DocumentCode :
2983386
Title :
Communication by sleeping: Optimizing a relay channel under wake and transmit power costs
Author :
Prabhakaran, Vinod ; Kumar, P.R.
Author_Institution :
Coordinated Sci. Lab., Univ. of Illinois, Champaign, IL, USA
fYear :
2009
fDate :
June 28 2009-July 3 2009
Firstpage :
859
Lastpage :
863
Abstract :
In many low-power networks, the power cost for a node to remain ON to listen to transmissions from other nodes or to transmit to other nodes can constitute a significant part of the total power consumption by the radio. Thus, unlike the traditional relay channel model, under a low power constraint, the relay node cannot stay ON and listen to the entire duration of the transmission. We study the slope of the capacity-power function at zero power for relay channels where the power cost of remaining ON is explicitly taken into account. We show that in this low-power limit, information is conveyed primarily through the ON-OFF activity of the source. The relay node should have significantly more power compared to the source node in order to improve the slope at zero power. The rough intuition is that, in order for a relay node to be useful, it needs to stay ON and listen during a significant portion of the time during which the source node may transmit. This fact limits the utility of the relay to those cases where the it has much higher power than the source node it is trying to help.
Keywords :
AWGN channels; channel capacity; capacity-power function; low-power networks; relay channel; wake and transmit power costs; zero power; AWGN channels; Additive white noise; Contracts; Cost function; Energy consumption; Gaussian noise; Pulse modulation; Radio transmitters; Relays; Timing;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Information Theory, 2009. ISIT 2009. IEEE International Symposium on
Conference_Location :
Seoul
Print_ISBN :
978-1-4244-4312-3
Electronic_ISBN :
978-1-4244-4313-0
Type :
conf
DOI :
10.1109/ISIT.2009.5205616
Filename :
5205616
Link To Document :
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