GPS射频前端设计及GPS信号捕获方法研究
摘要
GPS射频前端和GPS信号捕获方法在GPS接收机中占有重要的地位,前者的性能优劣直接影响着GPS接收机的接收灵敏度以及后继信号处理部分的性能。后者的性能决定着接收机截获有用信号的能力。因此,本文的主要目的在于对GPS射频前端和GPS信号捕获方法的研究。其中对GPS信号捕获方法的研究主要分为两个方面,即高动态环境下的GPS信号捕获和低信噪比环境下的GPS信号捕获。
首先,本文在研究GPS基本原理和射频电路设计基本原理的基础上,探讨了GPS射频前端的设计问题,应用Zarlink公司的GP2010芯片设计出了符合要求的GPS射频前端。
其次,本文以传统捕获方法为依托,重点对能满足高动态GPS信号快速捕获要求的基于码相位的FFT捕获方法和基于载波的FFT捕获方法进行了研究。研究表明:前一种方法能够在搜索一个频率单元的同时完成对所有码相位点的搜索,其速度远优于传统的滑动相关捕获方法。后一种方法能够在搜索一个码相位单元的基础上完成对整个多普勒频率的搜索,并且其频率搜索范围大,硬件易于实现。
最后,本文对低信噪比环境下的GPS信号捕获技术进行了研究。通过对相干积分和非相干积分算法的研究和实验性能仿真,表征出了这两种算法分别存在的问题:比特翻转和平方损耗。最后,重点介绍了一种差分相干方法,实验仿真说明该方法能够消除上面的缺点,性能远优于相干积分和非相干积分方法,非常适合低信噪比环境下的GPS信号捕获。
与此同时,通过对捕获门限的研究,特别对自适应门限中的噪声功率估计方法的研究,提出了三种能有效估计噪声功率的方法。为了提高捕获的检测概率,同时对唐搜索检测器和N中取M搜索检测器的性能进行评估,本文推导了检测器的总虚警概率,总检测概率和平均驻留时间的计算公式。通过数值验证讨论了检测器各参数作用及对捕获性能的影响。其研究结果对实际检测器参数确定具有一定的指导作用。
GPS RF front end end and GPS signal acquisition method are very important in GPS receiver.The performance of the former directly affect on GPS receiver sensitivity and signal processing.The performance of the later determine the receiver capability of useful signal capture. So this paper is mainly purpose to study GPS RF Front and GPS signal acquisition method.
Firstly, based on studying the basic knowledge of GPS and RF circuit design, this paper discusses the method of GPS RF front design and how to apply Zarlink GP2010 to design it.
Secondly, this paper study FFT acquisition method respectively based on carrier wave and code phase.The results show that FFT acquisition method based on code phase can search all code phase cells at searching one doppler cell and FFT acquisition method based on carrier wave can search all doppler cells at searching one code phase cell, having large frequency range and hardware is realized easily.
Then the GPS signal acquisition technique under low SNR environment is studied. By reaserching and simulating coherent integration and non-coherent integration, this paper shows that respective disadvantage of them.Finally, differentially coherent integration method is introduced emphatically. The simulation results prove that this method is very suitable for GPS signal acquisition under low SNR environment because it can eliminate the shortcoming of above methods and its performance is far better than them.
At the same time, this paper put forward three method of noise power estimaton by acquisition thresholds study, especially noise power estimation study in adaptive threshold. And eventually put In order to increase the detection probability of acquisition, and evaluate the performance of the Tong detector and M of N detector, this paper deduces theoretical formulas for the overall probability of false alarms, the overall probability of detection, and the mean number of dwell times. The function of detector parameters and acquisition performance are demonstrated by numerical simulations.The results contribute to how to confirm detector parameters.
首先,本文在研究GPS基本原理和射频电路设计基本原理的基础上,探讨了GPS射频前端的设计问题,应用Zarlink公司的GP2010芯片设计出了符合要求的GPS射频前端。
其次,本文以传统捕获方法为依托,重点对能满足高动态GPS信号快速捕获要求的基于码相位的FFT捕获方法和基于载波的FFT捕获方法进行了研究。研究表明:前一种方法能够在搜索一个频率单元的同时完成对所有码相位点的搜索,其速度远优于传统的滑动相关捕获方法。后一种方法能够在搜索一个码相位单元的基础上完成对整个多普勒频率的搜索,并且其频率搜索范围大,硬件易于实现。
最后,本文对低信噪比环境下的GPS信号捕获技术进行了研究。通过对相干积分和非相干积分算法的研究和实验性能仿真,表征出了这两种算法分别存在的问题:比特翻转和平方损耗。最后,重点介绍了一种差分相干方法,实验仿真说明该方法能够消除上面的缺点,性能远优于相干积分和非相干积分方法,非常适合低信噪比环境下的GPS信号捕获。
与此同时,通过对捕获门限的研究,特别对自适应门限中的噪声功率估计方法的研究,提出了三种能有效估计噪声功率的方法。为了提高捕获的检测概率,同时对唐搜索检测器和N中取M搜索检测器的性能进行评估,本文推导了检测器的总虚警概率,总检测概率和平均驻留时间的计算公式。通过数值验证讨论了检测器各参数作用及对捕获性能的影响。其研究结果对实际检测器参数确定具有一定的指导作用。
GPS RF front end end and GPS signal acquisition method are very important in GPS receiver.The performance of the former directly affect on GPS receiver sensitivity and signal processing.The performance of the later determine the receiver capability of useful signal capture. So this paper is mainly purpose to study GPS RF Front and GPS signal acquisition method.
Firstly, based on studying the basic knowledge of GPS and RF circuit design, this paper discusses the method of GPS RF front design and how to apply Zarlink GP2010 to design it.
Secondly, this paper study FFT acquisition method respectively based on carrier wave and code phase.The results show that FFT acquisition method based on code phase can search all code phase cells at searching one doppler cell and FFT acquisition method based on carrier wave can search all doppler cells at searching one code phase cell, having large frequency range and hardware is realized easily.
Then the GPS signal acquisition technique under low SNR environment is studied. By reaserching and simulating coherent integration and non-coherent integration, this paper shows that respective disadvantage of them.Finally, differentially coherent integration method is introduced emphatically. The simulation results prove that this method is very suitable for GPS signal acquisition under low SNR environment because it can eliminate the shortcoming of above methods and its performance is far better than them.
At the same time, this paper put forward three method of noise power estimaton by acquisition thresholds study, especially noise power estimation study in adaptive threshold. And eventually put In order to increase the detection probability of acquisition, and evaluate the performance of the Tong detector and M of N detector, this paper deduces theoretical formulas for the overall probability of false alarms, the overall probability of detection, and the mean number of dwell times. The function of detector parameters and acquisition performance are demonstrated by numerical simulations.The results contribute to how to confirm detector parameters.
引文
【1】[美]Kaplan E D.GPS原理与应用[M].第二版.寇艳红,译.北京:电子工业出版社,2007.
【2】 熊志昂,李红瑞,赖顺香.GPS技术与工程应用[M].北京:国防工业出版社,2005.
【3】 张勤,李家权.GPS测量原理及应用[M].北京:科学出版社,2005.
【4】 Jame Bao-Yen Tsui.Fundamentals of Global Positioning System Receiver:A soft Approach[M].John Wiley & Sons,Inc.2000
【5】 李小民.高动态环境GPS应用中的几个关键问题研究[D].北京:北京航空航天大学,1999
【6】 蔡昌听,皮亦鸣.高灵敏度GPS技术的研究进展[J].2006,
【7】 C.Mehlen,D.Laurichese.Real time GEO orbit determination using TOPSTAR3000GPS receiver [J].Navigation,2001,48(3):169-180
【8】 陈家鸿.全球卫星定位系统(GPS)接收器RF module设计与制作[D].台湾:国立中央大学通讯工程研究所,2002.
【9】 Braasch Michael S,Van Dierendonck.A.J.GPS Receiver Architectures and Measurements[J].Proceedings of the IEEE,87(1):48-64
【10】 杨小丽.GPS天线的圆极化和小型化研究[D].上海:华东师范大学,2006.
【11】 宋立众.GPS接收天线系统的研究[D].哈尔滨:哈尔滨工业大学,2000.
【12】 黄继东.应用微处理器ARM设计高性能GPS接收机[D].北京:中国科学院.
【13】 李绪益.微波技术与微波电路[M].广州:华南理工大学出版社,2007.
【14】 李洋.扩频接收机的研究[D].长春:长春理工大学,2003.
【15】 蔡承融.在DS-CDMA通讯系统中PN码同步程序的机制与性能分析[D].台湾:国立中山大学,2002
【16】 王立冬,胡卫东,郁文贤.时延-多普勒频移对伪码捕获影响的性能分析[J].系统工程与电子技术,2001,(6):79-86.
【17】 吕艳梅,李小民,孙江生.高动态环境下的GPS信号接收及其算法研究[J].电光与控制2006,13(4):24-27
【18】 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版社,2006.
【19】 扩频同步技术研究与系统的FPGA实现[D].杭州:浙江大学,2006.
【20】 王飞雪.直接序列扩频信号的全数字式快速捕获[D].长沙:国防科技大学,1998,
【21】 胡永辉.GPS信号快速捕获的FPGA实现[D].陕西:中国科学院国家授时中心,2005.
【22】 Van Nee,D.J.R.Coenen,A.J.R,M.New Fast GPS Code-Acquisition Technique Using FFT.Electronics Letters,1991,27(2):158-160.
【23】 Sascha M.Spangenberg,et al.An FFT-based Approach Acquisition in Spread Spectrum Communication Systems[J].Wireless Personal Communications.2000,13:27-56
【24】 薛文芳,邵定容,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,2003,29(6):489-492.
【25】 李继忠,李巍.GPS信号快速捕获方案研究[J].航空电子技术,2006,37(2):1-5
【26】 J.B.Lozow.Analysis of Direct P(Y)-Code Acquisition[J].Navigation.1997,44(1):87-97
【27】 Grant,P.M.and Spangenberg,S.M.Doppler estimation for fast acquisitionin spread spectrum communication systems.Spread Spectrum Techniques and Applications,1998.Proceedings.1998IEEE5th International Symposium on,vol.1,1998:P.106-110
【28】 Frederic Bastide,Oliver Julien,Christophe Macabiau,et al.Study of Acquisition,Tracking and Data Demodulation Threshold[C].ION GPS 2002.2002
【29】 朱华,黄辉宁等.随机信号分析[M].北京:北京理工大学出版社,2004
【30】 崔哲,阎鸿森,惠卫华等.GPS信号信噪比对接收即捕获性能的影响[J].时间频率学报2004,27(2):120-128
【31】 John G.Proakis.数字通信[M].第四版.北京:电子工业出版社,2003
【32】 Barron,S.M of Nsearch Detector.Personal Correspondence,Texas Instruments Incorporated,Dallas,Texas,May 25,1995
【33】 唐卫涛等.一种新的微弱GPS信号捕获算法研究[J].遥测遥控,2007,28(3):25-30
【34】 D.K.Barton.modern radar system analysis[M].ION GPS 1999.
【35】 寇艳红,张其善.微弱信号捕获算法研究[J].遥测遥控,2005,26(4):61-65
【36】 Deuk Jae Cho,et all.An Assisted GPS Acquisition Method Using L2 Civil Signal in Weak Signal Environment[J].Journal of Global Positioning System,2004,3(1-2)25-31
【37】 L.Vittorini,B.Robinson.Frequency standards:Key enable to optimizing indoor GPS performance.ION GPS 2003
【38】 Henug Choi,et al.A Novel weak Signal Acquisition Scheme for Assisted GPS[C].ION GPS 2002
【39】 O-S.Shin and K.B.Lee.Differential Coherent combing for Double Dwell code Acquisition inDSCAMA System[J].IEEE Transations on Communications,2003,Vol51(7):1046-1050
【40】 David M.An Efficient Weak Signal Acquisition Algorithm for a Software GPS Receiver[J].
【41】 Glenn D.Mac Gougan.High Sensitivity GPS Performance Analysis in Degraded Signal Environments[D].Canada:the University of Calgary,2003
【42】 Ming-Yu Chang and Kai-Ten Feng.Adaptive GPS Acquisition Technique in Weak Siganl Environment[J].Vehicular Technology Conference,2006,VTC,2006-Spring.IEEE 63~(rd).Vol6:2612-2616
【2】 熊志昂,李红瑞,赖顺香.GPS技术与工程应用[M].北京:国防工业出版社,2005.
【3】 张勤,李家权.GPS测量原理及应用[M].北京:科学出版社,2005.
【4】 Jame Bao-Yen Tsui.Fundamentals of Global Positioning System Receiver:A soft Approach[M].John Wiley & Sons,Inc.2000
【5】 李小民.高动态环境GPS应用中的几个关键问题研究[D].北京:北京航空航天大学,1999
【6】 蔡昌听,皮亦鸣.高灵敏度GPS技术的研究进展[J].2006,
【7】 C.Mehlen,D.Laurichese.Real time GEO orbit determination using TOPSTAR3000GPS receiver [J].Navigation,2001,48(3):169-180
【8】 陈家鸿.全球卫星定位系统(GPS)接收器RF module设计与制作[D].台湾:国立中央大学通讯工程研究所,2002.
【9】 Braasch Michael S,Van Dierendonck.A.J.GPS Receiver Architectures and Measurements[J].Proceedings of the IEEE,87(1):48-64
【10】 杨小丽.GPS天线的圆极化和小型化研究[D].上海:华东师范大学,2006.
【11】 宋立众.GPS接收天线系统的研究[D].哈尔滨:哈尔滨工业大学,2000.
【12】 黄继东.应用微处理器ARM设计高性能GPS接收机[D].北京:中国科学院.
【13】 李绪益.微波技术与微波电路[M].广州:华南理工大学出版社,2007.
【14】 李洋.扩频接收机的研究[D].长春:长春理工大学,2003.
【15】 蔡承融.在DS-CDMA通讯系统中PN码同步程序的机制与性能分析[D].台湾:国立中山大学,2002
【16】 王立冬,胡卫东,郁文贤.时延-多普勒频移对伪码捕获影响的性能分析[J].系统工程与电子技术,2001,(6):79-86.
【17】 吕艳梅,李小民,孙江生.高动态环境下的GPS信号接收及其算法研究[J].电光与控制2006,13(4):24-27
【18】 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版社,2006.
【19】 扩频同步技术研究与系统的FPGA实现[D].杭州:浙江大学,2006.
【20】 王飞雪.直接序列扩频信号的全数字式快速捕获[D].长沙:国防科技大学,1998,
【21】 胡永辉.GPS信号快速捕获的FPGA实现[D].陕西:中国科学院国家授时中心,2005.
【22】 Van Nee,D.J.R.Coenen,A.J.R,M.New Fast GPS Code-Acquisition Technique Using FFT.Electronics Letters,1991,27(2):158-160.
【23】 Sascha M.Spangenberg,et al.An FFT-based Approach Acquisition in Spread Spectrum Communication Systems[J].Wireless Personal Communications.2000,13:27-56
【24】 薛文芳,邵定容,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,2003,29(6):489-492.
【25】 李继忠,李巍.GPS信号快速捕获方案研究[J].航空电子技术,2006,37(2):1-5
【26】 J.B.Lozow.Analysis of Direct P(Y)-Code Acquisition[J].Navigation.1997,44(1):87-97
【27】 Grant,P.M.and Spangenberg,S.M.Doppler estimation for fast acquisitionin spread spectrum communication systems.Spread Spectrum Techniques and Applications,1998.Proceedings.1998IEEE5th International Symposium on,vol.1,1998:P.106-110
【28】 Frederic Bastide,Oliver Julien,Christophe Macabiau,et al.Study of Acquisition,Tracking and Data Demodulation Threshold[C].ION GPS 2002.2002
【29】 朱华,黄辉宁等.随机信号分析[M].北京:北京理工大学出版社,2004
【30】 崔哲,阎鸿森,惠卫华等.GPS信号信噪比对接收即捕获性能的影响[J].时间频率学报2004,27(2):120-128
【31】 John G.Proakis.数字通信[M].第四版.北京:电子工业出版社,2003
【32】 Barron,S.M of Nsearch Detector.Personal Correspondence,Texas Instruments Incorporated,Dallas,Texas,May 25,1995
【33】 唐卫涛等.一种新的微弱GPS信号捕获算法研究[J].遥测遥控,2007,28(3):25-30
【34】 D.K.Barton.modern radar system analysis[M].ION GPS 1999.
【35】 寇艳红,张其善.微弱信号捕获算法研究[J].遥测遥控,2005,26(4):61-65
【36】 Deuk Jae Cho,et all.An Assisted GPS Acquisition Method Using L2 Civil Signal in Weak Signal Environment[J].Journal of Global Positioning System,2004,3(1-2)25-31
【37】 L.Vittorini,B.Robinson.Frequency standards:Key enable to optimizing indoor GPS performance.ION GPS 2003
【38】 Henug Choi,et al.A Novel weak Signal Acquisition Scheme for Assisted GPS[C].ION GPS 2002
【39】 O-S.Shin and K.B.Lee.Differential Coherent combing for Double Dwell code Acquisition inDSCAMA System[J].IEEE Transations on Communications,2003,Vol51(7):1046-1050
【40】 David M.An Efficient Weak Signal Acquisition Algorithm for a Software GPS Receiver[J].
【41】 Glenn D.Mac Gougan.High Sensitivity GPS Performance Analysis in Degraded Signal Environments[D].Canada:the University of Calgary,2003
【42】 Ming-Yu Chang and Kai-Ten Feng.Adaptive GPS Acquisition Technique in Weak Siganl Environment[J].Vehicular Technology Conference,2006,VTC,2006-Spring.IEEE 63~(rd).Vol6:2612-2616