OFDM based FFT compared with OFDM based wavelet transform

Abstract

In recent year the orthogonal frequency division multiplexing widely used in wireless communication system, the conventional structure of OFDM used Inverse Fast Fourier Transform for modulation and multiplexing the data at the transmitter side and used Fast Fourier Transform at the receiver to demodulation and demultiplexing the data. In this paper, Inverse Wavelet Transform IWT used in transmitter instead of IFFT and Wavelet Transform WT in receiver side instead of FFT and compared between two methods with different noise in the AWGN channel. The performance found by bit error rate BER. Also different modulation scheme have been used (16-QAM, 32-QAM, 64-QAM and 128-QAM) and different types of wavelet filters Daubechies (Db-3, Db-5, Db-8, Db-10) and Haar filter. to compare between them and find which achieved better performance.

A Novel Selected Subcarrier Method for Digital Video Broadcasting

“…In conventional FFT there is a requirement cyclic prefix insertion to reduce the intersymbol interference, which consumes large bandwidth. [15][16][17][18].To overcome this, the wavelet OFDM is introduced. This saves bandwidth of nearly 20% to 40%.…”