CIF:Small:Non-Orthogonal Multiple Access with Imperfect Assumptions

无线通信在生活的各个方面都出现了大量的新应用。这些新的应用和相应的机会提高了生活质量，提供了经济增长，并帮助扩大了新的业务。下一代无线网络被称为5G，它承诺通过设计更高效的无线通信网络来满足对更高传输数据速率的需求。为了提高新兴无线网络的效率，本项目所追求的不同用户的并发传输是不可避免的。这一长达一年的项目的成果将有助于为下一代无线通信标准提供信息，并推动新的研究方向，从而大大提高用于无线通信的无线电频谱的效率。最近，非正交多址(NOMA)被建议作为一种有效的方法，使多个用户能够在相同的频率/时间资源块中并发传输。它提供了许多良好的特性，包括高带宽效率，不同用户之间的公平性，以及超高的连接性。虽然上述性质可能非常有利，但它们是在完美假设下获得的，例如完全同步的可用性。对于NOMA是基本技术的多用户/多小区环境，这些假设更有可能被违反。在这个探索性项目中，研究人员研究了多用户NOMA系统中不完美的定时同步的影响，并设计了高性能的NOMA系统。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

There has been a tremendous emergence of new applications of wireless communications in different aspects of life. These new applications and the corresponding opportunities have improved the quality of life, provided economical growth, and helped the expansion of new businesses. The next generation of wireless, dubbed 5G, promises unmet demands for higher transmission data rates through designing more efficient wireless communication networks. To increase the efficiency of the emerging wireless networks, the concurrent transmission of different users, as pursued in this project, is unavoidable. The outcomes of this year-long project can help inform future generations of wireless communications standards and spur a new direction of research that can greatly increase the efficiency of radio spectrum used for wireless communications.Recently, Non-Orthogonal Multiple Access (NOMA) has been suggested as an efficient method to enable the concurrent transmission of multiple users in the same frequency/time resource block. It provides many nice properties including high bandwidth efficiency, fairness among different users, and ultra-high connectivity. While the above properties can be very advantageous, they are obtained under perfect assumptions, such as the availability of perfect synchronization. For the multiuser/multi-cell environments for which NOMA is an essential technology, these assumptions are more likely to be violated. In this exploratory project, the investigator studies the effects of imperfect timing synchronization in multi-user NOMA systems and design high performance NOMA systems.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.