Secure adaptive transmission in two-way relay wiretap channels

In this work we investigate, for the first time, the secrecy performance of a single-input single-output single antenna eavesdropper two-way relay wiretap channel, in which only statistical channel state information from the eavesdropper is available at the sources. We propose a secure adaptive transmission scheme for this two-way relay wiretap channel in which the sum effective secrecy throughput is utilized as the performance metric. Given our adopted system model, we determine the wiretap code rate parameters for the two sources which maximize this performance metric. In addition, we explore the relationship between the sum effective secrecy throughput and the transmit powers at the sources, demonstrating how the sum effective secrecy for the adopted system is maximized at certain transmit powers. Given the practical system model we investigate, the results reported here are important for the deployment of physical layer security in two-way relay wiretap channels.