{
  "abstract": "This paper investigates RIS-assisted downlink UAV communications based on NOMA. Since conventional NOMA becomes difficult to scale as the number of UAVs grows, we develop a cluster-based UAV-NOMA framework in which a BS serves multiple UAV groups with the aid of partitionable RISs. Within this framework, we consider direct, RIS-only indirect, and composite links, and develop an analytical model for the received SNR and outage performance under Nakagami-$m$ and double Nakagami-$m$ fading with imperfect SIC. To enable scalable transmission, we introduce a greedy RIS-aware (GRIS) clustering method, which groups UAVs according to spatial and channel-related features. Based on the resulting clusters and RIS assignment, we formulate an efficiency-reliability bilevel optimization problem that jointly optimizes inter-cluster BS power allocation, intra-cluster NOMA power coefficients, and RIS element assignment. Specifically, the outer efficiency problem maximizes the average throughput across clusters, while the inner reliability problem minimizes the worst-UAV outage probability within each cluster. To solve the formulated problem, we propose a two-level iterative framework consisting of an inter-cluster outer-efficiency solver (IOS) and an intra-cluster inner-reliability solver (I2S), where I2S combines a grid-based progressive search (GPS) for NOMA power refinement with reliability-guided RIS element reassignment, and IOS updates the BS power weights. Numerical results demonstrate the effectiveness of GRIS clustering, while pre-optimization analysis reveals efficiency-reliability trade-offs in power allocation. Baseline comparisons illustrate the ability of IOS-I2S to balance efficiency and reliability, while ablation studies highlight the importance of joint optimization.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.30410",
  "author_total": 3,
  "authors": [
    {
      "name": "Masoud Ghazikor"
    },
    {
      "name": "Ly V. Nguyen"
    },
    {
      "name": "Morteza Hashemi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0xy26y1ed916d.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.30410",
  "fulltext_url": null,
  "id": "0xy26y1ed916d",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.30410",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cs.IT"
    ],
    [
      "arxiv",
      "math.IT"
    ],
    [
      "openalex",
      "2208|Advanced Wireless Communication Technologies"
    ]
  ],
  "openalex": "W7223328145",
  "pdf_url": "https://arxiv.org/pdf/2610.30410",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-21",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0xy26y1ed916d.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:38Z",
      "native_id": "2610.30410",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.30410"
    }
  ],
  "subjects": [
    {
      "field": "mathematics",
      "origin": "arxiv:math.IT",
      "subfield": "general"
    }
  ],
  "title": "Outage Analysis and Bilevel Resource Optimization in RIS-Assisted Clustered UAV-NOMA Networks",
  "title_text": "Outage Analysis and Bilevel Resource Optimization in RIS-Assisted Clustered UAV-NOMA Networks",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:38Z",
  "url": "https://research.draconitic.com/paper/0xy26y1ed916d",
  "venue": "arXiv",
  "versions": []
}