Secure Directional Modulation Technique Based on Spectrum Division Transmission

Direction modulation (DM) is a physical layer security (PLS) technology that has attracted extensive research. In this article, we propose a directional modulation scheme based on spectrum division transmission (SDT-DM). The original signal is divided into different sub-spectrum signals by filter bank and a phase shift related to the direction angle is added to each subspectrum signal. By theotical analysis, the received signal in any non-cooperator direction is proved to be subjected to complex inter-symbol and cross-symbol interference, while the combined signal in the cooperator direction is not affected. Simulation results demonstrate that the proposed SDT-DM scheme can achieve narrow secure zone and confuse constellations for noncooperator.