This paper aims at the system design on the MC-CDMA uplink. In this paper, we compare the performance and the complexity of MC-CDMA systems with and without iterative detectors and multiple receive antenna arrays. Through extensive computer simulation, we demonstrate that the following four combinations are good solutions: a single-antenna receiver with an iterative PIC detector initialized by the MF and with 3 iterations, a two-antenna receiver with MMSE-MUD or an iterative PIC detector initialized by the MF and with 2 iterations, and a four-antenna receiver with a simple MF detector. Therefore, non-iterative detectors can be used with multiple receive antenna arrays to substitute complicated iterative detectors and it is a promising solution for the 4G up-link MC-CDMA systems where multiple receive antennas are available. In this paper, we have also considered pilot-aided channel estimation with weighted delay profile technique and investigated the impact of channel estimation error on different systems