Impact of secondary user communication on security communication of primary user

• Published in: Security and communication networks Vol. 8; no. 18; pp. 4177 - 4190
• Main Authors: Sibomana, Louis, Tran, Hung, Tran, Quang Anh
• Format: Journal Article
• Language: English
• Published: London Blackwell Publishing Ltd 01.12.2015; John Wiley & Sons, Inc
• Subjects: achievable rate; Channels; Codes; Cognitive radio; cognitive radio network; Communication; Communications systems; Exact solutions; Interference; Mathematical analysis; Mathematical models; Networks; Outages; secrecy capacity; secrecy outage probability; Security; symbol error probability
• ISSN: 1939-0114; 1939-0122; 1939-0122
• DOI: 10.1002/sec.1333

Cognitive radio network concept has been considered as a promising solution to improve the spectrum utilization. However, it may be vulnerable to security problems as the primary user (PU) and secondary user (SU) access the same resource. In this paper, we consider a system model where an eavesdropper (EAV) illegally listens to the PU communication in the presence of a SU transmitter (SU‐Tx) communicating with a SU receiver (SU‐Rx). The SU‐Tx transmit power is subject to the peak transmit power constraint of the SU and outage probability constraint of the PU. Given this context, the effect of the interference from the SU‐Tx to the EAV on the primary system security is investigated. In particular, analytical expressions of the probability of existence of non‐zero secrecy capacity and secrecy outage probability of the PU are derived. Moreover, the performance analysis of the secondary network is examined where closed‐form expressions of the symbol error probability and achievable rate are presented. Numerical examples are provided to evaluate the impact of the primary system parameters and channel conditions among users on the system performance of secondary and primary networks. Interestingly, our results reveal a fact that the security of the primary network strongly depends on the channel condition of the SU‐Tx to the EAV link and the transmit power policy of the SU‐Tx. Copyright © 2015 John Wiley & Sons, Ltd. In the presence of an eavesdropper (EAV) who passively overhears the primary communication, intentional interference from the secondary user to the EAV is exploited to improve the primary network security in a spectrum sharing. The analysis and the results presented in this paper provide valuable insights to system designers where the interference can be managed to bring more benefit to the heterogeneous wireless networks with secrecy constraints.