Joint User Association and Power Allocation for Millimeter-Wave Ultra-Dense Networks

摘要: To meet the demand of various high-speed data rate services as well serving an exponential increment mobile devices, millimeter-Wave (mmWave) communication in ultra-dense networks (UDNs) has been considered a promising technology for future wireless systems. By deploying multiple small-cell base stations (SBSs), dense topology combining high frequency mmWave is expected to grow not only users (UEs) throughput but also energy efficiency (EE) whole networks. Exploiting benefits from and UDNs, this paper, we introduce new approach jointly optimizing SBS-UE association power allocation maximize system EE while guaranteeing quality service (QoS) constraints each UE. Specifically, fairness among UEs taken into account by formulating UE maxmin problem. Unfortunately, such problem poses challenge since it reflects complex mixed-integer non-convex On other hand, nonconvexity structure, which impossible handle with concurrently. Tackling those issues, alternating descent method proposed separate primal optimization two subproblems one-by-one at iteration. In particular, reformulated using penalty approach. Then, successive convex programming developed convert simple quadratic functions Numerical results are provided demonstrate convergence low-complexity our schemes, where objective function guaranteed