A low-complexity iterative symbol timing estimator for turbo receivers

We consider the problem of symbol timing synchronization at low SNR without a training sequence in this paper. A low-complexity iterative joint symbol timing and carrier synchronization algorithm making use of the extrinsic information from the soft-input soft-output (SISO) decoder is proposed. The nondata-aided (NDA) algorithms are used for initial synchronization. The simulation results show that the proposed low-complexity solution works effectively and can converge after a few iterations. The receiver with the proposed iterative synchronizers can reach the ideal performance with perfect synchronization at very low SNR.