiple merging coefficients is the first total energy, the sum of the energies of the multiple merging coefficients is the second total energy, and the ratio of the first total energy to the second total energy is equal to the first ratio.

[0252] Case 2: The multiple merging coefficients include a first merging coefficient and a second merging coefficient, the sum of the energies of the merging coefficients in the multiple merging coefficients that are greater than or equal to the energy of the first merging coefficient is the first total energy, the sum of the energies of the multiple merging coefficients is the second total energy, and the sum of the energies of the merging coefficients in the multiple merging coefficients that are greater than or equal to the energy of the second merging coefficient is the third total energy; the energy of the first merging coefficient is greater than the energy of the second merging coefficient, and when the multiple merging coefficients are sorted from large to small according to energy, the first merging coefficient and the second merging coefficient are adjacent in sequence, that is, when the multiple merging coefficients are sorted from large to small according to energy, the first merging coefficient and the second merging coefficient do not include merging coefficients whose energy is greater than or less than the energy of the second merging coefficient.

[0253] In case 2, the ratio of the first total energy to the second total energy is smaller than the first ratio, and the ratio of the third total energy to the second total energy is larger than the first ratio.

[0254] Case 3: The multiple combining coefficients include a first combining coefficient and a third combining coefficient. The sum of the energies of the combining coefficients with an energy greater than or equal to the first combining coefficient among the multiple combining coefficients is a first total energy, the sum of the energies of the multiple combining coefficients is a second total energy, and the sum of the energies of the combining coefficients with an energy greater than or equal to the third combining coefficient among the multiple combining coefficients is a fourth total energy. The energy of the third combining coefficient is greater than the energy of the first combining coefficient, and when the multiple combining coefficients are sorted from large to small according to energy, the third combining coefficient and the first combining coefficient are adjacent in sequence. That is, when the multiple combining coefficients are sorted from large to small according to energy, there is no combining coefficient between the third combining coefficient and the first combining coefficient whose energy is greater than or less than the energy of the first combining coefficient.

[0255] In case three, the ratio of the first total energy to the second total energy is greater than the first ratio, and the ratio of the fourth total energy to the second total energy is less than the first ratio.

[0256] In this application, the value of the first ratio is not limited, for example, the first ratio is 95%. The first ratio can be configured by the access network device, determined by the terminal device, or a pre-agreed value, which is not limited in this application.

[0257] In this application, the second energy may be implemented in multiple ways. In one implementation, the second energy is the product of the energy of the largest combining coefficient among the multiple combining coefficients and the second coefficient, where the second coefficient is greater than 0 and less than 1.

[0258] In another implementation, the second energy is the energy of the fourth combining coefficient in the first set.

[0259] The first set includes all merging coefficients whose energy is greater than or equal to the first energy among the multiple merging coefficients, or the first set includes Y3 merging coefficients whose energy is the largest among the multiple merging coefficients.

[0260] In this application, the fourth combining coefficient may satisfy any of the following conditions:

[0261] Case four: the sum of the energies of the merging coefficients in the first set that are less than or equal to the energy of the fourth merging coefficient is the fifth total energy, the sum of the energies of all the merging coefficients included in the first set is the sixth total energy, and the ratio of the fifth total energy to the sixth total energy is equal to the second ratio.

[0262] Case five: the first set includes the fourth combining coefficient and the fifth combining coefficient. The sum of the energies of the combining coefficients in the first set that are less than or equal to the energy of the fourth combining coefficient is the fifth total energy. The sum of the energies of all the combining coefficients included in the first set is the sixth total energy. The sum of the energies of the combining coefficients in the first set that are less than or equal to the energy of the fifth combining coefficient is the seventh total energy.

[0263] The energy of the fourth combining coefficient is greater than the energy of the fifth combining coefficient, and when all the combining coefficients included in the first set are sorted from large to small according to energy, the fourth combining coefficient and the fifth combining coefficient are adjacent in sequence, that is, when all the combining coefficients included in the first set are sorted from large to small according to energy, the fourth combining coefficient and the fifth combining coefficient do not include combining coefficients whose energy is greater than or less than the energy of the fifth combining coefficient.

[0264] In case five, the ratio of the fifth total energy to the sixth total energy is greater than the second ratio, and the ratio of the seventh total energy to the sixth total energy is less than the second ratio.

[0265] Case six: the first set includes the fourth combining coefficient and the sixth combining coefficient. The sum of the energies of the combining coefficients in the first set that are less than or equal to the energy of the fourth combining coefficient is the fifth total energy. The sum of the energies of all the combining coefficients included in the first set is the sixth total energy. The sum of the energies of the combining coefficients in the first set that are less than or equal to the energy of the sixth combining coefficient is the eighth total energy.

[0266] The energy of the sixth combining coefficient is greater than the energy of the fourth combining coefficient, and when all combining coefficients included in the first set are sorted from large to small according to energy, the sixth combining coefficient and the fourth combining coefficient are adjacent in sequence. That is, when all combining coefficients included in the first set are sorted from large to small according to energy, there is no combining coefficient between the sixth combining coefficient and the fourth combining coefficient whose energy is greater than or less than the energy of the fourth combining coefficient.

[0267] In case six, the ratio of the fifth total energy to the sixth total energy is smaller than the second ratio, and the ratio of the eighth total energy to the sixth total energy is larger than the second ratio.

[0268] In this application, the value of the second ratio is not limited, for example, the second ratio is 40%. The second ratio can be configured by the access network device, determined by the terminal device, or a pre-agreed value, which is not limited in this application.

[0269] Through the above method, the terminal device only needs to feed back the positions of some combining coefficients among the multiple combining coefficients, thereby reducing feedback overhead and improving feedback efficiency.

[0270] In the present application, at least one merging coefficient among the multiple merging coefficients may be divided into K merging coefficient groups, where K is an integer greater than 0.

[0271] In one implementation, the second matrix corresponding to the X spatial-domain vectors and the multiple frequency-domain vectors includes K sub-matrices, where each of the K sub-matrices corresponds to one or more spatial-domain vectors in the X spatial-domain vectors and one or more frequency-domain vectors in the multiple frequency-domain vectors. In this application, the position range corresponding to each sub-matrix may also be referred to as a "small window."

[0272] The K merging coefficient groups correspond one-to-one to the K sub-matrices. Each of the K merging coefficient groups is located within a sub-matrix of the K sub-matrices. That is, the merging coefficients included in a merging coefficient group are part or all of the merging coefficients included in the sub-matrix corresponding to the merging coefficient group. The ratio of the number of merging coefficients in a merging coefficient group to the number of merging coefficients in the sub-matrix corresponding to the merging coefficient group is greater than or equal to a preset value. The preset value can be predefined or configured by the access network device. For example, a sub-matrix includes 10 merging coefficients, and the corresponding merging coefficient group includes 8 merging coefficients. These 8 merging coefficients are part of the 10 merging coefficients included in the sub-matrix.

[0273] In one implementation, when the preset value is 1, the number of merging coefficients included in a sub-matrix is the same as the number of merging coefficients included in the merging coefficient group included in the sub-matrix.

[0274] In one possible implementation, the starting spatial domain vector corresponding to a submatrix can be the spatial domain vector with the smallest index among all the spatial domain vectors corresponding to the merging coefficient group corresponding to the submatrix; the ending spatial domain vector corresponding to a submatrix can be the spatial domain vector with the largest index among all the spatial domain vectors corresponding to the merging coefficient group corresponding to the submatrix.

[0275] In one possible implementation, the starting spatial domain vector corresponding to a submatrix can be the spatial domain vector with the largest index among all the spatial domain vectors corresponding to the merging coefficient group corresponding to the submatrix; the ending spatial domain vector corresponding to a submatrix can be the spatial domain vector with the smallest index among all the spatial domain vectors corresponding to the merging coefficient group corresponding to the submatrix.

[0276] Among them, the starting spatial vector corresponding to a submatrix may refer to the spatial vector corresponding to the first row of merging coefficients in the submatrix; the ending spatial vector corresponding to a submatrix may refer to the spatial vector corresponding to the last row of merging coefficients in the submatrix.

[0277] In one possible implementation, the starting frequency domain vector corresponding to a submatrix can be the frequency domain vector with the smallest index among all frequency domain vectors corresponding to the merging coefficient group corresponding to the submatrix; the ending frequency domain vector corresponding to a submatrix can be the frequency domain vector with the largest index among all frequency domain vectors corresponding to the merging coefficient group corresponding to the submatrix.

[0278] In one possible implementation, the starting frequency domain vector corresponding to a submatrix can be the frequency domain vector with the largest index among all frequency domain vectors corresponding to the merging coefficient group corresponding to the submatrix; the ending frequency domain vector corresponding to a submatrix can be the frequency domain vector with the smallest index among all frequency domain vectors corresponding to the merging coefficient group corresponding to the submatrix.

[0279] Among them, the starting frequency domain vector corresponding to a submatrix may refer to the frequency domain vector corresponding to the first column of merging coefficients in the submatrix; the ending frequency domain vector corresponding to a submatrix may refer to the frequency domain vector corresponding to the last column of merging coefficients in the submatrix.

[0280] For example, as shown in Figure 4(h), the submatrix corresponds to spatial domain vectors 1 to 4, and to frequency domain vectors 6 to 9. The submatrix includes 16 merging coefficients, where the filled cells in the submatrix represent merging coefficients belonging to the merging coefficient group corresponding to the submatrix, and the blank cells represent merging coefficients not belonging to the merging coefficient group corresponding to the submatrix.

[0281] Any two sub-matrices among the K sub-matrices, for example, the first sub-matrix and the second sub-matrix, may satisfy one or more of the following conditions.

[0282] The first condition is that the maximum row coordinate corresponding to the first submatrix in the second matrix is less than the minimum row coordinate corresponding to the second submatrix in the second matrix, and the difference between the minimum row coordinate and the maximum row coordinate is greater than or equal to a first threshold.

[0283] For example, if Figure 5As shown, it is assumed that the first threshold is 2. In the figure, the maximum row coordinate corresponding to the first submatrix in the second matrix is 1, and the minimum row coordinate corresponding to the second submatrix in the second matrix is 4.

[0284] The second condition is that the maximum column coordinate corresponding to the first submatrix in the second matrix is less than the minimum column coordinate corresponding to the second submatrix in the second matrix, and the difference between the minimum column coordinate and the maximum column coordinate is greater than or equal to a second threshold.

[0285] For example, if Figure 6 As shown, it is assumed that the second threshold is 2. In the figure, the maximum column coordinate corresponding to the first submatrix in the second matrix is 5, and the minimum column coordinate corresponding to the second submatrix in the second matrix is 9.

[0286] The third condition is that the absolute value of the difference between the maximum row coordinate corresponding to the second submatrix in the second matrix and the maximum row coordinate corresponding to the first submatrix in the second matrix is greater than or equal to a third threshold, and / or the absolute value of the difference between the minimum row coordinate corresponding to the second submatrix in the second matrix and the minimum row coordinate corresponding to the first submatrix in the second matrix is greater than or equal to the third threshold.

[0287] For example, if Figure 7 As shown, it is assumed that the third threshold is 2. In the figure, the minimum row coordinate corresponding to the first submatrix in the second matrix is 1, the maximum row coordinate corresponding to the first submatrix in the second matrix is 4, the minimum row coordinate corresponding to the second submatrix in the second matrix is 4, and the maximum row coordinate corresponding to the second submatrix in the second matrix is 7.

[0288] The fourth condition is that the absolute value of the difference between the maximum column coordinates corresponding to the second submatrix in the second matrix and the maximum column coordinates corresponding to the first submatrix in the second matrix is greater than or equal to the fourth threshold, and / or the absolute value of the difference between the minimum column coordinates corresponding to the second submatrix in the second matrix and the minimum column coordinates corresponding to the first submatrix in the second matrix is greater than or equal to the fourth threshold.

[0289] For example, if Figure 8 As shown, it is assumed that the fourth threshold is 2. In the figure, the minimum column coordinate corresponding to the first submatrix in the second matrix is 0, the maximum column coordinate corresponding to the first submatrix in the second matrix is 3, the minimum column coordinate corresponding to the second submatrix in the second matrix is 3, and the maximum column coordinate corresponding to the second submatrix in the second matrix is 6.

[0290] The above are just examples. The first sub-matrix and the second sub-matrix may also meet other conditions, which are not limited in this application.

[0291] In the present application, the first information may be used to indicate the positions of the K merging coefficient groups in the second matrix, thereby reducing feedback overhead. If the first information indicates the positions of the K merging coefficient groups to indicate at least one merging coefficient, the first information may include at least one of the following:

[0292] The position of the starting spatial vector corresponding to the submatrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0293] The position of the end spatial domain vector corresponding to the submatrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0294] The number of spatial vectors corresponding to the submatrices corresponding to each of the K merging coefficient groups;

[0295] The position of the starting frequency domain vector corresponding to the submatrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0296] The position of the ending frequency domain vector corresponding to the submatrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0297] The number of frequency domain vectors corresponding to the submatrix of each merging coefficient group in the K merging coefficient groups

[0298] If a submatrix includes A1 row merging coefficients, then the submatrix corresponds to A1 spatial domain vectors; if a submatrix includes A2 column merging coefficients, then the submatrix corresponds to A2 frequency domain vectors, where A1 and A2 are both integers greater than 0. The values of A1 and A2 corresponding to different submatrices can be different.

[0299] If the number of rows of the second matrix is X, the overhead for indicating the position of the starting spatial vector or the ending spatial vector corresponding to each submatrix may be greater than or equal to bits; the overhead used to indicate the number of spatial vectors corresponding to each submatrix can be greater than or equal to bits. In this application, Indicates a round-up operation. X1 is the number of candidate submatrix row numbers, and X1 is less than or equal to X.

[0300] If the number of columns of the second matrix is T, the overhead for indicating the position of the starting frequency domain vector or the ending frequency domain vector corresponding to each sub-matrix may be greater than or equal to bits; the overhead used to indicate the number of frequency domain vectors corresponding to each sub-matrix can be greater than or equal to bits. T1 is the number of candidate submatrix column numbers, and T1 is less than or equal to T.

[0301] In the present application, for a receiving antenna port, the multiple sub-matrices corresponding to the receiving antenna port can directly indicate the position of a sub-matrix (for example, the sub-matrix is the first sub-matrix) through the first information, and for the positions of other sub-matrices, such as the second sub-matrix, the difference information between the position of the second sub-matrix and the position of the first sub-matrix can be fed back, and the difference information includes but is not limited to the difference between the positions of the starting spatial domain vectors of the two sub-matrices, the difference between the positions of the ending spatial domain vectors of the two sub-matrices, the difference between the positions of the starting frequency domain vectors of the two sub-matrices, the difference between the positions of the ending frequency domain vectors of the two sub-matrices, the difference between the number of spatial domain vectors corresponding to the two sub-matrices, and the difference between the number of frequency domain vectors corresponding to the two sub-matrices. For example, if the position of the starting spatial domain vector corresponding to the first submatrix is the same as the position of the starting spatial domain vector corresponding to the second submatrix, then the first information can directly indicate the position of the starting spatial domain vector corresponding to the first submatrix. When the first information indicates the position of the starting spatial domain vector corresponding to the second submatrix, the indicated value can be 0. For example, if the number of spatial domain vectors corresponding to the first submatrix is A3 greater than the number of spatial domain vectors corresponding to the second submatrix, then the first information can directly indicate the number of spatial domain vectors corresponding to the first submatrix. When the first information indicates the number of spatial domain vectors corresponding to the second submatrix, the indicated value can be A3. Other situations can be deduced by analogy and will not be repeated here. In the above description, the submatrix can also be replaced by a merging coefficient group.

[0302] In the present application, for multiple receiving antenna ports of a terminal device, the terminal device can directly feedback the position of at least one submatrix corresponding to a receiving antenna port (for example, the first receiving antenna port), and for other antenna ports, such as the second receiving antenna port, it can feedback the difference information between the position of at least one submatrix corresponding to the second receiving antenna port and the position of at least one submatrix corresponding to the first receiving antenna port. For example, the position of the starting spatial domain vector corresponding to the first submatrix corresponding to the first receiving antenna port is the same as the position of the starting spatial domain vector corresponding to the second submatrix corresponding to the second receiving antenna port, then the first information can directly indicate the position of the starting spatial domain vector corresponding to the first submatrix corresponding to the first receiving antenna port, and when the first information indicates the position of the starting spatial domain vector corresponding to the second submatrix corresponding to the second receiving antenna port, the indicated value can be 0; for example, the number of frequency domain vectors corresponding to the first submatrix is less than the number of frequency domain vectors corresponding to the second submatrix by -A4, then the first information can directly indicate the number of frequency domain vectors corresponding to the first submatrix, and when the first information indicates the number of frequency domain vectors corresponding to the second submatrix, the indicated value can be -A4. Other situations can be deduced by analogy and will not be repeated here. In the above description, the submatrix can also be replaced by a merging coefficient group.

[0303] In the present application, for multiple receiving antenna ports of a terminal device, such as a first receiving antenna port and a second receiving antenna port, the first receiving antenna port corresponds to K1 combining coefficient groups, the second receiving antenna port corresponds to K2 combining coefficient groups, and each combining coefficient group corresponds to a submatrix. If there are submatrices with the same position in the K1 submatrices and the K2 submatrices, then the positions of multiple submatrices with the same position can be fed back only once. For example, if the positions of the K3 submatrices are the same, then for the first receiving antenna port, the positions of the K1 submatrix can be fed back; for the second receiving antenna port, the positions of the K3 submatrices with the same position in the K1 submatrix in the K2 submatrix are no longer fed back, and only the positions of the remaining K2-K3 submatrices are fed back. In the above description, the submatrix can also be replaced by a combining coefficient group.

[0304] In the present application, for a receiving antenna port of a terminal device, different downlink reference signals may be received at different times. For each downlink reference signal, the terminal device can determine multiple combining coefficients corresponding to each receiving antenna port, and the multiple combining coefficients corresponding to each receiving antenna port correspond to at least one sub-matrix. The terminal device can directly feedback the position of a sub-matrix obtained by a receiving antenna port (for example, a first receiving antenna port) by receiving the first downlink reference signal. For the position of the sub-matrix obtained by receiving other downlink reference signals, such as the second downlink reference signal, the difference information between the position of at least one sub-matrix corresponding to the second downlink reference signal and the position of at least one sub-matrix corresponding to the first downlink reference signal can be fed back. For details, please refer to the previous description and will not be repeated here. In the above description, the sub-matrix can also be replaced by a combining coefficient group.

[0305] In this application, for the mth sub-matrix corresponding to the rth receiving antenna port, the position of the starting spatial vector corresponding to the sub-matrix can be expressed as The number of spatial vectors corresponding to this submatrix is expressed as The position of the starting frequency domain vector corresponding to the submatrix is expressed as The number of frequency domain vectors corresponding to this submatrix is expressed as Here, b represents the beam domain or spatial domain, and d represents the delay domain or frequency domain. This is just an example, and other methods can also be used to represent the above parameters. For example, if there is only one receiving antenna port, There may be no subscript r in ; for example, if the rth receiving antenna port corresponds to only one submatrix, then There can be no subscript m in . For example, if the starting spatial vector of each submatrix corresponding to the receiving antenna port r is in the same position, then There may be no subscript m, etc., and other cases will not be described in detail.

[0306] For the multiple frequency domain vectors corresponding to each receiving antenna port, it is possible that not every frequency domain vector corresponds to a combining coefficient in at least one combining coefficient group corresponding to the receiving antenna port. For this purpose, the frequency domain range of M consecutive frequency domain vectors including at least one combining coefficient can be used as the first position range, that is, the first position range is the position corresponding to M consecutive frequency domain vectors in the multiple frequency domain vectors, and the frequency domain vector corresponding to each combining coefficient in at least one combining coefficient is one of the M consecutive frequency domain vectors, or the frequency domain vectors corresponding to all combining coefficients in at least one combining coefficient are one of the M consecutive frequency domain vectors after the same cyclic shift, where M is an integer greater than 0. The first position range can also be called a "large window".

[0307] In one implementation, for each receiving antenna port of the terminal device, a first position range can be determined based on at least one combining coefficient corresponding to each receiving antenna port, that is, one first position range corresponds to one receiving antenna port.

[0308] In this implementation, the terminal device may further send second information to the access network device, where the second information is used to indicate the first location range. Specifically, the second information may be used to indicate the number M of frequency domain vectors corresponding to the first location range, and / or the second information may be used to indicate the index of the first frequency domain vector or the index of the last frequency domain vector among the M frequency domain vectors within the first location range.

[0309] By this method, among the K merging coefficient groups, the number of bits occupied by the position of the starting frequency domain vector of the submatrix corresponding to each merging coefficient group is Since M is less than or equal to T, the feedback overhead of the terminal device can be further reduced.

[0310] In this implementation, for each receiving antenna port of the terminal device, a first information may be fed back according to the above method, that is, the first information is used to indicate the position of at least one combining coefficient corresponding to the receiving antenna port.

[0311] For example, if Figure 9 As shown, assuming K=2, that is, the receiving antenna port corresponds to two combining coefficient groups. Among them, combining coefficient group 1 (group 1 in the figure) is located in sub-matrix 1, and combining coefficient group 2 (group 2 in the figure) is located in sub-matrix 2.

[0312] Submatrix 1 corresponds to spatial domain vector 1 to spatial domain vector 4, and corresponds to frequency domain vector 6 to frequency domain vector 9; submatrix 2 corresponds to spatial domain vector 1 to spatial domain vector 2, and corresponds to frequency domain vector 12 to frequency domain vector 14.

[0313] In submatrix 1, filled cells represent the merged coefficients belonging to merged coefficient group 1, and blank cells represent the merged coefficients not belonging to merged coefficient group 1. Similarly, in submatrix 2, filled cells represent the merged coefficients belonging to merged coefficient group 2, and all merged coefficients included in submatrix 2 belong to merged coefficient group 2.

[0314] According to the above description, among all the frequency domain vectors corresponding to submatrix 1 and submatrix 2, the frequency domain vector with the smallest index is frequency domain vector 6, and the frequency domain vector with the largest index is frequency domain vector 14. Then the first position range can be from frequency domain vector 6 to frequency domain vector 14, a total of 9 continuous frequency domain vectors.

[0315] In another implementation, the first position range may be determined by the terminal device based on the frequency domain vectors corresponding to at least one combining coefficient corresponding to multiple receiving antenna ports, that is, one first position range corresponds to multiple receiving antenna ports. For example, for multiple receiving antenna ports, if the number of continuous frequency domain vectors corresponding to at least one combining coefficient corresponding to one receiving antenna port is the largest, the frequency domain range of the continuous multiple frequency domain vectors corresponding to the at least one combining coefficient corresponding to the receiving antenna port may be used as the first position range. For other receiving antenna ports, the second matrix corresponding to the receiving antenna port may be cyclically shifted, and the range of the frequency domain vector of the at least one combining coefficient corresponding to the receiving antenna port after cyclic shift is located within the first position range.

[0316] In this implementation, all receiving antenna ports of the terminal device correspond to a first position range, and the terminal device may also feedback the cyclic shift value corresponding to each receiving antenna port. If the cyclic shift value of a receiving antenna port is zero, the cyclic shift value of the receiving antenna port may not be fed back.

[0317] For example, combining Figure 9 ,like Figure 10 As shown, the first receiving antenna port corresponds to two combining coefficient groups. Among them, combining coefficient group 1 (group 1 in the figure) is located in sub-matrix 1, and combining coefficient group 2 (group 2 in the figure) is located in sub-matrix 2. For details about sub-matrix 1 and sub-matrix 2, please refer to Figure 9 Description in .

[0318] The second receive antenna port corresponds to three combining coefficient groups. Combining coefficient group 3 (Group 3 in the figure) is located in submatrix 3, combining coefficient group 4 (Group 4 in the figure) is located in submatrix 4, and combining coefficient group 5 (Group 5 in the figure) is located in submatrix 5. Within each submatrix, filled cells represent combining coefficients belonging to the combining coefficient group corresponding to that submatrix, while blank cells represent combining coefficients not belonging to the combining coefficient group corresponding to that submatrix.

[0319] Submatrix 3 corresponds to spatial domain vector X, and corresponds to frequency domain vector 1 to frequency domain vector 3; submatrix 4 corresponds to spatial domain vector 1 to spatial domain vector 4, and corresponds to frequency domain vector 4 to frequency domain vector 7; submatrix 5 corresponds to spatial domain vector 4, and corresponds to frequency domain vector 8 to frequency domain vector 9.

[0320] According to the above description, among all the frequency domain vectors corresponding to submatrix 3, submatrix 4, and submatrix 5, the frequency domain vector with the smallest index is frequency domain vector 1, and the frequency domain vector with the largest index is frequency domain vector 9. If the first receive antenna port and the second receive antenna port correspond to the same first position range, which includes frequency domain vector 6 to frequency domain vector 14, then the two submatrices corresponding to the first receive antenna port can be shifted right by 0 frequency domain vectors, and the three submatrices corresponding to the second receive antenna port can be shifted right by 5 frequency domain vectors, that is, the cyclic shift value corresponding to the first receive antenna port is 0, and the cyclic shift value corresponding to the second receive antenna port is 5.

[0321] For example, Figure 11 As shown, after the three sub-matrices corresponding to the second receive antenna port are shifted right by 5 frequency domain vectors, the frequency domain vector with the smallest index among all frequency domain vectors corresponding to the three sub-matrices corresponding to the second receive antenna port is frequency domain vector 6, and the frequency domain vector with the largest index is frequency domain vector 14. In this way, the first receive antenna port and the second receive antenna port correspond to the same first position range. In this case, the terminal device can feedback a cyclic shift value of 5 corresponding to the second receive antenna port.

[0322] In the figure, both the first receiving antenna port and the second receiving antenna port correspond to X spatial vectors. In actual applications, the number of spatial vectors corresponding to the two receiving antenna ports may also be different.

[0323] In the present application, the terminal device may also feed back the phase of each combining coefficient in at least one combining coefficient to the access network device. In one implementation, the terminal device may send third information to the access network device, where the third information includes at least one of the following:

[0324] The phase of the merging coefficient at the center of the submatrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0325] Among the K merging coefficient groups, the angular gradient of the submatrix corresponding to each merging coefficient group in the matrix row direction;

[0326] Among the K merging coefficient groups, the angular gradient of the submatrix corresponding to each merging coefficient group in the matrix column direction.

[0327] Among them, for the mth sub-matrix corresponding to the rth receiving antenna port, its center position can satisfy the following form:

[0328]

[0329]

[0330] Wherein, Cen1 represents the specific position of the frequency domain vector at the center position of a sub-matrix, and Cen2 represents the specific position of the spatial domain vector at the center position of a sub-matrix. In this application, floor() represents a rounding-down operation.

[0331] Among them, for the mth sub-matrix corresponding to the rth receiving antenna port, the angle gradient in the matrix row direction can satisfy the following form:

[0332] or,

[0333] in, The phase of the merging coefficient determined by the spatial domain vector corresponding to the center position of the submatrix and its corresponding end frequency domain vector, The phase of the merging coefficients is determined by the spatial domain vector corresponding to the center position of the submatrix and its corresponding starting frequency domain vector.

[0334] Among them, for the mth sub-matrix corresponding to the rth receiving antenna port, the angle gradient in the matrix column direction can satisfy the following form:

[0335] or,

[0336] in, The phase of the merging coefficient determined by the frequency domain vector corresponding to the center position of the submatrix and its corresponding end spatial domain vector, The phase of the merging coefficients is determined by the frequency domain vector corresponding to the center position of the submatrix and its corresponding starting spatial domain vector.

[0337] After obtaining the third information, the access network device can correct the phase of this part of the combining coefficient. For example, the originally estimated combining coefficient is ke jφ , and the phase of the combined coefficient should be θ according to the third information, so the combined coefficient is rotated, that is, multiplied by the coefficient e j(θ-φ) , so that the actual merging coefficient becomes ke jφ *e j(θ-φ) =ke jθ , thereby completing the phase correction and making the combining coefficient more accurate.

[0338] In this application, for the K sub-matrices corresponding to the K merging coefficient groups, the terminal device can also calculate the autocorrelation matrix of each sub-matrix in the K sub-matrices, and the terminal device can feedback the autocorrelation matrix of each sub-matrix in the K sub-matrices to the access network device.

[0339] The specific calculation method of the autocorrelation matrix is not limited in this application. For example, for each sub-matrix, it contains Space-frequency combining coefficients. For each sub-matrix, it is equivalent to containing a length of The S samples are expanded into a vector of dimension N r，m *S vector or matrix X r，m , then the autocorrelation matrix of the submatrix can be expressed as Among them, the S samples can be S measurement results of the combining coefficient corresponding to the current receiving antenna port and the current sub-matrix obtained by the terminal device based on multiple downlink reference signal measurements.

[0340] In one implementation, the terminal device may send fourth information to the access network device, where the fourth information includes all coefficients of the autocorrelation matrix of each submatrix in the K submatrices, or the fourth information includes the first H1 eigenvalues of the autocorrelation matrix of each submatrix in the K submatrices and the eigenvectors corresponding to the first H1 eigenvalues, or the fourth information includes the first H2% eigenvalues of the autocorrelation matrix of each submatrix in the K submatrices and the eigenvectors corresponding to the first H2% eigenvalues, where H1 and H2 are preset values.

[0341] The access network device can obtain the autocorrelation matrix of the combining coefficients of each submatrix using the fourth information. Because the combining coefficients in each submatrix include both signal and noise, and the signal portion conforms to the distribution characteristics of the autocorrelation matrix, while the noise does not, the autocorrelation matrix can be used to perform noise reduction (e.g., minimum mean square error estimation noise reduction) to make the combining coefficients more accurate.

[0342] In the previous process, the description is based on the example of a terminal device performing channel estimation based on a downlink reference signal. In the present application, the terminal device can also measure multiple downlink reference signals. The terminal device can obtain multiple space-frequency matrices at different times. These space-frequency matrices are combined and the dimensions are expanded to obtain a "space-frequency-time three-dimensional matrix". The space-frequency-time three-dimensional matrix can be used to obtain a merging coefficient three-dimensional matrix. The terminal device can indicate the position of the merging coefficient in the merging coefficient three-dimensional matrix.

[0343] like Figure 12 FIG. 1 is a flow chart of a communication method provided in an embodiment of the present application. The method can be applied to a TDD system or an FDD system. The method includes:

[0344] S1201: The access network device sends multiple downlink reference signals to the terminal device; correspondingly, the terminal device receives multiple downlink reference signals from the access network device.

[0345] S1202: The terminal device determines at least one spatial domain vector, multiple frequency domain vectors, and multiple time domain vectors based on multiple downlink reference signals.

[0346] For each receiving antenna port of the terminal device, the terminal device performs channel estimation based on multiple downlink reference signals received through the receiving antenna port, and can determine the space-frequency-time three-dimensional matrix corresponding to the receiving antenna port. The detailed process of determining the space-frequency-time three-dimensional matrix is not limited in this application and will not be repeated here.

[0347] The space-frequency-time three-dimensional matrix corresponding to each receiving antenna port can correspond to at least one space-domain vector, multiple frequency-domain vectors, multiple time-domain vectors, and a merging coefficient three-dimensional matrix including multiple merging coefficients. The merging coefficient three-dimensional matrix is referred to as the first three-dimensional matrix below. The first three-dimensional matrix includes multiple merging coefficients, each merging coefficient is a merging coefficient of a space-domain vector, a frequency-domain vector, and a time-domain vector, and the position of each merging coefficient can be represented by a space-domain vector, a frequency-domain vector, and a time-domain vector. Among them, in Figure 12 In the process shown, the combining coefficient refers to the space-frequency combining coefficient. The specific meaning of the space-frequency combining coefficient can be referred to the previous description and will not be repeated here.

[0348] Among them, the dimension of the first three-dimensional matrix can be L×T×Q, where L can be determined according to the number of transmitting antenna ports of the access network device; T can be determined by the number of frequency domain units to be reported pre-configured in the reporting bandwidth, or by the length of the reporting bandwidth, or by a protocol predefined value; Q is determined according to the number of downlink reference signals.

[0349] A combining coefficient may include information about a Doppler path coefficient corresponding to a delay path corresponding to a beam. The information about the Doppler path coefficient may include the amplitude and phase of the path coefficient. The position of a combining coefficient in the three-dimensional combining coefficient matrix may include a Doppler path position corresponding to a delay path corresponding to a beam. The Doppler path position may include a relative position of the Doppler path within a Doppler range. The Doppler range may be determined by the time interval between two downlink reference signals among the multiple downlink reference signals. The Doppler path position may also include an absolute Doppler offset (e.g., 10 Hz).

[0350] In one implementation, for each receive antenna port, a portion of the spatial domain vectors may be extracted from the L spatial domain vectors, and a portion of the time domain vectors may be extracted from the Q time domain vectors. The extracted portion of the spatial domain vectors, the multiple frequency domain vectors, and the combining coefficients corresponding to the extracted portion of the time domain vectors in the first three-dimensional matrix are combined as a three-dimensional matrix. In the following description, this three-dimensional matrix is referred to as the second three-dimensional matrix. For example, the access network device or the terminal device may select Z1 spatial domain vectors from at least one spatial domain vector corresponding to a receive antenna port, and select Z2 time domain vectors from the multiple time domain vectors corresponding to the receive antenna port, where Z1 and Z2 are integers greater than 0. For any receive antenna port of the terminal device, the three-dimensional matrix formed by the combining coefficients corresponding to the Z1 spatial domain vectors, the multiple frequency domain vectors, and the Z2 time domain vectors in the first three-dimensional matrix corresponding to the receive antenna port may be considered the second three-dimensional matrix. The values of Z1 and Z2 corresponding to different receive antenna ports may be different.

[0351] For ease of description, in this application, the second three-dimensional matrix may correspond to Z1 spatial domain vectors, multiple frequency domain vectors, and Z2 time domain vectors. The Z1 spatial domain vectors are part or all of the spatial domain vectors in at least one spatial domain vector, and the Z2 time domain vectors are part or all of the time domain vectors in the multiple time domain vectors, where Z1 and Z2 are integers greater than 0.

[0352] S1203: The terminal device sends first information to the access network device. Correspondingly, the access network device receives the first information from the terminal device.

[0353] The first information is used to indicate the position of at least one merging coefficient among the multiple merging coefficients; the at least one merging coefficient may satisfy any one of conditions 1 to 5 in S303, and the specific details are not repeated here.

[0354] Similar to S303, in the present application, at least one merging coefficient among multiple merging coefficients can be divided into K merging coefficient groups, wherein each merging coefficient among the at least one merging coefficient is a merging coefficient of a spatial domain vector among Z1 spatial domain vectors, a frequency domain vector among multiple frequency domain vectors, and a time domain vector among Z2 time domain vectors.

[0355] The second three-dimensional matrix includes K sub-three-dimensional matrices, the K merging coefficient groups correspond one-to-one to the K sub-three-dimensional matrices, and each sub-three-dimensional matrix corresponds to at least one spatial vector among the Z1 spatial vectors, at least one frequency vector among the multiple frequency vectors, and at least one time vector among the Z2 time vectors. Different sub-three-dimensional matrices may correspond to different numbers of spatial vectors, frequency vectors, and time vectors.

[0356] Each of the K merging coefficient groups is located within a sub-three-dimensional matrix of the K sub-three-dimensional matrices, that is, the merging coefficients included in a merging coefficient group are part or all of the merging coefficients included in the sub-three-dimensional matrix corresponding to the merging coefficient group. The number of merging coefficients in a merging coefficient group accounts for a proportion of the number of merging coefficients in the sub-three-dimensional matrix corresponding to the merging coefficient group that is greater than or equal to a preset value, which may be predefined or configured by an access network device. For example, a sub-three-dimensional matrix includes 10 merging coefficients, and the corresponding merging coefficient group includes 8 merging coefficients, and these 8 merging coefficients are a portion of the 10 merging coefficients included in the sub-three-dimensional matrix.

[0357] In one implementation, when the preset value is 1, the number of merging coefficients included in a sub-three-dimensional matrix is the same as the number of merging coefficients included in the merging coefficient group included in the sub-three-dimensional matrix.

[0358] In one possible implementation, the starting spatial domain vector corresponding to a sub-three-dimensional matrix can be the spatial domain vector with the smallest index among all the spatial domain vectors corresponding to the merging coefficient group corresponding to the sub-three-dimensional matrix; the ending spatial domain vector corresponding to a sub-three-dimensional matrix can be the spatial domain vector with the largest index among all the spatial domain vectors corresponding to the merging coefficient group corresponding to the sub-three-dimensional matrix.

[0359] In one possible implementation, the starting spatial domain vector corresponding to a sub-three-dimensional matrix can be the spatial domain vector with the largest index among all the spatial domain vectors corresponding to the merging coefficient group corresponding to the sub-three-dimensional matrix; the ending spatial domain vector corresponding to a sub-three-dimensional matrix can be the spatial domain vector with the smallest index among all the spatial domain vectors corresponding to the merging coefficient group corresponding to the sub-three-dimensional matrix.

[0360] In one possible implementation, the starting frequency domain vector corresponding to a sub-three-dimensional matrix can be the frequency domain vector with the smallest index among all frequency domain vectors corresponding to the merging coefficient group corresponding to the sub-three-dimensional matrix; the ending frequency domain vector corresponding to a sub-three-dimensional matrix can be the frequency domain vector with the largest index among all frequency domain vectors corresponding to the merging coefficient group corresponding to the sub-three-dimensional matrix.

[0361] In one possible implementation, the starting frequency domain vector corresponding to a sub-three-dimensional matrix can be the frequency domain vector with the largest index among all frequency domain vectors corresponding to the merging coefficient group corresponding to the sub-three-dimensional matrix; the ending frequency domain vector corresponding to a sub-three-dimensional matrix can be the frequency domain vector with the smallest index among all frequency domain vectors corresponding to the merging coefficient group corresponding to the sub-three-dimensional matrix.

[0362] In one possible implementation, the starting time domain vector corresponding to a sub-three-dimensional matrix can be the time domain vector with the smallest index among all the time domain vectors corresponding to the merging coefficient group corresponding to the sub-three-dimensional matrix; the ending time domain vector corresponding to a sub-three-dimensional matrix can be the time domain vector with the largest index among all the time domain vectors corresponding to the merging coefficient group corresponding to the sub-three-dimensional matrix.

[0363] In one possible implementation, the starting time domain vector corresponding to a sub-three-dimensional matrix can be the time domain vector with the largest index among all the time domain vectors corresponding to the merging coefficient group corresponding to the sub-three-dimensional matrix; the ending time domain vector corresponding to a sub-three-dimensional matrix can be the time domain vector with the smallest index among all the time domain vectors corresponding to the merging coefficient group corresponding to the sub-three-dimensional matrix.

[0364] In the present application, any two sub-three-dimensional matrices among the K sub-three-dimensional matrices, for example, the first sub-three-dimensional matrix and the second sub-three-dimensional matrix, may satisfy one or more of the following conditions.

[0365] The first condition is that the maximum coordinate corresponding to the first sub-three-dimensional matrix in the spatial dimension of the second three-dimensional matrix is less than the minimum coordinate corresponding to the second sub-three-dimensional matrix in the spatial dimension of the second three-dimensional matrix, and the difference between the minimum coordinate and the maximum coordinate is greater than or equal to the first threshold.

[0366] The second condition is that the maximum coordinate corresponding to the first sub-three-dimensional matrix in the frequency domain dimension of the second three-dimensional matrix is less than the minimum coordinate corresponding to the second sub-three-dimensional matrix in the frequency domain dimension of the second three-dimensional matrix, and the difference between the minimum coordinate and the maximum coordinate is greater than or equal to the second threshold.

[0367] The third condition is that the maximum coordinate corresponding to the first sub-three-dimensional matrix in the time domain dimension of the second three-dimensional matrix is less than the minimum coordinate corresponding to the second sub-three-dimensional matrix in the time domain dimension of the second three-dimensional matrix, and the difference between the minimum coordinate and the maximum coordinate is greater than or equal to the third threshold.

[0368] The fourth condition is that the absolute value of the difference between the maximum coordinate of the second sub-three-dimensional matrix in the second three-dimensional matrix corresponding to the spatial dimension and the maximum coordinate of the first sub-three-dimensional matrix in the second three-dimensional matrix corresponding to the spatial dimension is greater than or equal to the fourth threshold, and / or the absolute value of the difference between the minimum coordinate of the second sub-three-dimensional matrix in the second three-dimensional matrix corresponding to the spatial dimension and the minimum coordinate of the first sub-three-dimensional matrix in the second three-dimensional matrix corresponding to the spatial dimension is greater than or equal to the fourth threshold.

[0369] The fifth condition is that the absolute value of the difference between the maximum coordinate of the second sub-three-dimensional matrix in the frequency domain dimension and the maximum coordinate of the first sub-three-dimensional matrix in the second three-dimensional matrix is greater than or equal to the fifth threshold, and / or the absolute value of the difference between the minimum coordinate of the second sub-three-dimensional matrix in the frequency domain dimension and the minimum coordinate of the first sub-three-dimensional matrix in the second three-dimensional matrix is greater than or equal to the fifth threshold.

[0370] The sixth condition is that the absolute value of the difference between the maximum coordinate corresponding to the second sub-three-dimensional matrix in the time domain dimension in the second three-dimensional matrix and the maximum coordinate corresponding to the first sub-three-dimensional matrix in the time domain dimension in the second three-dimensional matrix is greater than or equal to the sixth threshold, and / or the absolute value of the difference between the minimum coordinate corresponding to the second sub-three-dimensional matrix in the time domain dimension in the second three-dimensional matrix and the minimum coordinate corresponding to the first sub-three-dimensional matrix in the time domain dimension in the second three-dimensional matrix is greater than or equal to the sixth threshold.

[0371] In the present application, the first information may be used to indicate the positions of the K merging coefficient groups in the second three-dimensional matrix, thereby reducing feedback overhead. If the first information indicates the positions of the K merging coefficient groups to indicate at least one merging coefficient, the first information may include at least one of the following:

[0372] The position of the starting spatial domain vector of the sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0373] The position of the ending spatial domain vector of the sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0374] The number of spatial vectors included in the sub-three-dimensional matrix corresponding to each of the K merging coefficient groups;

[0375] The position of the starting frequency domain vector of the sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0376] The position of the ending frequency domain vector of the sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0377] The number of frequency domain vectors included in the sub-three-dimensional matrix corresponding to each of the K merging coefficient groups;

[0378] The position of the starting time-domain vector of the sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0379] The position of the end domain vector of the sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0380] In the K merging coefficient groups, the number of time domain vectors included in the sub-three-dimensional matrix corresponding to each merging coefficient group.

[0381] In the present application, for a receiving antenna port, the multiple sub-three-dimensional matrices corresponding to the receiving antenna port can directly indicate the position of a sub-three-dimensional matrix (for example, the sub-three-dimensional matrix is the first sub-three-dimensional matrix) through the first information, and for the positions of other sub-three-dimensional matrices, such as the second sub-three-dimensional matrix, the difference information between the position of the second sub-three-dimensional matrix and the position of the first sub-three-dimensional matrix can be fed back, and the difference information includes but is not limited to the difference between the positions of the starting spatial domain vectors of the two sub-three-dimensional matrices, the difference between the positions of the ending spatial domain vectors of the two sub-three-dimensional matrices, the difference between the positions of the starting frequency domain vectors of the two sub-three-dimensional matrices, the difference between the positions of the ending frequency domain vectors of the two sub-three-dimensional matrices, the difference between the positions of the starting time domain vectors of the two sub-three-dimensional matrices, the difference between the positions of the ending time domain vectors of the two sub-three-dimensional matrices, the difference between the number of spatial domain vectors corresponding to the two sub-three-dimensional matrices, the difference between the number of frequency domain vectors corresponding to the two sub-three-dimensional matrices, and the difference between the number of time domain vectors corresponding to the two sub-three-dimensional matrices. For example, if the position of the starting spatial domain vector corresponding to the first sub-three-dimensional matrix is the same as the position of the starting spatial domain vector corresponding to the second sub-three-dimensional matrix, then the first information can directly indicate the position of the starting spatial domain vector corresponding to the first sub-three-dimensional matrix. When the first information indicates the position of the starting spatial domain vector corresponding to the second sub-three-dimensional matrix, the indicated value can be 0; for example, the number of spatial domain vectors corresponding to the first sub-three-dimensional matrix is A5 greater than the number of spatial domain vectors corresponding to the second sub-three-dimensional matrix. Then the first information can directly indicate the number of spatial domain vectors corresponding to the first sub-three-dimensional matrix. When the first information indicates the number of spatial domain vectors corresponding to the second sub-three-dimensional matrix, the indicated value can be A5. Other situations can be deduced by analogy and will not be repeated here. In the above description, the sub-three-dimensional matrix can also be replaced by a merging coefficient group.

[0382] In the present application, for multiple receiving antenna ports of a terminal device, the terminal device can directly feedback the position of at least one sub-three-dimensional matrix corresponding to a receiving antenna port (for example, a first receiving antenna port), and for other antenna ports, such as a second receiving antenna port, it can feedback the difference information between the position of at least one sub-three-dimensional matrix corresponding to the second receiving antenna port and the position of at least one sub-three-dimensional matrix corresponding to the first receiving antenna port. For example, the position of the starting spatial domain vector corresponding to the first sub-three-dimensional matrix corresponding to the first receiving antenna port is the same as the position of the starting spatial domain vector corresponding to the second sub-three-dimensional matrix corresponding to the second receiving antenna port. Then, the first information can directly indicate the position of the starting spatial domain vector corresponding to the first sub-three-dimensional matrix corresponding to the first receiving antenna port. When the first information indicates the position of the starting spatial domain vector corresponding to the second sub-three-dimensional matrix corresponding to the second receiving antenna port, the indicated value can be 0; for example, the number of frequency domain vectors corresponding to the first sub-three-dimensional matrix is less than the number of frequency domain vectors corresponding to the second sub-three-dimensional matrix by -A4. Then, the first information can directly indicate the number of frequency domain vectors corresponding to the first sub-three-dimensional matrix. When the first information indicates the number of frequency domain vectors corresponding to the second sub-three-dimensional matrix, the indicated value can be -A4. Other situations can be deduced by analogy and will not be repeated here. In the above description, the sub-three-dimensional matrix can also be replaced by a merging coefficient group.

[0383] In the present application, for multiple receiving antenna ports of a terminal device, such as a first receiving antenna port and a second receiving antenna port, the first receiving antenna port corresponds to K1 combining coefficient groups, and the second receiving antenna port corresponds to K2 combining coefficient groups, and each combining coefficient group corresponds to a sub-three-dimensional matrix. If there are sub-three-dimensional matrices in the same position in the K1 sub-three-dimensional matrix and the K2 sub-three-dimensional matrix, then the positions of the multiple sub-three-dimensional matrices in the same position can be fed back only once. For example, if the positions of the K3 sub-three-dimensional matrices are the same, then for the first receiving antenna port, the positions of the K1 sub-three-dimensional matrix can be fed back; for the second receiving antenna port, the positions of the K3 sub-three-dimensional matrices in the K2 sub-three-dimensional matrix that are in the same position as the K1 sub-three-dimensional matrix are no longer fed back, and only the positions of the remaining K2-K3 sub-three-dimensional matrices are fed back. In the above description, the sub-three-dimensional matrix can also be replaced by a combining coefficient group.

[0384] In the present application, for a receiving antenna port of a terminal device, different downlink reference signals may be received at different times. For each downlink reference signal, the terminal device can determine multiple combining coefficients corresponding to each receiving antenna port, and the multiple combining coefficients corresponding to each receiving antenna port correspond to at least one sub-three-dimensional matrix. The terminal device can directly feedback the position of a sub-three-dimensional matrix obtained by a receiving antenna port (for example, a first receiving antenna port) by receiving the first downlink reference signal. For the position of the sub-three-dimensional matrix obtained by receiving other downlink reference signals, such as the second downlink reference signal, the difference information between the position of at least one sub-three-dimensional matrix corresponding to the second downlink reference signal and the position of at least one sub-three-dimensional matrix corresponding to the first downlink reference signal can be fed back. For details, please refer to the previous description and will not be repeated here. In the above description, the sub-three-dimensional matrix can also be replaced by a combining coefficient group.

[0385] In this application, for the mth sub-three-dimensional matrix corresponding to the rth receiving antenna port, the position of the starting spatial vector corresponding to the sub-three-dimensional matrix can be expressed as The number of spatial vectors corresponding to the sub-three-dimensional matrix is expressed as The position of the starting frequency domain vector corresponding to the sub-three-dimensional matrix is expressed as The number of frequency domain vectors corresponding to this sub-three-dimensional matrix is expressed as The position of the starting time domain vector corresponding to the sub-three-dimensional matrix is expressed as The number of time domain vectors corresponding to this sub-three-dimensional matrix is expressed as Here, b represents the beam domain or spatial domain, d represents the delay domain or frequency domain, and t represents the Doppler domain or time domain. This is just an example, and other methods can also be used to represent the above parameters. For example, if there is only one receiving antenna port, There may be no subscript r in ; for example, if the rth receiving antenna port corresponds to only one sub-3D matrix, then There can be no subscript m in . For example, if the starting spatial vector of each sub-three-dimensional matrix corresponding to the receiving antenna port r is in the same position, then There may be no subscript m, etc., and other cases will not be described in detail.

[0386] In the present application, a position range can also be set, such as a second position range, where the second position range includes positions corresponding to M1 consecutive frequency domain vectors in multiple frequency domain vectors, and positions corresponding to M2 consecutive time domain vectors in multiple time domain vectors, where M1 and M2 are integers greater than 0.

[0387] In one implementation, for each receiving antenna port of the terminal device, the second position range can be determined based on at least one combining coefficient corresponding to each receiving antenna port, that is, one second position range corresponds to one receiving antenna port.

[0388] In this implementation, the terminal device may further send second information to the access network device, where the second information is used to indicate the second position range corresponding to each antenna port. Specifically, the second information may be used to indicate at least one of the following: the number M1 of frequency domain vectors corresponding to the second position range; the index of the first frequency domain vector or the index of the last frequency domain vector among the M1 frequency domain vectors within the second position range; the number M2 of time domain vectors corresponding to the second position range; and the index of the first time domain vector or the index of the last time domain vector among the M2 time domain vectors within the second position range.

[0389] In one implementation, all receiving antenna ports of the terminal device correspond to a second position range. For each receiving antenna port of the terminal device, if the second three-dimensional matrix corresponding to the receiving antenna port is cyclically shifted, the range of the frequency domain vector of at least one combining coefficient corresponding to the receiving antenna port after cyclic shift is located within the second position range, and the range of the time domain vector of at least one combining coefficient corresponding to the receiving antenna port after cyclic shift is located within the second position range.

[0390] In this implementation, the terminal device may also send second information to the access network device, where the second information is used to indicate the second position range corresponding to all receiving antenna ports. Specifically, the second information may be used to indicate at least one of the following: the number M1 of frequency domain vectors corresponding to the second position range; the index of the first frequency domain vector or the index of the last frequency domain vector in the M1 frequency domain vectors within the second position range; the number M2 of time domain vectors corresponding to the second position range; the index of the first time domain vector or the index of the last time domain vector in the M2 time domain vectors within the second position range. When the terminal device indicates the second position range through the second information, the terminal device may also feed back the cyclic shift value corresponding to each receiving antenna port. Wherein, if the cyclic shift value of a receiving antenna port is zero, the cyclic shift value of the receiving antenna port may not be fed back.

[0391] By this method, among the K merging coefficient groups, the number of bits occupied by the position of the starting frequency domain vector of the sub-three-dimensional matrix corresponding to each merging coefficient group is Since M1 is less than or equal to T, the feedback overhead of the terminal device can be further reduced. Similarly, in the K merging coefficient groups, the number of bits occupied by the position of the starting time domain vector of the sub-three-dimensional matrix corresponding to each merging coefficient group is Since M2 is less than or equal to Q, the feedback overhead of the terminal device can be further reduced.

[0392] In the present application, the terminal device may also feed back the phase of each combining coefficient in at least one combining coefficient to the access network device. In one implementation, the terminal device sends third information to the access network device, and the third information includes at least one of the following:

[0393] The phase of the merging coefficient at the center position of the sub-three-dimensional matrix corresponding to each merging coefficient group in the K merging coefficient groups;

[0394] Among the K merging coefficient groups, the angular gradient of the sub-three-dimensional matrix corresponding to each merging coefficient group in the spatial dimension;

[0395] Among the K merging coefficient groups, the angular gradient of the sub-three-dimensional matrix corresponding to each merging coefficient group in the frequency domain dimension;

[0396] Among the K merging coefficient groups, the angular gradient of the sub-three-dimensional matrix corresponding to each merging coefficient group in the time domain dimension.

[0397] Among them, for the mth sub-three-dimensional matrix corresponding to the rth receiving antenna port, its center position can satisfy the following form:

[0398]

[0399]

[0400]

[0401] Wherein, Cen1 represents the specific position of the frequency domain vector at the center of a sub-3D matrix, Cen2 represents the specific position of the spatial domain vector at the center of a sub-3D matrix, and Cen3 represents the specific position of the time domain vector at the center of a sub-3D matrix. In this application, floor() represents a rounding-down operation.

[0402] Among them, for the mth sub-three-dimensional matrix corresponding to the rth receiving antenna port, its angle gradient in the frequency domain dimension can satisfy the following form:

[0403] or,

[0404] in, The phase of the merging coefficient determined by the spatial domain vector, time domain vector and the corresponding end frequency domain vector corresponding to the center position of the sub-three-dimensional matrix, The phase of the combining coefficient is determined by the spatial domain vector, the time domain vector and the corresponding starting frequency domain vector corresponding to the center position of the sub-three-dimensional matrix.

[0405] Among them, for the mth sub-three-dimensional matrix corresponding to the rth receiving antenna port, its angle gradient in the spatial dimension can satisfy the following form:

[0406] or,

[0407] in, The phase of the merging coefficient determined by the frequency domain vector, time domain vector and the corresponding end spatial domain vector corresponding to the center position of the sub-three-dimensional matrix, The phase of the combining coefficient is determined by the frequency domain vector, the time domain vector and the corresponding starting spatial domain vector corresponding to the center position of the sub-three-dimensional matrix.

[0408] Among them, for the mth sub-three-dimensional matrix corresponding to the rth receiving antenna port, its angle gradient in the time domain dimension can satisfy the following form:

[0409] or,

[0410] in, The phase of the merging coefficient determined by the spatial domain vector, frequency domain vector and the corresponding end domain vector corresponding to the center position of the sub-three-dimensional matrix, The phase of the combining coefficient is determined by the spatial domain vector, the frequency domain vector and the corresponding starting time domain vector corresponding to the center position of the sub-three-dimensional matrix.

[0411] In the present application, for the K sub-three-dimensional matrices corresponding to the K merging coefficient groups, the terminal device may further calculate an autocorrelation matrix for each of the K sub-three-dimensional matrices, and the terminal device may provide feedback of the autocorrelation matrix for each of the K sub-three-dimensional matrices to the access network device. This application does not limit the specific calculation method of the autocorrelation matrix.

[0412] The terminal device can send fourth information to the access network device, where the fourth information includes all coefficients of the autocorrelation matrix of each sub-three-dimensional matrix in the K sub-three-dimensional matrices, or the fourth information includes the first H1 eigenvalues of the autocorrelation matrix of each sub-three-dimensional matrix in the K sub-three-dimensional matrices and the eigenvectors corresponding to the first H1 eigenvalues, or the fourth information includes the first H2% eigenvalues of the autocorrelation matrix of each sub-three-dimensional matrix in the K sub-three-dimensional matrices and the eigenvectors corresponding to the first H2% eigenvalues, where H1 and H2 are preset values.

[0413] The terminal device sends a reference signal to the access network device. This reference signal is used by the access network device to perform channel estimation and obtain channel state information (CSI). This CSI represents the channel state at the moment the access network device receives the reference signal (time 1). The access network device performs downlink precoding based on this CSI and uses this downlink precoding to transmit data to the terminal device (at time 2).

[0414] Due to the time delay between time 1 and time 2, in the terminal device mobility scenario, the channel of the terminal device at time 2 may have changed dramatically compared to time 1, resulting in a mismatch between the downlink precoding and the channel of the terminal device at time 2, resulting in performance degradation, which is also known as the "channel aging" problem. In one or another method provided by the present application, the terminal device combines the downlink channel (CSI-RS, TRS, etc.) measurement information of multiple time moments and feeds back information related to its Doppler shift to the access network device. The Doppler shift can provide time domain related information of the channel. The channel at time 1 and the channel obtained by several reference signals before time 1, as well as the Doppler shift information, can be used to obtain a more accurate channel state at time 2, enabling the access network device to perform channel prediction and overcome the performance degradation problem caused by channel aging. This will be described in detail below.

[0415] like Figure 13 FIG. 1 is a flow chart of a communication method provided in an embodiment of the present application. The method can be applied to a TDD system or an FDD system. The method includes:

[0416] Step 1301: The access network device sends a downlink reference signal to the terminal device; correspondingly, the terminal device receives the downlink reference signal from the access network device.

[0417] The downlink reference signal is a CSI-RS, and may also be a tracking reference signal (TRS), or may be other types of signals, which is not limited in the present application.

[0418] Step 1302: The terminal device sends first indication information to the access network device; correspondingly, the access network device receives the first indication information from the terminal device.

[0419] In one implementation, the access network device may use one or more transmitting antenna ports to send a downlink reference signal, and the terminal device may use multiple or one or more receiving antenna ports to receive the downlink reference signal.

[0420] The terminal device can perform channel estimation based on the downlink reference signal to determine all frequency domain bases corresponding to the downlink reference signal and their corresponding Doppler shifts. The specific implementation method of the above process is not limited in this application and will not be repeated here.

[0421] The terminal device may indicate at least one Doppler shift through the first indication information, where the at least one Doppler shift is associated with at least two frequency domain bases. Accordingly, the access network device may determine, based on the first indication information, the at least one Doppler shift indicated by the first indication information. In the embodiment of the present application, the frequency domain base may also be referred to as a delay path. Therefore, it can also be said that at least two delay paths correspond to the at least one Doppler shift.

[0422] The first indication information may be independently transmitted signaling, or may be a field added to an existing uplink reference signal or uplink signaling, such as adding the first indication information to an SRS or a precoding matrix indicator (PMI), which is not limited in this application.

[0423] In the present application, the meaning and method of how the first indication information specifically indicates the Doppler shift may be predefined, or the terminal device may notify the access network device, or the access network device may notify the terminal device. Possible implementation methods are described below.

[0424] In one possible implementation, the first indication information indicates at least one Doppler shift by indicating the index of the Doppler basis corresponding to the at least one Doppler shift. For example, if the index of the Doppler basis is 1 to 100, the first indication information indicates 2 and 50, indicating that the Doppler shifts associated with at least two frequency domain basis are Doppler shifts corresponding to basis 2 and basis 50. The Doppler basis and the index of the Doppler basis may be predefined, or may be notified by the terminal device to the access network device, or may be notified by the access network device to the terminal device. The first indication information indicates the index of the Doppler basis by directly indicating the numerical value of the index or by indicating it through bit mapping. For example, if the index of the Doppler basis is 1 to 8, the first indication information may indicate the Doppler shifts associated with at least two frequency domain basis as basis 3, basis 4, basis 7, and basis 8 through a bit vector of length 8: [0, 0, 1, 1, 0, 0, 1, 1].

[0425] In one possible implementation, the terminal device indicates at least one Doppler shift by indicating the value of the Doppler shift through first indication information. For example, the terminal device indicates 10 through the first indication information, indicating that a Doppler shift associated with at least two frequency domain bases is 10 Hz. The specific indication dimension of the first indication information, such as hertz (Hz) or kilohertz (kHz) corresponding to 10, and the number of quantization bits of the indicated Doppler shift value can be predefined, or can be notified by the terminal device to the access network device, or can be notified by the access network device to the terminal device.

[0426] The at least one Doppler shift may be one or more groups of Doppler shifts, each group of the one or more groups of Doppler shifts including at least two Doppler shifts, and the at least two Doppler shifts included in each group of Doppler shifts are continuous. The at least two Doppler shifts being continuous here may mean that the indices of the Doppler bases corresponding to the at least two Doppler shifts are continuous. For example, the indices of the Doppler bases are from 1 to 100, and the indices of the Doppler bases corresponding to the group of Doppler shifts indicated by the first indication information are {17, 18, 19, 20, 21}. In this case, the group of Doppler shifts indicated by the first indication information is continuous. Alternatively, the at least two Doppler shifts being continuous here may mean that the values of the at least two Doppler shifts are equally spaced. For example, the values of the group of Doppler shifts indicated by the first indication information are {10, 12, 14, 16}, indicating that the Doppler shifts are {10 Hz, 12 Hz, 14 Hz, 16 Hz}, respectively. In this case, the group of Doppler shifts indicated by the first indication information is continuous. In this example, the interval between the Doppler shift values is 2 Hz. The terminal device and the access network device can pre-configure, pre-define, or reach a consensus on the quantization interval of the Doppler shift value through signaling interaction. For example, the interval of 2 Hz is the quantization interval. Then, when the interval between the values of a group of Doppler shifts indicated by the first indication information is 2 Hz, it can be considered that the multiple Doppler shifts in the group of Doppler shifts are continuous. In one possible example, for a group of Doppler shifts with values of {10, 14, 18, 22}, although the multiple Doppler shifts are equally spaced, the interval is not equal to the quantization interval of 2 Hz, and the group of Doppler shifts is discontinuous. Here, the quantization interval of 2 Hz is just an example. In another example, it can also be considered that as long as a group of Doppler shifts are equally spaced, the group of Doppler shifts is continuous.

[0427] In one possible implementation, the at least one Doppler shift indicated by the first indication information is one or more groups of Doppler shifts. For each group of Doppler shifts, the first indication information indicates the indices of two Doppler bases, where the indices of the two Doppler bases are, respectively, the largest and smallest numerical indices among the indices of the Doppler bases corresponding to the group of Doppler shifts. For example, if the indices of the Doppler bases corresponding to the group of Doppler shifts are {17, 18, 19, 20, 21}, then the first indication information may indicate {17, 21}. Upon receiving the first indication information, the access network device may determine that the indices of the Doppler bases corresponding to the group of Doppler shifts associated with at least two frequency domain bases are {17, 18, 19, 20, 21}. For K groups of Doppler shifts, where K is greater than 1, the first indication information indicates the indices of K groups of two Doppler bases, with the indices of the two Doppler bases in each group corresponding to a group of Doppler shifts. For example, if K = 2 and the indices of the Doppler bases corresponding to the two sets of Doppler shifts are {17, 18, 19, 20, 21} and {30, 31, 32, 33}, then the first indication information may indicate {17, 21, 30, 33}. After receiving the first indication information, the access network device can determine that the indices of the Doppler bases corresponding to the two sets of Doppler shifts associated with the at least two frequency domain bases are {17, 18, 19, 20, 21} and {30, 31, 32, 33}.

[0428] In one possible implementation, the at least one Doppler offset indicated by the first indication information is one or more groups of Doppler offsets, and for each group of Doppler offsets, the first indication information indicates two Doppler offset values, where the two Doppler offset values are respectively the maximum value and the minimum value of the Doppler offsets in the group of Doppler offsets. For example, the values of the group of Doppler offsets are: {17, 19, 21}, and the interval between the Doppler offset values is 2 Hz, then the first indication information may indicate: 17 and 21. After receiving the first indication information, the access network device can determine that a group of Doppler offsets associated with at least two frequency domain bases is {17 Hz, 19 Hz, 21 Hz}. For K groups of Doppler offsets, where K is greater than 1, the first indication information indicates K groups of two Doppler offset values, and each group of two Doppler offset values corresponds to a group of Doppler offsets. For example, if K = 2 and the two sets of Doppler shift values are {17, 19, 21} and {31, 33, 35}, the first indication information may indicate {17, 21, 31, 35}. After receiving the first indication information, the access network device can determine that the two sets of Doppler shifts associated with the at least two frequency domain bases are {17 Hz, 19 Hz, 21 Hz} and {31 Hz, 33 Hz, 35 Hz}.

[0429] In one possible implementation, the at least one Doppler shift indicated by the first indication information is one or more groups of Doppler shifts. For each group of Doppler shifts, the first indication information indicates an index of a Doppler basis and an index length value. The index of the one Doppler basis and the index length value are used to determine each Doppler shift in the group of Doppler shifts. The index of the one Doppler basis is the index of the Doppler basis corresponding to the group of Doppler shifts, and can be the largest index or the smallest index. For example, if the indices of the Doppler basis corresponding to the group of Doppler shifts are {17, 18, 19, 20, 21}, the first indication information can indicate 17 and 5. After receiving the first indication information, the access network device can determine that the indices of the Doppler basis corresponding to the group of Doppler shifts associated with at least two frequency domain basis are {17, 18, 19, 20, 21}. For K groups of Doppler shifts, where K is greater than 1, the first indication information indicates K groups of values, each of which includes a Doppler basis index and an index length value. Each group of values in the K groups of values corresponds to a group of Doppler shifts in the K groups of Doppler shifts. For example, if K = 2, and the indices of the Doppler basis corresponding to two groups of Doppler shifts are {17, 18, 19, 20, 21} and {30, 31, 32, 33}, the first indication information may indicate {17, 5, 30, 4}. Upon receiving the first indication information, the access network device determines that the indices of the Doppler basis corresponding to the two groups of Doppler shifts associated with at least two frequency-domain basis are {17, 18, 19, 20, 21} and {30, 31, 32, 33}.

[0430] In one possible implementation, the at least one Doppler shift indicated by the first indication information is one or more groups of Doppler shifts. For each group of Doppler shifts, the first indication information indicates a Doppler shift value and a numerical span. The Doppler shift value and the numerical span are used to determine each Doppler shift in the group of Doppler shifts, and the Doppler shift value is the maximum or minimum value in the group of Doppler shifts. For example, if the group of Doppler shift values is {17, 19, 21}, and the interval between Doppler shift values is 2 Hz, then the first indication information may indicate 17 and 4. Upon receiving the first indication information, the access network device may determine that the group of Doppler shifts associated with at least two frequency domain bases is {17 Hz, 19 Hz, 21 Hz}. For K groups of Doppler shifts, where K is greater than 1, the first indication information indicates K groups of values, each group of values including a Doppler shift value and a numerical span, and each group of values in the K groups of values corresponds to a group of Doppler shifts in the K groups of Doppler shifts. For example, if K = 2 and the two sets of Doppler shift values are {17, 19, 21} and {31, 33, 35}, the first indication information may indicate {17, 4, 31, 4}. After receiving the first indication information, the access network device can determine that the two sets of Doppler shifts associated with the at least two frequency domain bases are {17 Hz, 19 Hz, 21 Hz} and {31 Hz, 33 Hz, 35 Hz}.

[0431] In one possible implementation, the at least one Doppler shift indicated by the first indication information is one or more groups of Doppler shifts, and for each group of Doppler shifts, the first indication information indicates an index length value of a Doppler basis, and the index length value and the index of a Doppler basis are used to determine each of the Doppler shifts in the group of Doppler shifts, and the index of the one Doppler basis is predefined, or the index of the one Doppler basis is indicated by the fourth indication information. For example: the access network device and the terminal device predefine a Doppler basis index of 1, or the access network device indicates a Doppler basis index of 1 through the fourth indication information, or the terminal device indicates a Doppler basis index of 1 through the fourth indication information, and the index of the Doppler basis corresponding to the group of Doppler shifts is: {1, 2, 3, 4, 5}, then the first indication information can indicate: 5. After receiving the first indication information, the access network device, combined with the known index of a Doppler basis being 1, determines that the indices of the Doppler basis corresponding to a set of Doppler shifts associated with at least two frequency domain basis are {1, 2, 3, 4, 5}. For K groups of Doppler shifts, where K is greater than 1, the first indication information indicates K groups of values, each group of values including an index length value, and each group of values in the K groups of values corresponds to a group of Doppler shifts in the K groups of Doppler shifts. For example, if K = 2, and the indices of the Doppler basis corresponding to the two groups of Doppler shifts are {17, 18, 19, 20, 21} and {30, 31, 32, 33}, the first indication information may indicate {5, 4}; the fourth indication information may indicate or predefine the indices of the Doppler basis corresponding to the two Doppler shifts as {17, 30}. After receiving the first indication information, the access network device can determine that the indexes of the Doppler bases corresponding to the two groups of Doppler shifts associated with the at least two frequency domain bases are {17, 18, 19, 20, 21} and {30, 31, 32, 33}.

[0432] In one possible implementation, the at least one Doppler shift indicated by the first indication information is one or more groups of Doppler shifts. For each group of Doppler shifts, the first indication information indicates a numerical span of the Doppler shifts. The numerical span and the value of the Doppler shift are used to determine each Doppler shift in the group of Doppler shifts. The value of the Doppler shift is predefined, or the value of the Doppler shift is indicated by fourth indication information. For example, if the access network device and the terminal device predefine a Doppler shift value of 0, or the access network device indicates a Doppler shift value of 0 via fourth indication information, or the terminal device indicates a Doppler shift value of 0 via fourth indication information, and the group of Doppler shift values is {0, 1, 2, 3, 4}, then the first indication information may indicate 5. After receiving the first indication information, the access network device, combined with the known value of a Doppler shift of 0, can determine that the group of Doppler shifts associated with at least two frequency domain bases is {0 Hz, 1 Hz, 2 Hz, 3 Hz, 4 Hz}. For K groups of Doppler shifts, where K is greater than 1, the first indication information indicates the numerical span of each Doppler shift in each of the K groups. The numerical span of each Doppler shift in each group corresponds to one group of Doppler shifts. For example, if K = 2 and the values of the two groups of Doppler shifts are {0, 1, 2, 3, 4} and {30, 31, 32}, the first indication information may indicate {5, 3}. The fourth indication information may indicate or predefine the values of the two Doppler shifts as {0, 30}. Upon receiving the first indication information, the access network device may determine that the two groups of Doppler shifts associated with the at least two frequency domain bases are {30 Hz, 31 Hz, 32 Hz}.

[0433] In one possible implementation, the at least one Doppler offset indicated by the first indication information is one or more groups of Doppler offsets, and for each group of Doppler offsets, the first indication information indicates the value of each Doppler offset in the group of Doppler offsets. For example, the values of the group of Doppler offsets are: {17, 19, 21}, and the interval between the values of the Doppler offsets is 2 Hz, then the first indication information may indicate: {17, 19, 21}. After receiving the first indication information, the access network device can determine that a group of Doppler offsets associated with at least two frequency domain bases is {17 Hz, 19 Hz, 21 Hz}. For K groups of Doppler offsets, where K is greater than 1, the first indication information indicates the values of K groups of Doppler offsets, and the value of each group of Doppler offsets corresponds to a group of Doppler offsets.

[0434] In one possible implementation, the at least one Doppler shift indicated by the first indication information is one or more groups of Doppler shifts. For each group of Doppler shifts, the first indication information indicates the index of the Doppler basis corresponding to each Doppler shift in the group of Doppler shifts. For example, if the indices of the Doppler basis corresponding to the group of Doppler shifts are {17, 18, 19, 20, 21}, then the first indication information may indicate: {17, 18, 19, 20, 21}. For another example, if the indices of all Doppler basis are 1 to 8, and the indices of the Doppler basis corresponding to the group of Doppler shifts are {4, 5, 6, 7}, then the first indication information may indicate, via a bit vector of length 8: [0, 0, 0, 1, 1, 1, 0], that the indices of the Doppler basis corresponding to the group of Doppler shifts are {4, 5, 6, 7}. For K groups of Doppler shifts, where K is greater than 1, the first indication information indicates the indices of the K groups of Doppler bases, with the index of each group of Doppler bases corresponding to a group of Doppler shifts. For example, if K = 2, and the indices of the Doppler bases corresponding to two groups of Doppler shifts are {17, 18, 19, 20, 21} and {30, 31, 32, 33}, the first indication information may indicate {17, 18, 19, 20, 21} and {30, 31, 32, 33}. Upon receiving the first indication information, the access network device determines that the indices of the Doppler bases corresponding to the two groups of Doppler shifts associated with at least two frequency-domain bases are {17, 18, 19, 20, 21} and {30, 31, 32, 33}. The first indication information may also indicate the indexes of the Doppler bases corresponding to all K groups of Doppler shifts. For example, K=2, the indexes of all frequency domain bases are 1 to 8, and the indexes of the two groups of Doppler bases are {1,2}, {4,5,6,7}. The first indication information may be indicated by a bit vector of length 8: [1,1,0,1,1,1,1,0], indicating that the indexes of the Doppler bases corresponding to the two groups of Doppler shifts are {1,2}, {4,5,6,7}.

[0435] The at least one Doppler shift may also be one or more discontinuous Doppler shifts.

[0436] In this scenario, in one possible implementation, the first indication information indicates the value of each of the at least one Doppler shift. For example, if the at least one Doppler shift value is {17, 25, 29}, the first indication information may indicate {17, 25, 29}. Upon receiving the first indication information, the access network device can determine that the at least one Doppler shift associated with the at least two frequency domain bases is {17 Hz, 25 Hz, 29 Hz}.

[0437] In this scenario, in one possible implementation, the first indication information indicates the index of the Doppler basis corresponding to each of the at least one Doppler shift. For example, if the index of the Doppler basis corresponding to the at least one Doppler shift is {17, 19, 22}, the first indication information may indicate {17, 19, 22}.

[0438] The at least one Doppler shift may also be one or more groups of Doppler shifts and one or more discontinuous Doppler shifts.

[0439] In this scenario, one possible implementation is that the first indication information may include two parts. The first part indicates one or more groups of Doppler shifts within the at least one Doppler shift, using a method similar to the method for indicating one or more groups of Doppler shifts described above. The second part indicates one or more discontinuous Doppler shifts within the at least one Doppler shift, using the method for indicating one or more discontinuous Doppler shifts described above. For example, if the indexes of the Doppler basis corresponding to the at least one Doppler shift are {17, 18, 19, 20, 21, 35}, the first indication information may be {17, 5, 35}. After receiving the first indication information, the access network device determines the indexes of a group of continuous Doppler basis as {17, 18, 19, 20, 21} based on 17 and 5, and determines the index of a Doppler basis as 35 based on 35. Based on the above, the access network device determines the indexes of the Doppler basis corresponding to the at least one Doppler shift as {17, 18, 19, 20, 21, 35}.

[0440] In this scenario, a possible implementation method is that the first indication information indicates the index of the Doppler basis corresponding to each of the at least one Doppler shift. For example, if the index of the Doppler basis corresponding to the at least one Doppler shift is {17, 18, 19, 20, 21, 35}, the first indication information may be {17, 18, 19, 20, 21, 35}. For another example, if the indexes of all Doppler basis are 1 to 8, and the index of the Doppler basis corresponding to the at least one Doppler shift is {1, 6, 7}, the first indication information may be a bit vector of length 8: [1, 0, 0, 0, 1, 1, 0], indicating that the index of the Doppler basis corresponding to the at least one Doppler shift is {1, 6, 7}.

[0441] In this scenario, in one possible implementation, the first indication information indicates the value of each of the at least one Doppler shift. For example, if the at least one Doppler shift value is {17, 19, 21, 35} and the interval between Doppler shift values is 2 Hz, the first indication information may indicate {17, 19, 21, 35}. Upon receiving the first indication information, the access network device can determine that the at least one Doppler shift associated with the at least two frequency domain bases is {17 Hz, 19 Hz, 21 Hz, 35 Hz}.

[0442] The access network device may determine the at least two frequency domain bases in a predefined manner, for example, by determining the at least two frequency domain bases through a table preset and aligned with the terminal device, or may determine the at least two frequency domain bases through an uplink reference signal, and send the information to the terminal device through a downlink reference signal or other indication information. After determining the at least two frequency domain bases, the terminal device determines that at least one Doppler shift is associated with the at least two frequency domain bases. Alternatively, the terminal device may send second indication information to the access network device, and the second indication information indicates the at least two frequency domain bases. Upon receiving the second indication information, the access network device may determine at least two frequency domain bases associated with the at least one Doppler shift indicated by the first indication information.

[0443] The second indication information may be a signaling sent independently, or may be combined with the first indication information and sent in the same signaling, or may be added to an existing uplink reference signal or uplink signaling by adding a field, for example, adding the second indication information to the SRS or PMI. This application does not limit this.

[0444] The specific meaning and method of the frequency domain basis indicated by the second indication information may be predefined, or may be notified by the terminal device to the access network device, or may be notified by the access network device to the terminal device.

[0445] In one possible implementation, the second indication information indicates the at least two frequency domain bases by indicating the indexes of the at least two frequency domain bases. For example: the indexes of all the frequency domain bases are 1 to 100, and the second indication information indicates 2 and 50, indicating that the at least two frequency domain bases are base 2 and base 50. The frequency domain bases, and the indexes of the frequency domain bases, can be predefined, or can be notified by the terminal device to the access network device, or can be notified by the access network device to the terminal device. The second indication information indicates the indexing method of the frequency domain base, which can be a direct indication of the index value, or can be indicated by a bit mapping method, for example: the indexes of all the frequency domain bases are 1 to 8, and the second indication information can be indicated by a bit vector of length 8: [0,0,1,1,0,0,1,1], indicating that the four frequency domain bases are base 3, base 4, base 7 and base 8.

[0446] In one possible implementation, at least two frequency domain bases may be one or more groups of frequency domain bases, and for each group of the frequency domain bases, the second indication information indicates the indexes of the two frequency domain bases, and the indexes of the two frequency domain bases are respectively the index with the largest value and the index with the smallest value in the index of the group of the frequency domain bases. For example, if the indexes of the group of frequency domain bases are: {17, 18, 19, 20, 21}, then the second indication information may indicate: 17 and 21. After receiving the second indication information, the access network device can determine that the index of a group of frequency domain bases in the at least two frequency domain bases is {17, 18, 19, 20, 21}. For K groups of frequency domain bases, where K is greater than 1, the second indication information indicates K groups of indexes, each group of indexes corresponds to a group of frequency domain bases, and each group of indexes includes the index with the largest value and the index with the smallest value in the index of the group of frequency domain bases corresponding to the group of indexes. For example, if K = 2 and the indexes of the two frequency domain bases are {17, 18, 19, 20, 21} and {30, 31, 32, 33}, the second indication information may indicate {17, 21} and {30, 33}. After receiving the second indication information, the access network device determines that the indexes of the two frequency domain bases in the at least two frequency domain bases are {17, 18, 19, 20, 21} and {30, 31, 32, 33}.

[0447] In one possible implementation, the at least two frequency domain bases may be one or more groups of frequency domain bases. For each group of frequency domain bases, the second indication information indicates an index of a frequency domain base and an index length value. The index of the frequency domain base and the index length value are used to determine each frequency domain base in the group of frequency domain bases. The index of the frequency domain base is the index with the largest value or the index with the smallest value among the indexes of the frequency domain bases. For example, if the indexes of the group of frequency domain bases are {17, 18, 19, 20, 21}, the second indication information may indicate 17 and 5. After receiving the second indication information, the access network device may determine that the indexes of the group of frequency domain bases are {17, 18, 19, 20, 21}. For K groups of frequency domain bases, where K is greater than 1, the second indication information indicates the index of a frequency domain base and an index length value of K groups. The index of a frequency domain base and an index length value of each group correspond to a group of frequency domain bases. For example, if K = 2 and the indexes of the two frequency domain bases are {17, 18, 19, 20, 21} and {30, 31, 32, 33}, the second indication information can indicate {17, 5} and {30, 4}. After receiving the second indication information, the access network device can determine that the indexes of the two frequency domain bases are {17, 18, 19, 20, 21} and {30, 31, 32, 33}.

[0448] In one possible implementation, at least two frequency domain bases may be one or more groups of frequency domain bases, and for each group of the frequency domain bases, the second indication information indicates an index length value of a frequency domain base, and the index length value and the index of a frequency domain base are used to determine each of the frequency domain bases in the group of frequency domain bases, and the index of the frequency domain base is predefined, or the index of the frequency domain base is indicated by the fifth indication information. For example: the access network device and the terminal device predefine the index of a frequency domain base as 1, or the access network device indicates that the index of a frequency domain base is 1 through the fifth indication information, or the terminal device indicates that the index of a frequency domain base is 1 through the fifth indication information, and the index of the group of frequency domain bases is: {1, 2, 3, 4, 5}, then the second indication information may indicate: 5. After receiving the second indication information, the access network device, combined with the known index of a frequency domain base as 1, can determine that the index of at least one group of frequency domain bases is {1, 2, 3, 4, 5}. For K groups of frequency domain bases, where K is greater than 1, the second indication information indicates K groups of values, each of which includes an index length value. Each group of values in the K groups of values corresponds to a group of frequency domain bases in the K groups of frequency domain bases. For example, if K = 2 and the indexes of the two groups of frequency domain bases are {17, 18, 19, 20, 21} and {30, 31, 32, 33}, the second indication information may indicate 5 and 4, and the fifth indication information may indicate 17 and 30. After receiving the second and fifth indication information, the access network device determines that the indexes of the two groups of frequency domain bases are {17, 18, 19, 20, 21} and {30, 31, 32, 33}.

[0449] In one possible implementation, at least two frequency domain bases may be one or more groups of frequency domain bases, and for each group of the frequency domain bases, the second indication information indicates the index of each frequency domain base in the group of the frequency domain bases. For example, if the index of the group of frequency domain bases is {17, 18, 19, 20, 21}, the second indication information may indicate {17, 18, 19, 20, 21}. For another example, if the indexes of all frequency domain bases are 1 to 8 and the index of the group of frequency domain bases is {4, 5, 6, 7}, the second indication information may be a bit vector of length 8: [0, 0, 0, 1, 1, 1, 0], indicating that the index of the group of frequency domain bases is {4, 5, 6, 7}. For K groups of frequency domain bases, where K is greater than 1, the second indication information indicates the index of the K groups of frequency domain bases, and the index of the frequency domain base in each group corresponds to a group of frequency domain bases. For example, if K = 2 and the indexes of the two frequency domain bases are {17, 18, 19, 20, 21} and {30, 31, 32, 33}, the second indication information can indicate {17, 18, 19, 20, 21} and {30, 31, 32, 33}. After receiving the second indication information, the access network device can determine that the indexes of the two frequency domain bases are {17, 18, 19, 20, 21} and {30, 31, 32, 33}. The second indication information can also indicate the indexes of all K groups of frequency domain bases. For example, K=2, the indexes of all frequency domain bases are 1 to 8, and the indexes of the two groups of frequency domain bases are {1,2}, {4,5,6,7}. The second indication information can be indicated by a bit vector of length 8: [1,1,0,1,1,1,1,0], indicating that the indexes of the two groups of frequency domain bases are {1,2}, {4,5,6,7}.

[0450] The at least two frequency domain bases may also be multiple discontinuous frequency domain bases. In one possible implementation, the second indication information indicates the index of each frequency domain base in the at least two frequency domain bases. For example, if the indexes of the at least two frequency domain bases are {17, 19, 22}, the second indication information may indicate {17, 19, 22}.

[0451] The at least two frequency domain bases may also be one or more groups of frequency domain bases and one or more discontinuous frequency domain bases. A possible implementation method is that the second indication information includes indication information of one or more groups of frequency domain bases in the at least two frequency domain bases and indication information of one or more discontinuous frequency domain bases in the at least two frequency domain bases, and the indication method of the indication information is a combination of the aforementioned indication methods. For example, the indexes of the at least two frequency domain bases are: {17, 18, 19, 20, 21, 35}, and the second indication information may be {17, 5, 35}. After receiving the second indication information, the access network device determines that the index of a group of continuous frequency domain bases is {17, 18, 19, 20, 21} based on 17 and 5, and determines that the index of a frequency domain base is 35 based on 35. Based on the above aspects, the access network device determines that the indexes of the at least two frequency domain bases are {17, 18, 19, 20, 21, 35}. In this scenario, one possible implementation method is that the second indication information indicates the index of each frequency domain basis of the at least two frequency domain basis. For example, if the indexes of the at least two frequency domain basis are {17, 18, 19, 20, 21, 35}, the second indication information may be {17, 18, 19, 20, 21, 35}. For another example, if the indexes of all frequency domain basis are 1 to 8 and the indexes of the at least two frequency domain basis are {1, 6, 7}, the second indication information may be a bit vector of length 8: [1, 0, 0, 0, 0, 1, 1, 0], indicating that the indexes of the at least two frequency domain basis are {1, 6, 7}.

[0452] The access network device determines at least two frequency domain bases and at least one Doppler shift associated therewith through the first indication information and the second indication information or other methods to form multiple Doppler shift and frequency domain base pairs. Figure 14 As shown, the at least one Doppler shift indicated by the first indication information is: three Doppler shifts corresponding to the indexes {1,3,4}, and the second indication information indicates that the at least two frequency domain bases are: three frequency domain bases indexed as {2,4,5}, then the access network device determines 3*3=9 Doppler shift and frequency domain base pairs, namely (1,2), (1,4), (1,5), (3,2), (3,4), (3,5), (4,2), (4,4), (4,5); these 9 Doppler shift and frequency domain base pairs can correspond to the shaded squares in the figure. The access network device can obtain the Doppler shift information corresponding to the delay path through this information, that is, it determines the time correlation information of the channel, and then can construct a channel predictor, thereby using the channel predictor to predict the channel information at the time when data is sent to the terminal device. One possible method is:

[0453] If the K Doppler frequency offsets indicated by the first indication information are: f1, f2, ..., f K, then the normalized Doppler power spectrum can be calculated as:

[0454]

[0455] The channel time domain autocorrelation function is calculated using the Doppler power spectrum:

[0456]

[0457] If the first indication information indicates K groups of Doppler frequency offsets, the union of these K groups of Doppler frequency offsets is Ω=Ω1∪Ω2∪…∪Ω K , where each Ω k =[f k，1 , f k，2 ] corresponds to a Doppler frequency deviation interval, f 1，1 <f 1，2 <f 2，1 <f 2，2 <… <f K，1 <f K，2 , then the normalized Doppler power spectrum can be calculated as:

[0458]

[0459] in The channel time domain autocorrelation function is calculated using the Doppler power spectrum:

[0460]

[0461] The unit of τ above is seconds, and the unit of f is Hz. Then, the coefficient matrix A of the channel predictor is calculated based on the channel time domain autocorrelation function R(τ). The channel predictor uses the channel at a total of Q moments as input. The channel predictor acts on each OFDM symbol of the channel at each moment to predict each OFDM symbol corresponding to the channel at the next P moments. For an OFDM symbol, the index set of its Q moments is {k1, k2, ..., k Q}, the index set of the OFDM symbols where the channels at P moments to be predicted are {l1, l2, ..., l P}, the symbol period is T OS The autocorrelation matrix can be calculated by the following formula and the cross-correlation matrix The various elements:

[0462]

[0463] R 12 [i, j] = R((k i -l j )T OS )

[0464] in is an error parameter that can be configured through training and adjustment. Finally, the coefficient matrix A of the channel predictor is obtained as:

[0465]

[0466] By multiplying the channel at Q moments on the left by matrix A, we can obtain the channel prediction results for the next P moments, which can be used to calculate the downlink precoding at the future moments, overcoming the channel aging problem. This implementation method can be called a minimum mean squared error (MMSE) channel predictor. This application does not limit the specific method.

[0467] In one implementation, the terminal device may also send a third indication information to the access network device, wherein the third indication information is used to indicate one or more Doppler shift and frequency domain basis pairs, each of the Doppler shift and frequency domain basis pairs including a Doppler shift and a frequency domain basis; the Doppler shift included in each of the Doppler shift and frequency domain basis pairs belongs to at least one Doppler shift indicated by the first indication information, and the frequency domain basis included in each of the Doppler shift and frequency domain basis pairs belongs to the at least two frequency domain basis.

[0468] The third indication information may be independently transmitted signaling, or may be combined with the first indication information and the second indication information and sent in the same signaling, or may be combined with only the second indication information and sent in the same signaling, or may be added to an existing uplink reference signal or uplink signaling by adding a field, for example, adding the third indication information to the SRS or PMI. This application does not limit this.

[0469] The meaning and method of the specific indication of the third indication information of one or more Doppler shift and frequency domain basis pairs may be predefined, or may be notified by the terminal device to the access network device, or may be notified by the access network device to the terminal device.

[0470] The access network device receives the third indication information and further determines one or more Doppler shift and frequency domain basis pairs, thereby obtaining Doppler shift information corresponding to a more refined delay path. Specifically, the third indication information indicates at least one Doppler shift and frequency domain basis pair from the multiple Doppler shift and frequency domain basis pairs. For example, the third indication information may indicate five of the nine Doppler shift and frequency domain basis pairs: (1, 2), (3, 4), (3, 5), (4, 2), and (4, 4).

[0471] In one possible implementation, the third indication information uses a bitmap vector of length F to indicate one or more Doppler shift and frequency domain basis pairs, where F may be the number of Doppler shift and frequency domain basis pairs indicated by the first indication information, and F is an integer greater than 0. For example: Figure 15 As shown, the third indication information is {1,0,0,0,1,1,1,1,0}. From the nine Doppler shift and frequency domain basis pairs (1,2), (1,4), (1,5), (3,2), (3,4), (3,5), (4,2), (4,4), (4,5) indicated by the first indication information, five Doppler shift and frequency domain basis pairs (1,2), (3,4), (3,5), (4,2), (4,4) are further indicated, thereby obtaining Doppler shift information corresponding to a more refined delay path. In the figure, the squares marked with 1 represent the Doppler shift and frequency domain basis pairs indicated by the third indication information among the nine Doppler shift and frequency domain basis pairs indicated by the first indication information; the squares marked with 0 represent the Doppler shift and frequency domain basis pairs not indicated by the third indication information among the nine Doppler shift and frequency domain basis pairs indicated by the first indication information. The arrangement mode or arrangement order of the indication Doppler shift and frequency domain basis pairs in the third indication information may be predefined, or may be notified by the terminal device to the access network device, or may be notified by the access network device to the terminal device.

[0472] In one possible implementation, the third indication information indicates R Doppler shift and frequency domain basis pairs, R is less than or equal to F, and the energy corresponding to the R Doppler shift and frequency domain basis pairs is greater than or equal to the energy of the other FR Doppler shift and frequency domain basis pairs in the F Doppler shift and frequency domain basis pairs; R can be predefined, or it can be notified to the terminal device by the access network device through the sixth indication information, or it can be notified to the access network device by the terminal device through the sixth indication information.

[0473] In one possible implementation, the third indication information indicates a Doppler shift and frequency domain basis pair whose corresponding energy among multiple Doppler shift and frequency domain basis pairs is greater than or equal to a first energy; the first energy can be predefined, or it can be notified to the terminal device by the access network device through the sixth indication information, or it can be notified to the access network device by the terminal device through the sixth indication information.

[0474] According to the above method, embodiments of the present application indicate at least one Doppler shift through first indication information, eliminating the need to feed back all Doppler shifts determined based on the downlink reference signal, thereby reducing feedback overhead and improving feedback efficiency. Furthermore, when performing channel estimation, the access network device can determine the time-domain related information of the channel based on the Doppler shift indicated by the first indication information. This allows the access network device to utilize the channel at the time of channel estimation, the channel at several past times, and Doppler shift information to obtain a more accurate channel state, enabling the access network device to perform channel prediction and overcome performance degradation caused by channel aging.

[0475] In the embodiments provided above, the methods provided in the embodiments of the present application are described from the perspective of interaction between various devices. In order to implement the various functions in the methods provided in the embodiments of the present application, the access network device or the terminal device may include a hardware structure and / or a software module, and implement the above functions in the form of a hardware structure, a software module, or a hardware structure plus a software module. Whether a function of the above functions is executed in the form of a hardware structure, a software module, or a hardware structure plus a software module depends on the specific application and design constraints of the technical solution.

[0476] The division of modules in the embodiments of the present application is illustrative and is merely a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the present application may be integrated into a single processor, or may exist physically separately, or two or more modules may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or software functional modules.

[0477] Same as above idea, Figure 16 As shown, an embodiment of the present application further provides a communication device for implementing the functions of the access network device or terminal device in the above method. For example, the device may be a software module or a chip system. In the embodiment of the present application, the chip system may be composed of a chip, or may include a chip and other discrete devices. The communication device 1600 may include: a processing unit 1601 and a communication unit 1602.

[0478] In the embodiment of the present application, the communication unit may also be referred to as a transceiver unit, and may include a sending unit and / or a receiving unit, which are respectively used to execute the sending and receiving steps of the access network device or terminal device in the above method embodiment.

[0479] The following, combined Figures 16 and 17 The communication device provided in the embodiment of the present application is described in detail. It should be understood that the description of the device embodiment corresponds to the description of the method embodiment, so that the contents not described in detail can be referred to the method embodiment above, and for the sake of brevity, they are not repeated here.

[0480] The communication unit may also be referred to as an interface circuit, transceiver, or transceiver device. The processing unit may also be referred to as a processor, processing board, processing module, or processing device. Optionally, the device in communication unit 1602 that implements the receiving function may be considered a receiving unit, and the device in communication unit 1602 that implements the transmitting function may be considered a transmitting unit. That is, communication unit 1602 includes both a receiving unit and a transmitting unit. A communication unit may also be referred to as a transceiver, interface circuit, or transceiver circuit. A receiving unit may also be referred to as a receiver, receiver, or receiving circuit. A transmitting unit may also be referred to as a transmitter, transmitter, or transmitting circuit.

[0481] In one implementation, the communication device implements Figure 3 The functions of the terminal equipment shown are:

[0482] A communication unit, configured to receive a downlink reference signal from an access network device;

[0483] a processing unit, configured to determine, based on a downlink reference signal, at least one spatial domain vector and multiple frequency domain vectors, where the at least one spatial domain vector and the multiple frequency domain vectors correspond to a first matrix, the first matrix including multiple combining coefficients, each combining coefficient being a combining coefficient of a spatial domain vector and a frequency domain vector, and a position of the combining coefficient being represented by a spatial domain vector and a frequency domain vector;

[0484] A communication unit, used to send first information to an access network device; the first information is used to indicate the position of at least one combining coefficient among multiple combining coefficients; at least one combining coefficient satisfies any of the following conditions: at least one combining coefficient is a combining coefficient whose energy is greater than or equal to the first energy and less than or equal to the second energy among multiple combining coefficients, and the second energy is less than the energy of the combining coefficient with the largest energy among the multiple combining coefficients; at least one combining coefficient is the Y2 combining coefficients with the smallest energy among the Y1 combining coefficients with energy greater than or equal to the first energy among multiple combining coefficients, where Y2 is an integer less than Y1 and greater than 0; at least one combining coefficient is the Y4 combining coefficient with the smallest energy among the Y3 combining coefficients with the largest energy among multiple combining coefficients, where Y4 is an integer less than Y3 and greater than 0; at least one combining coefficient is the Y3 combining coefficients with the largest energy among multiple combining coefficients, where energy is less than or equal to the second energy, and the second energy is less than the energy of the combining coefficient with the largest energy among the multiple combining coefficients.

[0485] In one implementation, the communication device implements Figure 3 The functions of the access network equipment shown are:

[0486] A communication unit, configured to send a downlink reference signal to a terminal device; receive first information from the terminal device; wherein the first information is used to indicate the position of at least one combining coefficient among multiple combining coefficients included in the first matrix; the first matrix corresponds to at least one spatial domain vector and multiple frequency domain vectors, at least one spatial domain vector and multiple frequency domain vectors are determined according to the downlink reference signal, each combining coefficient is a combining coefficient of a spatial domain vector and a frequency domain vector, and the position of the combining coefficient is represented by a spatial domain vector and a frequency domain vector; at least one combining coefficient satisfies any of the following conditions: at least one combining coefficient is a combining coefficient whose energy is greater than or equal to the first energy and less than or equal to the second energy among the multiple combining coefficients The second energy of the merging coefficient is less than the energy of the merging coefficient with the largest energy among the multiple merging coefficients; at least one merging coefficient is the Y2 merging coefficient with the smallest energy among the Y1 merging coefficients with energy greater than or equal to the first energy among the multiple merging coefficients, and Y2 is an integer less than Y1 and greater than 0; at least one merging coefficient is the Y4 merging coefficient with the smallest energy among the Y3 merging coefficients with the largest energy among the multiple merging coefficients, and Y4 is an integer less than Y3 and greater than 0; at least one merging coefficient is the merging coefficient with energy less than or equal to the second energy among the Y3 merging coefficients with the largest energy among the multiple merging coefficients, and the second energy is less than the energy of the merging coefficient with the largest energy among the multiple merging coefficients.

[0487] In one implementation, the communication device implements Figure 12 The functions of the terminal equipment shown are:

[0488] A communication unit, configured to receive multiple downlink reference signals from an access network device;

[0489] a processing unit, configured to determine, based on multiple downlink reference signals, at least one spatial domain vector, multiple frequency domain vectors, and multiple time domain vectors, where the at least one spatial domain vector, the multiple frequency domain vectors, and the multiple time domain vectors correspond to a first three-dimensional matrix, the first three-dimensional matrix including multiple combining coefficients, each combining coefficient being a combining coefficient of a spatial domain vector, a frequency domain vector, and a time domain vector, and a position of the combining coefficient being represented by a spatial domain vector, a frequency domain vector, and a time domain vector;

[0490] A communication unit, used to send first information to an access network device; the first information is used to indicate the position of at least one combining coefficient among multiple combining coefficients; at least one combining coefficient satisfies any of the following conditions: at least one combining coefficient is a combining coefficient among multiple combining coefficients whose energy is greater than or equal to the first energy and less than or equal to the second energy, and the second energy is less than the energy of the combining coefficient with the largest energy among the multiple combining coefficients; at least one combining coefficient is the Y2 combining coefficients with the smallest energy among the Y1 combining coefficients among the multiple combining coefficients whose energy is greater than or equal to the first energy, where Y2 is an integer less than Y1 and greater than 0; at least one combining coefficient is the Y4 combining coefficient with the smallest energy among the Y3 combining coefficients with the largest energy among the multiple combining coefficients, where Y4 is an integer less than Y3 and greater than 0; at least one combining coefficient is a combining coefficient among the Y3 combining coefficients with the largest energy among the multiple combining coefficients whose energy is less than the second energy, and the second energy is less than the energy of the combining coefficient with the largest energy among the multiple combining coefficients.

[0491] In one implementation, the communication device implements Figure 12 The functions of the access network equipment shown are:

[0492] A communication unit, configured to send multiple downlink reference signals to a terminal device; and receive first information from the terminal device; wherein the first information is used to indicate the position of at least one combining coefficient among multiple combining coefficients included in a first three-dimensional matrix; the first three-dimensional matrix corresponds to at least one spatial domain vector, multiple frequency domain vectors, and multiple time domain vectors, and the at least one spatial domain vector, multiple frequency domain vectors, and multiple time domain vectors are determined based on multiple downlink reference signals, each combining coefficient is a combining coefficient of a spatial domain vector, a frequency domain vector, and a time domain vector, and the position of the combining coefficient is represented by a spatial domain vector, a frequency domain vector, and a time domain vector; at least one combining coefficient satisfies any of the following conditions: at least one combining coefficient is a combining coefficient having energy greater than or equal to a first energy and less than or equal to a second energy among multiple combining coefficients, and the second energy is less than the energy of the combining coefficient with the largest energy among the multiple combining coefficients; at least one combining coefficient is Y2 combining coefficients having the smallest energy among Y1 combining coefficients having energy greater than or equal to the first energy among the multiple combining coefficients, and Y2 is an integer less than Y1 and greater than 0;

[0493] At least one merging coefficient is the Y4 merging coefficient with the smallest energy among the Y3 merging coefficients with the largest energy among the multiple merging coefficients, where Y4 is an integer less than Y3 and greater than 0; at least one merging coefficient is the Y3 merging coefficient with the largest energy among the multiple merging coefficients, where the energy is less than the second energy, and the second energy is less than the energy of the merging coefficient with the largest energy among the multiple merging coefficients.

[0494] In one implementation, the communication device implements Figure 13 The functions of the terminal equipment shown are:

[0495] a processing unit, configured to receive a downlink reference signal from an access network device through a communication unit;

[0496] A processing unit is used to send a first indication information to the access network device through a communication unit, where the first indication information indicates at least one Doppler shift, the at least one Doppler shift is determined based on the downlink reference signal, and the at least one Doppler shift is associated with at least two frequency domain bases.

[0497] In one possible implementation, the first indication information is used to indicate at least one Doppler shift, including: the first indication information indicates the at least one Doppler shift by indicating the index of the Doppler basis corresponding to the Doppler shift, or the first indication information indicates the at least one Doppler shift by indicating the value of the Doppler shift.

[0498] In one possible implementation, the at least one Doppler offset is one or more groups of Doppler offsets, each group of Doppler offsets in the one or more groups of Doppler offsets includes at least two Doppler offsets, and the at least two Doppler offsets are continuous, and the continuity is that the indexes of the Doppler bases corresponding to the Doppler offsets are continuous or the values of the Doppler offsets are equally spaced.

[0499] In a possible implementation, for each group of the Doppler shifts, the first indication information indicates the indexes of two Doppler bases, where the indexes of the two Doppler bases are respectively the index with the largest value and the index with the smallest value among the indexes of the Doppler bases corresponding to a group of the Doppler shifts.

[0500] In a possible implementation, for each group of Doppler shifts, the first indication information indicates an index of a Doppler basis and an index length value, and the index of the Doppler basis and the index length value are used to determine each Doppler shift in the group of Doppler shifts.

[0501] In a possible implementation, the index of the one Doppler basis is an index with the largest value or an index with the smallest value among a group of indices of the Doppler basis corresponding to the Doppler shift.

[0502] In one possible implementation, for each group of Doppler shifts, the first indication information indicates an index length value of a Doppler basis, the index length value and the index of a Doppler basis are used to determine each of the Doppler shifts in the group of Doppler shifts, the index of the Doppler basis is predefined, or the index of the Doppler basis is indicated by fourth indication information.

[0503] In a possible implementation, for each group of Doppler shifts, the first indication information indicates two Doppler shift values, where the two Doppler shift values are respectively a maximum value and a minimum value of the Doppler shift in the group of Doppler shifts.

[0504] In a possible implementation, for each group of Doppler offsets, the first indication information indicates a Doppler offset value and a numerical span, and the Doppler offset value and the numerical span are used to determine each Doppler offset in the group of Doppler offsets.

[0505] In a possible implementation manner, the value of the Doppler shift is a maximum value or a minimum value in a group of the Doppler shifts.

[0506] In one possible implementation, for each group of Doppler offsets, the first indication information indicates a numerical span of a Doppler offset, and the numerical span and the value of a Doppler offset are used to determine each of the Doppler offsets in the group of Doppler offsets, and the value of the Doppler offset is predefined, or the value of the Doppler offset is indicated by fourth indication information.

[0507] In a possible implementation, for each group of Doppler offsets, the first indication information indicates the value of each Doppler offset in a group of Doppler offsets, or the first indication information indicates the index of the Doppler basis corresponding to each Doppler offset in a group of Doppler offsets.

[0508] In a possible implementation, the first indication information indicates the value of each of the at least one Doppler shift, or the first indication information indicates the index of the Doppler basis corresponding to each of the at least one Doppler shift.

[0509] In a possible implementation manner, the communication unit is further configured to: send second indication information to the access network device, where the second indication information indicates the at least two frequency domain bases.

[0510] In one possible implementation, the at least two frequency domain bases are one or more groups of frequency domain bases, each group of frequency domain bases in the one or more groups of frequency domain bases includes at least two frequency domain bases, and the at least two frequency domain bases are continuous, and the continuity is the continuity of the indexes of the frequency domain bases.

[0511] In a possible implementation, for each group of the frequency domain bases, the second indication information indicates the indexes of two frequency domain bases, and the indexes of the two frequency domain bases are respectively the index with the largest value and the index with the smallest value in the index of a group of the frequency domain bases.

[0512] In one possible implementation, for each group of frequency domain bases, the second indication information indicates the index and index length value of a frequency domain base, and the index and index length of the frequency domain base are used to determine each frequency domain base in the group of frequency domain bases.

[0513] In a possible implementation, the index of one frequency domain basis is an index with the largest value or an index with the smallest value among a group of indices of the frequency domain basis.

[0514] In one possible implementation, for each group of frequency domain bases, the second indication information indicates an index length value of a frequency domain base, the index length value and the index of a frequency domain base are used to determine each of the frequency domain bases in the group of frequency domain bases, the index of the frequency domain base is predefined, or the index of the frequency domain base is indicated by the fifth indication information.

[0515] In a possible implementation manner, for each group of the frequency domain bases, the second indication information indicates each of the frequency domain bases in the group of the frequency domain bases.

[0516] In a possible implementation manner, the second indication information indicates an index of each frequency domain basis of the at least two frequency domain basis.

[0517] In one possible implementation, the Doppler basis is a discrete Fourier transform (DFT) basis related to at least one of the number of downlink reference signals and the time interval of the downlink reference signals; or, the Doppler basis is a Doppler value basis based on at least one bit quantization; or, the Doppler basis is a basis constructed based on a first cyclic shift sequence.

[0518] In a possible implementation manner, the frequency domain basis is a DFT basis related to at least one of a bandwidth of the downlink reference signal and a frequency domain granularity of the downlink reference signal;

[0519] Alternatively, the predefined frequency domain basis is a delay value basis based on at least one bit quantization;

[0520] Alternatively, the predefined frequency domain basis is a basis constructed based on a second cyclic shift sequence.

[0521] In one possible implementation, the communication unit is further configured to:

[0522] Send third indication information, where the third indication information is used to indicate one or more Doppler shift and frequency domain basis pairs, each of the Doppler shift and frequency domain basis pairs including a Doppler shift and a frequency domain basis; the Doppler shift included in each of the Doppler shift and frequency domain basis pairs belongs to at least one Doppler shift indicated by the first indication information, and the frequency domain basis included in each of the Doppler shift and frequency domain basis pairs belongs to the at least two frequency domain basis.

[0523] In one possible implementation, the at least one Doppler shift indicated by the first indication information and the at least two frequency domain bases constitute multiple Doppler shift and frequency domain base pairs; the energy corresponding to one or more Doppler shift and frequency domain base pairs indicated by the third indication information is greater than or equal to the energy corresponding to other Doppler shift and frequency domain base pairs in the multiple Doppler shift and frequency domain base pairs; or, the energy corresponding to one or more Doppler shift and frequency domain base pairs indicated by the third indication information is a Doppler shift and frequency domain base pair in the multiple Doppler shift and frequency domain base pairs whose corresponding energy is greater than or equal to the first energy.

[0524] In a possible implementation manner, the number of the one or more Doppler shift and frequency domain basis pairs is indicated by sixth indication information or predefined, or the first energy is indicated by sixth indication information or predefined.

[0525] In one implementation, the communication device implements Figure 13 The functions of the access network equipment shown are:

[0526] A processing unit, configured to send a downlink reference signal to a terminal device via a communication unit;

[0527] A processing unit is used to receive first indication information from the terminal device through a communication unit, wherein the first indication information is used to indicate at least one Doppler shift, the at least one Doppler shift is determined based on the downlink reference signal, and the at least one Doppler shift is associated with at least two frequency domain bases.

[0528] The above is just an example. The processing unit 1601 and the communication unit 1602 can also perform other functions. For more detailed description, please refer to Figure 3 or Figure 12 or Figure 13 The relevant descriptions in the illustrated embodiments are omitted here for brevity.

[0529] like Figure 17 FIG. 1 is a schematic diagram of a communication device provided in an embodiment of the present application. Figure 17 The device shown can be Figure 16The communication device can be applied to the flowchart shown above to perform the functions of the terminal device or access network device in the above method embodiment. For the convenience of explanation, Figure 17 Only the main components of the communication device are shown.

[0530] like Figure 17 As shown, communication device 1700 includes a processor 1710 and an interface circuit 1720. Processor 1710 and interface circuit 1720 are coupled to each other. It is understood that interface circuit 1720 can be an interface circuit, a pin, an interface circuit, or an input / output interface. Optionally, communication device 1700 may also include a memory 1730 for storing instructions executed by processor 1710, input data required by processor 1710 to execute instructions, or data generated after processor 1710 executes instructions.

[0531] When the communication device 1700 is used to implement Figure 3 or Figure 12 or Figure 13 In the method flow shown, the processor 1710 is used to implement the functions of the above-mentioned processing unit 1601, and the interface circuit 1720 is used to implement the functions of the above-mentioned communication unit 1602.

[0532] When the communication device is a chip used in a terminal device, the terminal device chip implements the functions of the terminal device in the above method embodiments. The terminal device chip receives information from other modules in the terminal device (such as a radio frequency module or antenna), and the information is sent by the access network device to the terminal device; or the terminal device chip sends information to other modules in the terminal device (such as a radio frequency module or antenna), and the information is sent by the terminal device to the access network device.

[0533] When the aforementioned communication device is a chip used in an access network device, the access network device chip implements the functions of the access network device in the aforementioned method embodiments. The access network device chip receives information from other modules in the access network device (such as a radio frequency module or antenna), where the information is sent by the terminal device to the access network device; or the access network device chip sends information to other modules in the access network device (such as a radio frequency module or antenna), where the information is sent by the access network device to the terminal device.

[0534] It is understood that the processor in the embodiments of the present application may be a central processing unit, or may be other general-purpose processors, digital signal processors, application-specific integrated circuits, or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0535] In the embodiments of the present application, the memory may be a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, a register, a hard disk, a mobile hard disk, or any other form of storage medium known in the art.

[0536] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, optical storage, etc.) that contain computer-usable program code.

[0537] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0538] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0539] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include these modifications and variations.

Claims

1. A communication method, characterized in that: include: The terminal device receives a downlink reference signal from the access network device; The terminal device sends first indication information and second indication information to the access network device, where the first indication information indicates at least one Doppler shift, where the at least one Doppler shift is determined according to the downlink reference signal, and the at least one Doppler shift is associated with at least two frequency domain bases; The second indication information indicates the at least two frequency domain bases.

2. The method according to claim 1, characterized in that The first indication information is used to indicate at least one Doppler shift, including: The first indication information indicates the at least one Doppler shift by indicating an index of a Doppler basis corresponding to the Doppler shift, or the first indication information indicates the at least one Doppler shift by indicating a value of the Doppler shift.

3. The method according to claim 2, characterized in that The at least one Doppler offset is one or more groups of Doppler offsets, each group of Doppler offsets in the one or more groups of Doppler offsets includes at least two Doppler offsets, and the at least two Doppler offsets are continuous, and the continuity is that the indexes of the Doppler bases corresponding to the Doppler offsets are continuous or the values of the Doppler offsets are equally spaced.

4. The method according to claim 3, characterized in that For each group of the Doppler shifts, the first indication information indicates the indexes of two Doppler bases, where the indexes of the two Doppler bases are respectively the index with the largest value and the index with the smallest value among the indexes of the Doppler bases corresponding to a group of the Doppler shifts.

5. The method according to claim 3, characterized in that For each group of Doppler shifts, the first indication information indicates an index of a Doppler basis and an index length value, where the index of the Doppler basis and the index length value are used to determine each Doppler shift in the group of Doppler shifts.

6. The method according to claim 5, characterized in that The index of one Doppler basis is an index with the largest value or an index with the smallest value among a group of indices of the Doppler basis corresponding to the Doppler shift.

7. The method according to claim 3, characterized in that For each group of Doppler shifts, the first indication information indicates an index length value of a Doppler basis, the index length value and the index of a Doppler basis are used to determine each of the Doppler shifts in the group of Doppler shifts, the index of the Doppler basis is predefined, or the index of the Doppler basis is indicated by fourth indication information.

8. The method according to claim 3, characterized in that For each group of Doppler offsets, the first indication information indicates two Doppler offset values, where the two Doppler offset values are respectively the maximum value and the minimum value of the Doppler offset in the group of Doppler offsets.

9. The method according to claim 3, characterized in that For each group of Doppler shifts, the first indication information indicates a value and a numerical span of a Doppler shift, and the value and the numerical span of the Doppler shift are used to determine each of the Doppler shifts in the group of Doppler shifts.

10. The method according to claim 9, characterized in that The value of the Doppler shift is a maximum value or a minimum value in a group of the Doppler shifts.

11. The method according to claim 3, characterized in that For each group of Doppler offsets, the first indication information indicates a numerical span of a Doppler offset, the numerical span and the value of a Doppler offset are used to determine each of the Doppler offsets in the group of Doppler offsets, the value of the Doppler offset is predefined, or the value of the Doppler offset is indicated by fourth indication information.

12. The method according to claim 3, characterized in that For each group of Doppler shifts, the first indication information indicates a value of each Doppler shift in the group of Doppler shifts, or the first indication information indicates an index of a Doppler basis corresponding to each Doppler shift in the group of Doppler shifts.

13. The method according to claim 2, characterized in that The first indication information indicates a value of each of the at least one Doppler shift, or the first indication information indicates an index of a Doppler basis corresponding to each of the at least one Doppler shift.

14. The method according to any one of claims 1 to 13, characterized in that: The at least two frequency domain bases are one or more groups of frequency domain bases, each group of frequency domain bases in the one or more groups of frequency domain bases includes at least two frequency domain bases, and the at least two frequency domain bases are continuous, and the continuity is that the indexes of the frequency domain bases are continuous.

15. The method according to claim 14, characterized in that For each group of the frequency domain bases, the second indication information indicates the indexes of two frequency domain bases, where the indexes of the two frequency domain bases are respectively the index with the largest value and the index with the smallest value in the indexes of a group of the frequency domain bases.

16. The method according to claim 14, characterized in that For each group of the frequency domain bases, the second indication information indicates an index and an index length value of a frequency domain base, and the index and the index length of the frequency domain base are used to determine each of the frequency domain bases in the group of frequency domain bases.

17. The method according to claim 16, characterized in that The index of one frequency domain basis is an index with the largest value or an index with the smallest value among a group of indexes of the frequency domain basis.

18. The method according to claim 14, characterized in that For each group of frequency domain bases, the second indication information indicates an index length value of a frequency domain base, the index length value and the index of a frequency domain base are used to determine each of the frequency domain bases in the group of frequency domain bases, the index of the frequency domain base is predefined, or the index of the frequency domain base is indicated by the fifth indication information.

19. The method according to claim 14, wherein For each group of the frequency domain bases, the second indication information indicates each of the frequency domain bases in the group of the frequency domain bases.

20. The method according to claim 14, wherein The second indication information indicates an index of each frequency domain basis of the at least two frequency domain basis.

21. The method according to claim 2, characterized in that The Doppler basis is a discrete Fourier transform (DFT) basis related to at least one of the number of the downlink reference signals and the time interval of the downlink reference signals; Alternatively, the Doppler basis is based on at least one bit quantized Doppler value basis; Alternatively, the Doppler basis is a basis constructed based on a first cyclic shift sequence.

22. The method according to claim 1, wherein The frequency domain basis is a DFT basis related to at least one of a bandwidth of the downlink reference signal and a frequency domain granularity of the downlink reference signal; Alternatively, the frequency domain basis is a delay value basis based on at least one bit quantization; Alternatively, the frequency domain basis is a basis constructed based on a second cyclic shift sequence.

23. The method according to claim 14, wherein The method further comprises: The terminal device sends third indication information to the access network device, where the third indication information is used to indicate one or more Doppler shift and frequency domain basis pairs, each of the Doppler shift and frequency domain basis pairs including a Doppler shift and a frequency domain basis; the Doppler shift included in each of the Doppler shift and frequency domain basis pairs belongs to at least one Doppler shift indicated by the first indication information, and the frequency domain basis included in each of the Doppler shift and frequency domain basis pairs belongs to the at least two frequency domain basis.

24. The method according to claim 23, wherein The method further comprises: The at least one Doppler shift indicated by the first indication information and the at least two frequency domain bases constitute a plurality of Doppler shift and frequency domain base pairs; The energy corresponding to the one or more Doppler shift and frequency domain basis pairs indicated by the third indication information is greater than or equal to the energy corresponding to other Doppler shift and frequency domain basis pairs in the multiple Doppler shift and frequency domain basis pairs; Alternatively, the energies corresponding to the one or more Doppler shift and frequency domain basis pairs indicated by the third indication information are Doppler shift and frequency domain basis pairs whose corresponding energies among the multiple Doppler shift and frequency domain basis pairs are greater than or equal to the first energy.

25. The method according to claim 24, characterized in that The method further comprises: The number of the one or more Doppler shift and frequency domain basis pairs is indicated by or predefined in sixth indication information, or the first energy is indicated by or predefined in sixth indication information.

26. A communication method, characterized in that: include: The access network device sends a downlink reference signal to the terminal device; The access network device receives first indication information and second indication information from the terminal device, where the first indication information is used to indicate at least one Doppler shift, where the at least one Doppler shift is determined according to the downlink reference signal, and the at least one Doppler shift is associated with at least two frequency domain bases; The second indication information indicates the at least two frequency domain bases.

27. The method according to claim 26, characterized in that The first indication information is used to indicate at least one Doppler shift, including: The first indication information indicates the at least one Doppler shift by indicating an index of a Doppler basis corresponding to the Doppler shift, or the first indication information indicates the at least one Doppler shift by indicating a value of the Doppler shift.

28. The method according to claim 27, characterized in that The at least one Doppler offset is one or more groups of Doppler offsets, each group of Doppler offsets in the one or more groups of Doppler offsets includes at least two Doppler offsets, and the at least two Doppler offsets are continuous, and the continuity is that the indexes of the Doppler bases corresponding to the Doppler offsets are continuous or the values of the Doppler offsets are equally spaced.

29. The method according to claim 28, characterized in that For each group of the Doppler shifts, the first indication information indicates the indexes of two Doppler bases, where the indexes of the two Doppler bases are respectively the index with the largest value and the index with the smallest value among the indexes of the Doppler bases corresponding to a group of the Doppler shifts.

30. The method according to claim 28, wherein For each group of Doppler shifts, the first indication information indicates an index of a Doppler basis and an index length value, where the index of the Doppler basis and the index length value are used to determine each Doppler shift in the group of Doppler shifts.

31. The method according to claim 30, wherein The index of one Doppler basis is an index with the largest value or an index with the smallest value among a group of indices of the Doppler basis corresponding to the Doppler shift.

32. The method according to claim 28, wherein For each group of Doppler shifts, the first indication information indicates an index length value of a Doppler basis, the index length value and the index of a Doppler basis are used to determine each of the Doppler shifts in the group of Doppler shifts, the index of the Doppler basis is predefined, or the index of the Doppler basis is indicated by fourth indication information.

33. The method according to claim 28, wherein For each group of Doppler offsets, the first indication information indicates two Doppler offset values, where the two Doppler offset values are respectively the maximum value and the minimum value of the Doppler offset in the group of Doppler offsets.

34. The method according to claim 28, wherein For each group of Doppler shifts, the first indication information indicates a value and a numerical span of a Doppler shift, and the value and the numerical span of the Doppler shift are used to determine each of the Doppler shifts in the group of Doppler shifts.

35. The method according to claim 34, wherein The value of the Doppler shift is a maximum value or a minimum value in a group of the Doppler shifts.

36. The method according to claim 28, wherein For each group of Doppler offsets, the first indication information indicates a numerical span of a Doppler offset, the numerical span and the value of a Doppler offset are used to determine each of the Doppler offsets in the group of Doppler offsets, the value of the Doppler offset is predefined, or the value of the Doppler offset is indicated by fourth indication information.

37. The method according to claim 28, wherein For each group of Doppler shifts, the first indication information indicates a value of each Doppler shift in the group of Doppler shifts, or the first indication information indicates an index of a Doppler basis corresponding to each Doppler shift in the group of Doppler shifts.

38. The method according to claim 27, wherein The first indication information indicates a value of each of the at least one Doppler shift, or the first indication information indicates an index of a Doppler basis corresponding to each of the at least one Doppler shift.

39. The method according to any one of claims 26 to 38, characterized in that The at least two frequency domain bases are one or more groups of frequency domain bases, each group of frequency domain bases in the one or more groups of frequency domain bases includes at least two frequency domain bases, and the at least two frequency domain bases are continuous, and the continuity is that the indexes of the frequency domain bases are continuous.

40. The method according to claim 39, wherein For each group of the frequency domain bases, the second indication information indicates the indexes of two frequency domain bases, where the indexes of the two frequency domain bases are respectively the index with the largest value and the index with the smallest value in the indexes of a group of the frequency domain bases.

41. The method according to claim 39, wherein For each group of the frequency domain bases, the second indication information indicates an index and an index length value of a frequency domain base, and the index and the index length of the frequency domain base are used to determine each of the frequency domain bases in the group of frequency domain bases.

42. The method according to claim 41, wherein The index of one frequency domain basis is an index with the largest value or an index with the smallest value among a group of indexes of the frequency domain basis.

43. The method according to claim 39, wherein For each group of frequency domain bases, the second indication information indicates an index length value of a frequency domain base, the index length value and the index of a frequency domain base are used to determine each of the frequency domain bases in the group of frequency domain bases, the index of the frequency domain base is predefined, or the index of the frequency domain base is indicated by the fifth indication information.

44. The method according to claim 39, wherein For each group of the frequency domain bases, the second indication information indicates each of the frequency domain bases in the group of the frequency domain bases.

45. The method according to claim 39, wherein The second indication information indicates an index of each frequency domain basis of the at least two frequency domain basis.

46. The method according to claim 28, wherein The Doppler basis is a discrete Fourier transform (DFT) basis related to at least one of the number of the downlink reference signals and the time interval of the downlink reference signals; Alternatively, the Doppler basis is based on at least one bit quantized Doppler value basis; Alternatively, the Doppler basis is a basis constructed based on a first cyclic shift sequence.

47. The method according to claim 26, wherein The frequency domain basis is a DFT basis related to at least one of a bandwidth of the downlink reference signal and a frequency domain granularity of the downlink reference signal; Alternatively, the frequency domain basis is a delay value basis based on at least one bit quantization; Alternatively, the frequency domain basis is a basis constructed based on a second cyclic shift sequence.

48. The method according to claim 39, wherein The method further comprises: The terminal device sends third indication information to the access network device, where the third indication information is used to indicate one or more Doppler shift and frequency domain basis pairs, each of the Doppler shift and frequency domain basis pairs including a Doppler shift and a frequency domain basis; the Doppler shift included in each of the Doppler shift and frequency domain basis pairs belongs to at least one Doppler shift indicated by the first indication information, and the frequency domain basis included in each of the Doppler shift and frequency domain basis pairs belongs to the at least two frequency domain basis.

49. The method according to claim 48, characterized in that The method further comprises: The at least one Doppler shift indicated by the first indication information and the at least two frequency domain bases constitute a plurality of Doppler shift and frequency domain base pairs; The energy corresponding to the one or more Doppler shift and frequency domain basis pairs indicated by the third indication information is greater than or equal to the energy corresponding to other Doppler shift and frequency domain basis pairs in the multiple Doppler shift and frequency domain basis pairs; Alternatively, the energies corresponding to the one or more Doppler shift and frequency domain basis pairs indicated by the third indication information are Doppler shift and frequency domain basis pairs whose corresponding energies among the multiple Doppler shift and frequency domain basis pairs are greater than or equal to the first energy.

50. The method according to claim 49, wherein The method further comprises: The number of the one or more Doppler shift and frequency domain basis pairs is indicated by or predefined in sixth indication information, or the first energy is indicated by or predefined in sixth indication information.

51. A communication device, characterized in that The method comprises a module or a unit for executing the method according to any one of claims 1 to 50.

52. A communication device, characterized in that including processor and memory; The processor is configured to execute the computer program or instructions stored in the memory, so that the communication device implements the method according to any one of claims 1 to 50.

53. A computer-readable storage medium, characterized in that A computer program or instruction is stored, and when the computer program or instruction is executed on a computer, the computer is caused to implement the method according to any one of claims 1 to 50.

54. A chip, characterized in that The method comprises a processor coupled to a memory and configured to execute a computer program or instructions stored in the memory. When the processor executes the computer program or instructions, the method according to any one of claims 1 to 50 is performed.

55. A computer program product, characterized in that Computer-readable instructions are stored therein, and when a communication device reads and executes the computer-readable instructions, the communication device executes the method according to any one of claims 1 to 50.

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