Energy-effective Offloading Scheme in UAV-assisted C-RAN System

In this paper, we aim to minimize the total power of all the user equipments (UEs) by jointly optimizing user association, computation capacity, transmit power, and the location of UAVs in an unmanned aerial vehicles (UAVs) assisted cloud radio access network (C-RAN). In order to solve this non-convex problem, we use block coordinate descent (BCD) and successive convex approximation (SCA) to transform this problem into four tractable subproblems, and an effective algorithm by solving four subproblems iteratively. The simulation results demonstrate that the proposed algorithm can greatly reduce the total power consumption of UEs.

I. Introduction

According to a report by Cisco [1], the connection of mobile devices is estimated up to 29.3 billion by the year of 2023. It is urgent to introduce new techniques to improve the performance of the existing wireless communication. Unmanned aerial vehicles (UAVs) assisted communications as one of the most effective solutions have attracted extensive research attention [2]. UAV-assisted networks can provide higher mobility and probability of line-of-sight (LoS) networks links between UAVs and user equipments (UEs). UAVs can be utilized as flying relay [3] and wireless power transfer station [4], etc.