水声DS-CDMA通信中多相位假设码片速率自适应判决反馈均衡算法研究

研究了直接序列扩频码分复用(DS-CDMA)通信中基于多相位假设的码片速率自适应判决反馈均衡算法.水声信道的衰落和多普勒频移会严重影响扩频信号的相关特性,需要在做解扩频之前进行多普勒频移补偿和信道自适应均衡.将空间分集-多普勒频移补偿-自最佳自适应判决反馈均衡算法应用到DS-CDMA通信中,提出一种基于多相位假设的码片速率自适应判决反馈均衡算法,并用实际的千岛湖实验数据和仿真数据对算法性能进行了分析.结果表明算法以增加计算复杂性为代价显著提高了DS-CDMA通信性能,在复杂快变的多途和多普勒频移条件下可以保证低的误符号率,在低信噪比条件下能够稳定工作,总体性能良好.

A study of chip rate phase hypothesis adaptive decision feedback equalization for DS-CDMA underwater acoustic communication

A study of chip rate phase hypothesis adaptive decision feedback equalization algorithm for DS-CDMA underwater acoustic communication is presented.Underwater acoustic communication channel is a delay-Doppler double spreading channel.Fading and Doppler spreading severely degrade the correlation characteristic of the spread spectrum signals,so Doppler shift compensation and equalization are needed before decoding.By applying Space diversity-Doppler compensation-Fast Self-Optimized adaptive decision feedback equalization algorithm into DS-CDMA communication,a chip rate phase hypothesis adaptive decision feedback equalization algorithm for DS-CDMA underwater acoustic communication is proposed and its performance is analyzed with real lake trial data and simulation data.At the price of computational complexity,the algorithm dramatically improves DS-CDMA communication quality.Very low symbol error rate is achieved under fast changing multi-path and Doppler shift condition,and the equalizer is stable under low SNR.The overall performance of this algorithm is satisfactory.