Simulation and analysis of MC-CDMA system using discrete wavelet transform

It is always desired to have high transmission rates over severe time-dispersive multi-path channels without usage of a complex receiver implementation. In this case the Multicarrier Code Division Multiple Access (MC-CDMA) is used which is a combination of conventional Code Division Multiple Access (CDMA) and Orthogonal Frequency Division Multiplexing (OFDM). Better BER performances are achieved by high code rate systems, which are achieved by MC-CDMA exploiting frequency diversity via the different subcarriers. Also time synchronization requirement is made much lower than traditional direct sequence CDMA schemes due to the spreading in the frequency domain. Performance of MC-CDMA under various channels like the AWGN channel and Rayleigh channel, is analyzed using various spreading codes like Walsh codes, PN sequence and gold sequence. BER versus SNR graphs are plotted and their performance is studied.