GNSS软件接收机信号仿真及捕获

发布时间：2018-06-02 00:21

本文选题：卫星导航系统 + 北斗卫星信号　；参考：《昆明理工大学》2013年硕士论文

【摘要】：开发现代的GNSS接收机中,应用软件定义的无线电技术代表了演变过程中的一个阶段。与用专用的集成电路的传统接收机相反,软件无线电通过可编程微处理器或数字信号处理器实现所有的数字信号处理。它将硬件中的模拟信号环境条件与软件中的数字信号处理分离独立开来,导致了很明显的优点,如：多模化、多系统、多传感器、测试和质量控制及软件开发的持续进行。这种信号处理方法在GNSS情况下显得特别重要。软件接收机是一种变得越来越重要的设计理念。实际的软件接收机,处理有限的带宽的信号,选择连续频带的子带,用现有的技术以软件接收机加以实现。 GNSS软件接收机的关键技术包括对卫星信号的捕获和跟踪技术,为了能够跟踪卫星信号并进行信息解码,就必须先用捕获程序来监测信号的存在。一旦检测到,就必须取得一些必要参数,传送给跟踪程序,再由跟踪程序得到如导航电文这样的有用信息。由此可见信号捕获在研究GNSS软件接收机过程中至关重要。本文首先介绍了三种常用的卫星导航系统的概况和主要特点,并重点分析了各卫星导航系统的信号结构和调制方式。从基础的二进制随机序列入手,介绍了M码和GOLD码的生成机理,引出了GPS卫星的C/A码分配规定。这项工作完成之后又介绍了卫星信号的调制原理,从简单的BPSK,到后来的BOC从原理入手,介绍了各自的特点,及应用范围,并在Simulink环境下做了仿真。其次介绍信号处理方法的基础上说明了对卫星高频信号的主要处理手段,包括采样和量化等。最后,基于上述信号处理完成,本文开始讨论导航卫星软件接收机三种比较常用的捕获方法：串行捕获、并行频域捕获和并行码相位捕获。通过M语言实现了上述三种方法,并以实际采集的GPS中频信号为例,对较优的并行码相位方法进行验证。
[Abstract]:In the development of modern GNSS receivers, the application of software defined radio technology represents a stage in the evolution process. In contrast to traditional receivers using ASIC, software radio performs all digital signal processing through programmable microprocessors or digital signal processors. It separates analog signal environment conditions in hardware from digital signal processing in software, resulting in obvious advantages such as multimode, multi-system, multi-sensor, testing and quality control, and continuous software development. This signal processing method is particularly important in the case of GNSS. Software receiver is an increasingly important design concept. The actual software receiver processes the limited bandwidth signal, selects the subband of the continuous band, and realizes it with the software receiver with the existing technology. The key technology of GNSS software receiver includes acquisition and tracking of satellite signal. In order to track and decode the satellite signal, it is necessary to monitor the existence of the signal by the acquisition program. Once detected, the necessary parameters must be obtained and transmitted to the tracker, which in turn obtains useful information such as navigation messages. This shows that signal acquisition is very important in the research of GNSS software receiver. This paper first introduces the general situation and main characteristics of three kinds of commonly used satellite navigation systems, and emphatically analyzes the signal structure and modulation mode of each satellite navigation system. Starting with the basic binary random sequence, the generation mechanism of M code and GOLD code is introduced, and the C / A code allocation rule of GPS satellite is introduced. After this work is finished, the modulation principle of satellite signal is introduced. From the simple BPSK to the later BOC, the characteristics and application range are introduced, and the simulation is done under the Simulink environment. Secondly, based on the introduction of signal processing methods, the main processing methods of satellite high frequency signals, including sampling and quantization, are explained. Finally, based on the above signal processing, this paper begins to discuss three common acquisition methods of navigation satellite software receiver: serial acquisition, parallel frequency domain acquisition and parallel code phase acquisition. The above three methods are realized by M language, and the better parallel code phase method is verified by taking the actual GPS intermediate frequency signal as an example.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P228.4

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