Iteratively Detected Multi-Carrier Interleave Division Multiple Access

In this paper a novel transceiver is proposed, which amalgamates the benefits of multi-carrier transmissions with those of interleave division multiple access (IDMA), leading to the concept of multi-carrier IDMA (MC-IDMA), which invokes spreading in both the time as well as in the frequency domain. In the proposed MC-IDMA system the classic position of spreading and interleaving is reversed and hence the chips are interleaved, which are then mapped to multiple carriers. The different users are distinguished by their unique, user-specific interleavers. With the aid of turbo-style iterative joint detection and decoding, MCIDMA becomes capable of supporting a large user-population. This is particularly so, when sophisticated non-linear detectors are used. More quantitatively, it is demonstrated for example that the proposed MC-IDMA system is capable of supporting three times more users than the spreading gain of G = 16, while maintaining a modest complexity.