北斗基带信号的同步技术的研究
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摘要
卫星导航系统对一个国家的政治、经济、军事、文化等领域都发挥着非常重要的作用,对维护国家利益具有重大意义。建设具有全球导航定位能力的北斗卫星导航系统,对我国经济建设和国防建设产生着深远的影响。
北斗二代卫星系统是我国独立自主研制的新一代卫星导航系统。北斗卫星系统的发展越来越完善,作为其重要组成部分的北斗用户机的广泛应用已经迈入了新的台阶。基带信号处理模块是北斗用户机的核心模块之一,它实现的功能主要是完成模数转换、数字下变频、载波提取、载波锁定指示、扩频码同步、解扩以及信号判决等。可见,同步技术是北斗用户机的关键技术。
本文主要探讨了北斗用户机的同步技术。首先介绍了本课题研究的背景与意义,然后结合扩频通信的理论描述了北斗用户机的工作原理及北斗卫星信号的结构及其调制方法,详细阐述了伪码捕获技术,并提出两种改进的捕获算法,在捕获速度捕获效率以及硬件复杂度等方面基于Tong检测算法做了详细分析和仿真。最后讨论了载波跟踪算法。采用锁相环(PLL)和锁频环(FLL)相结合并加以载波辅助的载波跟踪算法,通过对跟踪后的载波多普勒频移与预设的门限相比较,实现在PLL与FLL之间自动切换。经过验证表明本文设计的跟踪环路能够稳定的实现对载波和码相位的跟踪。理论分析及仿真表明,本文所提方案具有可行性,达到了预期设计的目标。
On a country's political, economic, military, cultural and other fields of satellite navigation system plays a very important role, is of great significance to safeguard the interests of the state. The construction of Compass with global navigation and positioning capabilities, has a profound impact on China's economic construction and national defense construction.
The two generation Compass is a new generation of satellite navigation system which is developed by China stand on its'own. With the gradual improvement of the Compass, large-scale application of Compass user machine has entered a substantive stage. The baseband signal processing module is the core module of the Compass user machine, the function of it is mainly to complete the analog-to-digital conversion, digital down conversion,carrier extracted, carrier locked indication,PN code synchronization, signal de-spreading and judgments and so on.
This paper mainly discusses the baseband signal processing algorithm based on Compass.First of all.this paper introduces the researched background and significance of the topic.Then combining the concept of the spread spectrum communication, the article introduces the working principle of Compass user machine.meanwhile introducing its signal structure and modulation methods. And then putting forward two new acquisition schemes in the several common acquisition algorithm of PN code.which can improve SNR well.and weak the carrier Doppler frequency shift. In addition,based on the Tong detection algorithm for the acquisition performance of the system are analyzed in detail. Finally discussing the carrier tracking algorithm.Using phase-locked loop (FLL)and frequency locked loop(FLL)combined with some auxiliary carrier tracking algorithm, Based on the carrier Doppler frequency shift track after comparing with a preset threshold, to realize the automatic switching between PLL and FLL. After verification it shows that the pseudo-code frequency fluctuation of carrier Doppler frequency shift is to be greatly offset.
The theory analysis and simulation indicates that the proposed method is feasible, and it can achieve the expected design goals.
北斗二代卫星系统是我国独立自主研制的新一代卫星导航系统。北斗卫星系统的发展越来越完善,作为其重要组成部分的北斗用户机的广泛应用已经迈入了新的台阶。基带信号处理模块是北斗用户机的核心模块之一,它实现的功能主要是完成模数转换、数字下变频、载波提取、载波锁定指示、扩频码同步、解扩以及信号判决等。可见,同步技术是北斗用户机的关键技术。
本文主要探讨了北斗用户机的同步技术。首先介绍了本课题研究的背景与意义,然后结合扩频通信的理论描述了北斗用户机的工作原理及北斗卫星信号的结构及其调制方法,详细阐述了伪码捕获技术,并提出两种改进的捕获算法,在捕获速度捕获效率以及硬件复杂度等方面基于Tong检测算法做了详细分析和仿真。最后讨论了载波跟踪算法。采用锁相环(PLL)和锁频环(FLL)相结合并加以载波辅助的载波跟踪算法,通过对跟踪后的载波多普勒频移与预设的门限相比较,实现在PLL与FLL之间自动切换。经过验证表明本文设计的跟踪环路能够稳定的实现对载波和码相位的跟踪。理论分析及仿真表明,本文所提方案具有可行性,达到了预期设计的目标。
On a country's political, economic, military, cultural and other fields of satellite navigation system plays a very important role, is of great significance to safeguard the interests of the state. The construction of Compass with global navigation and positioning capabilities, has a profound impact on China's economic construction and national defense construction.
The two generation Compass is a new generation of satellite navigation system which is developed by China stand on its'own. With the gradual improvement of the Compass, large-scale application of Compass user machine has entered a substantive stage. The baseband signal processing module is the core module of the Compass user machine, the function of it is mainly to complete the analog-to-digital conversion, digital down conversion,carrier extracted, carrier locked indication,PN code synchronization, signal de-spreading and judgments and so on.
This paper mainly discusses the baseband signal processing algorithm based on Compass.First of all.this paper introduces the researched background and significance of the topic.Then combining the concept of the spread spectrum communication, the article introduces the working principle of Compass user machine.meanwhile introducing its signal structure and modulation methods. And then putting forward two new acquisition schemes in the several common acquisition algorithm of PN code.which can improve SNR well.and weak the carrier Doppler frequency shift. In addition,based on the Tong detection algorithm for the acquisition performance of the system are analyzed in detail. Finally discussing the carrier tracking algorithm.Using phase-locked loop (FLL)and frequency locked loop(FLL)combined with some auxiliary carrier tracking algorithm, Based on the carrier Doppler frequency shift track after comparing with a preset threshold, to realize the automatic switching between PLL and FLL. After verification it shows that the pseudo-code frequency fluctuation of carrier Doppler frequency shift is to be greatly offset.
The theory analysis and simulation indicates that the proposed method is feasible, and it can achieve the expected design goals.
引文
[1]贾德伟.北斗一代接收机基带信号处理的设计与实现[D].[硕士学位论文].西安：西安电子科技大学,2011
[2]任江涛.北斗接收机基带信号的捕获算法研究[D].[硕士学位论文].安徽：合肥工业大学,2010
[3]许诺.陈培,王云等.匹配滤波器组与FFT结合的伪码快速捕获方案研究[J].微电子学与计算机,2009.26(2)：84-88
[4]黄隽讳,李荣冰,武成峰等.北斗B1/QPSK调制信号的高灵敏度捕获算法[J].航空计算技术,2012,5(42)：38-42
[5]谭述森,周兵,郭盛桃等.我国全球卫星导航信号设计研究[J].中国科学,2010,5(40)：514-519.
[6]耿海军.卫星导航定位系统大盘[J].科学中国,2007,(8)：34-36
[7]薛文芳,邵定蓉,李署坚.GPS接收机中伪随机码快速捕获技术的研究[J].北京航空航天大学学报,2003(6)
[8]祖秉法.“北斗二号”民用接收机关键技术研究[D].[硕士学位论文].哈尔滨：哈尔滨工程大学,2010
[9]Herbert J.Kramer.CNSS(Compass/Beidou Navigation Satellite System). http://directory.eoportal. Org/presentations/10001572/10001573.html November 10,2009
[10]周玮.基于DSP的GPS/BD2组合定位算法的研究与实现[D].[硕士学位论文].武汉：武汉理工大学,2008
[11]刘毓,邹星.GPS基带信号捕获算法及其仿真研究[J].小型微型计算机系统,2011,6(32)：1237-1239
[12]A Polydoros, C.L.Weber. A Unified Approach to Serial Search Spread-Spectrum Code Acquisition-part1:General Theory. IEEE Trans. On Commun,1984,COM-32(5):554-559
[13]Yu T. Su. Rapid Code Acquisition Algorithms Employing PN Matched Filters.IEEE Trans. On Commun,1988.36(6):724-733
[14]L.M.Leibowitz. Multiplexing Techniques for Digital Correlator Spped Improvement.IEEE Trans. On Commun,1985, COM-33(6):579-588
[15]R.T.Barghouthi et al.Rapid Sequence acquisition for DS/CDMA systems Employing Kasami Sequences. IEEE Trans. On Commun,1994,42(2/3/4):1967-2968
[16]S. Yoon et al. A DS-CDMA Code acquisition scheme robust to residual Code phase offset Variation. IEEE Trans. On Vehicular technology.2000,49(6):2405-2418
[17]谢钢.GPS原理与接收机设计[M].北京：电子工业出版社,2009：20-222,366,374-375
[18]仇梦跃,吴涛,马宏等.伪码测距中码跟踪环的设计与实现[J].装备指挥技术学院学报,2006.17(4)：83-86
[19]Yeon-Sil Yang. Design and Performance Analysis of a Noncoherent Code Tracking Loop with Variable Loop Bandwidth. The 14th IEEE 2003 International Symposium on Personal.In door and Mobile Radio Communication Proceedings.2003:1380-1384
[20]沈锋.徐定杰.薛冰.基于FLL/PLL相结合的载波跟踪在导航接收机中的应用[J].中国航海,2004(2)：51-54
[21]Pedro A.Roncagliolo,Cristian E.de Blasis,Carlos H.Muravchik. GPS Digital Tracking Loops Design for High Dynamic Launching Vehicles Spread Spectrum Techniques and Applications[C]. 2006 IEEE Ninth International Symposium on Aug,2006:41—45
[22]樊昌信,曹丽娜.通信原理[M].北京：国防工业出版社,2006：393-394
[23]贾世楼.信息理论基础[M]哈尔滨：哈尔滨工业大学出版社,1996：58-59
[24]卢晓春,陈清刚,胡永辉.卫星导航定位系统中伪随机码的研究[J].时间频率学报,2004
[25]田日才.扩频通信[M].北京：清华大学出版社,2007：33-45
[26]赵洪林,戚培钧Kasami序列随机多址扩频通信系统的容量分析[J].哈尔滨理工大学报,2003(5)：96-98
[27]戚云军,田红心,毕轶慧CDMA通信中多址序列相关性的研究及仿真[J].信息技术,2008(2)：74-76
[28]杨俊,武奇生.GPS基本原理及其Matlab仿真[M].西安：西安电子科技大学出社,2006：126-163
[29]北斗卫星导航系统空间信号接口控制文件.中国卫星导航系统管理办公室,2012
[30]何兴GNSS软件接收机的捕获跟踪算法研究[D].[硕士学位论文].武汉：武汉理工大学,2010
[31]刘晓莉,李云.一种基于FFT的高动态GPS信号快速捕获方法[J].系统仿真学报,2007,10(19)：2151-2155
[32]李飞.北斗接收机设计及定位算法的研究[D].[硕士学位论文].西安：西安电子科技大学,2010
[33]李思超,叶甜春,徐建.唐检测器的驻留时间及检测性能分析[J].电子测量技术,2009,34(3)：53-55
[34]陈熙源,张昆鹏.基于MATLAB的GPS软件接收机捕获与跟踪算法实现[J].中国惯性技术报,2007,4(15)：423-426
[35]Brown A.,May M.,Tanju B.,"Benefits of Software GPS Receivers for Enhanced Signal Processing,"GPS Solutions 4(1).pp.56-66,Summer 2000
[36]Feng Shen, Dingjie Xu, Bing Xue. An Approach to DS-SS Signal Acquisition Using Larger Step and Serial Acquisition Algorithm[C]. Proceedings of the2007IEEE International Conference on Mechatronics and Automation, August 5-8,2007.Harbin,China.
[37]陈希,张锐,帅涛.基于FFT的GPS快速并行捕获算法[J].宇航学报.报,2011,32(1)：162-166
[38]B.M. Ledvina, M.L. Psiaki, S.P. Powell, P.M. Kintner. Bit-Wise Parallel Algorithms for Efficient Software Correlation Applied to a GPS Software Receiver[C]. IEEE Transactions on Wireless Communications,3 (5). September 2004.
[39]W. H. Lin, W. L. Mao, H. W. Tsao, F. R. Chang, W. H. Huang. Acquisition of GPS Software Rec- -eiver Using Split-Radix FFT[C].2006 IEEE International Conference on Systems. Man. and Cybernetics, October 8-11.2006. Taipei. Taiwan
[40]鲁郁.GPS全球定位接收机原理与软件实现[M].北京：电子工业出版社,2009：58-67
[41]吴大正.信号与线性系统分析[M].北京：高等教育出版社.2006：134-135
[42]王浩为.GPS软件接收机基带信号处理算法研究及DSP实现[D].[硕士学位文].江苏：南京邮电大学,2009
[43]Kaplan E.Understanding GPS:Principles and Applications,Second Edition, Ar-tech House.Inc. 2006
[44]Lin D., Tsui J B Y. A weak signal tracking technique for a standalone software GPS receiver [A].ION GPS 2002 [C].1663-1667
[45]Betz, J.W., K.R.Kolodziejski. Generalized Theory of GPS Code-Tracking Accuracy with an Early-Late Discriminator.2000
[46]李金海,巴晓辉,SHERAZ Anjum等.基于自适应锁相环的高动态GPS信号载波跟踪算法[J].电子器件,2007,30(4)：1440-1443
[47]Floyd M.Gardner著,姚剑清译.锁相环技术[M].北京：人民邮电出版社,2007：5-12,54-58
[48]杨东凯,樊江滨,张波等译GNSS应用与方法[M].北京：电子工业出版社,2011：23-26
[49]Rinder P. Bertelsen N, Design of A Single Frequency Gps Software Receiver. [Master Thesis]. Aalborg University,Denmark,2004
[50]邹青.自适应调零GPS软件接收机研究及仿真实现[D].[硕士学位论文].四川：电子科技大学.2010
[51]Andreas Hansson, Per Ludvig Normark, Andreas Rosenlind, etc, Global Positioning System in a Digital Signal Processor for the TMS320 DSP Platform.
[52]Jovancevic A.,Brown A..Ganguly S.,Goda J.,Kirchner M.,Zigic S.,"Real-Time Dual Frequency Software Receiver,"ION GPS/GNSS,Portland,OR,2003
[2]任江涛.北斗接收机基带信号的捕获算法研究[D].[硕士学位论文].安徽：合肥工业大学,2010
[3]许诺.陈培,王云等.匹配滤波器组与FFT结合的伪码快速捕获方案研究[J].微电子学与计算机,2009.26(2)：84-88
[4]黄隽讳,李荣冰,武成峰等.北斗B1/QPSK调制信号的高灵敏度捕获算法[J].航空计算技术,2012,5(42)：38-42
[5]谭述森,周兵,郭盛桃等.我国全球卫星导航信号设计研究[J].中国科学,2010,5(40)：514-519.
[6]耿海军.卫星导航定位系统大盘[J].科学中国,2007,(8)：34-36
[7]薛文芳,邵定蓉,李署坚.GPS接收机中伪随机码快速捕获技术的研究[J].北京航空航天大学学报,2003(6)
[8]祖秉法.“北斗二号”民用接收机关键技术研究[D].[硕士学位论文].哈尔滨：哈尔滨工程大学,2010
[9]Herbert J.Kramer.CNSS(Compass/Beidou Navigation Satellite System). http://directory.eoportal. Org/presentations/10001572/10001573.html November 10,2009
[10]周玮.基于DSP的GPS/BD2组合定位算法的研究与实现[D].[硕士学位论文].武汉：武汉理工大学,2008
[11]刘毓,邹星.GPS基带信号捕获算法及其仿真研究[J].小型微型计算机系统,2011,6(32)：1237-1239
[12]A Polydoros, C.L.Weber. A Unified Approach to Serial Search Spread-Spectrum Code Acquisition-part1:General Theory. IEEE Trans. On Commun,1984,COM-32(5):554-559
[13]Yu T. Su. Rapid Code Acquisition Algorithms Employing PN Matched Filters.IEEE Trans. On Commun,1988.36(6):724-733
[14]L.M.Leibowitz. Multiplexing Techniques for Digital Correlator Spped Improvement.IEEE Trans. On Commun,1985, COM-33(6):579-588
[15]R.T.Barghouthi et al.Rapid Sequence acquisition for DS/CDMA systems Employing Kasami Sequences. IEEE Trans. On Commun,1994,42(2/3/4):1967-2968
[16]S. Yoon et al. A DS-CDMA Code acquisition scheme robust to residual Code phase offset Variation. IEEE Trans. On Vehicular technology.2000,49(6):2405-2418
[17]谢钢.GPS原理与接收机设计[M].北京：电子工业出版社,2009：20-222,366,374-375
[18]仇梦跃,吴涛,马宏等.伪码测距中码跟踪环的设计与实现[J].装备指挥技术学院学报,2006.17(4)：83-86
[19]Yeon-Sil Yang. Design and Performance Analysis of a Noncoherent Code Tracking Loop with Variable Loop Bandwidth. The 14th IEEE 2003 International Symposium on Personal.In door and Mobile Radio Communication Proceedings.2003:1380-1384
[20]沈锋.徐定杰.薛冰.基于FLL/PLL相结合的载波跟踪在导航接收机中的应用[J].中国航海,2004(2)：51-54
[21]Pedro A.Roncagliolo,Cristian E.de Blasis,Carlos H.Muravchik. GPS Digital Tracking Loops Design for High Dynamic Launching Vehicles Spread Spectrum Techniques and Applications[C]. 2006 IEEE Ninth International Symposium on Aug,2006:41—45
[22]樊昌信,曹丽娜.通信原理[M].北京：国防工业出版社,2006：393-394
[23]贾世楼.信息理论基础[M]哈尔滨：哈尔滨工业大学出版社,1996：58-59
[24]卢晓春,陈清刚,胡永辉.卫星导航定位系统中伪随机码的研究[J].时间频率学报,2004
[25]田日才.扩频通信[M].北京：清华大学出版社,2007：33-45
[26]赵洪林,戚培钧Kasami序列随机多址扩频通信系统的容量分析[J].哈尔滨理工大学报,2003(5)：96-98
[27]戚云军,田红心,毕轶慧CDMA通信中多址序列相关性的研究及仿真[J].信息技术,2008(2)：74-76
[28]杨俊,武奇生.GPS基本原理及其Matlab仿真[M].西安：西安电子科技大学出社,2006：126-163
[29]北斗卫星导航系统空间信号接口控制文件.中国卫星导航系统管理办公室,2012
[30]何兴GNSS软件接收机的捕获跟踪算法研究[D].[硕士学位论文].武汉：武汉理工大学,2010
[31]刘晓莉,李云.一种基于FFT的高动态GPS信号快速捕获方法[J].系统仿真学报,2007,10(19)：2151-2155
[32]李飞.北斗接收机设计及定位算法的研究[D].[硕士学位论文].西安：西安电子科技大学,2010
[33]李思超,叶甜春,徐建.唐检测器的驻留时间及检测性能分析[J].电子测量技术,2009,34(3)：53-55
[34]陈熙源,张昆鹏.基于MATLAB的GPS软件接收机捕获与跟踪算法实现[J].中国惯性技术报,2007,4(15)：423-426
[35]Brown A.,May M.,Tanju B.,"Benefits of Software GPS Receivers for Enhanced Signal Processing,"GPS Solutions 4(1).pp.56-66,Summer 2000
[36]Feng Shen, Dingjie Xu, Bing Xue. An Approach to DS-SS Signal Acquisition Using Larger Step and Serial Acquisition Algorithm[C]. Proceedings of the2007IEEE International Conference on Mechatronics and Automation, August 5-8,2007.Harbin,China.
[37]陈希,张锐,帅涛.基于FFT的GPS快速并行捕获算法[J].宇航学报.报,2011,32(1)：162-166
[38]B.M. Ledvina, M.L. Psiaki, S.P. Powell, P.M. Kintner. Bit-Wise Parallel Algorithms for Efficient Software Correlation Applied to a GPS Software Receiver[C]. IEEE Transactions on Wireless Communications,3 (5). September 2004.
[39]W. H. Lin, W. L. Mao, H. W. Tsao, F. R. Chang, W. H. Huang. Acquisition of GPS Software Rec- -eiver Using Split-Radix FFT[C].2006 IEEE International Conference on Systems. Man. and Cybernetics, October 8-11.2006. Taipei. Taiwan
[40]鲁郁.GPS全球定位接收机原理与软件实现[M].北京：电子工业出版社,2009：58-67
[41]吴大正.信号与线性系统分析[M].北京：高等教育出版社.2006：134-135
[42]王浩为.GPS软件接收机基带信号处理算法研究及DSP实现[D].[硕士学位文].江苏：南京邮电大学,2009
[43]Kaplan E.Understanding GPS:Principles and Applications,Second Edition, Ar-tech House.Inc. 2006
[44]Lin D., Tsui J B Y. A weak signal tracking technique for a standalone software GPS receiver [A].ION GPS 2002 [C].1663-1667
[45]Betz, J.W., K.R.Kolodziejski. Generalized Theory of GPS Code-Tracking Accuracy with an Early-Late Discriminator.2000
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