Cooperative transmissions for secondary spectrum access in cognitive radios |
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| Authors: | Zeyang Dai Jian Liu Keping Long |
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| Affiliation: | 1. School of Communication & Information Engineering (SCIE), University of Electronic Science and Technology of?China (UESTC), Chengdu, China;2. Institute of Advanced Network Technology and New Services (ANTS), University of Science and Technology Beijing?(USTB), Beijing, China |
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| Abstract: | In cognitive radio networks (CRNs), the primary users (PUs) and secondary users (SUs) will interfere with each other, which may severely degrade the performances of both primary and secondary transmissions. In this paper, we propose a two‐phase cognitive transmission (TCT) protocol for secondary spectrum access in CRNs, aiming at improving the secondary transmission performance while guaranteeing the quality‐of‐service (QoS) of primary transmissions. In TCT protocol, SUs gain the opportunities to access the licensed spectrum through assisting primary transmissions using superposition coding (SC), where SUs limit their transmit power to satisfy a given primary QoS requirement and also employ interference cancelation technique to mitigate the interference from PUs. Under the constraint of satisfying a required primary outage probability, we derive the closed‐form expressions of secondary outage probabilities over Rayleigh fading channels for proposed TCT protocol. Numerical and simulation results reveal that, with a guaranteed primary outage probability, TCT achieves better secondary transmission performance than traditional case. Copyright © 2013 John Wiley & Sons, Ltd. |
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| Keywords: | cognitive radio cooperative communication spectrum sharing superposition coding interference cancelation outage probability |
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