Multi-layer interleave-division multiple access: theory and practice

Direct-sequence code-division multiple access (DS-CDMA) is often put on the same level with CDMA, ignoring the fact that many different CDMA techniques exist. A special CDMA technique which has recently become popular is interleave-division multiple access (IDMA). In this semi-tutorial, focus is on a generalisation of IDMA referred to as interleave-division multiplexing (IDM)/IDMA or multi-layer IDMA for short. Multi-layer IDMA is a special form of superposition coding, and can be interpreted as a joint modulation, channel coding and multiple access scheme. Motivated by information theoretical arguments and practical functionalities, a wide range of subjects (such as capacity bounds, power allocation, receiver analysis, quality of service aspects, multi-layer ARQ and possible applications) are covered. This semi-tutorial consists of three parts: in the first part, an introduction to IDMA (Section 1) and multi-layer IDMA (Section 2) is given. In the second part, practical issues such as functionalities of multi-layer TDMA (Section 3) and multi-layer ARQ (Section 4) are studied. In the third part, information theoretical bounds in conjunction with power allocation (Section 5) and a receiver analysis (Section 6) are provided, before conclusions are drawn in Section 7. Copyright (C) 2008 John Wiley & Sons, Ltd.