Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
An Optimization Approach to Joint Cell and Power Allocation in Wireless Communication Networks
KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Since the seminal paper by Knopp and Humblet that showed that the system throughput of a singlecell system is maximized if only one terminal transmits at a time, there has been a large interest in opportunistic communications and its relation to various fairness measures. On the other hand, in multicell systems there is a need to allocate transmission power such that some overall utility function is maximized typically under fairness constraints. Furthermore, in multicell systems the degree of resource allocation freedom includes the serving cell selection that allows for load balancing and thereby the efficient use of radio resources. In this paper we formulate the joint serving cell selection (link selection) and power allocation problem as an optimization task whose purpose is to maximize either the minimum user throughput or the multicellsum throughput. The max-min problem and a simplified max throughput problem are both NP-hard and we therefore propose heuristic solution approaches. We present numerical results that give new and valuable insights into the trade off between fair and sum throughput optimal joint resource allocation strategies.

National Category
Computational Mathematics
Identifiers
URN: urn:nbn:se:kth:diva-40401OAI: oai:DiVA.org:kth-40401DiVA: diva2:441097
Note
Condensed version published in IEEE International Conference on Communications QC 20110914Available from: 2011-09-14 Created: 2011-09-14 Last updated: 2011-09-15Bibliographically approved
In thesis
1. Optimization of Joint Cell, Channel and Power Allocation in Wireless Communication Networks
Open this publication in new window or tab >>Optimization of Joint Cell, Channel and Power Allocation in Wireless Communication Networks
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In this thesis we formulate joint cell, channel and power allocation problems within wireless communication networks. The objectives are to maximize the user with mini- mum data throughput (Shannon capacity) or to maximize the total system throughput, referred to as the max-min and max-sum problem respectively. The complexity is stud- ied together with proposed optimization- and heuristic-based approaches.

In the first paper an overall joint cell, channel and power allocation max-min prob- lem is formulated. We show that the decision problem is NP-hard and that the op- timization problem is not approximable unless P is equal to NP, for instances with a sufficiently large number of channels. Further, it follows that for a feasible binary cell and channel allocation, the remaining continuous power allocation optimization problem is still not approximable unless P is equal to NP. In addition, it is shown that first-order optimality conditions give global optimum of the single channel power al- location optimization problem, although the problem is in general not convex.

In the following two papers heuristics for solving the overall problem are proposed. In the second paper we consider the single channel problem with convex combinations of the max-min and the max-sum objective functions. This variable utility provides the ability of tuning the amount of fairness and total throughput. The third paper investi- gates the multiple channel setting. On a system with three cells, eight mobile users and three channels, we perform an exhaustive search over feasible cell and channel alloca- tions. The exhaustive search is then compared to the less computationally expensive heuristic approaches, presenting potential earnings to strive for. A conclusion is that several of the proposed heuristics perform very well.

The final paper incorporates fixed relay stations into the overall joint cell, channel and power allocation max-min problem. The complexity is inherited from the formula- tion without relay stations. Further, we propose a heuristic channel allocation approach that shows good performance, compared to an optimization based approach, in numer- ical simulations on the relay setting.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2011. xxiv, 20 p.
Series
Trita-MAT. OS, ISSN 1401-2294 ; 11:05
Keyword
Wireless multicell networks, Optimization, OFDMA, Shannon capacity, Complexity, NP-hard, Relays, Allocation problems, Heuristic algorithms
National Category
Computational Mathematics Communication Systems Telecommunications
Identifiers
urn:nbn:se:kth:diva-40274 (URN)978-91-7501-084-7 (ISBN)
Public defence
2011-10-07, D3, Lindstedtsvägen 5, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note
Financial support by the Swedish Foundation for Strategic Research (SSF) QC 20110915Available from: 2011-09-15 Created: 2011-09-14 Last updated: 2011-09-15Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Fallgren, MikaelOddsdóttir, Æsa Hildur
By organisation
Optimization and Systems Theory
Computational Mathematics

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 59 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf