Maximum likelihood tracking algorithms for MIMO-OFDM

Tracking algorithms for carrier and sampling clock frequency offset are proposed for pilot assisted MIMO-OFDM in frequency selective channels. The methods are based on maximum likelihood estimation theory applied to observations of received pilot subcarriers at the output of the FFTs of the receiver. Simulation results show that larger MIMO configurations benefit from lower estimator variances, providing increased synchronization accuracy at low SNRs, or allowing for a reduction of the number of pilot subcarriers.