北斗MEO/IGSO卫星B1频点弱信号捕获方法  

B1 Frequency Point Weak Signal Acquisition Method for Beidou MEO/IGSO Satellite

作　　者：翟红英 齐建中 宋鹏 ZHAI Hongying;QI Jianzhong;SONG Peng(College of Electronic Information Engineering,North China University of Technology,Beijing 100144,China)

机构地区：[1]北方工业大学电子信息工程学院,北京100144

出　　处：《无线电工程》2018年第9期767-771,共5页Radio Engineering

摘　　要：采用微弱信号进行定位是当今研究的一个热点,这一技术的实现基于对弱信号的成功捕获。加长相干积分时间和非相干累加次数是实现微弱信号捕获的基本原理。针对北斗MEO/IGSO卫星因存在NH码二次调制而导致使用GPS捕获方法捕获灵敏度降低的问题,提出了串行剥离NH码加半比特积分方法。基于FPGA+DSP实现对北斗微弱信号进行捕获的方法,在保证捕获灵敏度的同时,控制捕获时间。测试结果表明,该算法可实现-142 d Bm信噪比条件下的北斗弱信号捕获,并可进一步提高卫星导航接收机灵敏度。The use of weak signals to position is a hot topic in today＇s research.The implementation of this technique is based on the successful capture of weak signals. Extending coherent integration time and increasing times of noncoherent accumulation are the basic principles of weak signal acquisition.In this paper,to solve the problem of reduced acquisition sensitivity of Beidou MEO/IGSO satellite due to the second modulation of NH code with GPS capture method,a serial stripping NH code plus half bit integration method is proposed.The acquisition of Beidou weak signal is realized based on FPGA ＋ DSP,and the acquisition time is controlled while the acquisition sensitivity is guaranteed.The test results show that the algorithm can realize the weak signal acquisition of Beidou under the condition of-142 d Bm SNR,and further improve the sensitivity of satellite navigation receiver.

关 键 词：北斗卫星导航系统 NH码调制 高灵敏度捕获 

分 类 号：TN911.7[电子电信—通信与信息系统]