Cluster-based energy-efficient joint user association and resource allocation for B5G ultra-dense network

Abstract Control and user plane split (CUPS) aided ultra-dense network (UDN) is considered as a promising technology in the fifth generation (5G) networks and will undoubtedly develop in beyond 5G (B5G), which can reduce control overhead and improve the system throughput of network. However, the serious interference and increased power consumption of ultra-dense networking due to densely deployed base stations are also inevitable. To mitigate the interference and improve the system energy efficiency (EE) in CUPS-based B5G UDN, we propose a cluster-based energy-efficient joint user association and resource allocation scheme. First, an improved clustering algorithm is introduced in base station clustering stage. We use orthogonal resource allocation within cluster to reduce co-tier interference and reuse the frequency resource in different clusters. Then, a joint user association, sub-channel allocation and power coordination problem is modeled as a mixed-integer programming problem, which is transformed into a convex optimization problem by using alternative optimization and variable relaxation methods. Finally, we analyze the complexity of our proposed algorithm. Simulation results show that our proposed algorithm can reduce the interference and approximately boost 88% on EE of CUPS-based B5G UDN.