Performance Analysis of Dwt- Ofdm and Fft-ofdm Systems

AbstractPerformance of Orthogonal Frequency Division Multiplexing (OFDM) systems using Fast Fourier Transforms (FFT) and Discrete Wavelet Transform (DWT) are analyzed in this paper. The performance of DWT-OFDM is assessed by various parameters such as BER, eye diagram and constellation diagram. BER is the ratio of the no. of bits with error to the total no. of bits transmitted through the channel. From the Eye diagram, we can find the eye height through which the interference can be calculated. By varying the different wavelets and the different modulation schemes the BER is calculated and the eye diagram and the constellation diagram are plotted with the aid of MATLABSIMULINK. In this work, performance of most widely used wavelet based OFDM systems Haar, Daubechies, Biorthogonal, and Reverse Biorthogonal wavelets are studied and wavelet basis suitable for optimum OFDM system is investigated. Bit Error Rate (BER) versus Signal to Noise Ratio (SNR) is used as system parameter.