北斗B1信号捕获跟踪算法的软件仿真研究

Software Simulation Study of Acquisition and Tracking Algorithms on Big Dipper B1 Signal

摘要:

针对北斗B1频率的I支路信号,设计并实现了北斗软件接收机的基带处理部分;阐述了北斗B1频点信号的扩频体制和产生过程,并行码相位搜索捕获策略以及鉴相辅助跟踪环路,并设计了二阶数字环路滤波器;同时采用Matlab软件,仿真北斗中频数字信号,编码实现捕获跟踪算法,并分别通过对仿真信号和真实卫星信号的捕获跟踪,验证捕获跟踪算法的可行性,并提出锁频环辅助锁相环算法的改进思路;为进一步开展北斗软件接收机相关技术研究打下了基础。

Abstract:

In our software receiver design,the focus is on the baseband signal processing of Big Dipper’s B1 band Branch I signals. In the paper,we introduce the theory of the Spread-spectrum System and process of Big Dipper’s B1 signal,the algorithms for parallel code phase search acquisition,and phase discrimination aided tracking loop. We also present a second-order digital loop filter of which parameters are ,(Hz). Meanwhile,Adopting Matlab software to simulate Big Dipper signals and realized the acquisition and tracking algorithm. And verifying the algorithm by processing simulation signal and the real satellite signal separately.We also put forward the improved method of frequency-locked loop(FLL)aided phase-locked loop(DLL).Then provide a basis for further study of Big Dipper software receiver.