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In cognitive radio networks (CRNs), spectrum sensing data falsification (SSDF) is one of the most typical attack which hugely degrades the detection performance of cooperative spectrum sensing (CSS). SSDF and defense strategies have been an active field of research, but countermeasures of existing researches are sensitive to the number of malicious users (MUs). In this paper, we propose a two-stage...
Recently, researches on mobile cognitive radio network (CRN) has been paid more attention to, involving spectrum sensing, power control and spectrum access, while no schemes considering both the power and spectrum assignment at the same time. In this paper, an efficient resource allocation (RA) scheme is proposed for the orthogonal frequency division multiple access (OFDMA)-based mobile underlay CRN...
In a cognitive radio system, proper configuration of sensing duration enables maximization of the data throughput. However, no existing straightforward formula is available, which is desirable in the mobile context due to tightness of computation time. A set of closed-form approximate formulae of optimal sensing duration for cognitive radio are derived under different signal to noise ratio (SNR)....
The opportunistic spectrum access in cognitive radio networks has always played a key role in improving the performance of secondary users. In this paper, we propose an optimal spectrum access strategy for multi-channel access of secondary users under multiple physical considerations. Firstly we integrate path loss and Nakagami-m fading of primary and secondary links with imperfect spectrum sensing...
In this paper, we propose a novel proportional fair scheduling algorithm for MAC-layer sensing in the cognitive radio networks (CRNs). According to the secondary user (SU) channel state information and primary user (PU) traffic patterns, the SUs are adaptively scheduled to carry out sensing and transmission in different channels. Moreover, we jointly consider multiple important design factors in the...
This paper considers cooperative sensing in cognitive networks under Spectrum Sensing Data Falsification attack (SSDF) in which malicious users can intentionally send false sensing information. One effective method to deal with the SSDF attack is the q-out-of-m scheme, where the sensing decision is based on q sensing reports out of m polled nodes. The major limitation with the q-out-of-m scheme is...
In cognitive radio systems, secondary users can be coordinated to perform cooperative spectrum sensing to overcome the hidden terminal problem. However, when the number of cooperative users tends to be very large, too many cooperative users will make the whole sensing time intolerantly long and huge consumption of system resource. In this paper, we studied optimal number of secondary users in cooperative...
In cognitive radio systems, cooperative spectrum sensing is employed to detect the presence of primary user quickly and accurately. In this paper, we propose a new TDMA cooperation protocol to improve the overall agility and spectrum efficiency compared to the existing protocols. By allowing the cognitive users operating in the same band to cooperate, the detection time is reduced and thus the average...
Cooperative spectrum sensing can mitigate the effects of shadowing and fading. However, when the number of cognitive users is very large, the bandwidth for reporting their sensing results will be insufficient. In order to eliminate the fail sensing problem for a cognitive radio system with double threshold detector, a new cooperative spectrum sensing algorithm is presented based on reputation in this...
In a cognitive radio network, cooperative spectrum sensing is conducted among the secondary users so as to improve the sensing performance. However, it's not necessary to cooperate all users to perform spectrum sensing while achieve a given error bound. In this paper, we investigate the problem of optimal number of secondary users in cooperative spectrum sensing. Moreover, an efficient and robust...
Spectrum sensing is a critical phase in building a cognitive radio network. However, when the number of cognitive user is very large, the bandwidth for reporting cognitive users' sensing results will be insufficient. In this paper, we propose a new cooperative spectrum sensing algorithm to alleviate the bandwidth problem of reporting channel. Compared with conventional method, only the cognitive users...
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