The Multi-Carrier Code Division Multiple Access (MC-CDMA) is becoming a very attractive multiple access technique for high-rate data transmission in the future wireless communication systems. MC-CDMA systems transmitting over multipath channels suffer from intersymbol interference (ISI) and multiple access interference (MAI). Recently, MCCDMA with equalization has attracted much attention for its ability to obtain an excellent performance even in strong frequency selective fading channels. In this paper, the proposed architecture uses the minimum mean square error (MMSE) with parallel interference cancellation (PIC) for downlink MC-CDMA system and compared with another system based on the rake receiver with PIC for downlink MC-CDMA system. A comparison between such architectures is presented. The effect of the tentative decision functions, the number of cancelled users and the effect of the loading users on the performance of the two proposed receivers are discussed and presented in this paper. Simulation results show that the combination of tentative decisions with PIC and equalization provides an efficient solution to suppress the MAI and ISI in downlink MC-CDMA systems over frequency selective fading channels.