阈值阵列系统中TCM编译码的随机共振现象

Stochastic Resonance of TCM Coding and Decoding in Threshold Array Systems

为了进一步降低网格编码调制(TCM)信号在接收端的误码率(BER),提高TCM码的译码性能。采用了一种离散的多阈值阵列系统与维特比译码器相结合的系统。并经过理论推导出阈值阵列系统输出端信号和TCM编码信号之间的互信息;同时通过仿真实验,分析了误码率的变化情况;并对两种不同测度下的变化情况进行了对比。理论分析表明,在适当噪声条件下,使信号无损传输到译码端;仿真实验也表明,在适当的噪声强度阈值阵列单元数量和噪声强度条件下,误码率会得到大幅度的降低。对比两种测度下的随机共振现象(SR),发现随机共振的存在性与测度有关。理论分析和仿真实验都表明,在该系统中适当的噪声能够显著提高互信息,降低误码率;随着阈值单元数的增加,这种效果也越发明显。

In order to further reduce the bit error rate(BER)of the trellis coded modulation(TCM)signal at the receiving end,the decoding performance of the TCM code is improved,A discrete multi-threshold array system combined with a Viterbi decoder is used.The mutual information between the output signal of the threshold array system and the TCM coded signal is deduced through theory.At the same time,the variation of the BER is analyzed through simulation experiments.The changes under two different measures are compared.Theoretical analysis shows that under proper noise conditions,the signal is transmitted losslessly to the decoding end;Simulation experiments also show that BER will be greatly reduced under the appropriate number of noise intensity threshold array elements and noise intensity.Comparing the stochastic resonance(SR)under two measures,we found that the existence of stochastic resonance is related to the measurement.Theoretical analysis and simulation experiments show that proper noise in this system can significantly improve mutual information and reduce BER.As the number of threshold cells increases,this effect becomes more pronounced.