On the performance of maximal ratio combining and maximum likelihood detection in M-QAM/MC-CDMA systems

This paper compares the performance of Multi-carrier Code Division Multiple Access (MC-CDMA) system using a correlation receiver with maximal ratio combining (MRC) and the performance of MC-CDMA using maximum likelihood detection (MLD). For this purpose, firstly analytical expressions to evaluate the mean symbol error rate (SER) and the mean bit error rate (BER) of MC-CDMA systems with MRC are obtained. Then, simulations using the Monte Carlo method are carried out with the aim of evaluating the analytical expressions tightness and to compare the performance of MRC and MLD. The performance is evaluated considering additive white gaussian noise, Rayleigh fading channel, M-QAM modulation and the presence of inter-cell interference (multiple access interference) and co-cell interference. An asynchronous uplink scenario with independent fading at different subcarriers is considered. Also, multiple co-cell interferers are assumed.