此研究聚焦于低地球轨道（LEO）卫星物联网（IoT）系统，旨在解决现有陆地物联网覆盖范围受限的问题。文章提出了一种结合速率拆分多址（RSMA）和集群式波束跳跃（CBH）的新型系统，以优化有限的星载资源利用并有效减轻波束间干扰。作者们共同设计了预编码向量、公共速率分配和CBH模式，目标是最大化每束的提供容量与流量需求比（ROCD）。通过分解问题并提出两阶段算法，数值结果表明该方案显著提高了最低满意度，并优于传统的非正交多址（NOMA）和空分多址（SDMA）基线方案。

Joint Design of Beam Hopping and Precoding for RSMA-Enabled LEO Satellite Internet of Things

Abstract:

Low-earth orbit (LEO) satellite Internet of Things (IoT) has emerged as a promising solution to address the limitations of terrestrial IoT by providing global coverage and seamless connectivity. Among the various techniques enhancing LEO satellite IoT, beam hopping (BH) stands out as an efficient approach that dynamically adjusts beam illumination to match the varying traffic demands of diverse IoT devices. This flexibility enables optimal utilization of limited on-board resources. However, while BH allows adaptive beam illumination planning, it can also introduce severe inter-beam interference, particularly when adjacent beams are simultaneously activated. To address this challenge, we propose a novel rate-splitting multiple access (RSMA)-enabled cluster-based beam hopping (CBH) LEO satellite IoT system. By leveraging RSMA, the proposed framework supports large-scale IoT devices access, and mitigates inter-beam interference introduced by CBH. Within this framework, we introduce a metric—the ratio of offered capacity to traffic demand (ROCD)—to quantify how well the required traffic sum rate aligns with the achievable sum rate for each beam. We then focus on jointly optimizing the precoding vector, common rate allocation, and CBH pattern design to maximize the worst-case ROCD among beams. To solve this problem efficiently, we decompose the original problem into three sub-problems and propose a two-stage algorithm. Numerical results demonstrate that our proposed scheme improves the minimum satisfaction rate by 14.10% and 39.59% compared to the non-orthogonal multiple access and space-division multiple access baselines, achieving effective interference mitigation.

Published in: IEEE Internet of Things Journal ( Early Access )

Page(s): 1 - 1

Date of Publication: 17 June 2025

ISSN Information:

Electronic ISSN: 2327-4662

CD: 2372-2541