Many applications running on smart devices generate or request sporadic data packets. Future wireless communication systems are required to accommodate such devices and also provide connectivity for emerging networks such as the Internet of Things. For such sporadic data, orthogonal resource allocation or request-approval based multiple access schemes are inefficient. There is need for designing a new type of grant-free multiple access mechanism that allow a large number of devices to share the communication medium for the delivery of infrequent and small-sized packet data. Desirable features include the ability to accommodate a large number of users, high bandwidth efficiency, high reliability, low latency, and high energy efficiency. It is also desirable that the transmissions can be asynchronous, be robust to multipath propagation and Doppler frequency shift, and require low processing complexity at the receivers.
With this need in mind, the objective of the project is to design novel signaling schemes for such uplink multiple access transmissions and efficient and reliable detection algorithms. The project will design non-orthogonal multiple access schemes including linear precoding based multiple access and coded multiple access that eliminate the need of signaling and scheduling overhead. Low-complexity detection algorithms will be developed that incorporate features of the wireless communications including channel fading and error control coding. The performance of the designed schemes and receiver algorithms will be evaluated using theoretical analysis and simulations. The resulted novel multiple access schemes and detection algorithms can improve the efficiency and throughput of future wireless networks and will be useful for applications such as Internet of Thing and metropolitan area networks.
