Characterization of secrecy capacity of time reversal technique for wireless physical layer security

Secrecy capacity with time reversal technique is characterized and investigated for both specular and dense diffuse scattering radio channels. The characterization of secrecy capacity of specular radio channel is conducted for two clustered channels with 6 and 60 clusters that are composed of 120 and 1200 rays, respectively. Diffuse scattering channels are tested under different delay spread values. The investigation addresses the behavior in increasing the secrecy capacity with SNR. The increase in secrecy capacity with SNR saturates at particular values of SNR for specular channels but that is not the case with diffuse radio channels. The SNR saturation threshold varies with number of multipath components in specular channels.