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Energy-Efficient Decentralized Cooperative Routing in Wireless Networks

Madan, Ritesh; Mehta, Neelesh B.; Molisch, Andreas LU and Zhang, Jin (2009) 45th Annual Allerton Conference on Communication, Control and Computing In Ieee Transactions On Automatic Control 54(3). p.512-527
Abstract
Wireless adhoc networks transmit information from a source to a destination via multiple hops in order to save energy and, thus, increase the lifetime of battery-operated nodes. The energy savings can be especially significant in cooperative transmission schemes, where several nodes cooperate during one hop to forward the information to the next node along a route to the destination. Finding the best multi-hop transmission policy in such a network which determines nodes that are involved in each hop, is a very important problem, but also a very difficult one especially when the physical wireless channel behavior is to be accounted for and exploited. We model the above optimization problem for randomly fading channels as a decentralized... (More)
Wireless adhoc networks transmit information from a source to a destination via multiple hops in order to save energy and, thus, increase the lifetime of battery-operated nodes. The energy savings can be especially significant in cooperative transmission schemes, where several nodes cooperate during one hop to forward the information to the next node along a route to the destination. Finding the best multi-hop transmission policy in such a network which determines nodes that are involved in each hop, is a very important problem, but also a very difficult one especially when the physical wireless channel behavior is to be accounted for and exploited. We model the above optimization problem for randomly fading channels as a decentralized control problem - the channel observations available at each node define the information structure, while the control policy is defined by the power and phase of the signal transmitted by each node. In particular, we consider the problem of computing an energy-optimal cooperative transmission scheme in a wireless network for two different channel fading models: (i) slow fading channels, where the channel gains of the links remain the same for a large number of transmissions, and (ii) fast fading channels, where the channel gains of the links change quickly from one transmission to another. For slow fading, we consider a factored class of policies (corresponding to local cooperation between nodes), and show that the computation of an optimal policy in this class is equivalent to a shortest path computation on an induced graph, whose edge costs can be computed in a decentralized manner using only locally available channel state information (CSI). For fast fading, both CSI acquisition and data transmission consume energy. Hence, we need to jointly optimize over both these; we cast this optimization problem as a large stochastic optimization problem. We then jointly optimize over a set of CSI functions of the local channel states, and a corresponding factored class of control policies corresponding to local cooperation between nodes with a local outage constraint. The resulting optimal scheme in this class can again be computed efficiently in a decentralized manner. We demonstrate significant energy savings for both slow and fast fading channels through numerical simulations of randomly distributed networks. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
multiple output (MIMO) systems, multiple input, Ad hoc networks, channel state information (CSI)
in
Ieee Transactions On Automatic Control
volume
54
issue
3
pages
512 - 527
publisher
IEEE--Institute of Electrical and Electronics Engineers Inc.
conference name
45th Annual Allerton Conference on Communication, Control and Computing
external identifiers
  • wos:000264397200008
  • scopus:63449103477
ISSN
0018-9286
DOI
10.1109/TAC.2009.2012979
language
English
LU publication?
yes
id
4264a745-116d-49c0-bf37-13df6490bb1a (old id 1401851)
date added to LUP
2009-06-15 09:42:53
date last changed
2017-10-01 04:30:41
@inproceedings{4264a745-116d-49c0-bf37-13df6490bb1a,
  abstract     = {Wireless adhoc networks transmit information from a source to a destination via multiple hops in order to save energy and, thus, increase the lifetime of battery-operated nodes. The energy savings can be especially significant in cooperative transmission schemes, where several nodes cooperate during one hop to forward the information to the next node along a route to the destination. Finding the best multi-hop transmission policy in such a network which determines nodes that are involved in each hop, is a very important problem, but also a very difficult one especially when the physical wireless channel behavior is to be accounted for and exploited. We model the above optimization problem for randomly fading channels as a decentralized control problem - the channel observations available at each node define the information structure, while the control policy is defined by the power and phase of the signal transmitted by each node. In particular, we consider the problem of computing an energy-optimal cooperative transmission scheme in a wireless network for two different channel fading models: (i) slow fading channels, where the channel gains of the links remain the same for a large number of transmissions, and (ii) fast fading channels, where the channel gains of the links change quickly from one transmission to another. For slow fading, we consider a factored class of policies (corresponding to local cooperation between nodes), and show that the computation of an optimal policy in this class is equivalent to a shortest path computation on an induced graph, whose edge costs can be computed in a decentralized manner using only locally available channel state information (CSI). For fast fading, both CSI acquisition and data transmission consume energy. Hence, we need to jointly optimize over both these; we cast this optimization problem as a large stochastic optimization problem. We then jointly optimize over a set of CSI functions of the local channel states, and a corresponding factored class of control policies corresponding to local cooperation between nodes with a local outage constraint. The resulting optimal scheme in this class can again be computed efficiently in a decentralized manner. We demonstrate significant energy savings for both slow and fast fading channels through numerical simulations of randomly distributed networks.},
  author       = {Madan, Ritesh and Mehta, Neelesh B. and Molisch, Andreas and Zhang, Jin},
  booktitle    = {Ieee Transactions On Automatic Control},
  issn         = {0018-9286},
  keyword      = {multiple output (MIMO) systems,multiple input,Ad hoc networks,channel state information (CSI)},
  language     = {eng},
  number       = {3},
  pages        = {512--527},
  publisher    = {IEEE--Institute of Electrical and Electronics Engineers Inc.},
  title        = {Energy-Efficient Decentralized Cooperative Routing in Wireless Networks},
  url          = {http://dx.doi.org/10.1109/TAC.2009.2012979},
  volume       = {54},
  year         = {2009},
}