Design Of OFDM Transmission System Based On FPGA

OFDM(Orthogonal Frequency Division Multiplexing)is a orthogonal frequency division multiplexing technology widely used in wireless communications.This technology has good anti-multipath and anti-interference performance,and has excellent characteristics of fast transmission rate and high spectrum utilization rate.It has become an important research direction in the field of modern communication,and has broad development space in the field of 5G technology and the Internet of Things.In this paper,the OFDM launching system is designed in the application field of vehicle network.In the traditional transmitter design,the channel is encoded by a certain bit rate and the data is modulated by one of the many digital modulation modes to achieve a single rate transmitter design.On this basis,considering that the situation of Io V is complex and changeable and there are many emergencies,this paper uses an adaptive coding and modulation scheme to realize an OFDM transmission system with adjustable rate.Adaptive OFDM technology can improve the spectrum utilization in wireless communication systems,which has far-reaching research significance for the development of OFDM technology in the Internet of vehicles.In this paper,the OFDM high-speed transmission system based on FPGA is implemented,and the key digital baseband module is researched and implemented.The main research contents of this design include:(1)The development history and research status of OFDM technology are expounded,and the characteristics of OFDM technology are studied.Determine the feasibility of the technology in the application context.(2)Study the basic theory of the core components in OFDM technology,and analyze the coding and modulation theory to give an adjustable design strategy.Finally,the overall structure of OFDM transmitter is given,and the frame structure of OFDM physical layer is designed and optimized for the application scenario of the transmitter in the Internet of vehicles.(3)Then the OFDM system framework design and OFDM baseband processing module are designed and simulated on Matlab and Simulink software.The ZC sequence is used as synchronous sequence,and the RS sequence whose length can be adjusted automatically according to the length of FFT data is given,so that the system can adjust parameters flexibly in different situations.Then the pilot signal of comb structure is used.Finally,the design and test of the digital baseband module are carried out.According to the design requirements,the specific coding and modulation module design scheme is given,and the simulation is completed on the software.(4)Finally,FPGA implementation of digital baseband is carried out on the hardware platform based on AD9361+ZYNQ7100.Capture data stream to verify the rationality of the design.Through the study of these key problems,the design and implementation of highspeed OFDM transmission system based on FPGA is finally realized,and meets the requirements of rate adaptive adjustment design.