This paper investigates system performance for an MC-CDMA (multi-carrier coded-division multiple-access) system, in which an operating environment with both single-cell and multiple-cell configurations and correlated-Nakagami-m statistics for fading channels are adopted. It is worthwhile noting that applying the joint characteristic function to determine the jpdf (joint probability density function) with a generalized Laguerre polynomial yields a simpler method. The traditional difficult methods for explicitly obtaining the jpdf are avoided for the sake of simplification. Some new closed-form formulas for average BER (bit-error rate) with statistical calculation of MAI (multiple-access interference) for MC-CDMA system operation in multi-cell environments were obtained in this study. For achieving accuracy in the derived formulas, an example of an MC-CDMA system with a dual-receiver branch operating in a multiple-cell structure with 12 surrounding cells is presented.