LED-ID detection and recognition method based on optical camera communication using discrete Fourier transform

Abstract

Optical camera communication (OCC) traditionally uses the bright and dark stripes of a rolling shutter pattern captured by the complementary metal–oxide–semiconductor image sensor to realize communication. We assign a unique identification [LED’s unique identification (LED-ID)] to each LED and introduce an LED-ID detection and recognition method of OCC using discrete Fourier transform (DFT). It is different from the traditional LED modulation and demodulation method. In this approach, LED-IDs are modulated to possess different frequency characteristics instead of transmitting data. Taking the DFT of the rolling shutter pattern to obtain a spectrum image, we can recognize the LED-ID according to the characteristics of the spectrum image. The experiment results show that the proposed method has good performance, with at least 426 recognizable LED-IDs and a recognition distance reaching 3 m. Therefore, the proposed method can be considered as one of the effective methods for OCC.