New Air Interface Techniques for Future Massive Machine Communications

未来的无线系统预计将构成一个超密集的无线网络，它支持数十亿的智能无线设备（或机器），为智能家居、智能城市、智能交通系统、智能医疗和智能环境等提供各种服务，除了支持传统的人类发起的移动通信。因此，未来无线通信系统所采用的通信技术被期望能够应对高度多样化的业务需求和通信环境，这两者都具有时变的性质。然而，传统的无线系统，如LTE/LTE- a，主要是为人类发起的移动通信而设计的，它依赖于由大量信号开销保证的严格同步。显然，由于这种开销，遗留系统对于以设备为中心的mMTC是低效的。此外，它们无法支持未来mMTC网络所需的大规模连接，因为在未来mMTC网络中，设备会严重争夺有限的可用通信资源。这个项目是在无数不同类型的智能无线设备正在通过互联网部署和连接的时候提出的，这有望成为移动生态系统的下一次革命。为了实现这些目标，需要一种新的设计范式来支持具有不同服务需求和独特流量特征的大量无线设备。在这个项目中，我们建议通过研究和设计新的非正交多址、灵活的双工和自适应相干-非相干传输方案，以及为未来的mMTC系统量身定制的新波形，来应对未来mMTC的挑战。我们的目标是减轻传统无线系统对严格同步性的要求，并显著提高其能力、网络性能以及自主mMTC节点的生命周期。这个项目的新奇之处总结如下。1. 针对mMTC系统，将开发新的非正交稀疏码多址（SCMA）方案，其中设备数量超过可用资源槽的数量，导致过载或广义秩亏条件。2. 未来的mMTC将设计新的多载波波形，通过最小化实现同步的开销来最大化频谱效率，并减少带外辐射。3. 通过共同利用时间、频率和空间域的可用资源，我们将设计非相干、部分相干和自适应相干-非相干传输方案，以便在实际mMTC场景中实现开销降低、能量和频谱效率、延迟和实现复杂性之间的最佳权衡。4. 我们将研究多载波分双工（MDD）方案的全部潜力，特别是通过将其与新型多载波波形、非正交SCMA技术和项目中开发的其他高效传输方案协同结合，将其应用于未来的mMTC。5. 此外，该项目开发的关键技术将被原型化并集成到萨里大学的5G创新中心（5GIC）测试平台设施中。这将使我们能够证明我们的新设计方法的可行性，以及加速知识转移和商业化。这项拟议的研究将由萨里大学的5GIC和南安普顿大学的南安普顿无线公司（SW）联合进行，由Xiao、Tafazolli、Yang和Hanzo领导。我们与经验丰富的学术界和工业界合作伙伴的合作，将进一步巩固该项目的研究和商业开发。

Future wireless systems are expected to constitute an ultra dense wireless network, which supports billions of smart wireless devices (or machines) to provide a wide varieties of services for smart homes, smart cities, smart transportation systems, smart healthcare, and smart environments, etc., in addition to supporting conventional human-initiated mobile communications. Therefore, the communication technologies employed in future wireless communication systems are expected to be capable of coping with highly diverse service requirements and communication environments, both of which also have time-varying nature. However, the legacy wireless systems, such as LTE/LTE-A, have been primarily designed for human-initiated mobile communications, which rely on strict synchronisation guaranteed by a substantial signalling overhead. Explicitly, due to this overhead legacy systems are inefficient for device-centric mMTC. Furthermore, they are unable to support the massive connectivity required by the future mMTC networks, where devices heavily contend for the limited resources available for communications. This project is proposed at the time, when myriads of smart wireless devices of different types are being deployed and connected via the Internet, which is expected to be the next revolution in the mobile ecosystem. To fulfil these objectives, a new design paradigm is required for supporting the massive number of wireless devices having diverse service requirements and unique traffic characteristics. In this project, we propose to meet the challenges of future mMTC by investigating and designing novel non-orthogonal multiple access, flexible duplexing, and adaptive coherent-noncoherent transmission schemes, as well as new waveforms that are tailored for the future mMTC systems. We aim for alleviating the strict synchronism demanded by the legacy wireless systems, and for significantly improving their capabilities, network performance as well as the lifetime of autonomous mMTC nodes. The novelties of this project are summarized as follows. 1. New non-orthogonal sparse code multiple access (SCMA) schemes will be developed for mMTC systems, where the number of devices exceeds the number of available resource-slots, resulting in an over-loaded or a generalized rank-deficient condition. 2. Novel multicarrier waveforms will be designed for future mMTC in order to maximize spectrum efficiency by minimizing the overhead for achieving synchronisation as well as for reducing the out-of-band radiation. 3. By jointly exploiting the resources available in the time, frequency and spatial domains, we will design noncoherent, partially-coherent and adaptive coherent-noncoherent transmission schemes, in order to strike the best possible trade-off among overhead reduction, energy and spectral efficiency, latency and implementation complexity in practical mMTC scenarios. 4. We will investigate the full potential of the multicarrier-division duplex (MDD) scheme and, especially, its applications to future mMTC by synergistically combining it with novel multicarrier waveforms, non-orthogonal SCMA techniques and other high-efficiency transmission schemes developed within the project. 5. Furthermore, the key techniques developed in the project will be prototyped and integrated into the 5G Innovation Centre (5GIC) test bed facilities at the University of Surrey. This will allow us to demonstrate the viability of our new design approaches, as well as to accelerate knowledge transfer and commercialisation. The proposed research will be conducted jointly by the 5GIC at the University of Surrey and Southampton Wireless (SW) at the University of Southampton, led by Xiao, Tafazolli, Yang & Hanzo. The research and commercial exploitation of the project will be further consolidated by our partnership with experienced academic and industrial partners.