Method and device for transmitting data optically

摘要

The method involves determining a switching phase of a pulse-width modulated LED (2) by using a switching phase-determination device (3) based on a series of switching conditions of the LED, where the switching conditions are detected by a light sensor. Data is modulated to a light signal emitted from the LED during the determined switching phases of the LED by using a modulation device (4), where the data is transmitted in data packets to a mobile terminal. A data signal modulated on a voltage supply signal is pulse-width modulated by a pulse-width modulator. An independent claim is also included for a device for optical transmission of data over a pulse-width modulated LED.