Optical Camera Communications for IoT–Rolling-Shutter Based MIMO Scheme with Grouped LED Array Transmitter

Shivani Rajendra Teli (1) , Vicente Matus (2) , Stanislav Zvanovec (1) , Rafael Perez-Jimenez (2) , Stanislav Vitek (1) , Zabih Ghassemlooy (3)

1 CTU - Czech Technical University in Prague
2 ULPGC - Universidad de las Palmas de Gran Canaria
3 University of Northumbria at Newcastle [United Kingdom]

In optical camera communications (OCC), the provision of both flicker-free illumination and high data rates are challenging issues, which can be addressed by utilizing the rolling-shutter (RS) property of the image sensors as the receiver (Rx). In this paper, we propose an RS-based multiple-input multiple-output OCC scheme for the Internet of things (IoT) application. A simplified design of multi-channel transmitter (Tx) using a 7.2 × 7.2 cm2 small 8 × 8 distributed light emitting diode (LED) array, based on grouping of LEDs, is proposed for flicker-free transmission. We carry out an experimental investigation of the indoor OCC system by employing a Raspberry Pi camera as the Rx, with RS capturing mode. Despite the small area of the display, flicker-free communication links within the range of 20–100 cm are established with data throughput of 960 to 120 bps sufficient for IoT. A method to extend link spans up to 1.8 m and the data throughput to 13.44 kbps using different configurations of multi-channel Tx is provided. The peak signal-to-noise ratio of ~14 and 16 dB and the rate of successfully received bits of 99.4 and 81% are measured for the shutter speeds of 200 and 800 µs for a link span of 1 m, respectively.

Mots clés: optical camera communications; rolling-shutter camera; Internet of things; multiple-input multiple-output; light-emitting diodes

Domaines: Sciences de l'ingénieur [physics]; Optique / photonique

Shivani Rajendra Teli, Vicente Matus, Stanislav Zvanovec, Rafael Perez-Jimenez, Stanislav Vitek, et al.. Optical Camera Communications for IoT–Rolling-Shutter Based MIMO Scheme with Grouped LED Array Transmitter. Sensors, 2020, 20 (12), pp.3361. ⟨10.3390/s20123361⟩. ⟨hal-03341228⟩