Design And Implementation Based On FPGA Of OFDM System

Modern science and technology is developing rapidly, and information techn-ology industry is changing with each passing day. At the same time of people' senjoying the high quality of life, there is a higher needs of quality of servi-ce.The demands of quality of communication service is increasing too.As a se-lected standard of wireless LAN IEEE802.11a and HIPERLAN2 protocal, Orth-ogonal Frequency Division Multiplexing (OFDM) technology will naturally be more and more popular for people of all ages.FPGA is field programmable gate array, it uses a structure of programmable look-up table(LUT),LUT is the smallest programmable unit of logical constitution.Today most of FPGA chips on the market adopt look-up table logic of the formation of structure based on SRAM (static random access memory).And the series of Spartan 3E chips of Xilinx company are designed to meet the needs of electronical applications of consumers who persuit high volume, but are sensitive to cost. It provides accuracy ranges from 100,000 to 1,600,000 system gates, and is produced by advanced 90nm process.Because of its low cost and short cycle of development, the series of Spartan 3E FPGA chips are widely used in home networks, broadband access, digital television equipment and other fields. This design adopts Series chips of Spartan 3E FPGA Xc3s500E. The author's main work and and the main conent of this paper are as following:1. Divide function modules according to the requirements of the system, and the entire system can be divided into two main parts, a part of sending and a part of receiving. The sending section mainly includs crambling,interleaving, di-gital modulation,IFFT,digital to analog conversion (DA)and other modules,while the receiving section mainly includes analog to digital conversion (AD),timing, correction of frequency offset, FFT, digital demodulation,deinterleaving,descram-bling module and etc.Then selecte circuit for each module,try to choose circu-it which costs less,and whose components are easy to buy, and high reliability. 2. Considering that it is difficult for us to implement real time sending and receiving data by a single board, that means we can't achieve sending and r-eceiveing synchronously in a single board, so we separate sending and receive-ngparts of the system in the design of the system, namely we implement the sending and receiving of data simultaneously by two boards. And then draw a diagram of the functional modules of the sending part and the receiving part, then determine the schematic package for each component, import schematic packages of components to the PCB, then lay out, and then produce the circ-uit board.3.Establish project files of each module with Xilinx tools ISE9.2,writing programs of the main module by Verilog HDL hardware language, and analyse the way of implemention of the modules.4. Sum up the whole system design, and further improvements of design and implementation of the system are given.