直扩信号的深度盲检测方法研究

A Method for Blind Detection of DSSS Signal at Lower SNR

提出一种基于四阶累积量切片和非线性滤波的直扩信号盲检测算法,新方法充分利用四阶累积量能有效提取直扩信号谐频分量的特性,结合了非线性滤波能深度抑制背景噪声的优点,极大降低了直扩信号的检测和参数估计的门限。理论分析和仿真试验表明,新算法可以实现在超低信噪比下DSSS/BPSK信号的检测和扩频码周期的精确估计,具有计算量小、检测概率高的特点,易于工程实现。

A novel method for blind detection based on the fourth cumulant and nonlinear filtering of DSSS signal is proposed. Combining with the advantage of nonlinear filtering and utilizing the characteristic of fourth order cumulant, it is capable of detecting and estimating DSSS signal at very much lower SNR. Theoretic analysis and simulations show that the method not only detects and accurately estimates the period of PN sequence of DSSS/BPSK signal at much lower SNR, but also has lower computation complexity and higher detect probability, which is easy for hardware implementation.