An Improved Symbol Synchronization Method for OFDM Systems

We present an improved symbol synchronization method based on maximum likelihood estimator for OFDM systems. The approach proposed here is an improvement of the previously proposed estimation method given by Van de Beek, Sandel and Borjesson (see IEEE Trans. on Signal Processing, vol. 45, no. 3, p. 1800-05, 1997). Our research indicates that the correlation coefficient in the ML estimator is the function of symbol synchronization position during the ergodic process to find the maximum of likelihood function and it should not be treated as a constant. Based on this observation, an improved calculation procedure for the ML estimator of symbol synchronization position is derived. The results from computer simulations and actual experiments show that the improved ML estimator of symbol synchronization position has better performance than the previous one.