Optimization of VLC Link Performance using Commercial High-Power LEDs and Photodiodes

The effect of the parameters of high-power commercial Phosphorus Light Emitting Diodes (PLEDs) of different correlated color temperature (CCTs) and photodiodes on optimizing the Visible light communication (VLC) system using OOK-NRZ modulation technique has been presented in this paper. The performance of a Line of Sight (LoS) VLC link is investigated using LEDs of different CCTs, including 2200 K, 3000 K, and 5700 K and photodiode models S5107, S5973-01, and S7686. The results showed that CCTs of 3000 K and 5700 K LEDs outperform with photodiode S5107, supporting a maximum data rate of 200 Mbps for a distance of 11 m. These performances are reduced to 160 Mbps for CCT of 2200 K. The LEDs with lower CCT values have fewer yellow spectral components, directly impacting the data rate. The photodiode S5107 parameters, including high responsivity, large photosensitive area and broad spectral range, play a key role in the best performance. The performance of S7686 is slightly better than that of S5973-01 photodiode with all LEDs due to a comparatively larger detection area. The performance of LEDs with CCT 3000K & 5700 K with photodiode S7686 supports a maximum data rate of 200 Mbps for 1 m, which is increased to 2m for the same data rate with CCT 2200 K. The performance of LEDs with CCT of 3000 K and 5700 K with photodiode S5973-01 have the worst performance due to lowest photosensitive area of 12 x 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, ends up supporting data rate of only 80 Mbps for 1 m which it is increased to 2m for the same data rate considering CCT 2200 K. The logarithm of the bit-error-ratio (BER) metric is used to characterize the VLC system performance.