Secrecy Capacity Achievable Time Reversal Pre-filter in MISO Communication System and the Unequal Secrecy Protection Application

Classical time reversal (TR) pre-filtering has been considered as one of the key physical layer security techniques for wireless communication applications in the last decade. This paper proposes a secrecy capacity achievable time reversal pre-filter to further enhance the confidentiality of a multi-input single-output (MISO) wireless communication system. In addition, an unequal secrecy protection (UESP) MISO broadcast configuration is constructed in frequency selective channels by exploiting classical and secrecy capacity achievable TR pre-filters, so that UESP wireless communication services can be offered. Theoretical proofs and simulation results show that the proposed TR pre-filter achieves the secrecy capacity in frequency selective channels (HIPERLAN/2 BranA), and the MISO broadcast configuration can provide mobile users with three levels of UESP hierarchical services in terms of public, private and confidential messages.