摘要
随着GNSS的广泛应用,许多新技术和新领域对GNSS弱信号捕获提出了新要求,其关键技术之一就是弱信号捕获跟踪算法的实现。在相干积分和非相干积分的基础上,通过相位补偿和时延修正、奇偶分路等方法,可以在盲搜索中捕获到比正常信号低25dB的弱信号,实现了对粗捕到的弱信号进行载波频率精化,并分别利用仿真数据和实测数据验证了算法的正确性。此外,分析了信号相位翻转对信号捕获的影响,对GNSS弱信号应用领域具有重要的参考价值。
With wide applications of GNSS,new technologies and domains bring forward new demands to GNSS weak signal acquisition,where the realization of acquisition and tracking of weak signal is a key process.On the basis of coherent and incoherent integration,signal 25 dB lower than normal can be captured by means of phase compensation,time delay correction and odd-even branches,whose carrier frequency can also be refined subsequently.The validity of this algorithm is proved with simulated and observed data.Besides,this article analyzes the effects of phase reversion on signal acquisition.The methods and results may be useful in weak GNSS signal application.
出处
《全球定位系统》
2011年第5期12-16,21,共6页
Gnss World of China
关键词
GPS
弱信号
捕获
相干积分
奇偶分路
GPS
weak signal
acquisition
coherent integration
odd-even branches
