Patent ID: 8995557
Filing Date: 2015-03-31
Classification: H04B,H04L,H04W

Abstract:
1. A base station apparatus comprising: a codebook storing section configured to store an extended codebook which is generated by combining a first basic codebook and a second basic codebook along the column direction, wherein the first basic codebook includes N groups, each consisting of four basic pre-coding matrices that are orthogonal to each other (N is a natural number equal to or larger 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 receiving section configured to receive information including an index (a pre-coding matrix indicator (PMI)) for identifying one pre-coding matrix from among the 4N pre-coding matrices included in the extended codebook, from a terminal apparatus; and a transmitting section configured to pre-code data using a pre-coding matrix corresponding to the PMI included in the received information and to transmit the pre-coded data to the terminal apparatus.