基于并联Duffing振子的微弱QPSK信号解调  

Demodulation of Weak QPSK Signal Based on Parallel Duffing Oscillator

作　　者：魏世朋[1] 张天骐[1] 侯瑞玲[1] 高春霞[1] 

机构地区：[1]重庆邮电大学信号与信息处理重庆市重点实验室,重庆400065

出　　处：《电视技术》2011年第23期81-87,共7页Video Engineering

基　　金：国家自然科学基金项目(61071196);国家自然科学基金-中物院NSAF联合基金项目(10776040);教育部新世纪优秀人才支持计划项目(NCET-10-0927);信号与信息处理重庆市市级重点实验室建设项目(CSTC;2009CA2003);重庆市自然科学基金项目(CSTC;2009BB2287CSTC;2010BB2398CSTC;2010BB2411)

摘　　要：针对微弱QPSK信号传统解调方法误码率高且其存在相位模糊的缺点,提出了一种基于并联Duffing振子的解调方法。该方法利用混沌振子对待测信号相位的敏感性,先将微弱QPSK信号通过并联Duffing振子系统,系统的输出是交替出现的周期状态与混沌状态,再计算信号功率谱密度的熵加以区别,进而判决解调QPSK信号。仿真结果表明,该方法可解调信噪比低至-27 dB的QPSK信号,并且避免了相位模糊问题。Concerning the high BER and the phase ambiguity of the FSK signal＇s traditional demodulation method in low SNR, the demodulation method based on parallel Dulling oscillator system is studied. This method using the feature that the Duffing oscillator is sensitive to the tested signal＇ s phase. First, the weak QPSK signal is put into the parallel Duffing oscillator system, the output of the system is the chaos status and the cycle status relative to the binary data. The simulation results show that by using this method to demodulate the QPSK signal, it does not have the conventional coherent demod- ulation, and can avoide the phase ambiguity.

关 键 词：相位敏感性 并联Duffing振子 QPSK信号 功率谱熵 

分 类 号：TN911.72[电子电信—通信与信息系统]