Carrier phase and frequency recovery for MIMO-OFDM

A new carrier phase and frequency recovery scheme is proposed for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. The algorithm uses an extended Kalman filter (EKF) to estimate the instantaneous phase and frequency offset. A linear minimum mean squared error (LMMSE) data-channel extractor is used to isolate the phase and frequency dependent term from the received signal. The proposed algorithm can provide both phase and carrier frequency recovery and has lower complexity than other approaches in the literature. In addition there is very little latency associated with the proposed approach. Simulation results show that the proposed algorithm can track quickly carrier phase and frequency offset and the performance loss compared to the synchronous case is very small.