Frequency synchronization of MIMO OFDM systems with frequency-selective weighting

OFDM transmission requires accurate carrier frequency offset correction between transmitter and receiver to avoid ICI (inter-carrier interference). The paper proposes a novel method to estimate the frequency offset at the receiver in MIMO and MISO systems; it has improved accuracy compared to previous solutions. The proposed training sequence uses frequency bands that are non-overlapping or partially overlapping for every transmit antenna. The algorithm weights the received signal at every receive antenna with an estimate of SNR derived from the magnitude of cross-correlation with the transmitted training symbols. Carrier frequency offset is then estimated from the autocorrelation of the weighted signal.