Patent Document ID: 9319251
Application ID: 12979479
Patent Flag: 1

Claim One:
1. A communication method of a receiver, the communication method comprising: calculating an eigenvector matrix comprising eigenvectors of a channel matrix or a channel covariance matrix; generating a codebook for each eigenvector of the eigenvector matrix such that each codebook has a different size based on eigenvalues of the channel matrix or the channel covariance matrix; quantizing each of the eigenvectors using the respective codebook for each eigenvector; and transmitting, to a transmitter, information associated with each of the quantized eigenvectors; wherein the generating comprises generating a largest size codebook for a codebook corresponding to a dominant eigenvector from among the eigenvectors, wherein the quantizing comprises: quantizing an ith eigenvector using the codebook corresponding to the ith eigenvector; projecting the codebook corresponding to an (i+1)th eigenvector onto a null space of the quantized ith eigenvector; and quantizing the (i+1)th eigenvector using the projected codebook corresponding to the (i+1)th eigenvector.