Skip to main content
Kent Academic Repository

Joint User Selection and Energy Minimization for Ultra-Dense Multi-channel C-RAN with Incomplete CSI

Pan, Cunhua, Zhu, Huiling, Gomes, Nathan J., Wang, Jiangzhou (2017) Joint User Selection and Energy Minimization for Ultra-Dense Multi-channel C-RAN with Incomplete CSI. IEEE Journal on Selected Areas in Communications, 35 (8). pp. 1809-1824. ISSN 0733-8716. (doi:10.1109/JSAC.2017.2710858) (KAR id:61755)


This paper provides a unified framework to deal with the challenges arising in dense cloud radio access networks (C-RAN), which include huge power consumption, limited fronthaul capacity, heavy computational complexity, unavailability of full channel state information (CSI), etc. Specifically, we aim to jointly optimize the remote radio head (RRH) selection, user equipment (UE)-RRH associations and beam-vectors to minimize the total network power consumption (NPC) for dense multi-channel downlink C-RAN with incomplete CSI subject to per-RRH power constraints, each UE’s total rate requirement, and fronthaul link capacity constraints. This optimization problem is NP-hard. In addition, due to the incomplete CSI, the exact expression of UEs’ rate expression is intractable. We first conservatively replace UEs’ rate expression with its lower-bound. Then, based on the successive convex approximation (SCA) technique and the relationship between the data rate and the mean square error (MSE), we propose a single-layer iterative algorithm to solve the NPC minimization problem with convergence guarantee. In each iteration of the algorithm, the Lagrange dual decomposition method is used to derive the structure of the optimal beam-vectors, which facilitates the parallel computations at the Baseband unit (BBU) pool. Furthermore, a bisection UE selection algorithm is proposed to guarantee the feasibility of the problem. Simulation results show the benefits of the proposed algorithms and the fact that a limited amount of CSI is sufficient to achieve performance close to that obtained when perfect CSI is possessed.

Item Type: Article
DOI/Identification number: 10.1109/JSAC.2017.2710858
Projects: intelligent Converged network consolidating Radio and optical access aRound USer equipment, iNtellIgent, heteRogeneous, VirtuAlised Networking infrAstructure
Uncontrolled keywords: Cloud radio access network (C-RAN), 5G ultra-dense networks, limited fronthaul capacity, incomplete CSI
Subjects: T Technology > TK Electrical engineering. Electronics. Nuclear engineering > TK5101 Telecommunications
Divisions: Divisions > Division of Computing, Engineering and Mathematical Sciences > School of Engineering and Digital Arts
Funders: Organisations -1 not found.
Depositing User: Huiling Zhu
Date Deposited: 17 May 2017 09:51 UTC
Last Modified: 04 May 2024 03:10 UTC
Resource URI: (The current URI for this page, for reference purposes)

University of Kent Author Information

  • Depositors only (login required):

Total unique views for this document in KAR since July 2020. For more details click on the image.