On the performance of a CDMA opportunistic system in Rayleigh fading channel with inter-cell and co-cell interference

An opportunistic transmission method over a CDMA system is proposed. The performance is analyzed considering a Rayleigh fading channel and the presence of inter-cell (multiple access interference) and co-cell interference. In the opportunistic transmission the transmitter and the receiver are in constant communication through a feedback link and just when the fading amplitude at an instant of time is above a threshold value the receiver indicates to the transmitter that it should transmit. It is supposed that random spreading sequences are employed by CDMA opportunistic system. The performance evaluation of the CDMA opportunistic system is based on the mean bit error rate (mean BER), for which analytical expressions are proposed. The results obtained demonstrate that the CDMA opportunistic system can combat the fading efficiently. These expressions are verified using Monte-Carlo simulations with excellent agreement between both results.