We present an unsourced multiple access (UMAC) scheme tailored to high-mobility wireless channels. The proposed construction is based on orthogonal time frequency space (OTFS) modulation and sparse interleaver division multiple access (IDMA) in the delay-Doppler (DD) domain. The receiver runs a compressive-sensing joint activity-detection and channel estimation process followed by a single-user decoder which harnesses multipath diversity via the maximal-ratio combining (MRC) principle. Numerical results show the potential of DD-based uncoordinated schemes in the presence of double selectivity, while remarking the design tradeoffs and remaining challenges introduced by the proposed design.
@article{arxiv.2601.13065,
title = {OTFS-IDMA: An Unsourced Multiple Access Scheme for Doubly-Dispersive Channels},
author = {Davide Bergamasco and Federico Clazzer and Paolo Casari},
journal= {arXiv preprint arXiv:2601.13065},
year = {2026}
}