Evaluation of Physical Layer Security in Underwater Acoustic OFDM System Using Time-Reversal.

Physical layer security (PLS) is a new approach of information security and has great potential for underwater acoustic (UWA) communication. Time-reversal (TR) technique has characteristics of temporal compression and spatial focusing. It can be applied to orthogonal frequency division multiplexing (OFDM) system to achieve PLS. This paper focuses on the evaluation of physical layer security in multi-input-single-output (MISO) UWA OFDM system and compares to the system without using TR technique to clarify the advantages of TR technique. For evaluation, we propose a scheme of UWA TR OFDM system and give a received signal model on the block transmission. Simulation results show that the secrecy rate of UWA OFDM system is significantly improved when applying TR technique. And the eavesdropper cannot obtain effective information.