Abstract
Power control is important in interference-limited cellular, ad-hoc, and cognitive underlay networks, when the objective is to ensure a certain quality of service to each connection. Power control has been extensively studied in this context, including distributed algorithms that are particularly appealing in ad-hoc and cognitive settings. A long-standing issue is that the power control problem may be infeasible, thus requiring appropriate admission control. The power and admission control parts of the problem are tightly coupled, but the joint optimization problem is NP-hard. We begin with a convenient reformulation which enables a disciplined convex approximation approach. This leads to a centralized approximate solution that is numerically shown to outperform the prior art, and even yield close to optimal results in certain cases-at affordable complexity. The issue of imperfect channel state information is also considered. A distributed implementation is then developed, which alternates between distributed approximation and distributed deflation-reaching consensus on a user to drop, when needed. Both phases require only local communication and computation, yielding a relatively lightweight distributed algorithm with the same performance as its centralized counterpart.
Original language | English (US) |
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Article number | 6059438 |
Pages (from-to) | 4110-4121 |
Number of pages | 12 |
Journal | IEEE Transactions on Wireless Communications |
Volume | 10 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2011 |
Bibliographical note
Funding Information:Manuscript received August 3, 2010; revised January 18, 2011 and April 6, 2011; accepted August 30, 2011. The associate editor coordinating the review of this paper and approving it for publication was S. Valee. A preliminary conference version of parts of this work appear in Proc. IEEE IWCMC 2008 [20], and IEEE ICASSP 2010 [21]. I. Mitliagkas and N. D. Sidiropoulos were with the Department of Electronic and Computer Engineering, Technical University of Crete, 73100 Chania - Crete, Greece, where the work was supported in part by ARL/ERO contract W911NF-09-1-0004. I. Mitliagkas is now at UT Austin. N. D. Sidiropoulos (corresponding author) is with the Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455 - U.S.A. (e-mail: nikos@ece.umn.edu). A. Swami is with the Army Research Lab, Adelphi, MD, 20783, U.S.A. Digital Object Identifier 10.1109/TWC.2011.100811.101381
Keywords
- Power control
- ad-hoc
- admission control
- and cognitive radio networks
- convex optimization
- distributed implementation
- dual decomposition
- peer-to-peer
- sub-gradient