The Simulation Research Of OFDM Software And Hardware System

Data transmission in wireless channels with high speed and reliability is required in future wireless systems. OFDM, with the anvantage of high spectrum efficiency and easy realization, can strongly combat multi-path and dispersive channel interference, so its application is remarkable and it will be the key technology of 4G without question. At the same time, a software and hardware simulation system is necessary for obtaining the best performance and testing the new arithmetic.First, this paper detailedly introduces the principles of OFDM and the baseband simulation model of OFDM in Rayleigh channel by simulink. In this model, LDPC vs RS, QPSK vs 16-QAM are tested for the performance of SNR. A new arithmetic of channel estimate based on PN code is also tested, which has better performance compared to the LS, MMSE arithmetic.Second, this paper simulates the FFT processer in FPGA which is the key block of OFDM hardware system. The FFT processer adopts the pipeline and parallel technology and can complete 64 points FFT computation in 64 clocks. It is able to meet the need of OFDM system.The last, Based on the simulation of OFDM and FFT processor, this paper simulates a OFDM modulation block in FPGA. This block concludes serial to parallel block, RS coder, QPSK map block besides FFT processor. With adopting the three level-pipeline technology, the process speed has reached 17Mbits/s, so this block can meet the need of practical application.