BASE STATION APPARATUS AND TRANSMISSION METHOD

摘要

PROBLEM TO BE SOLVED: To increase feed back accuracy to a multiple antenna array without increasing the size of a codebook in a wireless communication system including plural antenna arrays.SOLUTION: The base station apparatus stores an extended codebook obtained by combining a first basic codebook having N (N is a natural number 2 or larger) groups including four basic pre-coding matrixes perpendicular to each other and a second basic codebook generated by applying phase offset of values different from each other among every group to each of N groups in a column direction; and receives a piece of information including an index (PMI) for identifying any one of the pre-coding matrix in 4N pre-coding matrixes included in the extended codebook from the terminal apparatus; performs a pre-coding on the data by using a pre-coding matrix corresponding to the PMI included in the received information; and transmits the pre-coded data to a terminal apparatus.