PERFORMANCE IMPROVEMENT ANALYSIS OF TIME DISPERSIVE CHANNEL USING DISCRETE WAVELET TRANSFORM

Abstract

This paper presents a model which is discrete wavelet transform based (orthogonal frequency division multiplexing) OFDM system for next generation wireless communication. Fourier transform based OFDM system signals only overlap in the frequency domain while the wavelet transform signals overlap both in the time and frequency domain so there is no need of the cyclic prefix(CP) in the proposed model. There are different types of wavelet transform are available .the performance of the wavelet based OFDM system using modulation QAM was assessed by various parameters such as Bit error rate and constellation diagram. In OFDM inter symbol interference and the inter carrier interference exist. Due to the multipath wireless channel. wavelet based transmission is investigated and its shown that this technique is better at suppressing ISI and ICI than conventional OFDM. the results presented in this paper are based on computer simulation performed using MATLAB software.