A Feasibility Study on Modulation-Domain Waveform Design for Physical Layer Security

Information security in wireless communication is imperative for emerging applications. In the field of physical layer security, power-domain and coding-domain schemes are implemented to ensure the confidentiality. However, existing methods enhance system security based on information theory, neglecting the potential in modulation process. To this end, this letter proposes a modulation-domain waveform design to capture the impact of channel fading, realizing a new dimension of security in the physical layer. Moreover, Security Symbol Ratio (SSR) is defined from a probabilistic perspective, which is more appropriate for measuring the security contribution of transmission waveform to original messages. Simulation results demonstrate the feasibility of the proposed design and the effectiveness of the SSR, especially in scenarios where the energy of received signal is inferior at the legitimate user.