Patent ID: 9680539
Date: 2017-06-13
CPC Classifications: H04B,H04L

Claim:
1. A terminal that is configured to communicate with a base station, comprising: a feedback information generator configured to generate a precoding matrix indicator which corresponds to one of a codebook index in a first codebook, and a pair of codebook indices in a second codebook, for four antenna ports, whether the precoding matrix indicator corresponds to the codebook index in the first codebook or the pair of codebook indices in the second codebook is determined based on a parameter configured by a higher layer; and a transmitter configured to report the precoding matrix indicator, wherein the precoding matrix indicator is selected using codebook subset restriction, the codebook index in the first codebook indicates one of matrices in the first codebook, the pair of codebook indices in the second codebook indicates one of matrices in the second codebook, and a rank of the one of matrices in the first codebook is the same as a rank of the one of matrices in the second codebook.