直扩系统伪码序列串并组合捕获方案

Serial-parallel combined acquisition of PN sequences for DS/SS system

针对低信噪比条件下长伪码序列的快速捕获问题,提出了一种新的捕获方案,即串并组合捕获.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 new serialparallel combined acquisition scheme had been proposed for the acquisition of PN sequences for DS/SS system,and the acquisition problem of long sequences buried deeply in noise in particular. A block diagram had been given for the implementation of hardware, a mathematical model had been established for the acquisition system,and a mathematic expression had been derived using the state transfer function for the average acquisition time. The acquisition performance of the system had been analyzed in detail with phase error of PN sequences, Doppler shift and background noise taken into consideration.