Blind symbol timing estimation for OFDM/OQAM systems

In this paper we consider the problem of blind symbol timing estimation for pulse shaping orthogonal frequency-division multiplexing (OFDM) systems based on offset quadrature amplitude modulation (OQAM). In particular, under the assumption of low signal-to-noise ratio, the joint ML phase offset and symbol timing estimator for AWGN channels is derived. Since the phase estimate is in closed form, the symbol timing estimate requires only a one-dimensional maximization procedure with respect to a continuous parameter. Specifically, the cost function to be maximized to obtain the desired symbol timing estimate depends on both the unconjugate and the conjugate correlation functions of the transmitted OFDM/OQAM signal. The performance of the proposed blind estimator is assessed via computer simulations in AWGN and multipath channel.