UQPSK直扩信号的四阶累积量的检测研究  

Detection of DSSS/UQPSK Signal for Four-order Cumulants Algorithm

作　　者：石穗 张天骐[1] 徐昕[1] 张亚娟[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：《科学技术与工程》2014年第20期257-262,共6页Science Technology and Engineering

基　　金：国家自然科学基金项目(61071196;61102131);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(CSTC2009CA2003);重庆市杰出青年基金项目(CSTC2011jjjq40002);重庆市自然科学基金项目(CSTC2009BB2287;CSTC2010BB2398;CSTC2010BB2409;CSTC2010BB2411)资助

摘　　要：针对UQPSK(非均衡四相键控)直扩信号难于检测的问题,利用高斯白噪声的四阶累积量恒为零的性质,首先分析了UQPSK直扩信号的四阶累积量的相关理论知识和利用切片估计载频的可行性,其次提出了基于四阶累积量不同切片c4x(0,0,0)、c4x(0,0,τ)、c4x(0,τ,τ)、c4x(τ,τ,τ)的检测方法,最后对UQPSK直扩信号的各个切片的检测性能都做了仿真分析,且根据各个切片的频谱提取出了UQPSK直扩信号的载频。仿真表明,基于c4x(0,τ,τ)的检测性能最好,而c4x(τ,τ,τ)能在较低的信噪比下利用四阶累积量切片有效的估计出载频。提出的方法可行性高,具有实际应用价值。For the problem of direct sequence unbalance QPSK signal＇ s detection,by using the property that the fourth-order cumulant of the Gaussian White Noise is equal to zero,the theory knowledge of direct sequence unbalance QPSK signal was analyzed,carrier-frequency was estimated based on fourth-order statistic slice firstly.Then,a detecting method of the DSSS/UQPSK signal was proposed,the method was about the fourth-order cumulant different slices c4x （0,0,0） 、c4x （0,0,-） 、c4x （0,-,-） and c4x （τ,τ,τ）.Finally,the pefformance of the fourthorder cumulant different slices was acquired by doing some effectively simulations,and the DSSS/UQPSK signal＇carrier-frequency was acquired by the slices ＇ frequency spectrum.Experimental results show that the detection method based on c4x （0,τ,τ） is the best,while the fourth-order cumulant c4x （τ,τ,τ） can estimate the carrier-frequency effectively at low signal-to-noise ratio.The proposed methods has the high feasibility and the practical application value.

关 键 词：UQPSK 四阶累积量 信号检测 载频估计 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]