475 research outputs found
Energy Harvesting Cooperative Networks: Is the Max-Min Criterion Still Diversity-Optimal?
This paper considers a general energy harvesting cooperative network with M
source-destination (SD) pairs and one relay, where the relay schedules only m
user pairs for transmissions. For the special case of m = 1, the addressed
scheduling problem is equivalent to relay selection for the scenario with one
SD pair and M relays. In conventional cooperative networks, the max-min
selection criterion has been recognized as a diversity-optimal strategy for
relay selection and user scheduling. The main contribution of this paper is to
show that the use of the max-min criterion will result in loss of diversity
gains in energy harvesting cooperative networks. Particularly when only a
single user is scheduled, analytical results are developed to demonstrate that
the diversity gain achieved by the max-min criterion is only (M+1)/2, much less
than the maximal diversity gain M. The max-min criterion suffers this diversity
loss because it does not reflect the fact that the source-relay channels are
more important than the relay-destination channels in energy harvesting
networks. Motivated by this fact, a few user scheduling approaches tailored to
energy harvesting networks are developed and their performance is analyzed.
Simulation results are provided to demonstrate the accuracy of the developed
analytical results and facilitate the performance comparison.Comment: 30 pages, 7 figure
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