Multicarrier CDMA with OFDM as Data Enhancement Technique and BER Analysis

-To achieve high data rate Multi-Carrier Code Division Multiple Access (MC-CDMA) is a suitable choice for next generation wireless communication system. MCCDMA is the combination of CDMA and OFDM schemes along with receiver diversity including cyclic prefix and zero padding, resulting into getting the advantages of all of these schemes. Capacity improvement is one of the major issues in designing of wireless communication system. In wireless communication system capacity planning greatly depends on performance criteria called bit error rate (BER). This study investigates the BER performance of MCCDMA system over Rayleigh fading channel for different length of spreading code such as OVSF code. Various performance enhancements are done by using receiver diversity and rate matching is done using OVSF and cyclic prefix for N-point IFFT based OFDM implementation. Diversity used in the receiver is EGC (Equal gain Combining) and MRC (maximal ratio combining). Performance Analysis of the OFDM-CDMA for different spreading code length is carried out. Eb/No Vs BER plot for 64 point FFT based OFDM is also plotted for noise model like Rayleigh fading etc.