Fig. 4: Experimental validation of physical-layer secure transmission based on chaotic information metasurface.
From: Chaotic information metasurface for direct physical-layer secure communication
a Prototype of the metasurface and experimental setup. b Geometry of the meta-atom. c Reflection response of the meta-atom. d Measured results of CSI and constellation diagrams comparing the cases where mixed-chaotic and only focusing patterns are employed. The transmitter is positioned at (1.15 m, 0°, 0 m), the legitimate receiver is positioned at (3 m, 0°, −0.34 m), eavesdropper 1 and eavesdropper 2 are located at (3 m, 20°, −0.34 m), (3 m, 40°, −0.34 m), respectively. e As in panels (d), but the transmitter is positioned at (0.75 m, 0°, −0.57 m), the legitimate receiver is positioned at (3 m, 0°, 0 m), eavesdropper 1 and eavesdropper 2 are located at (3 m, 20°, 0 m), (3 m, 40°, 0 m), respectively. f XOR operation of transmit and receive bitstream in different positions for mixed chaotic patterns, for the transmitter positioned at (1.15 m, 0°, 0 m) and the legitimate receiver positioned at (3 m, 0°, −0.34 m). g As in panels (f), but the transmitter is positioned at (0.75 m, 0°, −0.57 m), and the legitimate receiver is positioned at (3 m, 0°, 0 m).
