基于SOC的精密授时卫星导航接收机设计与实现

发布时间：2018-01-10 05:11

本文关键词：基于SOC的精密授时卫星导航接收机设计与实现　出处：《北方工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：当代卫星导航系统中,卫星时钟均采用高精度的原子钟,该时钟能够长时间稳定的运行。但由于价格昂贵,所以使用范围非常小。对于卫星导航接收机来说,往往采用相对廉价的晶振作为基准时钟,为了能够得到与原子钟一样精准的时间,所以通过卫星导航接收机进行授时的意义重大。本文介绍一种基于SOC架构的精密授时卫星导航接收机的设计与实现方法。该接收机可实现三系统融合定位,分别为GPS、GLONASS和BDS(北斗)系统,接收机通过接收卫星信号实现定位解算并完成高精度授时功能。接收机使用的主芯片是Xilinx公司的XC7Z020芯片,该芯片具有尺寸小、功耗低和处理速度快的优点,所以更有助于提高接收机的性能。本文详细介绍了接收机分别工作在通用模式和触发模式下的授时原理和方法。通用模式是通过正常定位产生秒脉冲的方式实现授时,这种模式是接收机主要的工作模式。而触发模式是通过外部信号触发来实现定位授时工作,该模式主要用于测试时间同步。此外,还介绍了接收机授时功能关键技术的改善与优化。通过改善接收机跟踪环路失锁门限的判定方法来解决接收机在特殊环境下信号失锁的情况。通过改善信噪比算法,解决了信号较弱时信噪比计算不准确的现象。通过改善最小二乘法权值分配方法来解决卫星定位误差大的问题,并在此基础上提出一种通过伪距残差来实现对卫星权值的分配方法,该方法有效地解决了由于伪距误差过大所导致的定位误差问题。通过不断优化,接收机目前能够实现稳定、准确的授时工作,并且可以输出高精度的定位结果。
[Abstract]:In the modern satellite navigation system, the satellite clock uses the high-precision atomic clock, which can run steadily for a long time. However, because of the high price, the range of use is very small. A relatively cheap crystal oscillator is often used as the reference clock in order to be as accurate as an atomic clock. This paper introduces the design and implementation of a precise timing satellite navigation receiver based on SOC architecture. The receiver can realize the fusion positioning of three systems. It is GPS-GLONASS and BDS (Beidou) system, respectively. The receiver receives the satellite signal to realize the positioning solution and completes the high precision time service function. The main chip used in the receiver is the XC7Z020 chip of Xilinx Company, which has small size. The advantages of low power consumption and fast processing speed. Therefore, it is helpful to improve the performance of the receiver. In this paper, the principle and method of the receiver working in general mode and trigger mode are introduced in detail. The general mode is realized by normal positioning to generate second pulse. Timing. This mode is the main operating mode of the receiver, while the trigger mode is to achieve location-time service by external signal trigger, which is mainly used to test time synchronization. This paper also introduces the improvement and optimization of the key technology of receiver timing function. By improving the judgment method of receiver tracking loop lost lock threshold, the situation of receiver losing lock in special environment is solved. The signal to noise ratio is improved to calculate the signal to noise ratio. Law. The problem of large satellite positioning error can be solved by improving the least square method of weight allocation when the signal-to-noise ratio (SNR) calculation is not accurate when the signal is weak. On this basis, a method to allocate satellite weights by pseudo-range residuals is proposed. This method effectively solves the problem of positioning errors caused by excessive pseudo-range errors. At present, the receiver can work stably and accurately, and can output high precision positioning results.
【学位授予单位】：北方工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN965.5

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