Physical layer secrecy performance analysis of relay selection in a cooperative wireless network

This paper investigates the performance of physical (PHY) layer secrecy in a cooperative relaying with opportunistic relay selection, where an eavesdropper intercepts the transmit signals between the authorized users. At first, theoretical expressions are derived for three performance criteria for evaluating the PHY security, namely: the secrecy outage probability, the average of secrecy capacity, and the probability of non-zero secrecy capacity. Then the secrecy performance in information transmissions is investigated. Moreover, using the computer simulations, the validity of the derived expressions and the carried out analyses are examined and verified. To show the enhancement on the secrecy performance in the presented system that employs opportunistic relay selection, the secrecy outage probabilities of the opportunistic relay selection system, one relay cooperation system, and direct transmission system are also compared. (C) 2021 Elsevier B.V. All rights reserved.