The space-air-ground-sea integrated network (SAGSIN) plays an important role in offering global coverage. To improve the efficient utilization of spectral and hardware resources in the SAGSIN, integrated sensing and communications (ISAC) has drawn extensive attention. Most existing ISAC works focus on terrestrial networks and cannot be straightforwardly applied in satellite systems due to the significantly different electromagnetic wave propagation properties. In this work, we investigate the application of ISAC in massive multiple-input multiple-output (MIMO) low earth orbit (LEO) satellite systems. We first characterize the statistical wave propagation properties by considering beam squint effects. Based on this analysis, we propose a beam squint-aware ISAC technique for hybrid analog/digital massive MIMO LEO satellite systems exploiting statistical channel state information. Simulation results demonstrate that the proposed scheme can operate both the wireless communications and the target sensing simultaneously with satisfactory performance, and the beam-squint effects can be efficiently mitigated with the proposed method in typical LEO satellite systems.

中文翻译：

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面向混合大规模 MIMO LEO 卫星系统的波束斜视感知集成传感和通信

天海地海一体化网络（SAGSIN）在提供全球覆盖方面发挥着重要作用。为了提高SAGSIN中频谱和硬件资源的有效利用，集成传感与通信（ISAC）引起了广泛关注。大多数现有的 ISAC 工作都集中在地面网络上，由于电磁波传播特性明显不同，因此不能直接应用于卫星系统。在这项工作中，我们研究了 ISAC 在大规模多输入多输出 (MIMO) 低地球轨道 (LEO) 卫星系统中的应用。我们首先通过考虑光束斜视效应来表征统计波传播特性。基于这一分析，我们提出了一种波束斜视感知 ISAC 技术，用于利用统计信道状态信息的混合模拟/数字大规模 MIMO LEO 卫星系统。仿真结果表明，所提出的方案可以同时运行无线通信和目标传感，并具有令人满意的性能，并且在典型的低轨卫星系统中可以有效地减轻波束斜视效应。