弱信号下北斗二代定位算法研究

Research on Beidou Second Generation Location Algorithms under Weak Signal

北斗卫星导航定位系统运营至今已在诸多领域发挥了重要作用,相比其它已经完全成熟的导航定位系统,有明显优势,同时也存在一些应用上的缺陷及不足,很多情况下,北斗信号还不尽如人意,因此,研究接收机高灵敏度与辅助定位技术成为关键。本文主要研究了弱信号下北斗二代定位的频率采集算法。以PMF-FFT码的算法为基础,分别在时域和频域估计多普勒频偏,并将多普勒频偏估计与码和频率采集相结合。

Beidou Satellite Navigation and Positioning System has played an important role in many fields so far.Compared with other fully mature navigation and positioning systems,Beidou Satellite Navigation and Positioning System has obvious advantages.At the same time,it also has some shortcomings and shortcomings in application.In many cases,Beidou signal is not satisfactory.Therefore,the key is to study the high sensitivity of receivers and assistant positioning technology.This paper mainly studies the frequency acquisition algorithm of Beidou second generation positioning under weak signal.Based on the algorithm of PMF-FFT code,Doppler frequency offset is estimated in time domain and frequency domain respectively,and Doppler frequency offset estimation is combined with code and frequency acquisition.