An indoor IoT-based LiFi system using LEDs for sensor data transfer

The Internet of Things (IoT) has an ever more significant function in many areas of our modern world. It improves the overall quality of life, where almost everything, including objects and devices, can be linked to the cloud and thus be hyper-connected. Within this changing IoT system, this paper focuses on data transfer, emphasizing the critical role of light fidelity (LiFi) technology. LiFi technology is an up-and-coming technology that makes use of light-emitting diodes (LEDs) and photodetectors (PDs) as transmitters and receivers (R_X), respectively, for concurrent data communications and lighting. This paper proposes a single-input multiple-output IoT-based LiFi system using an LED array, phototransistor, and ambient light sensor-based R_XS for simultaneous data transmission. DHT11 sensor is used to measure the environmental conditions and store collected data via Wi-Fi in the cloud server using HTTP protocol. Through indoor LiFi communication, the cloud streaming data is transferred using pulse position modulation (PPM) at a frequency of 2 KHz. The experimental results illustrate transferring and receiving data successfully at a communication distance of 1 meter. MATLAB software is used to evaluate the performance of the spatial radiance pattern and illuminance intensity of an LED Array used and received power depending on a line-of-sight (LOS) channel.