Maximal power path detection for OFDM timing-advanced synchronization schemes

Fine timing estimation in timing synchronization scheme of orthogonal frequency division multiplexing systems gives an estimate of symbol starting time index corresponding to the path with maximal power within an interval suggested by coarse timing stage. The actual starting index fed to the following stages is brought forward by an amount that should be adaptive to the estimated index to optimize system performance. In this paper, a method of detecting the estimated starting time index of path with maximal power in channel impulse response is proposed based on conventional preamble with repetitive structure. To deal with the adverse effect of fractional timing offset on the detection metric, we propose a preamble composed of cyclic-shifted parts and the accompanying fine timing and detection scheme. Simulation with time-varying wireless channel shows the detection methods makes use of the time diversity provided by time-varying paths and has good error performance. The scheme with proposed preamble further reduces probability of error detection with the diversity in fractional timing offset provided inherently in the parts of preamble.