Performance Assessment of Channel Estimation in Wavelet-based OFDM System
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 several drawbacks like 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 channel
estimation is implemented to mitigate the execution of bit error rate (BER) 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). Moreover, it is essential to estimate a channel with more efficacy and sturdy against
the scenario of time varying fading channel conditions. Extensive analysis of simulation experiments disclosed that the
proposed system effectiveness over conventional FFT-OFDM system.
Keywords - Orthogonal Frequency Division Multiplexing, Discrete Fourier Transform, Fast Fourier Transform, Discrete
Wavelet Transform, Least Mean Square, Recursive Least Square, Normalized Least Mean Square, AWGN, Rayleigh, Rician
and Bit Error Rate.