Joint Power Allocation and Beamforming in Heterogeneous Cloud Radio Access Networks

摘要

In this paper, resource allocation for heterogeneous cloud radio access network (HC-RAN) network is investigated. By maximizing the sum rate of all the users in HC-RAN under the power constraints of macro base station (MBS) and remote radio heads (RRHs), the MBS beamforming vectors and RRHs transmit power are jointly optimized. To solve the above nonlinear and non convex programming problem, we propose an alternate iterative algorithm. In the algorithm, the original problem is first divided into two subproblems, one is the power allocation problem for RRHs and the other is the beamforming problem for MBS. For the former problem, the power allocation problem is transformed into equivalent difference-of-convex (D.C.) problem and an iterative power allocation algorithm is proposed. For the latter problem, we derive the structure of the optimal beamforming vectors according to the Lagrangian function, and propose a novel iterative beamforming algorithm. Finally, an alternate iterative power allocation and beamforming algorithm is proposed. The experimental results show that benefit from the joint power and beamforming optimization, the proposed algorithm is effective in improving the sum rate of HC-RAN.