Secure Transmission in FDD MBM Systems Using Analog Feedback

In this paper, the physical layer security (PLS) issue is studied for frequency-division duplex (FDD) multiple-input multiple-output (MIMO) media-based modulation (MBM) systems with a multiple-antenna eavesdropper. A more practical scenario is considered that only the statistic channel state information (CSI) of the eavesdropping link is available and the imperfect CSI of the legitimate link is acquired by analog feedback. Based on these imperfect CSI, an artificial-noised-aided precoding scheme is proposed, and an effective achievable ergodic secrecy rate (ESR) is derived when taking into account the feedback overhead. The secrecy performance of the proposed scheme is evaluated through simulations in terms of ESR and bit error rate (BER). The influences of the key parameters such as the power allocation ratio and the feedback duration are also discussed.