Optimum synchronization of orthogonal multi-carrier modulated signals

This paper proposes a new joint symbol timing, symbol period and frequency offset estimation method for orthogonal multi-carrier modulation signal. The method is based on the maximum likelihood criterion making effective use of “cyclostationary property” of the orthogonal multi-carrier modulation signal, and requires no special signal such as pilot tones to assist the estimation. After a likelihood function for the estimation is derived, an optimum estimator which maximizes the likelihood function is proposed. In addition, in order to reduce the estimator complexity, a suboptimum estimator is also proposed. Computer simulation results show that the optimum estimator requires only about 10 observation symbols for the accurate estimation in a frequency selective slow Rayleigh fading channel as well as in an additive white Gaussian noise channel, and the suboptimum estimator is effective because of the low complexity, although it requires a longer observation period