Research On Modulation Demodulation Design Of Digital IF Signal For Baseband Module

Digital signal transmission and reception components are an important part of the radar,it is located behind the radar antenna for the launch and receive RF signal module components.Transmitting and receivingmodule test system is a system designed to test the transmission and reception of digital signals.The baseband module in the transmitting and receivingsystem is to provide the excitation signal for the digital signal transmitting and receiving components,and to receive the test signal returned by the digital signal transmitting and receiving components.The performance of the baseband board affects the entire transmission and reception Module test system performance.This topic is a sub-proposition of the baseband board in the transmitting and receiving module test system,which is used to provide the modulated digital intermediate frequency test signal for the digital signal transmitting and receiving components while transmitting the modulated signal returned from the digital signal transmitting and receiving component demodulation.In this paper,the digital IF signal as the research object,which comes from the baseband module digital IF signal as the starting point for the actual needs of the relevant modules to complete the hardware and software design.The main achievements of the main work completed the following aspects:(1)To complete the core part of the baseband module-digital IF signal modulation / demodulation module of the overall program design.In this paper,the main hardware modules of the baseband module are designed and analyzed.The hardware modules include power module,RS422 serial communication module,FPGA core module and high-speed serial-to-parallel conversion circuit module.(2)The logical design of digital IF signal modulation / demodulation module is analyzed in detail.In this paper,the digital AM signal,ASK,FSK,PSK,GMSK,QPSK modulation and demodulation principle,modulation and demodulation methods and logic implementation are analyzed in detail,and the relevant module function simulation.In this paper,the logic design of the carrier signal generation module and the filter is analyzed and realized.(3)In this paper,the bit error rate of the different demodulation modes under different signal-to-noise ratio is tested and verified.According to the test results of the hardware test platform,this topic can meet the digital modulation and digital demodulation of the baseband board,and verify the feasibility of the design scheme.Through summarizing the whole paper,I point out the defects and shortcomings in the design realization,and put forward the next step of the related research.