title: Reciprocally-Benefited Secure Transmission for Spectrum Sensing-Based Cognitive Radio Sensor Networks.
abstract: The rapid proliferation of independently-designed and -deployed wireless sensor networks extremely crowds the wireless spectrum and promotes the emergence of cognitive radio sensor networks (CRSN). In CRSN, the sensor node (SN) can make full use of the unutilized licensed spectrum, and the spectrum efficiency is greatly improved. However, inevitable spectrum sensing errors will adversely interfere with the primary transmission, which may result in primary transmission outage. To compensate the adverse effect of spectrum sensing errors, we propose a reciprocally-benefited secure transmission strategy, in which SN's interference to the eavesdropper is employed to protect the primary confidential messages while the CRSN is also rewarded with a loose spectrum sensing error probability constraint. Specifically, according to the spectrum sensing results and primary users' activities, there are four system states in this strategy. For each state, we analyze the primary secrecy rate and the SN's transmission rate by taking into account the spectrum sensing errors. Then, the SN's transmit power is optimally allocated for each state so that the average transmission rate of CRSN is maximized under the constraint of the primary maximum permitted secrecy outage probability. In addition, the performance tradeoff between the transmission rate of CRSN and the primary secrecy outage probability is investigated. Moreover, we analyze the primary secrecy rate for the asymptotic scenarios and derive the closed-form expression of the SN's transmission outage probability. Simulation results show that: (1) the performance of the SN's average throughput in the proposed strategy outperforms the conventional overlay strategy; (2) both the primary network and CRSN benefit from the proposed strategy.
authors.affiliation: Department of Information and Communication Engineering, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China. wangdw@stu.xjtu.edu.cn.|Shaanxi Smart Networks and Ubiquitous Access Research Center, Xi'an 710049, China. wangdw@stu.xjtu.edu.cn.
authors.forename: Dawei
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Information and Communication Engineering, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China. pyren@mail.xjtu.edu.cn.|Shaanxi Smart Networks and Ubiquitous Access Research Center, Xi'an 710049, China. pyren@mail.xjtu.edu.cn.
authors.forename: Pinyi
authors.initials: P
authors.lastname: Ren
authors.affiliation: Department of Information and Communication Engineering, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China. duqinghe@mail.xjtu.edu.cn.|Shaanxi Smart Networks and Ubiquitous Access Research Center, Xi'an 710049, China. duqinghe@mail.xjtu.edu.cn.
authors.forename: Qinghe
authors.initials: Q
authors.lastname: Du
authors.affiliation: Department of Information and Communication Engineering, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China. lisun@mail.xjtu.edu.cn.|Shaanxi Smart Networks and Ubiquitous Access Research Center, Xi'an 710049, China. lisun@mail.xjtu.edu.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Sun
authors.affiliation: Department of Information and Communication Engineering, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China. wangyichen0819@mail.xjtu.edu.cn.|Shaanxi Smart Networks and Ubiquitous Access Research Center, Xi'an 710049, China. wangyichen0819@mail.xjtu.edu.cn.|Key Laboratory of Wireless Sensor Network & Communication, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China. wangyichen0819@mail.xjtu.edu.cn.
authors.forename: Yichen
authors.initials: Y
authors.lastname: Wang
keywords: cognitive radio sensor network; power allocation; secrecy outage probability; spectrum sensing error