Energy Efficient Joint Resource Scheduling for Delay-Aware Traffic in Cloud-RAN

In this paper, we focus on the energy efficient joint resource scheduling scheme in time varying Cloud-RAN with delay sensitive traffic. We jointly consider the computation resources provided by baseband units (BBUs), which are modeled as the data processing rate of each virtual machine (VM) provided by the BBUs, and the antenna resources provided by the remote radio heads (RRHs), which are modeled as the beamforming vectors for each user equipment (UE) considering the limited fronthaul capacity and per-UE QoS requirement. Based on the Lyapunov optimization method, we divide the original problem into two subproblems, i.e., the BBU processing rate scheduling problem and the network-wide beamforming strategy problem. The first subproblem can be formulated as a convex programming problem, and we can solve the second subproblem with a weighted minimum mean square error (WMMSE) approach. With the detailed theoretical analysis and simulation results, it is clear that we can achieve a tradeoff between energy efficiency and traffic delay, which can be controlled by the control parameter V.