Experimental performance evaluation of feedback resistors and capacitors for indoor visible light communication system under realistic illumination setup for divergent optical power levels

Visible Light Communication (VLC) is a complementary transient-scale wireless communication technology established on IEEE P802.15.7 that seeks to combine illumination with communication using existing infrastructure. This experimental study focuses on building a low-cost experimental VLC model consisting of ultra-bright 5 mm Light Emitting Diodes (LEDs), BPW34 silicon photodiode and TLO81CP FET Operational Amplifier (OPAMP) for a distance of 1 m at a peak data rate of 1 Mbps using On–Off Keying Non-Return to Zero (OOK-NRZ). The experiment is accomplished under a realistic illumination set-up at five divergent output optical power levels and coverage scenarios. The objectives of this work are threefold-first to evaluate and model the impact of transpose in the output power levels on the quality of the received signal for the recursive channel model. Secondly, it aims to analyse the impact of change in feedback resistor and capacitor on the quality of received signal for different values of transmitted optical power. Lastly, it aims to propose appropriate feedback resistor and capacitor values to improve the quality of the received signal. The experimental work concludes that feedback resistors in the range of 33 K \(\Omega\) $\mathrm{\Omega }$ \(\le {R}_{F}\le\) $\le R_F\le$ 45 K \(\Omega\) $\mathrm{\Omega }$ combined with a \({C}_{F}\) $C_F$ value of \(9.4\text{ pF}\) $9.4\text{pF}$ is found to be most suitable to attain a stable VLC link having an output power in the range of \(6 mW\le {P}_{T}\le 7 mW.\) $6mW\le P_T\le 7mW.$ The VLC system successfully attains an estimated Bit Error Rate (BER) in the range of 10^–13 under realistic illumination setup. The work defines a suitable range of feedback resistors and a value of capacitor to work under power variation range of 6–7 mW. This work is applicable in VLC setups where a certain range of power spectrum is provided for necessary operation.