A Novel Frequency Offset Tracking Algorithm for Space-Time Block Coded OFDM Systems

A novel frequency offset tracking algorithm for Space-Time Block Coded (STBC) Orthogonal Frequency Division Multiplexing (OFDM) systems is proposed in this work. Tracking of a frequency offset between the transmitter and the receiver is often aided by transmitting pilots embedded in the data payload. The proposed algorithm mainly exploits the specific construction of the OFDM symbol in STBC-OFDM systems, which does not need any additional pilots or sequences in the data field, providing high efficiency in spectrum. The estimator is derived on the basis of the maximum likelihood (ML) theory. Simulation results show that in a 2 × 2 multiple input multiple output (MIMO) system, under the assumption that the antennas are uncorrelated to each other, this method can provide a significant performance improvement in terms of the estimation accuracy of the frequency offset.