Beamforming Design and BBU Computation Resource Allocation for Power Minimization in Green C-RAN

Abstract

This article focuses on the joint optimization of beamforming and baseband unit (BBU) computing resource allocation, with the goal of minimizing the network power consumption for the downlink cloud radio access network (C-RAN). To reduce the computational complexity, we split the joint optimization problem into two subproblems for transmission and computation respectively. The subproblem of minimizing power consumption for transmission is a network-wide beamforming design problem. By using positive semi-definite relaxation (SDR) technology, we transform it into a convex positive semi-definite programming (SDP) problem, which can be solved with effect. For the second subproblem, which intends to minimize the power consumption for computation, a computing resource allocation scheme based on the Simulated Annealing algorithm is proposed, which minimizes the active servers in the BBU pool to save power while meeting each user’s computing resource requirement. The simulation results demonstrate that the algorithm proposed in this paper has a better performance compared with the existing algorithms.