System and Method for Visible Light Communications

A visible light transmission apparatus comprising:

• a light emitting module comprising a plurality of light emitting devices having different spectral distributions configured to emit light;
• a light emitting device driver for driving the light emitting devices to emit light with a set of light intensities;
• and
• a data-to-modulation mapper configured to convert a data symbol to the set of intensities of the light emitting devices.

A visible light communication method in a visible light communication system comprising a transmission apparatus with a plurality of light emitting devices which have different spectral distributions and a reception apparatus with a plurality of photo detection devices which have different responsitity distributions, the method comprising:

• configuring a constellation having a set of points in a color space corresponding to a set of data symbols by the transmission apparatus;
• mapping each data symbol of the set of data symbols to a point of the constellation in the color space by the transmission apparatus;
• calculating a set of intensities of the light emitting devices corresponding to the point in the color space based on their different spectral distributions by the transmission apparatus;
• controlling intensities of the light emitting devices by the transmission apparatus;
• calculating a point in the color space of the total received light signal, by using intensities of the signals received from the photo detection devices and their points in the color space corresponding to their responsivity distributions by the reception apparatus;
• determining a data symbol recovered from the point of the total received light signal in the color space by the reception apparatus;
• and
• calculating the target color from points of recovered sets of data symbols by the reception apparatus.

A visible light communication method in a visible light transmission apparatus with a plurality of light emitting devices having different spectral distributions to emit light which is represented by a point in a color space, the method comprising:

• configuring a constellation having a set of points in the color space corresponding to a set of data symbols;
• mapping each data symbol of the set of data symbols to a point of the constellation in the color space;
• calculating a set of intensities of the light emitting devices corresponding to the point in the color space based on their different spectral distributions;
• and
• controlling intensities of the light emitting devices.

A visible light communication method in a visible light reception apparatus with a plurality of photo detection devices to recover the transmitted data symbol by calculating a point of the received signal in a color space, the method comprising:

• calculating a point of a photo detection device in the color space corresponding to its responsivity distribution;
• calculating a point of the total received light signal in the color space;
• configuring a constellation having a set of points in the color space corresponding to a set of data symbols;
• determining a data symbol transmitted from the point of the total received light signal in the color space;
• and
• calculating the target color from points of recovered sets of data symbols.