Spectral Signature Multiplexing in Multispectral Camera Communication.

Optical camera communication (OCC) is a technology foreseen to have a fundamental role in future communication applications due to the ubiquity of the cameras embedded in most consumer electronic devices and their increasing capabilities (high resolution, scanning frequency, etcetera). However, high-spectral-resolution cameras, such as multispectral cameras, present particular characteristics that can be exploited to provide new features to OCC links. Furthermore, as LED spectral responses are different when their temperature changes, more than one communication channel can be achieved using the same LED device if the camera can capture those modifications and distinguish the different LED spectral signatures due to the temperature variation. This novel approach is followed in this research, including some equalization techniques applied to the channel matrix to improve the extraction of the transmitted signal in the receiver reducing the inter-channel interference (ICI). This work shows that up to two distinct channels can be obtained with the same LED at different temperatures, getting a bit error rate (BER) below the forward error correction (FEC) limit.