多元导航信号模拟器的设计与实现

Design and Implementation of Satellite signal simulator

摘要:

为给多模复合导航系统闭环半实物仿真实验提供高稳定度、高精度、可复现的卫星信号，并检验卫星导航算法的正确性，设计了一款卫星信号模拟器；本文设计的卫星信号模拟器以DSP+FPGA作为核心芯片，并配有上变频射频通道，能够模拟BD2 B1、BD2 B3、GPS L1、GLONASS L1四个频点卫星信号，并且能够生成各个频点的压制式及欺骗式的干扰信号，每频点不少于12个卫星通道，模拟GPS/BD2/GLONASS多体制多颗卫星在轨的位置分布和运动；根据载体的姿态、接收机天线布置、天线方向图等因素，模拟卫星导航信号的到达入射角、强弱和延时；并具有人机交互界面，通过设置卫星的卫星号、伪距、多普勒等参数对系统进行控制；通过软件和硬件升级，可以增加BD3 B1C、B2A等频点导航系统的扩展；经测试分析对四个卫星信号功率的控制精度优于1dB，控制范围大于60dB，且卫星信号与干扰信号具备同步机制。

Abstract:

To provide high stability, high precision, and reproducible satellite signals for the closed-loop hardware-in-the-loop simulation experiments of the multi-mode integrated navigation system, and to verify the correctness of satellite navigation algorithms, a satellite signal simulator was designed. The satellite signal simulator designed in this paper utilizes DSP+FPGA as the core chip and is equipped with an up-conversion RF channel. It can simulate satellite signals at four frequency points: BD2 B1, BD2 B3, GPS L1, and GLONASS L1. Additionally, it can generate jamming signals of both suppression and deception types at each frequency point. Each frequency point has no fewer than 12 satellite channels, simulating the on-orbit position distribution and motion of multiple satellites from multiple systems, including GPS/BD2/GLONASS. Based on factors such as the carrier"s attitude, receiver antenna layout, and antenna pattern, it simulates the arrival angle, strength, and delay of satellite navigation signals. It also features a human-computer interface, allowing system control by setting parameters such as satellite number, pseudo-range, and Doppler. Through software and hardware upgrades, it can be extended to include navigation systems at frequency points such as BD3 B1C and B2A. Testing and analysis have shown that the control accuracy for the power of the four satellite signals is better than 1dB, with a control range exceeding 60dB. Furthermore, the satellite signals and jamming signals have a synchronization mechanism.