Patent ID: 7881395

Claim:
A method of transmitting data using a plurality of subcarriers in a multi-antenna wireless communication system, the method comprising: receiving feedback information from a mobile station (MS) related to at least a channel encoding, a modulation or a spatial multiplexing rate; performing the channel encoding and the modulation independently on a plurality of user data units to produce a plurality of data streams using the received feedback information; determining a phase shift-based precoding matrix using a precoding matrix selected from a codebook based on the spatial multiplexing rate, wherein the codebook includes a first precoding matrix corresponding to a first value of the spatial multiplexing rate and a second precoding matrix corresponding to a second value of the spatial multiplexing rate, wherein the second value is higher than the first value, and wherein the first precoding matrix is part of the second precoding matrix; performing precoding, at a precoder, using the determined phase shift-based precoding matrix on the plurality of data streams to produce output signals; and transmitting the output signals to the MS.