New Air Interface Techniques for Future Massive Machine Communications

未来的无线系统有望构成一个超密集的无线网络，除了支持传统的人类发起的移动通信外，还将支持数十亿个智能无线设备(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广泛的服务。因此，未来无线通信系统所采用的通信技术应该能够应对高度多样化的业务需求和通信环境，而这些业务需求和通信环境也具有时变性。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，这依赖于由大量信令开销保证的严格同步。显然，由于这种开销，传统系统对于以设备为中心的MMTC是低效的。此外，它们无法支持未来的MMTC网络所需的大规模连接，在未来的MMTC网络中，设备将激烈竞争可用于通信的有限资源。这个项目是在无数不同类型的智能无线设备被部署并通过互联网连接的时候提出的，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例来支持具有不同服务要求和独特流量特性的大量无线设备。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系统量身定做的新波形来应对未来MMTC系统的挑战。我们的目标是缓解传统无线系统对严格同步的要求，并显著提高其能力、网络性能以及自主MMTC节点的生命周期。该项目的创新之处概括如下。1.将为MMTC系统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时隙的数量，导致过载或广义秩亏缺条件。2.将为未来的MMTC设计新的多载波波形，以便通过最小化实现同步的开销以及减少带外辐射来最大限度地提高频谱效率。3.通过联合利用时间域、频域和空域的可用资源，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场景中在开销减少、能量和频谱效率、时延和实现复杂度之间取得最佳平衡。4.我们将研究多载波分割双工(MDD)方案的全部潜力，特别是它在未来MMTC中的应用，将其与新的多载波波形、非正交SCMA技术以及在该项目中开发的其他高效传输方案协同结合。5.此外，项目中开发的关键技术将进行原型制作，并整合到萨里大学的5G创新中心(5GIC)试验台设施中。这将使我们能够证明我们的新设计方法的可行性，以及加快知识转移和商业化。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联合进行，由肖、塔法佐利、杨和汉佐领导。通过我们与经验丰富的学术和工业合作伙伴的合作，该项目的研究和商业开发将进一步得到巩固。

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.