Derivation of new expressions of bit error rate for MC-CDMA system in Nakagami fading channel
Résumé
In this paper, new expressions for the bit error rate (BER) of MC-CDMA signals operating in Nakagami fading channel are derived. The proposed formulas can be easily computed numerically and hence, can be usefully exploited in the performance evaluation of digital mobile radio systems. Also, we show that MC-CDMA suffers from the near far problem. The effects of the near-far problem on the performance of MC-CDMA system is evaluated for different cases of the communication channel. Simulation results show that the error probability deteriorates considerably as the number of users in the system increase. It is also noticed that the performance deteriorates substantially in the Nakagami fading channel for little values of fading parameter as compared to the non-fading case due to the near-far problem, which results in a severe reduction of the multiple access capability of the MC-CDMA system. This problem has already been noticed in DS-CDMA.