Feedback method, receiving method and device for precoding matrix indication

Abstract

The embodiment of the present invention discloses a feedback method, a receiving method and a device for a precoding matrix indication. A user equipment UE receives a reference signal sent by a base station; based on the reference signal, the UE transmits a codebook for the system in the bandwidth. Each first subband in the N first subbands selects a precoding matrix, wherein the codebook includes at least two precoding matrices, and each precoding matrix is ​​at least indicated by the first precoding matrix PMI and The second PMI represents, wherein, each first subband in the N first subbands corresponds to a second PMI, and each second subband in the M second subbands corresponds to a first PMI; The UE feeds back the first PMI corresponding to each second subband to the base station, and feeds back the second PMI corresponding to each first subband 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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