Interleave-division Multiple-access (idma) Communications 1

In this paper, we study a multiple access scheme referred to as interleave-division multipleaccess (IDMA), in which interleavers are used as the only means for user separation. IDMA inherits many advantages from CDMA, such as diversity against fading and mitigation of the worst-case other-cell user interference problem. A low-cost iterative chip-by-chip multi-user detection algorithm is described with complexity independent of the user number and increasing linearly with the path number. The advantages of low-rate coded systems are demonstrated using analytical and simulation results. Throughput of 3 bits/chip is observed with one receive antenna and 6 bits/chip with two receive antennas in multipath channels. Performance in a Gaussian multiple access channel at 1.4 dB away from the theoretical limit is demonstrated. These low-cost, high performance advantages can be maintained in asynchronous multipath environments.