A New Paradigm for Non-Geosynchronous Satellite Communications and Radio Astronomy Systems

频谱是各种有源（发送和接收）和无源（仅接收）无线系统的宝贵自然资源，两者都为社会提供了许多好处。然而，有源无线系统和相关频谱分配的显著增长导致了频谱观测机会的减少和无源无线系统射频干扰（RFI）的增加。值得特别关注的有源无线系统的扩展之一是大规模非地球同步轨道卫星通信系统（NGSO）的出现。这种大规模卫星通信系统的前景给射电天文系统（RAS）等无源无线系统带来了令人担忧的RFI状况。射电天文学使人们能够研究宇宙、天体物理学和天体化学，以及检验基础物理定律，因此它的发展对推动科学和知识发现至关重要。现有的频谱分配/接入模式难以适应RAS和NGSO SCS的共同增长。该项目的目的是为RAS和NGSO SCS开发一种新的范例，在这种范例中，两种类型的系统可以共存，并扩展到现有范例所能实现的范围之外。该项目没有将大型NGSO卫星导航系统视为RFI的威胁，而是将其视为开发大型NGSO- scs和NGSO-RAS集成系统的机会，该系统除了提供主要通信服务外，还可以提供天基RAS观测服务。通过实现大规模NGSO-RAS，所提出的范式将为RAS开启一个新的时代，具有许多增强的能力和观测机会。这可以在更大的范围内导致新的令人兴奋的科学发现。另一方面，原本分配给RAS的一些频谱可以重新用于有源无线系统，从而刺激更多的无线应用和有源无线系统的商业机会。整体频谱利用效率也将大幅提升。本项目通过将大型NGSO SCS转化为集成的大型NGSO-SCS和NGSO-RAS，为RAS和NGSO-RAS引入了一种新的频谱接入范式。这与目前的范例不同，在目前的范例中，在地面上实现的RASs容易受到由scs引起的RFI的影响，并且无法解决来自scs和RASs的冲突频谱需求。为了具有更广泛的适用性，该项目考虑了三种类型的综合系统：i)包含所有双用途卫星（每个卫星都有SCS和RAS接收器）的系统，ii)混合使用双用途卫星和单一用途SCS卫星的系统，iii)混合使用单一用途SCS卫星和单一用途RAS卫星的系统。对于每种类型的集成系统，进一步详细的技术发展如下：1)该项目将为新范例所需的频谱接入和资源分配开发创新方法。该项目还将研究RAS数据速率、SCS数据速率和中断性能方面新的可实现性能。此外，将针对新范例研究有希望的部署场景和频率分配规则的建议更改。2)该项目将在几种部署场景和实际约束条件下研究拟议的大规模NGSO-RAS的新功能。此外，还将开发新的解决办法，以便在分配给高轨道卫星系统的波段进行RAS观测。3)该项目将在几种部署场景和优化指标下，为延迟敏感的SCS数据和星载延迟不敏感的RAS数据开发有效的数据传输策略。资源分配和数据传输的联合设计也将被开发，以进一步提高性能。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Spectrum is a precious natural resource for various active (transmit and receive) and passive (receive only) wireless systems, both of which provide several benefits to the society. However, phenomenal growth of active wireless systems and related spectrum allocations have caused less spectrum observation opportunities and greater chances of radio frequency interference (RFI) for passive wireless systems. One of the expansions of active wireless systems that deserves a special attention is the emergence of large-scale non-geosynchronous orbit (NGSO) satellite communication systems (SCSs). The prospects of such large-scale SCSs impose a distressing RFI situation to passive wireless systems such as radio astronomy system (RAS). Radio astronomy enables study of the universe, astro-physics and astro-chemistry as well as testing of the laws of fundamental physics, thus its growth is crucial for advancing science and knowledge discovery. The existing spectrum allocation/access paradigm is difficult to accommodate mutual growths of RAS and NGSO SCS. The purpose of this project is to develop a new paradigm for RAS and NGSO SCS where both types of systems can coexist and expand beyond what is achievable in the existing paradigm. Instead of viewing large-scale NGSO SCSs as a threat of RFI, this project views them as an opportunity to develop an integrated large-scale NGSO-SCS and NGSO-RAS system that can provide space-based RAS observation services, in addition to their main communication services. By enabling a large-scale NGSO-RAS, the proposed paradigm will open a new era for RAS with numerous enhanced capabilities and observation opportunities. This can lead to new exciting science discoveries on a larger scale. On the other hand, some spectrum originally allocated to RAS can be re-purposed for active wireless systems, thus stimulating more wireless applications and business opportunities for active wireless systems. The overall spectrum utilization efficiency will also be substantially enhanced.This project introduces a new paradigm of spectrum access for RAS and NGSO SCS by means of transforming a large-scale NGSO SCS into an integrated large-scale NGSO-SCS and NGSO-RAS. This is different from the current paradigm where RASs implemented on ground are prone to RFI caused by SCSs, and conflicting spectrum needs from both SCSs and RASs cannot be resolved. To have broader applicability, the project considers three types of integrated systems: i) a system with all dual-purpose satellites (each with SCS and RAS receivers), ii) a system with a mixture of dual-purpose satellites and single-purpose SCS-only satellites, iii) a system with a mixture of single-purpose SCS-only satellites and single-purpose RAS-only satellites. For each type of the integrated systems, further detailed technical developments are as follows: 1) The project will develop innovative approaches for spectrum access and resource allocation needed for the new paradigm. The project will also study new achievable performance in terms of RAS data rate, SCS data rate, and outage performance. Furthermore, promising deployment scenarios and recommended changes of frequency allocation rules will be investigated for the new paradigm. 2) The project will study new capabilities of the proposed large-scale NGSO-RAS under several deployment scenarios and practical constraints. In addition, novel solutions to enable RAS observations in the bands assigned to higher-orbit satellite systems will also be developed. 3) The project will develop efficient data transport strategies for both delay-sensitive SCS data and space-borne delay-insensitive RAS data under several deployment scenarios and optimization metrics. Joint design of resource allocation and data transport will also be developed for further performance improvement.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.