Research And Realization Of OFDM Communication Transmission System Based On FPGA

Orthogonal frequency division multiplexing (OFDM) is suitable for high speed wireless communication system, because it has a good resistance multipath fading and high spectral utilization efficiency. International Telecommunication Union-Radiocom-munication sector (ITU-R) has accepted LTE-Advanced (include TD-LTE-Advanced) and Wireless MAN-Advanced as the 4th generation mobile communication system (4G) standards in november of 2010. OFDM technology is used in both of the standard. Consequently, the study on OFDM technology has been one research focus of 4G. Field Programmable Gate Array (FPGA) has been obtained good application opportunites for air interface and network of 3G, because of its design flexibility, reusability and development of fast, short cycle and so on, no difficult to find that FPGA will have more greater requirement in the technology of 4G.IEEE802.11a wireless local area network (LAN) standard as a typical application system of OFDM physical layer access mode, it is the foundation of OFDM technology research. The author has made the detailed design of scheme of OFDM communication by the in-depth studying and researching of OFDM basic principle and 802.11a, and adopts to Top-down design method of FPGA. a complete deign and FPGA implementation of the OFDM communication transmission system has been accomplished on Register-Transfer Layer (RTL). In the ISE8.2i of Xilinx development environment, the Verilog hardware description language (VerilogHDL) has been made to training sequence, scrambler, multi-rate convlutional code, interweave,16QAM mapping, pilot insertion, IFFT modulation, cyclic prefix and windowed, and main control unit design of system module; Modelsim6.5a and Matlab7.0 simulation tools have been used to make system design and simulation; and accomplished the designed OFDM communication transmission system to download to the FPGA hardware platform of Spartan-Ⅲseries of Xilinx and finished the system test, besides, according to the result of system software simulation and hardware test made the analysis. which focuses on the analysis of windowed and cyclic prefix for the system performance influence of OFDM. Simulation and test results show that the OFDM communication transmission system designed can accomplish function of each module and system function, software simulation and download test results of each module and total system are absolutely correct.