Patent ID: 7965780

Claim:
A method of determining a pre-coding matrix in an Orthogonal Frequency Division Multiple Access (OFDMA) communication system having a plurality of sub-carriers grouped into a number, M, of resource blocks, wherein the communication system employs a plurality of transmit antennas, the method comprising: determining a frequency selectivity of a channel through which received signals have propagated; determining, as a function of the frequency selectivity, a number N of selected resource blocks for which pre-coding matrices will be determined, wherein N<M; determining the pre-coding matrices for the N selected resource blocks; determining pre-coding matrices for a remaining M−N of the M resource blocks by means of interpolation applied to the N pre-coding matrices determined for the N selected resource blocks; determining a Doppler error estimate of received signals; and using the Doppler error estimate to determine a pre-coding matrix update interval.