基于大步进串行捕获的DS/BPSK导航接收机捕获性能研究

Research on acquisition performance of DS/BPSK navigation receiver based on larger step and serial acquisition

针对低信噪比条件下导航接收机长伪码序列的快速捕获问题,提出了一种大步进串行捕获方案,实行区间与区间之间串行捕获,区间内并行捕获.给出了系统硬件实现的原理框图,建立了系统的数学模型,采用状态转移函数推导了系统平均捕获时间的计算表达式.在综合考虑伪码相位误差、多普勒频移和噪声干扰的基础上,详细分析了系统的捕获性能.

A larger step and serial acquisition scheme is proposed to solve the quick acquisition problem of long PN code sequences with low SNR in the DS/BPSK navigation receiver, which realizes the serial acquisition between intervals and parallel acquisition within interval. The hardware implementation of the scheme is provided. The mathematical model of the acquisition system is presented. The mathematical expression of average acquisition time is derived based on the state transfer function of the acquisition system. The acquisition performance of the system is analyzed with consideration of the phase error of PN sequences, Doppler shift and background noise.