PERFORMANCE COMPARİSON OF OFDMA AND MC-CDMA OVER WİRELESS CHANNEL

This work has been interested about the application of OFDM in downlink multi-user systems (OFDMA and MC-CDMA techniques) such that the performance of each system was analyzed in the presence of frequency selective fading channel. As the data symbols spread by code sequence, more resistance has been gained due to the interference rejection caused by spreading process, where a gain of 5dB is obtained utilizing a code of 50 chips to spread the data in the frequency domain as compared to OFDMA performance where the same number of users are multiplexed to be transmitted over the channel. Moreover, the simulated error rates show an enhancement in MC-CDMA performance against the delay spread and Doppler shift in the mobile reception