An Optimized Joint Time Synchronization and Channel Estimation Scheme for OFDM Systems

This paper proposes a new joint time synchronization and channel estimation scheme based on a conventional training sequence. The training sequence is composed of a maximal length sequence attached by both cyclic prefix and postfix. By analyzing the probability density functions of the corresponding correlator outputs at different time indexes, an optimal threshold is derived to distinguish the correct time index from its preceding ones. Based on the optimal threshold, the correct time index in conjunction with the channel impulse response can be estimated jointly. The proposed joint scheme involves low complexity and shows superiority over a lately-proposed one.