Applying the Sum of Correlated Gamma Variates in Approximate Error Probability Evaluation for MC-DS-CDMA Systems Operating in Frequency Selective Fading Channels

In this paper, the system performance of an MC-DS-CDMA (multi-carrier directsequence coded-division multiple-access) system operating in Nakagami-m fading channels with correlation characteristics is studied. In order to avoid the difficulty of explicitly obtaining the pdf (probability density function) for the SNR (signal-to-noise ratio) at the output of Rake receiver, an expression of distribution with the sum of Gamma varieties is applied in the derivation of closed form for system performance with BER (bit error rate) performance. Two cases, single-user and multipleuser exemplified for validating the fact that the performance degradation of the MC-DS-CDMA is sensitive to the correlation coefficient between the fading branches. Besides, the assumption of PBI (partial band interference) between the subcarriers is considered in this study.