Robust timing and frequency synchronization for TDS-OFDM over multipath fading channels

Abstract

Time domain synchronous orthogonal frequency division multiplex (TDS-OFDM) is an effective multi-carrier modulation scheme to improve spectrum efficiency. Conventional synchronization algorithm based on the time-domain differential correlation of the pseudo noise (PN) sequence may not work well in severe multipath fading channels. In this paper, a robust synchronization algorithm is proposed where the frame head is considered as a cyclic prefixed-OFDM (CP-OFDM) training symbol. In the time domain, the autocorrelation based on the cyclic structure of the frame head is adopted for timing and fine carrier frequency offset (CFO) estimation, while in the frequency domain, a differential correlation is applied for large CFO estimation. Simulations verify that the proposed synchronization algorithm could achieve satisfactory performance in presence of large CFOs over multipath fading channels.