Unlocking Potentials of MIMO Full-duplex Radios for Heterogeneous Networks (UPFRONT)

该项目将开发多天线全双工技术，以在HetNets（异构网络）中实现高效的频谱利用。全双工无线电不仅仅是当前文献中所认为的容量翻倍。更明确地说，我们认为它正在使不可能的通信技术成为可能。全双工通信的含义是变革性的。允许同时传输和接收的全双工，激发了对无线网络设计和优化方式的根本性反思。然而，发射信号的功率比接收信号的功率大得多（超过100分贝），这一事实使人们相信，在单个信道上分离它们是不可能的。最近，随着斯坦福大学的Choi等人的开创性工作，这种情况开始发生变化，他们展示了在单频道上工作的全双工无线电。我们设想，全双工可以改变无线网络的运营，并有望在HetNets中带来巨大的好处。HetNets被广泛认为是通过大蜂窝和小蜂窝之间的复杂互操作来提供未来无线通信（包括5G）的一项关键无线技术。对HetNets的巨大兴趣是由于其提供高区域容量和灵活覆盖的能力，更重要的是其基础设施成本低。在HetNets中，从大蜂窝到小蜂窝（如微蜂窝和飞蜂窝）的各种无线覆盖区域获得了无线覆盖的马赛克。移动运营商越来越感兴趣的是客户安装的飞蜂窝，它可以极大地提高室内覆盖范围，但与宏蜂窝共用同一频段。在HetNets的资源分配和物理层设计与优化方面有很大的研究范围。该项目将通过设计一个将天线设计、物理层信号处理和网络资源分配互连起来的整体解决方案，充分挖掘HetNets中MIMO全双工的全部潜力，以解决全双工的固有挑战，并实现其巨大的端到端优势。为了实现这一目标，UPFRONT首先提出了专门针对宽带MIMO全双工的新天线设计，这比现有的窄带单天线情况更具挑战性。接下来，我们利用强大的MIMO信号处理来处理被忽视的小区内干扰和全双工操作引入的新干扰，这些干扰对于提供全双工HetNets的端到端优势至关重要，但之前没有得到很好的研究。此外，UPFRONT将探索尚未开发的全双工机会，以解决在共享相同移动频谱的更大宏蜂窝结构下采用全双工小蜂窝所带来的全网资源分配挑战。UPFRONT的研究结果将阐明采用整体方法进行全双工设计的重要性，并对未来无线网络的基础和实际研究产生影响。

This project will develop multi-antenna full-duplex technology to achieve highly efficient spectrum usage in HetNets (heterogeneous networks). Full-duplex radios are much more than just doubling the capacity as perceived in current literature. More explicitly speaking, we believe that it is making communication technologies impossible become possible. The implications of full-duplex communications are transformative. Full duplex, which permits simultaneous transmission and reception, motivates a fundamental rethinking of the ways wireless networks are designed and optimised.However, the fact that the power of the transmitting signal is so much larger (over 100 dB) than that of the receiving signal has fuelled the belief that it is impossible to separate them on a single channel. Recently, this picture has begun to change, following the pioneering work by Choi et al. from Stanford University who demonstrated a working full-duplex radio on a single channel.We envisage that full-duplexing can transform the operations of wireless networks and is expected to have massive benefits in HetNets. HetNets are widely regarded as one key wireless technology for the provision of future wireless communications (including 5G) by complex interoperation between macrocells and small cells. The enormous interest for HetNets is due to their capability of providing high regional capacities and flexible coverage, and more importantly their low infrastructure costs. In HetNets, a mosaic of wireless coverage is obtained by a variety of wireless coverage zones from macrocell to small cell such as, pico- and femtocell. Of increasing interest to mobile operators are the customers' installed femtocells that can greatly improve indoor coverage but share the same frequency band as the macrocells. There is a huge scope of research in resource allocation and physical-layer design and optimisation in HetNets. This project will exploit the full potential of MIMO full-duplexing in HetNets by designing a holistic solution that interconnects antenna design, physical-layer signal processing, and network resource allocation to address the inherent challenges of full-duplexing and realise its massive end-to-end benefits. To achieve this goal, UPFRONT first proposes new antenna design specially for wideband MIMO full-duplexing, which is substantially more challenging than the existing narrowband single-antenna case. Next we leverage the powerful MIMO signal processing to handle the overlooked in-tercell interference and new interference introduced by the full-duplex operation, which are critical to deliver the end-to-end benefits of full-duplex HetNets but were not well studied before. Furthermore, UPFRONT will explore the unexplored full-duplexing opportunities to address the networking-wide resource allocation challenges associated with the adoption of full-duplexing small cells under the greater macrocell structure sharing the same mobile spectrum. The outcomes of UPFRONT will elucidate the importance of a holistic approach to full-duplexing design and have impact in fundamental and practical research of future wireless networks.