Downlink and Uplink Energy Minimization Through User Association and Beamforming in Cloud RAN
The Cloud Radio Access Network (C-RAN) concept, in which densely deployed Access Points (APs) are empowered by cloud computing to cooperatively support Mobile Users (MUs), to improve mobile data rates, has been recently proposed. However, the high density of active (\"On\") APs results in severe interference and also inefficient energy consumption. Moreover, the growing popularity of highly interactive applications with stringent UpLink (UL) requirements, e.g. network gaming and real-time broadcasting by wireless users, means that the UL transmission is becoming more crucial and requires special attention. Therefore in this paper, the authors propose a joint DownLink (DL) and UL MU-AP association and beam-forming design to coordinate interference in the C-RAN for energy minimization, a problem which is shown to be NP hard.