This paper is concerned with multi-user detection techniques for
orthogonal frequency division multiplexing – interleave division
multiple access (OFDM-IDMA) and IDMA with cyclic prefix (IDMACP).
These two schemes have attractive features such as low-cost
multi-user detection/equalization and flexible rate adaptation. We will
show that significant performance improvement (i.e., the so-called
multi-user gain) can be achieved by allowing concurrent multiple user
transmission on common carries.