Indexed Random Interleaving Technique for IDMA Systems

Interleave division multiple access (IDMA) is a recently proposed technique for multiple access communications, which is known for property of orthogonality amongst its user-specific interleavers. In IDMA systems users are separated by user-specific chip-level interleavers unlike conventional CDMA scheme. The interleavers are therefore referred as the heart of IDMA transceivers. Thus, the interleaver must be carefully designed to ensure good performance, low memory requirements and low computational complexity. Interleaver for IDMA systems are generated using two different approaches, random approach and non-random approach. Both the approaches have distinct characteristics. In random approach Bit error rate is favored and in non-random approach memory requirement is favored. In this paper we propose a new interleaver technique named indexed random interleaver based on random generation approach. Simulation results show that the proposed interleaver gives better average bit error rate performance than conventional random interleaver.