基于GNU Radio和USRP平台的时频分析研究

近年来,随着航天技术、嵌入式技术、软件无线电的飞速发展,现代无线通信技术突破了传统硬件电路的限制,实现了利用软件控制、操纵“硬件电路”.与此同时,便携式卫星编队地面站也成为空间技术发展的一个重要的突破方向,具有成本低、灵活、使用方便等特点.通过对便携式卫星编队地面站信号处理关键技术和USRP进行研究,提出一种高效、低成本的基于软件无线电思想的FSK调制解调设计方案,并对其关键技术进行理论分析和实现.通过FPGA产生的基带信号控制,在AD9364这款芯片上用正交调制产生的两个不同频率信号的输出实现FSK调制,并通过高度集成的射频收发器AD9364发射出去,由RTL2832U+ R820T进行接收,通过RTL2832U+R820T内部器件的混频、滤波、采样等操作后变成基带I/Q信号,最终通过USB发送到PC机,利用GNU Radio软件完成解调.

Study and Analysis of Time-Frequency Based on GNU Radio and USRP

In recent years,with the rapid development of space technology,embedded technology and software radio,wireless communication technology has broken through the limitations of traditional hardware circuit to achieve the goal of using modem software to manipulate "hardware circuit".At the same time,the study of portable satellite ground stations has become a focus in the development of space technology,which is cheaper,smarter,and more convenient.By studying signal processing and analyzing the modulation of portable ground stations of satellite,a high-efficient,low-cost design on FSK modulation and demodulation,based on the software defined radio,is proposed.Moreover,its key technology is analyzed theoretically and implemented.The baseband signal and control signal,generated by FPGA,are transmitted to AD9364 (high performance,high integrated RF agile transceiver),in which the FSK quadrature modulation with two signals of different frequencies is achieved.The modulated signals are processed by RTL2832U + R820T receiver.The received signals are converted into baseband IQ signal through mixing,filtering,sampling and other processing,and then transmitted to the PC via USB.Finally,the software platform of GNU Radio is used to complete the demodulation.