Joint User Association and Downlink Beamforming for Green Cloud-RANs with Limited Fronthaul

TL;DR

This paper introduces a joint user association and downlink beamforming scheme for green Cloud-RANs with limited fronthaul capacity, aiming to minimize power consumption through an efficient convex optimization approach.

Contribution

It formulates the problem as a mixed integer nonlinear program and proposes a polynomial-time inflation algorithm to solve it effectively.

Findings

The proposed algorithm reduces network power consumption.

Simulation shows improved performance over LTE-A schemes.

Efficiently handles limited fronthaul constraints.

Abstract

With the explosive growth of smart devices and mobile data traffic, limited fronthaul capacity has become a notable bottleneck of green communication access networks, such as cloud radio access networks(C-RANs). In this paper, we proposed a joint user association and downlink beamforming scheme for green C-RANs to minimize the network power consumption with the limited fronthaul links. We first formulate the design problem as a mixed integer nonlinear programming (MINLP), and then transformed the MINLP problem into a mixed integer second-order cone program (MI-SOCP) which is a convex program when the integer variables are fixed. By relaxing the integer variables to continuous ones, an inflation algorithm, which can be finished within polynomial time, was proposed to solved the problem. The simulation results are presented to validate the effectiveness of our proposed algorithm compared with the the scheme adopted by LTE-A.