English

Scalable Cross-Attention Transformer for Cooperative Multi-AP OFDM Uplink Reception

Signal Processing 2026-04-08 v2 Information Theory Machine Learning math.IT

Abstract

We propose a cross-attention Transformer for joint decoding of uplink OFDM signals received by multiple coordinated access points. A shared per-receiver encoder learns the time-frequency structure of each grid, and a token-wise cross-attention module fuses the receivers to produce soft log-likelihood ratios for a standard channel decoder without explicit channel estimates. Trained with a bit-metric objective, the model adapts its fusion to per-receiver reliability and remains robust under degraded links, strong frequency selectivity, and sparse pilots. Over realistic Wi-Fi channels, it outperforms classical pipelines and strong neural baselines, often matching or surpassing a local perfect-CSI reference while remaining compact and computationally efficient on commodity hardware, making it suitable for next-generation coordinated Wi-Fi receivers.

Keywords

Cite

@article{arxiv.2602.04728,
  title  = {Scalable Cross-Attention Transformer for Cooperative Multi-AP OFDM Uplink Reception},
  author = {Xavier Tardy and Grégoire Lefebvre and Apostolos Kountouris and Haïfa Fares and Amor Nafkha},
  journal= {arXiv preprint arXiv:2602.04728},
  year   = {2026}
}

Comments

7 pages, 3 figures, 2 tables, conference submission