T-TCM系统中的SNR失配分析  

On SNR Mismatch in T-TCM Systems

作　　者：闫涛[1] 茹乐[1] 张曦[1] 杜兴民[1] 

机构地区：[1]空军工程大学工程学院,西安710038

出　　处：《电子与信息学报》2009年第1期61-65,共5页Journal of Electronics & Information Technology

基　　金：国家部级基金资助课题

摘　　要：该文基于AWGN信道研究了SNR失配对T-TCM系统性能的影响。蒙特卡洛仿真结果表明,SNR欠估计偏差不大于4dB时,T-TCM系统性能基本不受影响,更大的SNR估计偏差则会导致系统性能迅速下降;而SNR过估计始终不会造成系统性能折损。该文结合雅可比对数式及迭代译码算法的特点从理论上给出了解释,进一步提出无需SNR估计的T-TCM译码方案,在保证性能没有损失的前提下降低了T-TCM的应用要求与实现复杂度。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.

关 键 词：TURBO网格编码调制 SNR失配 S-Log-MAP算法 雅可比对数式 

分 类 号：TN919[电子电信—通信与信息系统]