Precoding matrix indication feedback method, receiving method and device

Abstract

The embodiment of the invention discloses a precoding matrix indication feedback method, receiving method and device. User equipment (UE) receives a reference signal sent by a base station; The UE selects a precoding matrix for each first sub-band in N first sub-bands in the system transmission bandwidth from the codebook is based on the reference signal, wherein the codebook at least comprises two pre-coding matrixes; wherein each precoding matrix is at least represented by a first precoding matrix indicator PMI and a second PMI, each first sub-band in the N first sub-bands corresponds to onesecond PMI, and each second sub-band in the M second sub-bands corresponds to one first PMI; And the UE feeds back the first PMI corresponding to each second sub-band to the base station, and feeds back the second PMI corresponding to each first sub-band to the base station.

Description

technical field [0001] The present invention relates to the field of wireless communication, in particular to a feedback method, receiving method and device for a precoding matrix indication. Background technique [0002] The codebook-based precoding method is to pre-store a codebook (that is, a set of precoding matrices) at the receiving end, and the receiving end selects the best precoding matrix according to a certain criterion according to the current channel state, and indicates the precoding matrix ( The precoding matrix indicator (PMI for short) is fed back to the transmitter. Because of its small amount of feedback and good compatibility, it has been widely used in the field of wireless communication. [0003] Each precoding in the codebook adopted by the existing 3GPP LTE R10 system for 8 antennas can be expressed as W=W 1 W 2 , where W 1 Used to characterize broadband / long-term channel characteristics and represented by the first PMI, W 2 For characterizing the...

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Problems solved by technology

[0003] Each precoding in the codebook adopted by the existing 3GPP LTE R10 system for 8 antennas can be expressed as W=W 1 W 2 , where W 1 Used to characterize broadband / long-term channel characteristics and represented by the first PMI, W 2 For characterizing the subband / short-term channel characteristics and represented by the second PMI, when the ranks are 1 and 2, W 1 It is composed of 4 consecutive beam vectors, and the distance between adjacent beam vectors is Therefore, in the 8Tx dual codebook, W 1 The covered beam phase variation range is: In the scene where the beam phase changes greatly, W 1 Beam phase changes that cannot cover the entire bandwidth cause a large loss in system performance

[0004] Furthermore, the existing 3GPP LTE R12 system also adopts a dual codebook structure for codebooks with 4 antenna ranks of 1 and 2, and each precoding matrix in the codebook can be expressed as W=W 1 W 2 , where W 1 It is composed of 4 columns of beam vectors with large spacing, and the spacing between adjacent beam vectors is W 1 It completely covers the range of beam variation from 0 to 2π, but the minimum granularity between adjacent beams is The granularity of beam quantization is poor, and the system performance loss is also large

[0005] To sum up, in the prior art, when the beam phase changes greatly, W 1 Beam phase changes that cannot cover the entire bandwidth, and when the beam phase changes are small, the beam quantization granularity is poor, which will reduce the system performance. In this way, the codebook in the prior art is inconsistent with the beam phase scene match, reducing system performance

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