Performance Evaluation Of Orthogonal Frequency Division Multiplexing System

Abstract

Orthogonal frequency division multiplexing (OFDM) is a special form of multi carrier transmission which has found its application in a number of wireless and wireline systems. In an OFDM scheme, a large number oforthogonal, overlapping, narrow band sub-channels or subcarriers, transmitted in parallel, divide the availabletransmission bandwidth. The separation of the subcarriers is theoretically minimal such that there is a verycompact spectral utilization. This project presents the overview and then the performance evaluation results of anOFDM system by using Fast Fourier Transform (FFT) and Discrete Wavelet Transform (DWT).OFDM suffer from some limitation like, cross-talk between the sub-carriers. the most important limitation to OFDM is inter-carrier interference (ICI) Bandwidth . This project compares the performance of Fourier transform based and Wavelet based OFDM systems, in terms of bit error rate probability, for different channel scenarios. From the performed simulations, in the Additive White Gaussian Noise channel, it was found that the DWT based OFDM system has better performance than that of the FFT-OFDM for both types of the modulations used . The results presented in the project are based on computer simulations performed using MATLAB; a highly efficient tool for different applications.