Base station apparatus and transmission method

摘要

The present disclosure provides a method of generating codebook in a wireless communication system with multiple antenna arrays, as well as a wireless communication system, base station and terminal using the codebook for communication. The method comprises steps of: providing a basic codebook which contains multiple pre-coding matrices; and assigning phase offsets to certain pre-coding matrices in the basic codebook to form a codebook with phase offset. The feedback overhead from a client to a base station side is reduced and a good precision of feedback for multi-antenna array is kept by applying the method of generating codebook and using the generated codebook in the wireless communication system, base station and terminal.

主权项

1. A communication apparatus using a multi-antenna array, the communication apparatus comprising: a codebook storage which, in operation, stores an extended codebook, which is generated by combining a first basic codebook and a second basic codebook along a column direction, wherein the first basic codebook includes N groups each consisting of four basic pre-coding column vectors that are orthogonal to each other (N is a natural number equal to or greater than 2), and wherein the second basic codebook is generated by applying phase offsets to the N groups, respectively, each of the phase offsets applied to the N groups being different from each other; a transmitter which, in operation, transmits, via the multi-antenna array to a base station, a pre-coding matrix indicator (PMI) that identifies one pre-coding extended column vector from among the 4N pre-coding extended column vectors included in the extended codebook; and a receiver which, in operation, receives, from the base station and via the multi-antenna array, downlink data that is pre-coded using the one pre-coding extended column vector identified by the PMI.