低信噪比下的直扩信号检测和多参数估计方法

Detection and Multiple Parameter Estimation Methods for Direct Sequence Spread Spectrum Signal at Lower SNR

直扩信号具有较低的功率谱密度,淹没在背景噪声中,信号侦察难度大。根据四阶矩一维切片可以有效地抑制高斯白噪声和充分包含直扩信号的载波、伪码信息这一特性,提出了一种基于四阶矩一维切片的直扩信号检测和多参数估计方法。该方法不需要任何先验信息,不仅能够检测直扩信号,还能同时估计载波频率、伪码周期和伪码速率等参数。仿真结果表明,这种方法可以在低信噪比下工作,具有一定的实用价值。

Due to its low power spectral density, the direct sequence spread spectrum signal always floods in the background noise, bringing difficulties to the signal＇s reconnaissance. According to the fact that the one - dimensional slice of the fourth - order moment can effectively suppress the Gaussian White Noise and contains the information of the carrier frequency, PN code of the direct sequence spread spectrum signal, a kind of detection and multiple parameter estimation methods based on the fourth - order moment one - dimensional slice were proposed. These methods did not use the prior message of the signal, could not only detect the signal, but simultaneously estimate its cartier frequency, period of the PN code and its rate. Simulation results indicate that this kind of methods can work well at much lower SNR and have certain feasibility and practical value.