关键词: 认知无线网络, 能量采集, 保密容量, 保密中断概率, 渐近保密中断概率

Abstract: Aiming at the problem that communication in energy harvesting cognitive radio network is easy to be eavesdropped, which seriously threatens information security, two antenna-user joint selection schemes were proposed and the Secrecy Outage Probability (SOP) of the system was analyzed. In a Cognitive Radio Network (CRN) with multiple primary user nodes, multiple secondary user nodes and an eavesdropping node, the energy of Secondary User Transmitting node (SUT) is limited and it transmits information by harvesting the radio frequency energy emitted by primary users. First, based on the joint selection of SUT antennas and secondary user receiving nodes, channel state Information of Eavesdropping channel is Known (IEK) and channel state Information of Eavesdropping channel is Unknown (IEU) selection schemes were proposed. Then, the closed-form expressions of the SOP and asymptotic SOP were derived, the secrecy diversity order and array gain were obtained accordingly. Finally, the performance of two schemes was compared and the influences of different parameters on SOP were analyzed through numerical simulations. The simulation results verify the correctness of the theoretical derivation and show that the security performance of IEK scheme is better than that of IEU scheme. The proposed scheme can reduce the risk of information being eavesdropped under the condition of limited energy for secondary transmitting users, thereby enhancing the security performance of radio frequency energy harvesting cognitive wireless network.

Key words: Cognitive Radio Network(CRN), energy harvesting, secrecy capacity, Secrecy Outage Probability(SOP), asymptotic secrecy outage probability