LDPC码在短波宽带信道中的性能研究

Performance of LDPC codes in wideband shortwave channel

为减小短波宽带信道中多径效应和多普勒效应对通信系统误比特率的影响,引入高可靠性LDPC码作为信道编码方式。寻找合适的校验矩阵,改进译码算法,结合能有效抑制多径干扰的MC-CDMA技术,提出了一种LDPC+OFDM+DSSS的设计方案。通过对ITS模型的短波宽带信道进行分析,利用信道均衡技术恢复接收信号,建立了系统仿真模型。仿真结果显示,所设计方案能够有效抑制信道间干扰和符号间干扰,降低通信系统对多普勒频移的敏感度,取得优异的误码率性能。

To reduce multipath effect and doppler effect in the shortwave broadband channel on the bit error rate performance,LDPC code with probable checking matrix and improved decoding algorithm is introduced as channel encoding for the effect of high reliability.Combined with MC-CDMA technology which can effectively inhibit the multipath interference,the LDPC＋OFDM＋DSSS scheme is proposed.By the analysis of shortwave broadband channel based on ITS model and using the equalization techniques recovery receiving signals,the communication simulation model is built.Simulation results show that the program can effectively inhibit the channel interference and symbol interference,reduce communication system of doppler frequency sensitivity and reach a better bit error rate performance.