In wireless communication, the fading is the major concern for researchers. The one of the solutions of fading phenomena lies with antenna diversity mechanism which is used to mitigate the effect of fading over wireless channel at relatively low cost. The credit of most commonly employed antenna diversity goes to receiver diversity where several uncorrelated replicas of the signals are combined at a receiver in order to improve the signal reconstruction. In this paper, we are presenting Maximal Ratio Receiver Combining (MRRC) diversity technique to mitigate the effect of fading in iterative IDMA systems using Prime interleaver with single transmit multiple receiving antennas in low rate coded environment. Simulation results demonstrate the significant improvement in bit error rate (BER) performance of iterative IDMA receivers using increased number of receiving antennas with Maximal Ratio Receiver Combining (MRRC) diversity mechanism.