Patent ID: 8654740

Claim:
An apparatus, comprising: a fixed device for a mobile broadband communications system utilizing an orthogonal frequency-division multiple access technique, the fixed device having a precoding module operative to, for each of a plurality of mobile devices, generate a precoding matrix using a received first codeword of a first base codebook, subsequently reconstruct the precoding matrix using a received polar-cap codeword of a polar-cap codebook, and periodically reset the precoding matrix to clear accumulated error at the fixed device using a received second codeword of a second base codebook, the fixed device to coordinate the periodic resettings of the precoding matrices for the plurality of mobile devices by using time and frequency domain multiplexing to receive the second codewords for the plurality of mobile devices using different sub-frames and different frequencies, such that when one of a plurality of sub-bands is in a reset state, the other sub-bands are in a tracking state.