Intelligent Reflecting Surface Empowered Transmission Techniques for Next-Generation Communication Systems

下一代通信系统预计将支持爆炸性的数据速率和超低延迟传输，并实现无处不在的连接。这种严格的要求对现有的蜂窝系统基础设施提出了严重的挑战，并且探索可以实现更高的频谱和能量效率以满足这种需求的新颖和创新的传输技术是非常有意义的。在过去的几十年中，已经提出了各种先进的技术，以促进在收发器的信号发送和接收，然而很少有人关注的无线传播环境。事实上，无线传播环境长期以来一直被认为是收发器之间的不可控和随机行为的实体。除了不可控之外，由于引入的信号衰减、衰落和干扰，环境通常对通信效率具有不利影响。 近来，对于可以利用传播环境的随机性以提高通信效率或简化收发器架构的新颖通信范例的需求日益增加。在这方面，智能反射表面（IRS）由于其能够通过软件控制的反射来重新配置传播环境而受到极大的关注。IRS是由许多低成本无源反射元件组成的平面表面，每个无源反射元件能够引起入射信号的幅度和相位变化，以实现细粒度的反射波束形成。 该提案将研究新型IRS授权传输技术，通过以下三个短期目标实现我们提高下一代蜂窝系统频谱和能量效率的长期目标：1）开发新型低复杂度资源分配和IRS辅助系统的波束成形技术; 2）研究IRS与下一代通信系统的其他候选技术（如毫米波、非正交多址和物理层安全）的集成;以及3）分析和量化各种传输损伤（例如不完美的信道状态信息、离散相移和随机相位噪声）对IRS辅助传输的性能的影响，并开发新颖的信号处理技术来对抗这种损伤。 拟议的研究计划将提供一个系统的框架，以解决各种设计问题，在IRS授权的物理层传输，并进一步提高下一代蜂窝系统的性能。因此，研究结果预计将引起学术界和工业界的关注，并导致研究合作。同时，拟议的研究计划将培养和装备高素质的人才，在通信理论和信号处理的基本技能，以促进加拿大的技术和学术部门。

Next-generation communication systems are expected to support explosive data rate and ultra-low latency transmissions and enable pervasive connectivity. Such stringent requirements pose serious challenges on the existing cellular systems infrastructure, and it is of great interest to explore novel and innovative transmission techniques that can achieve higher spectral- and energy-efficiencies to meet such demands. Over the past decades, various advanced techniques that facilitate signal transmission and reception at the transceivers have been proposed, however little attention has been paid to the wireless propagation environment. Indeed, the wireless propagation environment has long been perceived as an uncontrollable and randomly behaving entity between the transceivers. Aside from being uncontrollable, the environment usually has an adverse impact on the communication efficiency, owing to the signal attenuation, fading and interference introduced. Recently, there is increasing demand for novel communication paradigms that can exploit the randomness of the propagation environment, either to increase the communication efficiency or to simplify the transceiver architecture. In this regard, intelligent reflecting surface (IRS) has received great attention owing to its ability to reconfigure the propagation environment via software-controlled reflection. An IRS is a planar surface consisting of many low-cost passive reflecting elements, each able to induce an amplitude and phase change to the incident signal to achieve fine-grained reflective beamforming. This proposal will investigate novel IRS-empowered transmission techniques to realize our long-term goal of increasing the spectral- and energy-efficiencies of next-generation cellular systems, through the following three short-term thrusts: 1) developing novel and low-complexity resource allocation and beamforming techniques for IRS-assisted systems; 2) studying the integration of IRS with other candidate technologies for next-generation communication systems, such as millimeter wave, non-orthogonal multiple access, and physical layer security; and 3) analyzing and quantifying the effects of various transmission impairments, such as imperfect channel state information, discrete phase shifts, and random phase noise on the performance of IRS-assisted transmission and developing novel signal processing techniques to combat such impairments. The proposed research program will provide a systematic framework to address various design issues in IRS-empowered physical layer transmission, and further boost the performance of next-generation cellular systems. Therefore,  the research findings are anticipated to draw attention from both academia and industry, and lead to research collaboration. Meanwhile, the proposed research program will train and equip highly qualified personnel with essential skills in communication theory and signal processing to contribute to Canada's tech and academic sectors.