作者：胡辉1, 杨国艺1, 朱绍文2
作者单位：1. 华东交通大学信息工程学院, 江西 南昌 330013;
2. 哈尔滨工业大学电气工程及自动化学院, 黑龙江 哈尔滨 150006
关键词：GPS信号源;多通道;数字信号处理器;现场可编程门阵列
摘要：
卫星导航信号源是卫星导航接收机研制过程中的重要测试设备。采用软件无线电技术，实现了一种基于DSP+FPGA的多通道GPS中频信号源。基于GPS中频信号数学模型，给出了系统整体设计方案。采用模块化设计，详细阐述了DSP与FPGA的数据交互逻辑、总线接口模块、载波NCO模块、码模块和导航电文缓冲模块等系统关键部分的实现及重要参数设置的依据，并给出ModelSim-Altera 6.4a下各模块的仿真结果。实测结果表明，信号源生成中频信号波形、频谱符合GPS信号体制规范，且能够被软件接收机正确捕获、跟踪。该信号源具有良好的实时性和可扩展性，成本可控，可有效应用于实验室环境下接收机的性能测试。
Design and implementation of GPS IF signal source based on DSP and FPGA
HU Hui1, YANG Guoyi1, ZHU Shaowen2
1. College of Information Engineering, East China Jiaotong University, Nanchang 330013, China;
2. School of Electrical Engineering and Automation, Harbin Institude of Technology, Harbin 150006, China
Abstract: Satellite navigation signal source is an important test equipment for the development of satellite navigation receiver.Using software defined radio technology,a multi-channel GPS intermediate-frequency (IF) signal source was developed based on DSP and FPGA.According to the mathematical model of GPS IF signal,the system overall design scheme is given.Using block-based design,the key parts of the signal source and the bases of settings for significant parameters are fully detailed,including the data exchange logic between DSP and FPGA,bus interface module,carrier NCO module,code module and navigation message buffer module.The simulation results of these modules in ModelSim-Altera 6.4a are also presented.The practical test results show that waveform and spectrum of the IF signal generated by the signal source is in line with GPS signal specification and the IF signal can be acquired and tracked correctly by software receiver.The signal source has good real-time performance and scalability with controllable cost,which is able to be effectively used in the lab for the performance test of the receiver.
Keywords: GPS signal source;multi-channel;DSP;FPGA
2016, 42(11): 100-106,144 收稿日期: 2016-5-7;收到修改稿日期: 2016-5-7
基金项目: 江西省自然科学基金（20142BAB207001）江西省教育厅科学技术研究项目（GJJ14369）
作者简介: 胡辉(1970-),男,江西南昌市人,教授,博士,研究方向为卫星导航定位、并行算法与并行处理、机器视觉。
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