Abstract:In this paper, impact of SNR mismatch on the T-TCM performance is investigated in AWGN. The Monte Carlo simulation results indicate that when the under-estimate SNR offset is no more than 4dB, the T-TCM performance will not be badly affected, but greater offset can lead rapid performance degradation; Otherwise the overestimate of SNR will never lower the performance. A theoretical explanation is given by analyzing the Jacobian logarithm formula and iterative decoding algorithm, and based on the explanation a new T-TCM decoding scheme without SNR estimation is further proposed, with which the T-TCM systems have no performance loss and can be more conveniently applied and easily implemented.