基于辅助信号和相位预估的相干扩频快捕系统

提出一种基于辅助信号进行相位估计的捕获策略,算法引入一辅助信号和相位预估器,接收信号首先与辅助信号相关,相位预估器利用相关结果,获得输入信号相位估计值,再以该估计值为中心,向两侧延拓,形成一高概率包含未知相位的小区间,然后在该小区间使用滑动相关法搜索位置相位,从而捕获接收信号.一次过程实现捕获后转入跟踪状态,没有成功捕获就调整辅助信号相位重复这一过程.这样,接收方案形成一贝努利概型.与常规滑动相关法相比,本方案能够有效改善长PN码的捕获性能.

A coherent rapid acquisition system using an auxiliary sequence and pre-loop estimator

This paper proposed rapid coherent acquisition scheme, in which an auxiliary sequence and pre-loop estimating were introduced.After received sequences being correlated with the auxiliary ones,the phase estimation of input sequences were obtained in the phase estimator.Taking this estimation as a center,the phase estimation was expanded along its sides to form a small interval of high probability,in which some un-known phases were included.The phases of the positions were searched by sliding correction method in this interval to acquire the sequences.This acquisition process could be regarded as Bernoulli model.In comparison with the conventional coherent serial search receiver,the acquisition performance of long PN can be improved using this scheme.