Abstract: In this thesis, an overview of traditional multiple access techniques were presented. Advantages and disadvantages of each system were outlined. A classification of CDMA systems was given. The DS-CDMA was analyzed and a formula for evaluation the BER performance of the system was given. Three modern CDMA system were discussed, namely, Directsequnce-CDMA (DS-CDMA), Multicode CDMA (MC-CDMA) and Multicode-Multicarrier-CDMA (MC-MC-CDMA). The three systems were analyzed and formulas for evaluating the BER performance of the three systems were given. DS-CDMA, multicode CDMA, MC-CDMA and MC-MC-CDMA were simulated using computer programs. The BER performance of the four CDMA systems was evaluated using a computer programs under different conditions. The effect of increasing the number of users of the DS-CDMA system and increasing the length of the spreading code were studied. Multicode CDMA, MC-CDMA and MC-MC-CDAM performance were compared under the criterion of equal system bandwidth and the MC-MC-CDMA was show to be superior to the other two systems under different testing conditions. The simulation process was evaluated by comparing selected simulation results to values found analytically and shown to be efficient. All the simulations presented in this work are performed using MATLAB version7.2(R2006a).