Comparison the performance of OFDM system based on multiwavelet transform with different modulation schemes

Orthogonal frequency division multiplexing (OFDM) is a very interesting approach for high data rate transmission in a multipath fading environment that leads to intersymbol interference (ISI). In this paper, two steps are used to improve the error rate performance of OFDM system. First, the discrete multiwavelet transform (DMWT) is proposed instead of fast Fourier transform (FFT) to obtain high orthogonality between subcarriers and hence reduce (ISI). Second, the performance of OFDM based on DMWT is examined for different modulation schemes such as M-PSK (M-ary phase shift keying) and M-QAM (M-ary quadrature amplitude modulation) to achieve high data rate. The simulation results demonstrated that, for high capacity data rate transmission, the M-QAM modulation is better than the M-PSK modulation.