Analysis of spatial distribution of secret transmission performance of SSM using ray-tracing

Spatially selective modulation (SSM) is a physical layer secu-rity technique that uses multiple transmitting antennas and a single receiving antenna. SSM allows only the legitimate receiver to receive the desired mod-ulated signal correctly because of the location dependence of a multipath channel. Previous SSM studies have been statistically conducted using the Rayleigh fading channel. Here, we evaluated the secret transmission perfor-mance of SSM using ray-tracing, which is a deterministic propagation model. We assumed an indoor environment in the evaluation. We found that increas-ing the separation between the transmitting antenna elements improved the secret transmission performance of SSM in the assumed environment.