The Research Of Recever Technology OFDM Based On FPGA

Orthogonal frequency division multiplexing(OFDM) is a special multi-carriermodulation technology,which has a high spectral efficiency,and can combat multi-pathfading and impulse noise effectively.In recent years,OFDM has aroused widespreadattention and has been used in Asymmetrical Digital Subscriber Line(ADSL),DigitalVideo Broadcasting(DVB),Wireless Local Area Networks(WLAN) and Long TermEvolution(LTE) plans.At present,the OFDM technology has become the mainstreamtechnology of the fourth Generation mobile communication system.The digital processing technology has been developed greatly,and the FPGA(FieldProgrammable Gate Array,FPGA) has become more and more important in digitalsystem design in recent years.It is easy to reduce the circuit complexity to complete theOFDM communication system based on FPGA,and benefit to transplantation,integration and large-scale production.In this paper,based on the FPGA,OFDMreception technology was studied,the main content includes:First,This paper introduces the basic theory,fundamental operating principles andkey technologh of OFDM system,and shows more advanages than other modulationtechnology;A brief introduction to the FPGA design of the basic principles,the basicprocess and hardware description language.And then finished transmission andreception key modules of OFDM on the FPGA,Including: QPSK modulation/demodulation module realization,serial parallel conversion/parallel serial conversionmodule realization and IFFT/FFT of the module,the experimental results show that themodule can realize the corresponding function.Based on FPGA,the paper finallycompleted OFDM synchronization module design of repetitive structure trainingsymbol method.Among them, the timing detection module include data cache part,delayrelated calculation part and the relevant window calculation part;And the decimalfrequency offset compensation module by data shunt part,frequency offset estimationpart and frequency offset compensation part.Simulation and test results show that thisdesign can achieve OFDM timing detection and decimal frequency offsetcompensation.On this basis,use the Xilinx company XC6VL240T of Virtex–6 development board to download and test,and the test results comply with the designrequirements.