Performance Analysis of Indoor Light Fidelity Technology Propagation Using Fixed and Movable LED Panels

Light fidelity (Li-Fi) offers communication services with a wide bandwidth and is one of the options for telecommunications services in the future, especially indoor communication. However, Li-Fi requires accurate device positioning for line of sight (LOS) conditions to meet the main requirement for light communication. Conventional Li-Fi design models require a more dynamic transmitter and receiver device settings but can still serve LOS communication well. This study aims to design a Li-Fi communication model by varying the transmitting devices, such as the use of fixed and movable LEDs, and receiving devices, such as the addition of optical rectangle filters, low-pass filters, and trans-impedance amplifiers. The focus of observation includes the effect of changes in wavelength, data transmission speed, transmitter half-angle, irradiance angle, and incidence angle, as well as field of view (FOV) on received power parameters, signal-to-noise ratio, Q-factor, and bit error rate (BER). On the basis of the test results, the performance of all wavelength variations meets the ITU-T standard up to a variation of the transmission distance of 8 m, where the use of fixed and movable LEDs does not result in a significant difference in performance. The test results indicate that the wavelength parameter affects the signal quality due to the spectral response and LEDs emission. For short distances, the wavelength of 450 nm has better performance, whereas for distances up to 8 m, the wavelength of 650 nm has a better performance than other variations. Furthermore, increasing the transmitter half-angle increased the BER value and drastically decreased the Q factor. The use of a smaller FOV is recommended, as shown from the increase in distance resulting in a significant decrease in performance. The proposed system model can also be used for bit rates up to 30 Mbps, although it is only reliable up to 6 m. As for the 40 Mbps variation, the 75° half-angle transmitter, 60° FOV, and 90° FOV variations do not meet the standard. The two system models do not have a significant difference in performance. Thus, using movable LED instead of fixed LED will make the system more dynamic with a well-maintained LOS