Patent ID: 7609789
Filing Date: 2009-10-27
Classification: H04L

Abstract:
1. A method of reducing phase noise in OFDM systems the method comprising: obtaining a received data matrix Z that is diagonal and exhibits sampled OFDM signal values z in accordance with a received OFDM signal comprising transmitted OFDM signal multiplied by a known phase noise process over a channel having a matrix channel H, wherein the OFDM signal comprises at least one pilot tone; obtaining a covariance matrix of the known phase noise process; decomposing the covariance matrix into eigenvectors; creating a matrix V from all decomposed eigenvectors; calculating a discrete fourier transform matrix F representing the transformation from an OFDM symbol to OFDM signal in a particular OFDM system; diagonalizing the channel matrix H utilizing Matrix F; calculating a matrix W by multiplying an inverse matrix of the diagonalized H matrix, with matrix F, matrix Z, and matrix V; estimating the phase noise coefficients by multiplying W with the at least one OFDM pilot tone; and estimating a phase noise cancellation vector by multiplying the estimated phase noise coefficients with matrix V.