University of Oulu

K. Nguyen, Q. Vu, M. Juntti and L. Tran, "Energy Efficiency Maximization for C-RANs: Discrete Monotonic Optimization, Penalty, and$\ell _{0}$-Approximation Methods," in IEEE Transactions on Signal Processing, vol. 66, no. 17, pp. 4435-4449, 1 Sept.1, 2018. doi: 10.1109/TSP.2018.2849746

Energy efficiency maximization for C-RANs : discrete monotonic optimization, penalty, and ℓ₀-approximation methods

Saved in:
Author: Nguyen, Kien-Giang1; Vu, Quang-Doanh1; Juntti, Markku1;
Organizations: 1Centre for Wireless Communications, University of Oulu, Oulu FI-90014, Finland
2School of Electrical and Electronic Engineering, Uni- versity College Dublin, Dublin 4, U.K.
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 0.3 MB)
Persistent link:
Language: English
Published: Institute of Electrical and Electronics Engineers, 2018
Publish Date: 2018-08-02


We study downlink of multiantenna cloud radio access networks with finite-capacity fronthaul links. The aim is to propose joint designs of beamforming and remote radio head (RRH)-user association, subject to constraints on users’ quality-of-service, limited capacity of fronthaul links and transmit power, to maximize the system energy efficiency. To cope with the limited-capacity fronthaul we consider the problem of RRH-user association to select a subset of users that can be served by each RRH. Moreover, different to the conventional power consumption models, we take into account the dependence of the baseband signal processing power on the data rate, as well as the dynamics of the efficiency of power amplifiers. The considered problem leads to a mixed binary integer program which is difficult to solve. Our first contribution is to derive a globally optimal solution for the considered problem by customizing a discrete branch-reduce-and-bound approach. Since the global optimization method requires a high computational effort, we further propose two suboptimal solutions able to achieve the near optimal performance but with much reduced complexity. To this end, we transform the design problem into continuous (but inherently nonconvex) programs by two approaches: penalty and ℓ0 -approximation methods. These resulting continuous nonconvex problems are then solved by the successive convex approximation framework. Numerical results are provided to evaluate the effectiveness of the proposed approaches.

see all

Series: IEEE transactions on signal processing
ISSN: 1053-587X
ISSN-E: 1941-0476
ISSN-L: 1053-587X
Volume: 66
Issue: 17
Pages: 4435 - 4449
DOI: 10.1109/TSP.2018.2849746
Type of Publication: A1 Journal article – refereed
Field of Science: 213 Electronic, automation and communications engineering, electronics
Funding: This work was supported in part by the Academy of Finland under the projects “Wireless Connectivity for Internet of Everything–Energy Efficient Transceiver and System Design (WiConIE)” undern Grant 297803, “Flexible Uplink-Downlink Resource Management for Energy and Spectral Efficiency Enhancing in Future Wireless Networks (FURMESFuN)” under Grant 31089, and “6Genesis Flagship” under Grant 318927, and in part by the Science Foundation Ireland under Grant 17/CDA/4786. The work of K.-G Nguyen was supported by HPY Research Foundation, Nokia Foundation, Walter Ahlström Foundation, Finnish Foundation for Technology Promotion, Tauno Tönning Foundation.
Academy of Finland Grant Number: 297803
Detailed Information: 297803 (Academy of Finland Funding decision)
310898 (Academy of Finland Funding decision)
318927 (Academy of Finland Funding decision)
Copyright information: © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.