Precoding matrix indicator feedback method, receiving method, and apparatus

Abase station, wherein the base station comprises:

• a sending unit, configured to send a reference signal to UE;
• and
• a receiving unit, configured to receive a second PMI corresponding to each first subband of N first subbands and a first PMI corresponding to each second subband of M second subbands in a system transmission bandwidth that are fed back by the UE, wherein the M second subbands are determined from the N first subbands, there is at least one second subband comprising at least two first subbands in the M second subbands, and both N and M are positive integers not less than 2;
• and the base station has a codebook, wherein the codebook comprises at least two precoding matrixes, and selects a corresponding precoding matrix from the codebook according to the first PMI corresponding to each second subband and the second PMI corresponding to each first subband.

A precoding matrix indicator feedback method, wherein the method comprises:

• receiving, by user equipment UE, a reference signal sent by a base station;
• selecting, by the UE based on the reference signal, a precoding matrix for each first subband of N first subbands in a system transmission bandwidth from a codebook, wherein the codebook comprises at least two precoding matrixes, and each precoding matrix is denoted by at least a first precoding matrix indicator PMI and a second PMI, wherein each first subband of the N first subbands corresponds to a second PMI, each second subband of M second subbands corresponds to a first PMI, the M second subbands are determined from the N first subbands, and there is at least one second subband comprising at least two first subbands in the M second subbands, wherein both N and M are positive integers not less than 2;
• and
• feeding back, by the UE, the first PMI corresponding to each second subband to the base station, and feeding back the second PMI corresponding to each first subband to the base station.

A precoding matrix indicator receiving method, wherein the method comprises:

• sending, by a base station, a reference signal to UE;
• and
• receiving, by the base station, a second PMI corresponding to each first subband of N first subbands and a first PMI corresponding to each second subband of M second subbands in a system transmission bandwidth that are fed back by the UE, wherein the M second subbands are determined from the N first subbands, there is at least one second subband comprising at least two first subbands in the M second subbands, and both N and M are positive integers not less than 2;
• and the base station has a codebook, wherein the codebook comprises at least two precoding matrixes, and selects a corresponding precoding matrix from the codebook according to the first PMI corresponding to each second subband and the second PMI corresponding to each first subband.