Combination of Coarse Symbol Timing and Carrier Frequency Offset (CFO) Estimation Techniques for MIMO OFDM Systems

This paper presents a novel and accurate combination of data-aided techniques for simultaneous maximum likelihood (ML) coarse symbol timing and carrier frequency offset (CFO) estimation of multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) outdoor systems constructed by DVB-T subsystems. The embedded continual pilot tones in DVB-T are utilized to perform the coarse timing recovery with low system complexity. The inherent cyclic prefix (CP) of the DVB-T symbol is used for CFO estimation. By means of simulations, the proposed coarse timing method shows excellent robustness even at a very low SNR for the continuous transmission mode, and is also suitable for burst mode. In addition, the performance of the designed CFO estimator is close to the Cramer-Rao lower bound, increases for increasing delay of multipath spread and the number of receive antennas, and also performs as expected with timing estimation errors, which all agree well with the theoretical results