Research Article
New Insights to Cooperative Spectrum Sensing for Cognitive radios
@INPROCEEDINGS{10.1109/CROWNCOM.2007.4549834, author={Yunxue Liu and Dongfeng Yuan and Qingjia Lin and Quanquan Liang and Qingqing Jin}, title={New Insights to Cooperative Spectrum Sensing for Cognitive radios}, proceedings={2nd International ICST Conference on Cognitive Radio Oriented Wireless Networks and Communications}, publisher={IEEE}, proceedings_a={CROWNCOM}, year={2008}, month={6}, keywords={Cognitive radio; cooperative diversity; spectrum sensing; cooperative spectrum sensing.}, doi={10.1109/CROWNCOM.2007.4549834} }- Yunxue Liu
Dongfeng Yuan
Qingjia Lin
Quanquan Liang
Qingqing Jin
Year: 2008
New Insights to Cooperative Spectrum Sensing for Cognitive radios
CROWNCOM
IEEE
DOI: 10.1109/CROWNCOM.2007.4549834
Abstract
In cognitive radio networks, cognitive users have to detect the presence of primary users. In this paper, we exhibit the improvement in the probability of detection of an user U1 by allowing other user U2 to act as a relay. Assuming that users experience Rayleigh fading, and the decision statistic is the instantaneous power, at the same time, there is no transmit power constraint to relay, we find that the improvement can not be always achieved when the relay U2 receives larger power from a primary user than the user U1 does, which is different from the traditional viewpoint. Conclusions are confirmed by the theoretic proof and numerical simulations. We also exhibit that the improvement can be achieved if and only if the received power at the relay due to the primary user is larger than a certain value, which is named the gain point. We then derive the expression and present an approximated function for determining the gain point.