An OFDM Baseband Communication System Based On Xilinx FPGA

Because of its tremendous advantages,such as anti-fading and better bandwidth efficiency,OFDM has become a kind of hot technology in the field of wireless communications.With the development of digital signal processing,FPGA with its effeicient parallel processing capabilities and strong realtime performance,and has become a key element of high performance digital signal processing systems.FPGA can provide a verification platform for the algorithms and improvement of OFDM technology.On the base of OFDM technique theory,this thesis introduces the design and realization of an OFDM baseband commu-nication system,which is implemented on Xilinx FPGA.The OFDM baseband system consists of two main sub-system:receiver and transmitter.The whole system was divided into sever parts with individual function by using a top-to-bottom design mechanism.The transmitter is made up by data process block and control block.The data process block for one side,generates the training series for the future synchronization and channel estimation in receiver.On the other side,the data process block apply a series operations to the signal data,including Constellation Mapping,IFFT Modulation,Cyclic Prefix Addition and Windowing,to create the frame structure in this OFDM system.For the receiver,firstly,using delay correlation algorithm,packet detection is implemented with the short training symbol,determining the position of the beginning of received signals efficiently and reliably;then the Cyclic Prefix is deleted and FFT demodulation is applied.In this paper,a long training symbol is utilized to estimate and compensate the channel.In the end,the sent binary data is demodulated by transmitter through a 16QAM demap block.Joint debugging was applied to every block and an OFDM baseband model was built.The binary bit stream was generated with the help of MATLAB,storing in a RAM,and then transferred to the system as the sent signal.Transmitter system operates on the signal and transmits the OFDM frame to receiver,where the received signal is demodulated.This design has been verified on both systematic level and block level,with simulation,downloading,debugging and ChipScope on-line testing.On the base of OFDM technique theory,this project provides a good guide for the hardware realization of OFDM baseband system,meanwhile verifies the theory in return.Finished the design and verification of a OFDM baseband system,on the Xilinx Virtex-5 ML507 developing platform,with Xilinx ISE 14.4 developing software,using verilog-HDL.This project holds an important meaning for the algorithm verification and hardware implement of OFDM system,provides large amount of useful information for the future developing of OFDM technique.