DCT变换域滤波码捕获方法

 针对较小时频不确定度的卫星信号捕获,提出了一种结合离散余弦变换(DCT)的码捕获算法.首先对信号进行部分匹配滤波(PMF),然后对各个码相位对应的PMF输出矢量进行DCT变换域滤波及信号重构,最后对信号进行基于能量的检测.由于PMF输出信号和噪声时变特性不同,滤波重构后信号能量几乎无损,而噪声能量得到了明显降低,从而提高了相同虚警概率下的捕获概率.理论分析和仿真结果表明本文检测算法可以有效提升检测概率,并且具有较低的复杂度.

DCT Transform Domain Filtering Code Acquisition Method

Focusing on the satellite signal acquisition with low time and frequency uncertainty,we propose a novel code acquisition algorithm based on discrete cosine transform (DCT).Firstly,we obtained a set of time-domain related vectors by partial matched filter (PMF).Then we performed the transform domain filtering and signal reconstruction for every candidate code phase.Because the signals and noise produced by PMF have different time-varying property,noise is greatly reduced and the signals have almost no loss,thereby increasing the probability of detection under the same probability of false alarm.The theoretical analysis and simulation results show that the detection algorithm can effectively improve the detection probability,and has a lower complexity.