METHOD AND APPARATUS OF DECODING LOW-RATE VISIBLE LIGHT COMMUNICATION SIGNALS

摘要

Methods and apparatus related to the detection of low-rate visible light communication (VLC) signals and the recovery of information communicated by the VLC signals are described. Various methods and apparatus are well suited for embodiments in which a device, e.g., a smartphone, including a camera which uses a rolling shutter. The rolling shutter facilitates the collection of different time snapshots of a received low rate time varying VLC signal with different pixel rows in the image sensor of a frame corresponding to different time snapshots. In some embodiments, demodulation is used to recover and identify a single tone being communicated in a frame from among a plurality of possible alternative tones that may be communicated, each different tone corresponding to a different set of information bits.

主权项

1. A method of using a device including a camera to receive and recover information from a visible light communication (VLC) signal, the method comprising:
summing pixel values in each row of pixel values corresponding to a first region of an image sensor to generate a first array of pixel value sums, at least some of said pixel value sums representing energy recovered from different portions of said VLC light signal, said different portions being output at different times and with different intensities; and performing a first demodulation operation on the first array of pixel value sums to recover information communicated by the VLC signal.