This work investigates an uplink multiple access technique with Interleave Division Multiple Access using Random Interleaving and Extended Typical Urban (ETU) channel model. The crucial requirement is a better Bit performance of the proposed system. The article analyzes and compares the performance of proposed system, taking different block lengths and a different number of subscribers, against that SUI. The simulation results show that w increase in block length, the performance of random access block interleaving with the SUI channel we see that SUI performs better then AWGN channel. KeywordsRandom access block interleaving, ETU, Block length, BER