Blind estimation of multi-CFO for distributed MIMO-OFDM system in frequency-selective fading channels

A novel blind multiple carrier frequency offset (multi-CFO) estimation algorithm is developed for distributed multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) systems over frequency-selective fading channels. In the algorithm, different multiple CFOs are estimated by cyclostationarity (CS) of the received signals and least square (LS) criterion. Theory analysis shows that the blind algorithm adapts to synchronization under any distributed stationary noise. Meanwhile, it has no special limitation on the number of transmit and receive antennas. Simulation results verify that the proposed algorithm maintains stability at low signal-to-noise ratio (SNR). It can also achieve excellent performance in single-input singleoutput (SISO) OFDM systems.