CIF:Small: Asynchrony and Limited Feedback in Next Generation Multiple Access

Wireless communications have become an integral part of modern society, with significant impact in improving the quality of life. The applications of wireless communications in different parts of the economy and their use in creating and expanding new businesses have created a tremendous demand for higher data throughputs. The unmet need for higher transmission data rates requires designing more efficient wireless communication networks. To increase the efficiency of the next generation of wireless networks, the concurrent transmission of different users using the same resources is unavoidable. Understanding how to deal with asynchrony and limited feedback in the next generation of communication systems, as pursued in this project, is essential for designing the wireless networks of the future. The project will also integrate its findings into coursework and educational initiatives in next-generation wireless networks. Existing wireless communication standards heavily rely on orthogonal multiple access systems in which each user is allocated orthogonal time/frequency/code resources. This is not suitable for massive connectivity and simultaneous transmission of a huge amount of data. Therefore, more efficient multiple access methods that allow multiple users to simultaneously access the same wireless resources have been proposed as a remedy. The paradigm shift from orthogonal multiple access to other possible multiple access designs that are, for example, non-orthogonal and grant-free is dubbed next generation multiple access (NGMA). While perfect synchronization and channel state information assumptions may be reasonable for orthogonal multiple access, such assumptions are neither realistic nor desirable for NGMA systems. Therefore, there is an unmet need to revisit the role of asynchrony and limited channel state information in NGMA systems as considered in this project. Analyzing the performance and the design of different NGMA systems with asynchronous transmission and limited feedback will be performed in this project. 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.