一种适用于多径信道下DSSS信号检测新方法

针对多径信道下直接序列扩频信号检测的难题，在基于自相关二阶矩的检测算法基础上提出了新的检测参数，从而将加性高斯白噪声信道下的直接序列扩频信号检测算法推广到多径信道。本文算法首先分析了由多径信道导致的能量峰值和由直扩信号的伪码特性导致的自相关峰值的特点，并根据此特点定义了新的检测参数——多径因子，最后将该参数应用到基于自相关二阶矩的直接序列扩频信号检测算法中，实现了对多径信道下的直接序列扩频信号的检测。理论分析和仿真实验表明，本文提出的检测新参数能真实的反映多径信道对信号自相关函数的影响；当信噪比大于-14dB时，本文提出的多径信道下直扩信号检测算法性能与加性高斯白噪声信道下的检测性能相当。 

A New Detection Method for DSSS Signal in Multipath Channel

Based on the second order moment of the auto correlation estimator, a new detection parameter is proposed to extend the DSSS signal detection method in additive white Gaussian noise channel to multipath channel. The proposed detection method analyzes the characteristics of energy peak led by multipath channel and auto-correlation peak led by pseudo-code of signal at first; then according to these characteristics a new detection parameter called multipath factor is defined to eliminate the influence of multipath channel while using the second order moment of the autocorrelation estimator as the direct sequence spread spectrum signal detection method ; at last, combined with this new parameter and the second order moment of the autocorrelation estimator, a new detection method for direct sequence spread spectrum signal in multipath channel is get. The theoretical analysis and simulation results show that the proposed detection parameter can reflect the influence led by multipath channel effectively; when the signal to noise ratio is higher than -14dB, the detection performance of the proposed detection method apply to signal in multipath channel is closer to the signal in additive white Gaussian noise channel.