Codebook feedback method, terminal device, and network device

Abstract

The present disclosure discloses a codebook feedback method, a terminal device and a network device. The codebook feedback method, comprising: selecting, by a terminal device, M frequency domain Discrete Fourier Transform (DFT) vectors from a DFT array; determining, by the terminal device, a first frequency domain DFT vector indication set from a plurality of frequency domain DFT vector indication sets according to the M frequency domain DFT vectors, wherein an indication of the M frequency domain DFT vectors is equivalent to a first frequency domain DFT vector indication in the first frequency domain DFT vector indication set, and M is a positive integer; and sending, by the terminal device, an indication message to the network device, wherein the indication message is used for indicating the first frequency domain DFT vector indication set.

What is claimed is: 
     
         1 . A codebook feedback method, comprising:
 sending, by a terminal device, an indication message to a network device, wherein the indication message is used for indicating a position in a particular frequency domain Discrete Fourier Transform (DFT) vector in a DFT array corresponding to a strongest coefficient of a weighting coefficient array of a space-frequency domain of a codebook.   
     
     
         2 . The method of  claim 1 , wherein bit width of the indication message is log 2(2*L), wherein 2*L is a number of rows in a space-frequency domain matrix. 
     
     
         3 . The method of  claim 1 , further comprising:
 performing, by the terminal device, a cyclic shift operation on frequency domain DFT vectors corresponding to non-zero coefficients in a space-frequency domain matrix such that the strongest coefficient corresponds to a particular frequency domain DFT vector in the DFT array.   
     
     
         4 . The method of  claim 1 , wherein the particular frequency domain DFT vector is the first frequency domain DFT vector or a last frequency domain DFT vector in the DFT array. 
     
     
         5 . The method of  claim 1 , wherein the indication message is further used for indicating a first frequency domain DFT vector indication set:
 wherein the first frequency DFT vector indication set is determined by the terminal device from a plurality of frequency domain DFT vector indication sets according to M frequency domain DFT vectors that are selected from a DFT array, wherein an indication of the M frequency domain DFT vectors is equivalent to a first frequency domain DFT vector indication in the first frequency domain DFT vector indication set, and M is a positive integer.   
     
     
         6 . The method of  claim 5 , wherein the indication of the M frequency domain DFT vectors is equivalent to the first frequency domain DFT vector indication in the first frequency domain DFT vector indication set comprises:
 a sequence corresponding to the indication of the M frequency domain DFT vectors is different from a sequence corresponding to the first frequency domain DFT vector indication set, and the sequence corresponding to the indication of the M frequency domain DFT vectors has a cyclic shift relationship with the sequence corresponding to the first frequency domain DFT vector indication set; or   the first frequency domain DFT vector indication set comprises a plurality of frequency domain DFT vector indications, wherein sequences corresponding to any two frequency domain DFT vectors in the plurality of frequency domain DFT vector indications have a cyclic shift relationship, and the first frequency domain DFT vector indication set comprises the indication of the M frequency domain DFT vectors.   
     
     
         7 . A terminal device, comprising a processor and a transceiver, wherein:
 the transceiver is configured to send an indication message to a network device, wherein the indication message is used for indicating a position in a particular frequency domain Discrete Fourier Transform (DFT) vector in a DFT array corresponding to a strongest coefficient of a weighting coefficient array of a space-frequency domain of a codebook.   
     
     
         8 . The terminal device of  claim 7 , wherein bit width of the indication message is log 2(2*L), wherein 2*L is a number of rows in a space-frequency domain matrix. 
     
     
         9 . The terminal device of  claim 7 , wherein
 the processor is configured to perform a cyclic shift operation on frequency domain DFT vectors corresponding to non-zero coefficients in a space-frequency domain matrix such that the strongest coefficient corresponds to a particular frequency domain DFT vector in the DFT array.   
     
     
         10 . The terminal device of  claim 7 , wherein the particular frequency domain DFT vector is the first frequency domain DFT vector or a last frequency domain DFT vector in the DFT array. 
     
     
         11 . The terminal device of  claim 7 , wherein the indication message is further used for indicating a first frequency domain DFT vector indication set:
 wherein the first frequency DFT vector indication set is determined by the terminal device from a plurality of frequency domain DFT vector indication sets according to M frequency domain DFT vectors that are selected from a DFT array, wherein an indication of the M frequency domain DFT vectors is equivalent to a first frequency domain DFT vector indication in the first frequency domain DFT vector indication set, and M is a positive integer.   
     
     
         12 . The terminal device of  claim 11 , wherein the indication of the M frequency domain DFT vectors is equivalent to the first frequency domain DFT vector indication in the first frequency domain DFT vector indication set comprises:
 a sequence corresponding to the indication of the M frequency domain DFT vectors is different from a sequence corresponding to the first frequency domain DFT vector indication set, and the sequence corresponding to the indication of the M frequency domain DFT vectors has a cyclic shift relationship with the sequence corresponding to the first frequency domain DFT vector indication set; or   the first frequency domain DFT vector indication set comprises a plurality of frequency domain DFT vector indications, wherein sequences corresponding to any two frequency domain DFT vectors in the plurality of frequency domain DFT vector indications have a cyclic shift relationship, and the first frequency domain DFT vector indication set comprises the indication of the M frequency domain DFT vectors.   
     
     
         13 . The terminal device of  claim 11 , wherein each bit in the indication message is used for indicating any one bit in the sequence corresponding to the first frequency domain DFT vector indication set except a default bit, wherein bit width of the indication message is ┌ log 2(nchoosek(N3−x,M−y))┐, wherein N3 is a number of columns of the DFT array, and N3, n, k, x, y are positive integers, and wherein nchoosek indicates selecting k combinatorial numbers from n sequences. 
     
     
         14 . A network device, comprising a processor and a transceiver, wherein
 the transceiver is configured to receive an indication message sent by a terminal device, wherein the indication message is used for indicating a position in a particular frequency domain Discrete Fourier Transform (DFT) vector in a DFT array corresponding to a strongest coefficient of a weighting coefficient array in a space-frequency domain of a codebook.   
     
     
         15 . The network device of  claim 14 , wherein bit width of the indication message is log 2(2*L), wherein 2*L is a number of rows in a space-frequency domain matrix. 
     
     
         16 . The network device of  claim 14 , wherein the strongest coefficient corresponding to the particular frequency domain DFT vector in the DFT array is obtained through performing, by the terminal device, a cyclic shift operation on frequency domain DFT vectors corresponding to non-zero coefficients in a space-frequency domain matrix. 
     
     
         17 . The network device of  claim 14 , wherein the particular frequency domain DFT vector is the first frequency domain DFT vector or a last frequency domain DFT vector in the DFT array. 
     
     
         18 . The network device of  claim 14 , wherein the indication message is further used for indicating a first frequency domain DFT vector indication set;
 wherein the first frequency DFT vector indication set is determined by the terminal device from a plurality of frequency domain DFT vector indication sets according to M frequency domain DFT vectors that are selected from a DFT array, wherein an indication of the M frequency domain DFT vectors is equivalent to a first frequency domain DFT vector indication in the first frequency domain DFT vector indication set, and M is a positive integer.   
     
     
         19 . The network device of  claim 18 , wherein the indication of the M frequency domain DFT vectors is equivalent to the first frequency domain DFT vector indication in the first frequency domain DFT vector indication set comprises:
 a sequence corresponding to the indication of the M frequency domain DFT vectors is different from a sequence corresponding to the first frequency domain DFT vector indication set, and the sequence corresponding to the indication of the M frequency domain DFT vectors has a cyclic shift relationship with the sequence corresponding to the first frequency domain DFT vector indication set; or   the first frequency domain DFT vector indication set comprises a plurality of frequency domain DFT vector indications, wherein sequences corresponding to any two frequency domain DFT vectors in the plurality of frequency domain DFT vector indications have a cyclic shift relationship, and the first frequency domain DFT vector indication set comprises the indication of the M frequency domain DFT vectors.   
     
     
         20 . The network device of  claim 18 , wherein each bit in the indication message is used for indicating any one bit in the sequence corresponding to the first frequency domain DFT vector indication set except a default bit; wherein bit width of the indication message is ┌ log 2(nchoosek(N3−x,M−y))┐, wherein N3 is a number of columns of the DFT array, and N3, n, k, x, y are positive integers, and wherein nchoosek indicates selecting k combinatorial numbers from n sequences.