基于信噪比控制的自适应伪码捕获算法

针对复杂电磁环境下接收信噪比随机变化的特点,提出了一种基于信噪比控制的自适应伪码捕获算法,减少了捕获时间,降低了虚警概率。在分析滑动相关捕获法的性能基础上,构建了滑动相关伪码捕获的自适应结构,实现了在接收信噪比控制下积分时间和门限值的设置,研究了上述参数对捕获性能的影响,仿真结果表明:根据积分时间不同,在SNR>-3 dB时,平均捕获时间最大可以减少50％,在SNR<-7 dB时虚警概率下降5％～35％,满足信噪比变化情况下对捕获性能的设计需求。

An Adaptive Acquisition Algorithm of PN Codes Based on SNR Control

An adaptive acquisition algorithm of PN codes is presented based on SNR control because the acquiring SNR is time-varying in complex electromagnetism environment. The use of the algorithm can reduce the mean code acquisition time and the virtual alarm probability. Based on the performance analysis of the sliding correlation method, an adaptive scheme is constructed to achieve the goal to set the time of integral and the threshold in SNR control, and the influence of the above parameters on the performance of acquisition is studied as well. Simulation results show that the method can reduce the mean code acquisition time by 50% when SNR>-3 dB, and reduce the virtual alarm probability by 5%~35% when SNR<-7 dB, the method meets the design requirements of acquisition properties under the SNR change environment.