CDMA系统中卷积码的性能分析

Performance Analysis of Convolution Codes in CDMA System

研究CDMA系统在多径传输和AWGN信道的环境下卷积码的性能。通过模拟程序和理论分析画出误比特率和信噪比的曲线图,并得到其在硬判决和软判决解码中错误率的上限值。研究发现,软判决译码比硬判决译码2~3dB的增益,卷积码性能的提升在AWGN信道比更能体现出来。当AWGN信道信噪比超过-1dB时,采用硬判决译码算法的卷积码相对于未采用卷积码会性能更好。

In the paper,it studies the performance of convolution code of CDMAsystem under multi-path transmission and AWGNchannel.It gets the curve graphs of bit error rate and signal to noise ratio by simulation program and theoretical analysis,and upper limit of error rate which got from hard-decision decoding and soft-decision decoding.The results show that soft-decision decoding can increase 2~3dB compared with hard-decision decoding.The improvement of convolution code is better in AWGN channel.Convolution code used hard-decision decoding is better than that without hard-decision decoding,when signal to noise ratio of AWGN channel ismore than-1dB.