An efficient iterative algorithm for joint frequency synchronization and channel estimation in OFDM systems

We propose an efficient joint frequency synchronization and channel estimation algorithm based on maximum-likelihood criterion for orthogonal frequency division multiplexing systems. By incorporating a linear minimum mean square error combiner into the algorithm, an iterative process will smoothly lead us to the solutions for both the ML frequency offset and channel estimator without any exhaustive search or simplified approximation as required in most existing algorithms. Moreover, unlike many existing algorithms for which the ML estimator mean square errors will move above and away from Cramer-Rao bounds as signal-to-noise ratio value becomes large, our ML estimator MSEs continue to be tightly close to CRBs at large SNRs with a good tracking range.