DocumentCode :
1400283
Title :
Achievable rates for cognitive radios opportunistically permitting excessive secondary-to-primary interference
Author :
Chang, Woohyuk ; Chung, Sae-Young ; Lee, Yong H.
Author_Institution :
Dept. of Electr. Eng., KAIST, Daejeon, South Korea
Volume :
9
Issue :
2
fYear :
2010
fDate :
2/1/2010 12:00:00 AM
Firstpage :
674
Lastpage :
683
Abstract :
We propose a cognitive radio system in fading environments where the secondary sender opportunistically violates the secondary-to-primary (S-P) interference power limit. Assuming a slowly-varying fading interference channel with two-senders and two-receivers, the primary sender adjusts its rate and power depending on its own channel, while ignoring the secondary user. Through an optimization process, the secondary sender´s rate and power are determined and the decision is made on whether the secondary sender violates the S-P interference power limit. The primary receiver removes the effect of excessive S-P interference by multiuser decoding (MUD) which jointly decodes the primary and secondary senders´ data. Achievable rates of the proposed system are examined by computer simulation. It was observed that the proposed system tends to violate the SP interference power limit when the S-P channel gain is larger than the other channel gains. Remarkably, the proposed system can provide a considerably high data rate for the secondary user even without sacrificing the data rate for the primary user over a wide range of signal-to-noise ratios.
Keywords :
cognitive radio; decoding; fading channels; radiofrequency interference; channel gain; cognitive radio system; computer simulation; multiuser decoding; optimization process; primary user; secondary user; secondary-to-primary interference power limit; signal-to-noise ratios; slowly-varying fading interference channel; Chromium; Cognitive radio; Communication system control; Computer simulation; Decoding; Degradation; Fading; Interference channels; Multiuser detection; Signal to noise ratio; Cognitive radio, spectrum sharing, interference channel, interference-temperature, power control, water-filling.;
fLanguage :
English
Journal_Title :
Wireless Communications, IEEE Transactions on
Publisher :
ieee
ISSN :
1536-1276
Type :
jour
DOI :
10.1109/TWC.2010.02.081083
Filename :
5403548
Link To Document :
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