Performance Analysis of a Long-Range MIMO VLC System for Indoor IoT

Visible light communication (VLC) exhibits great potential in connecting Internet of Things (IoT) devices. The connection of a huge number of IoT devices by utilizing the existing radio-frequency spectrum is a challenging task. Therefore, a new frequency spectrum is required for a smooth operation. In this work, we investigate a multiple-input multiple-output (MIMO) VLC system capable of connecting IoT devices to achieve long-range indoor communication. To monitor the indoor environment, a monitoring system for collecting and transmitting particulate matter, temperature, and humidity data using MIMO VLC is proposed. Four different single-carrier techniques are tested, and their error performance is analyzed by experimental trials. Next, the maximum communication range, which is important for efficient network planning and uninterrupted connectivity, is evaluated. Two antenna configurations (2 <tex-math notation="LaTeX">× </tex-math> 2 and 4 <tex-math notation="LaTeX">× </tex-math> 4) are tested for MIMO VLC. In the 2 <tex-math notation="LaTeX">× </tex-math> 2 configuration, a 14.5–21 m transmission distance is achieved by employing four different modulation techniques. In the 4 <tex-math notation="LaTeX">× </tex-math> 4 communication, a 7–10 m transmission distance with a reliable error rate is achieved by employing three different modulation techniques. In addition, a lightweight encryption technique is used to enhance data security. The proposed system provides an efficient solution for monitoring different types of data using indoor IoT connectivity.