Wanglab Ph.D. graduate Aimin Tang clinched 2018 SJTU Distinguished Doctoral Dissertation Award with his dissertation on “full duplex communications and coded caching for 5G networks”, according to a recent SJTU announcement. The SJTU distinguished doctoral dissertation award aims to foster an atmosphere of upholding scholarism and innovation, encourage original scientific research by doctoral students under the meticulous care of their advisors, upgrade the quality of doctoral degree dissertations, and strengthen international competitiveness of the doctoral graduates.

Mobile internet has become an indispensable part of human life, as well as a key foundation of modern economic development of a country. Infrastructure of mobile internet heavily relies on the support of mobile cellular networks, especially the forthcoming 5G networks. Research and development of 5G has been regarded as a key field of competition for super powers vying for long-term development in the future.

Two advanced technologies, full duplex communications and coded caching, were explored in Dr. Tang’s dissertation for 5G networks under the guidance of his advisor Professor Xudong Wang. In Dr. Tang’s dissertation, full duplex communication was explored in 5G access networks in order to improve the network performance (spectrum efficiency, fairness, etc.). Besides, coded caching was developed to effectively alleviate congestions at base stations for 5G backhaul networks with heterogeneous channel conditions.

The dissertation first proposed an MAC protocol, which leverages the physical layer “capture-effect” to address the problem of efficient networking in full-duplex and half-duplex hybrid systems. Second, a high efficient CSMA/CD based random access MAC protocol for wireless OFDMA system was proposed. Then, a novel full-duplex D2D protocol was developed to extend the existing D2D modes so that the spectral efficiency was highly increased. The dissertation also proposed a brand new coded transmission mechanism to address the critical heterogeneous channel condition problem for the research on coded caching in backhaul networks, and completed both the algorithm design and theoretical analysis of coded caching for 5G heterogeneous backhaul networks, which took the lead in the world and provided research guidelines for the follow-up studies.