摘要
针对北斗反射信号捕获难度大问题,提出一种适用于北斗GNSS-R接收机中反射信号的捕获算法。该算法利用直射信号中的导航数据剥离掉反射信号中的导航数据,并通过周期累加运算和FFT相关,改进了传统的反射信号捕获算法。算法可以降低长时间相干积分的运算量,提高算法捕获速率。对新算法进行了MATLAB仿真,并与传统的捕获算法(相干非相干算法、差分相干算法)做了比较,仿真结果表明,该算法在捕获性能上明显优于传统的相干非相干与差分相干捕获算法。
Aiming at the difficulty of Beidou reflected signal acquisition, this paper presents a capture algorithm for the reflected signal in the Beidou GNSS-R receiver. The algorithm uses the navigation data in the direct signal to peel off the navigation data in the reflected signal, and improves the traditional reflection signal acquisition algorithm through the cyclic accumulation operation and the FFT correlation. The algorithm can greatly reduce the computational complexity and shorten the capture time of long time integral of the reflected signal. In this paper, the MATLAB simulation of the new algorithm is carried out, and compared with the traditional coherent-uncoupling algorithm and the difference coherence algorithm. The simulation results show that the algorithm in this paper is superior to the traditional coherent noncoherent and differential coherent acquisition algorithm in capturing performance.
引文
[1]李黄,夏青,尹聪,等.我国GNSS-R遥感技术的研究现状与未来发展趋势[J].雷达学报,2013,2(4):389-399.
[2]CARDELLACH E,RUFFINI G,PINO D,et al.Mediterranean balloon experiment:ocean wind speed sensing from the stratosphere,using GPS reflections[J].Remote Sensing of Environment,2003,88(3):351-362.
[3]RODRIGUEZ-ALVAREZ N,CAMPS A,VALL-LLOSSERA M,et al.Land geophysical parameters retrieval using the interference pattern GNSS-R technique[J].IEEE Transactions on Geoscience&Remote Sensing,2010,49(1):71-84.
[4]周旋,叶小敏,于暘,等.基于GNSS-R的海面风速探测技术研究[J].电子与信息学报,2013,35(7):1575-1580.
[5]杨东凯,张其善.GNSS反射信号处理基础与实践[M].北京:电子工业出版社,2012.
[6]ELDERS-BOLL H,DETTMAR U.Efficient differentially coherent code/Doppler acquisition of weak GPS signals[C].IEEE Eighth International Symposium on Spread Spectrum Techniques and Applications.IEEE,2005:731-735.
[7]陈学,徐建华,叶甜春,等.基于FFT的微弱GPS信号捕获算法[J].微电子学与计算机,2010,27(3):98-101.
[8]中国卫星导航系统管理办公室.北斗卫星导航系统信号接口控制文件公开服务信号(2.1版)[S].2013.
[9]鲁郁.北斗/GPS双模软件接收机原理与实现技术[M].北京:电子工业出版社,2016.
[10]徐晓苏,范金洋.GPS软件接收机捕获算法[J].中国惯性技术学报,2009,17(2):165-169.
[11]LIN D M,TSUI J B Y,LIOU L L,et al.Sensitivity limit of a stand-alone GPS receiver and an acquisition method[C].Proceedings of International Technical Meeting of the Satellite Division of the Institute of Navigation,2002:1663-1667.
[12]SCHMID A,NEUBAUER A.Performance evaluation of differential correlation for single shot measurement positioning[C].Proc.ION GNSS 2004,Long Beach,CA,2004:1998-2009.