Title: Energy efficiency of a per-hop relay selection scheme for sensor networks using cooperative MIMO

Authors: Seung-Jun Kim, Xiaodong Wang, Mohammad Madihian

Addresses: NEC Laboratories America, Princeton, NJ 08540, USA. ' Electrical Engineering Department, Columbia University, New York, NY 10027, USA. ' NEC Laboratories America, Princeton, NJ 08540, USA

Abstract: The energy efficiencies of cooperative Multi-Input Multi-Output (MIMO) schemes are analysed in the context of dense multi-hop wireless sensor networks. The framework of per-hop relay selection is employed, which decides on the next-hop relay based on a metric that captures the trade-off between the performance and the energy cost. Such a framework makes the analysis tractable and suggests a practical way to implement opportunistic cross-layer routing with physical layer adaptation. A few representative cooperative MIMO transmission schemes such as spatial multiplexing, Alamouti coding and selection diversity are analysed as well as an adaptive scheme that switches the transmission strategy based on channel conditions. Simulation results reveal that the cooperative MIMO schemes achieve significant performance enhancement over the Single-Input Single-Output (SISO) scheme when the circuit power consumption is small compared to the transmit power. However, when the circuit power consumption is not negligible compared to the transmit power, the cooperative MIMO may not be energy efficient in the cross-layer setting compared to the SISO scheme.

Keywords: cooperative MIMO; energy efficiency; wireless sensor networks; WSN; cross-layer; per-hop relay selection; wireless networks; simulation.

DOI: 10.1504/IJSNET.2008.019257

International Journal of Sensor Networks, 2008 Vol.4 No.1/2, pp.118 - 129

Published online: 04 Jul 2008 *

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