北斗信号的捕获跟踪算法研究
发布时间：2018-08-13 13:41
【摘要】：北斗系统是我国自行研制的卫星导航定位系统,它将卫星导航与定位通信集成一体,能够全天候、全天时为各类用户提供高精度、高可靠定位、导航、授时服务。北斗MEO/IGSO卫星1B频点1D信号调制的NH码,使信号每毫秒发生翻转的几率大大增加,这给捕获、跟踪方案带来了一系列的问题。本文在深入研究北斗MEO/IGSO卫星1B频点1D信号组成及捕获跟踪原理的基础上,重点研究C/A码和载波的捕获与跟踪方案。论文的主要工作如下:1.论文研究了扩频信号的各种捕获算法,分析了码并行捕获算法和基于部分匹配滤波器的PMF-FFT捕获算法两种常规方法,并论证了其对北斗信号的局限性。2.设计了两种基于并行码相位法的C/A码捕获算法,针对载波频率捕获精度较低的缺点,设计了“并行码相位法粗捕”和“频率串行细捕”相结合的方案,在小幅增加捕获时间和计算量的情况下,将载波频率捕获误差缩小。在MATLAB环境下的仿真结果表明,该方法不受NH码调制影响,捕获性能良好;还设计了一种基于部分匹配滤波器(PMF)与快速傅里叶变换(FFT)相结合的改进的C/A码快速捕获算法,仿真结果表明,与已有的PMF-FFT算法的仿真结果进行对比,所设计方法捕获性能提高2dB。3.论文设计了北斗信号的跟踪环路,该跟踪环路采用的鉴相器和鉴频器均可克服NH码调制带来的问题。载波跟踪环采用二阶锁频环与三阶锁相环的组合环路,并对环路参数进行了详细的设计,仿真结果表明所设计环路具有良好的跟踪性能。
[Abstract]:Beidou system is a satellite navigation and positioning system developed by our country. It integrates satellite navigation and positioning and communication, and can provide high precision, high reliability positioning, navigation and time service to all kinds of users all the time. The NH code modulated by 1B frequency 1D signal of Beidou MEO/IGSO satellite greatly increases the probability of signal flipping per millisecond, which brings a series of problems to the scheme of acquisition and tracking. On the basis of deeply studying the 1D signal composition of Beidou MEO/IGSO 1B frequency point and the principle of acquisition and tracking, this paper focuses on the acquisition and tracking scheme of C / A code and carrier. The main work of the thesis is as follows: 1: 1. In this paper, various acquisition algorithms for spread spectrum signals are studied, two conventional methods, code parallel acquisition algorithm and PMF-FFT acquisition algorithm based on partial matched filter, are analyzed, and its limitation to Beidou signal is demonstrated. Two C / A code acquisition algorithms based on parallel code phase method are designed. Aiming at the low accuracy of carrier frequency acquisition, a scheme of "parallel code phase coarse capture" and "frequency serial fine capture" is designed. The carrier frequency acquisition error is reduced when the acquisition time and computation are increased. The simulation results under MATLAB environment show that the method is not affected by NH code modulation and has good capture performance. An improved C / A code fast acquisition algorithm based on the combination of partial matched filter (PMF) and Fast Fourier transform (FFT) is also designed. The simulation results show that compared with the simulation results of the existing PMF-FFT algorithm, the acquisition performance of the proposed method is improved by 2dB.3. The tracking loop of Beidou signal is designed in this paper. The phase discriminator and frequency discriminator used in the tracking loop can overcome the problems caused by NH code modulation. The carrier tracking loop adopts the combination of second-order frequency locking loop and third-order phase-locked loop, and the loop parameters are designed in detail. The simulation results show that the designed loop has good tracking performance.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN967.1
本文编号：2181161
[Abstract]:Beidou system is a satellite navigation and positioning system developed by our country. It integrates satellite navigation and positioning and communication, and can provide high precision, high reliability positioning, navigation and time service to all kinds of users all the time. The NH code modulated by 1B frequency 1D signal of Beidou MEO/IGSO satellite greatly increases the probability of signal flipping per millisecond, which brings a series of problems to the scheme of acquisition and tracking. On the basis of deeply studying the 1D signal composition of Beidou MEO/IGSO 1B frequency point and the principle of acquisition and tracking, this paper focuses on the acquisition and tracking scheme of C / A code and carrier. The main work of the thesis is as follows: 1: 1. In this paper, various acquisition algorithms for spread spectrum signals are studied, two conventional methods, code parallel acquisition algorithm and PMF-FFT acquisition algorithm based on partial matched filter, are analyzed, and its limitation to Beidou signal is demonstrated. Two C / A code acquisition algorithms based on parallel code phase method are designed. Aiming at the low accuracy of carrier frequency acquisition, a scheme of "parallel code phase coarse capture" and "frequency serial fine capture" is designed. The carrier frequency acquisition error is reduced when the acquisition time and computation are increased. The simulation results under MATLAB environment show that the method is not affected by NH code modulation and has good capture performance. An improved C / A code fast acquisition algorithm based on the combination of partial matched filter (PMF) and Fast Fourier transform (FFT) is also designed. The simulation results show that compared with the simulation results of the existing PMF-FFT algorithm, the acquisition performance of the proposed method is improved by 2dB.3. The tracking loop of Beidou signal is designed in this paper. The phase discriminator and frequency discriminator used in the tracking loop can overcome the problems caused by NH code modulation. The carrier tracking loop adopts the combination of second-order frequency locking loop and third-order phase-locked loop, and the loop parameters are designed in detail. The simulation results show that the designed loop has good tracking performance.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN967.1
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1 倪光华;高动态环境下GPS C/A码信号的捕获与跟踪算法研究[D];西安电子科技大学;2008年
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