Secrecy Performance Analysis for TAS-MRC System With Imperfect Feedback

Abstract

Abstract-In this paper, we investigate the secrecy performance for a multiple-input multiple-output (MIMO) wiretap channel in the presence of a multi-antenna eavesdropper. In particular, the legitimate transmitter uses transmit antenna selection (TAS) to transmit on a single antenna with the largest signal-to-noise ratio (SNR) while both the legitimate receiver and the eavesdropper adopt maximal ratio combining (MRC) for reception. We derive exact closed-form expressions for the probabilities of positive secrecy rate and secrecy outage with imperfect feedbacks due to feedback delay and/or error. Furthermore, we derive the asymptotic secrecy outage probability at high signal-to-noise ratio (SNR) for the transmitter-receiver channel, which accurately reveals the secrecy diversity loss due to imperfect feedbacks. Simulation results are provided to verify our analytical results and illustrate the impacts of imperfect feedback on the secrecy performance of such a wiretap system.

Secure Transmission in MIMO Wiretap Channels Using General-Order Transmit Antenna Selection With Outdated CSI

“…Without loss of generality, the main channel and eavesdropper's channel are assumed to be quasi-static fading channel with independent non-identical distributed block Nakagami-m fading, so that the channel coefficients keep constant during the coherence time of the channel. The overall general-order TAS/MRC scheme is carried out in two phases [11], [12].…”

“…To construct the corresponding wiretap code, Bob has to feed back the current SNR value γ (kB) to Alice during the Transmission Phase. We assume that the feedback of γ (kB) is perfect, which is also adopted in [12]. Thus, Alice will use the main channel capacity of…”

“…However, one major drawback of [11] is that both legitimate receiver and eavesdropper are equipped with a single antenna, and hence the received diversity gain has not been understood well. In addition, [12] also investigated the effect of outdated CSI on the secrecy outage performance of MIMO wiretap channels using transmit antenna selection with receive maximum ratio combining in Rayleigh fading environments. However, it only considered a single eavesdropper and neglected the impact of channel fading severity on the secrecy performance of the MIMO wiretap channels.…”

A Location Prediction-Based Helper Selection Scheme for Suspicious Eavesdroppers

“…Although there still exist numerous studies on the unknown or imperfect CSI of eavesdroppers [25][26][27], all of these only focused on the wiretap by static eavesdroppers. The more general case is that eavesdroppers may have other behaviors.…”

Physical Layer Security With Threshold-Based Multiuser Scheduling in Multi-Antenna Wireless Networks

“…Additionally, TAS and receive generalized selection combining (TAS/GSC) was proposed for improving the security in the MIMO wiretap channels [9]. Furthermore, the work [10] investigated the secrecy performance for TAS and maximal ratio combining (TAS/MRC) system with imperfect feedback. More recently, TAS was also carried out both at the multi-antenna primary and secondary transmitter (ST) in cognitive wiretap systems [11], [12], where the ST acts as a friendly jammer to confound the eavesdropper and is granted to share the spectrum of the primary network as a reward.…”