Design and Implementation of 2D MIMO-Based Optical Camera Communication Using a Light-Emitting Diode Array for Long-Range Monitoring System

Abstract

Wireless technologies that use radio frequency (RF) waveforms are common in wireless communication systems, such as the mobile communication, satellite system, and Internet of Things (IoT) systems. It is more advantageous than wired communication because of the ease of installation. However, it can negatively impact human health if high frequencies are used to transmit data. Therefore, researchers are exploring the potential of optical wireless communication as an alternative, which uses the visible light bandwidth instead of RF waveforms. Three possibilities are being investigated: visible light communication, light fidelity, and optical camera communication. In this paper, we propose a multiple-input multiple-output modulation scheme using a light-emitting diode (LED) array, which is applicable to the IoT system, based on on–off keying modulation in the time domain. This scheme is compatible with the two popular types of camera in the market, rolling shutter cameras and global shutter cameras, as well as the closed-circuit television camera, which is used in factories, buildings, etc. Despite the small size of the LED array, implementing this scheme with 10 links in different positions at a communication distance of 20 m is possible for efficient performance (low error rate) by controlling the exposure time, shutter speed, focal length, channel coding and applying the matched filter.

A Nested Texture Inspired Novel Image Pattern Based Optical Camera Communication

“…However, it can be used in specific application environments. Thus, to offload the requirement of dedicated high-cost displays, a relatively very low-cost LED matrix was used to achieve pattern communication [18]. The author's proposed technique uses QR code-inspired patterns for transmitter identification and alignment, followed by an embedded data payload pattern.…”

Quantum-Chromodynamics-Inspired 2D Multicolor LED Matrix to Camera Communication for User-Centric MIMO

“…Ada f ruit_Neopixel is a class of the Adafruit library that provides access to functions used for controlling neopixel LEDs. pix is an object of the Ada f ruit_Neopixel class, and the constructor accepted the number of LEDs (64), connected pin number (6), and the type of the neopixel LEDs (NEO_GRB + NEO_KHZ800 ) as its parameters. delayVal is the delay between successive Tx frames.…”

“…On the receiver (Rx) side, depending on the modulation scheme, these features are extracted from the video stream, and corresponding signal demodulation and data reconstruction are performed. In an environment where the distance and orientation between Tx and Rx are constant, demodulation is performed using preset region-of-interest (RoI) extraction [6]. However, support for variable distance and orientation is required for a practical system.…”

“…LED array-based active marker design was proposed by Lorenz Gorse et al [18] to provide efficient marker detection for augmented reality and positioning applications under low-ambient-light conditions. In [6], a 2D LED array-based OCC system with rotation support and MIMO was proposed. The system provided BER of 10 −4 for 11 dB SNR; however, the throughput could be further enhanced by using the chromatic features of light [19,20].…”

The Way to Modern Shutter Speed Measurement Methods: A Historical Overview

“…The ubiquity of smartphones, equipped with good quality cameras, stimulates the research of OCC systems. Here, the cameras are utilized as sensors, to receive visually coded information [18][19][20], and the value of the exposure time (among other factors) determines the data rate, the bit-error-rate, and the achievable lized as sensors, to receive visually coded information [18][19][20], and the value of the exposure time (among other factors) determines the data rate, the bit-error-rate, and the achievable communication distance [21][22][23]. In camera-based positioning systems, OCC is often utilized to allow beacon identification [24,25].…”