双软扩频与π/4DPSK复合调制系统建模仿真  

Modeling and simulation of dual tamed spread spectrum and π/4DPSK modulation system

作　　者：申博[1] 王兵[1] 

机构地区：[1]北京卫星信息工程研究所,北京100086

出　　处：《电子设计工程》2011年第12期120-123,共4页Electronic Design Engineering

摘　　要：为了有效提高系统的抗干扰能力,在已有软扩频的基础上,提出了一种新的双软扩频与π/4DPSK复合调制系统,即发送端数据经过串并转换后,选取两组正交码扩频并与π/4DPSK调制信号复合后调制载波,接收端下变频后使用比特软值解调恢复出发送数据。并进行了系统建模和在AWGN和多径信道下的误码率性能仿真。结果表明,新系统在BER=10-5时比传统的硬判决解调算法性能提高约3 dB,具有较好的抗干扰与抗多径能力。In order to improve the anti-interference ability,a new dual tamed spread spectrum and π/4DPSK modulation system is proposed based on existed tamed spread spectrum systems.First,the system architecture is presented.Second,the model of the system is established.Finally,the simulation results of the BER performance in AWGN and multipath channel are provided.The results demonstrate that the BER performance of the new system achieves a 3dB improvement approximately when BER is equal to 10-5 compared with hard-decision algorithm,and it has a good anti-interference and anti-multipath ability.

关 键 词：软扩频 卷积编码 差分解调 比特软值 多径 

分 类 号：TN914[电子电信—通信与信息系统]