Performance Evaluation of Modulation Techniques with Iterative IDMA Receivers Using Optimum Tree Based Interleaver

The Interleave-Division Multiple-Access (IDMA) scheme is known for property of orthogonality amongst its user-specific interleavers. The interleavers are, therefore, referred has the heart of IDMA Transceivers. In the literature, researchers have proposed Tree Based Interleaver (TBI) which not only reduces the bandwidth requirement in comparison to that required in case of Random Interleavers (RI) but also reduces computational complexity drastically when compared with that of power interleavers. The memory requirement at receiver end and its cost problem are also solved by tree based interleaver with further reduction of the amount of information exchange between mobile stations and base stations required to specify the user-specific interleavers. In this paper, the performance analysis of iterative IDMA receivers have been evaluated with BPSK & QPSK modulation techniques employing tree based interleavers and random interleavers in uncoded and rate 1/2 covolutionally coded conditions with Additive White Gaussian Noise (AWGN) channel. During the simulation, it has been observed that IDMA system with QPSK modulation techniques employing TBI outperforms its counterparts optimally.