An Enhanced DWT-OFDM System with NLMS Equalization Approach

Abstract

In a field of communication, OFDM has turned out as a sterling methodology. The basic system of
OFDM comprises fast fourier transform (FFT), which computes the DFT of a source signal more
effectively with faster computations. However, the OFDM system with this FFT has
severaldrawbackslike lack of localization, higher error rates during high-speed data rates and minimal
spectral efficiency.To address these problems, wavelet based OFDM came into existence to replace
the FFT with discrete wavelet transform (DWT). In this, an enhanced DWT-OFDM system with
NLMS equalization approach is implemented to mitigate the execution of bit error rate values
compared to that of FFT-OFDM. In addition, an equalization of channel also proposed under the
environment of fading conditions like Rayleigh, Rician and additive white gaussian noise (AWGN).
Further, BER comparison also provided with various modulation levels which disclosed the proposed
system effectiveness over conventional FFT-OFDM system.