Structural Reduction in Front End Memory Requirement of Tree Based Interleaver Method Using the Concept of Invert Tree Based Interleaver in Multiuser Interleave Division Multiple Access Scheme

Interleave division multiple access (IDMA) scheme, uses interleavers for user separation. The selection of interleaver along with optimum design methodology for IDMA system leads to satisfactory results. An efficient interleaver must be easy to generate and should require low memory along with low correlation among interleavers. Existing Tree based interleaver has distinct advantage of low computational complexity but it suffers with the problem of higher memory requirement due to inherent transmission of two randomly generated interleavers. In this paper, a novel interleaver called Invert Tree Based Interleaver (ITBI) is proposed, which reduces the front-end memory requirement of Tree Based Interleaver by carrying out structural modifications. BER performance and correlation analysis of different interleavers for generating user specific interleaving sequences for different users in IDMA system is analyzed. To achieve similar BER performance, ITBI has simulated with lesser memory requirement and computational complexity compared to random and tree based interleaver in IDMA scheme.