Joint User-Association and Resource-Allocation in Virtualized C-RAN

The Cloud Radio Access Network (C-RAN), which is a novel architecture, has been proposed as a promising solution to overcome the challenges of Next Generation (5G) cellular networks, in terms of efficiency, capacity, scalability, flexibility and sustainability in a cost-effective way. In this paper, we develop an efficient resource allocation scheme in the fronthaul-constrained C-RAN to support users of different slices (service providers). Multiple slices (service providers) share the resource of an InP, each slice has its own quality-of-service (QoS) requirement. In specific, we formulate an optimization problem for maximizing network throughput by joint subcarrier, power allocation and user-RRH association assignment in the downlink transmission of C-RAN. This problem is NP-hard, therefore, we introduce a two-step suboptimal algorithm to solve it. The original problem is decomposed into joint power and subcarrier allocation subproblem and user-RRH association assignment subproblem. Firstly, we solving the user-RRH association subproblem under the fronthaul capacity constraint by the binary search algorithm. Then the dual decomposition algorithm is used to solve the power and subcarrier allocation subproblem. Simulation results demonstrate the effectiveness of our proposed algorithm.