基于FPGA的扩频通信测距测速系统设计与实现

发布时间：2018-05-06 21:12

本文选题：直接序列扩频通信 + 伪码同步　；参考：《华中科技大学》2014年硕士论文

【摘要】：本文介绍了一种基于FPGA实现的扩频测距测速系统，该系统用于空间卫星距离速度的测量，同时实现卫星与地面的扩频通信。本文设计的测距测速系统包括测距测速和遥控遥测两个通道。测距测速通道接收来自地面的两路扩频测量帧，解算出上行伪距、伪多普勒，并将上行伪距、伪多普勒插入到下行测量帧进行扩频调制、载波调制后发往地面。遥控遥测通道接收地面测控站发送的上行扩频遥控信号，完成解扩、解调，并将解扩解调后的遥控信号送遥控单元,同时接收遥控单元送来的遥测信号进行编码扩频调制输出。经过大量的理论分析和验证，本课题采用FPGA来实现扩频测距测速系统的基带电路，根据系统的各项参数和指标要求设计并实现发送信号的伪随机码调制、接收信号的伪码捕获与跟踪、载波跟踪、数据的解调以及与嵌入式处理器的接口设计。本文首先对扩频通信的基本原理和直接序列扩频通信系统的基本结构进行了阐述，解释了扩频通信用于测距测速的基本原理，然后根据系统的各项指标要求给出了系统总体的设计方案，并对扩频测距测速系统进行了功能划分，，然后对系统的FPGA逻辑设计和实现原理进行了详细完整的阐述。扩频测距测速接收机设计已经顺利完成，并进行了最终的测试，接收机工作稳定，各项指标均达到设计要求。
[Abstract]:In this paper, a spread spectrum ranging and velocimetry system based on FPGA is introduced. The system is used to measure the distance velocity of space satellite, and the spread spectrum communication between satellite and ground is realized at the same time. The system includes two channels: ranging and telemetry. The range measurement channel receives two spread spectrum measurement frames from the ground, solves the uplink pseudo-range, pseudo Doppler, and inserts the uplink pseudo-range, pseudo Doppler into the downlink measurement frame for spread spectrum modulation, then the carrier modulation is sent to the ground. The remote control channel receives the uplink spread spectrum remote control signal from the ground measurement and control station, completes the despreading and demodulating, and sends the despreading and demodulating remote control signal to the remote control unit, while receiving the remote sensing signal sent by the remote control unit to code the spread spectrum modulation output. After a lot of theoretical analysis and verification, this paper uses FPGA to realize the baseband circuit of spread spectrum ranging and velocimetry system, and designs and realizes the pseudorandom code modulation of the transmitted signal according to the system parameters and specifications. PN code acquisition and tracking, carrier tracking, data demodulation and interface design with embedded processor. In this paper, the basic principle of spread spectrum communication and the basic structure of direct sequence spread spectrum communication system are described, and the basic principle of spread spectrum communication used in ranging and velocimetry is explained. Then according to the requirements of each index of the system, the overall design scheme of the system is given, and the function of the spread spectrum ranging and velocimetry system is divided. Then, the FPGA logic design and the realization principle of the system are described in detail. The design of spread spectrum ranging and velocimetry receiver has been completed successfully and the final test has been carried out. The receiver works stably and each index meets the design requirements.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN914.42

【参考文献】