Rotational Interleaver for Iterative Interleave-Division Multiple-Access Scheme

In iterative IDMA scheme, the users are distinguished with various chip-level interleaving sequences instead of user-specific signature sequences as in conventional code-division multiple-access (CDMA) scheme. A set of interleavers is considered to be practical if it has zero correlation with each other and also easy to generate as well requires minimal bandwidth during communication process. A properly defined correlation between user-specific interleavers can be utilized to formulate a minimal collision criterion, where zero-correlation (i.e., orthogonality) implies no collision. In this paper, a practical interleaver has been proposed for interleave-division multiple-access (IDMA) systems. Simulation results show that the proposed interleaver performs even better to random interleavers initially reported for iterative IDMA system.