S2-psk optical wireless communication method and apparatus

An optical wireless communication apparatus comprising:

• a receiver;
• and
• a demodulator, wherein
• the receiver receives consecutively photographed images from an image sensor;
• and
• the demodulator outputs a first binary data signal of a binary value 0 when an ON/OFF phase of a first light source on the images is the same as an ON/OFF phase of a second light source on the images and a binary value 1 when the ON/OFF phase of the first light source is opposite to the ON/OFF phase of the second light source, or a binary value 1 when the ON/OFF phase of the first light source is the same as the ON/OFF phase of the second light source and a binary value 0 when the ON/OFF phase of the first light source is opposite to the ON/OFF phase of the second light source, on the basis of the images.

An optical wireless communication method comprising:

• generating, by a modulator, a reference signal periodically repeating binary value 0s and 1s;
• receiving, by the modulator, an input of a first binary data signal;
• outputting, by the modulator, a second binary data signal having a frequency the same as that of the reference signal, and a phase the same as that of the reference signal when the first binary data signal is a binary value 0 and a phase opposite to that of the reference signal when the first binary data signal is a binary value 1, or a phase the same as that of the reference signal when the first binary data signal is a binary value 1 and a phase opposite to that of the reference signal when the first binary data signal is a binary value 0;
• and
• turning on and off, by a transmitter, a first light source according to the reference signal, and turning on and off a second light source according to the second binary data signal.