The Design And Implementation Of OFDM Baseband Processing

Orthogonal frequency-division multiplexing (OFDM) is a method of transmitting data simultaneously over multiple equally spaced carrier frequencies, using Fast Fourier Transform processing for modulation and demodulation. OFDM offers many well-documented advantages for multicarrier transmission at high data rates, so it has been proposed or adopted for many types of radio systems such as wireless local-area networks and digital audio and digital video broadcasting.This paper mainly focused on the engineering implementation of an OFDM demostrator system , and presented an OFDM transceiver scheme based on software radio conception using DSPs and FPGA.Chapter 1 gave a brief description of the development of wireless mobile communications, and developed some advantages of OFDM on the study of long distance wireless communication channel characteristics.This thesis gives a solution for high speed wireless digital communication--OFDM.Chapter 2 introduced the principles of OFDM, and explained how to generate a guard intervel to eliminate ISI result from multipath in wireless channel.At the same time, we listed some important parametres and frame archtecture of IEEE802. 11a as a contrast to the system we introduced below.Chapter 3 gived the architecture of a hardware platform of a OFDM transceiver.In details, it specified how to design a baseband transceiver in the whole system use DSPs and FPGA.Chapter 4 focused on the software design of the system. In this chapter, we present a software implement scheme of OFDM modulation, demodulation and the channel estimation.It is a simplified version of the IEEE802. lla.At the end we gave a summary of the thesis and the perspective of the design of this demonstrator system.