Performance of COFDM with different orthogonal bases on AWGN and frequency selective channel

To dispose much higher bit rate transmission, the DFT based OFDM (DFT-OFDM) has currently drawn most of attention in the area of wireless communication. To combat ISI, ICl, cyclic prefix is insert between DFT-OFDM symbols, and this will take up nearly 25 percent of bandwidth. To improve the bandwidth efficiency further and reduce intersymbol interference (ISI), interchannel inference (ICI), wavelet based OFDM (WOFDM) is proposed. In this paper we give the comparisons of coded OFDM (COFDM) and uncoded OFDM system with different orthogonal base: DFT and DWT on AWGN and multipath fading channel. Simulation results show that WOFDM performs much better than DFT-OFDM on A WGN channels, but on multipath fading channel DFT-OFDM performs better than WOFDM in certain SNR conditions, and vice versa.