Method for feeding backchannel state information, user equipment, and base station

摘要

Embodiments of the present invention provide a method for feeding back channel state information, a user equipment, and a base station, to improve feedback precision of channel state information. The method includes: receiving a reference signal sent by a base station; selecting a precoding matrix W from a codebook according to the reference signal, where a column vector of the precoding matrix W may be expressed as α[v ejφv]T, v=[1 ejθ]; and sending a precoding matrix indicator PMI to the base station, where the PMI is corresponding to the selected precoding matrix W. The present invention may further improve quantization precision and achieve balance between overheads and the quantization precision. The base station performs precoding on a sent signal according to a fed back precoding matrix indicator, which can improve precoding precision, thereby improving a data transmission rate and system throughput.

主权项

1. A method for feeding back channel state information performed by a user equipment (UE), the method comprising:
receiving a reference signal sent by a base station; selecting a precoding matrix W from a matrix set based on the reference signal, wherein α column vector of the precoding matrix W is expressed as α[v ejφv]T, v=[1 ejθ], wherein α is a constant, θ and φ are phases, and [ ]T indicates transposing of a matrix or vector; and sending a precoding matrix indicator (PMI) to the base station, wherein the PMI corresponds to the selected precoding matrix W; wherein the matrix set is one of:{12⁡[1ⅇjθ1ⅇjθ],12⁡[1ⅇjθjjⅇjθ],12⁡[1ⅇjθ-1-ⅇjθ],12⁡[1ⅇjθ-j-jⅇjθ]};{18⁡[11ⅇjθⅇjθ1-1ⅇjθ-ⅇjθ],18⁡[11ⅇjθⅇjθj-jjⅇjθ-jⅇjθ]}⁢⁢or{18⁡[11ⅇjθⅇj⁡(θ+φ)1-1ⅇjθ-ⅇj⁡(θ+φ)],18⁡[11ⅇjθⅇj⁡(θ+φ)j-jjⅇjθ-jⅇj⁡(θ+φ)⁢]}wherein⁢⁢θ=π16⁢(2⁢i1+⌊i2/4⌋),i1=0,…⁢,15,i2=0,…⁢,15,⁢φ=π16,π8,…⁢,and └i2/4┘ indicates the greatest integer not greater than i2/4.