Maximum-likelihood frame timing instant and frequency offset estimation for OFDM communication over a fast Rayleigh-fading channel

A novel maximum-likelihood (ML) technique for frame timing instant and frequency offset estimation in an orthogonal frequency-division multiplexing system is investigated in this paper. By taking advantage of the cyclic prefix within the guard interval, the proposed technique can accurately estimate the frame timing instant and frequency offset with no assistance from pilot symbols. The proposed technique also takes fast Rayleigh fading into consideration for the purpose of wireless application. Furthermore, several combining techniques are also investigated in this paper in order to improve the performance of the proposed estimators. Extensive simulation experiments show that the proposed techniques can effectively achieve lower estimation errors in frame timing and frequency offset estimation.