MMSE estimation of OFDM symbol timing and carrier frequency offset in time-varying multipath channels

In this paper, we present a new algorithm for blind estimation of the symbol timing and frequency offset in a time-varying frequency-selective Rayleigh fading multipath channel for OFDM systems. It exploits the intrinsic structure of OFDM signals and only relies on second-order moment without knowledge of probability distribution function of received signals. Under minimum mean-square-error (MMSE) sense, the proposed estimators are totally optimum and easily implemented. Furthermore, we expand the estimation range of the frequency offset estimator and improve the timing estimator to be independent of the frequency offset. A more generalized channel model is considered in this paper. It is characterized by its power delay profile and time-varying scattering function. The channel has high reliability for real mobile environment.