Optimized Joint Timing Synchronization and Channel Estimation for OFDM Systems

This paper addresses training-sequence-based joint timing synchronization and channel estimation for orthogonal frequency division multiplexing (OFDM) systems. The proposed approach consists of three stages. First, a coarse timing offset estimate is obtained. Then an advanced timing, relative timing indices, and channel impulse response estimates are obtained by maximum-likelihood estimation based on a sliding observation vector. Finally, the fine time adjustment based on the minimum mean squared error criterion is performed. The simulation results show that the proposed approach has excellent performance of timing synchronization in several channel models at low signal-to-noise ratio (SNR) which is smaller than 1dB. Moreover, for a low-density parity-check coded 1x2 single-input multiple-output OFDM system with maximum ratio combining, zero bit-error-rate is achievable using our proposed approach when SNR exceeds 1dB.