Performance study of an efficient reduced-complexity time synchronization approach for DMT systems

This paper studies the performance of a recently proposed efficient reduced-complexity time synchronization approach, initially applied to OFDM systems, in the DMT systems. This approach uses a preamble of two identical parts and proceeds in two stages. In the first stage, a Cox and Schmidl-like metric is calculated to provide the coarse estimate. In the second stage, a differential correlation based metric is carried, over a short-length time window centered on the preamble start position coarse estimate. Assuming a successful coarse estimation, the performance of the fine estimation processing is here studied and evaluated in terms of probability of preamble start correct detection, for the DMT systems. Indeed, the closed form analytical expression of the correct detection probability is derived and compared to the experimental rate of correct detection. The simulation results provide a good match with the theoretical results. We also evaluate the performance degradation occasioned by a further complexity reduction obtained through replacing the differential correlation operations by sign changes. Both additive white Gaussian noise and multipath channels are here considered.