摘要
捕获是GNSS接收机信号处理的关键部分,在低信噪比条件下普通的捕获算法不能实现理想的捕获效果。介绍了导航信号的特点及低信噪比条件下的捕获思想和方法,分析了相干积分、非相干积分及二者相结合的原理以及各自的优缺点。仿真结果表明,采用相干积分与非相干积分结合的方法提高整体信号强度,避免多普勒现象产生的影响,实现对弱信号的捕获。采用20ms的相干积分时间和5次非相干积分,在没有互相关干扰的情况下,可以接收信噪比为-35dB的弱信号。
Signal acquisition is the key phase of GNSS signal processing. In the low SNR environments, common algorithm could not attain ideal acquisition results. This paper introduces the characteristics Of navigation signals and the capture ideas and methods in low SNR conditions, coherent integration, non-coherent integration,and a combination of both principles and their advantages and disadvantages. Simulation result show that combined coherent integration with non-coherent integration that not only improve overall signals strength but also avoids the effect of acquisition due to Doppler phenomenon. the receiver can detect weak signal of 160dBW for 20ms coherent and ls non-coherent integration without the interference of cross correlation.
出处
《国外电子测量技术》
2012年第7期20-23,共4页
Foreign Electronic Measurement Technology
