Phase noise compensation for MIMO WLAN systems

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.