Fig. 1. Experimental system of SPAD-VLC based on HDD indicator. (a) Schematic of experiment; (b) schematic of experimental link

Fig. 2. Comparison between traditional OOK modulation and PWLSK modulation. (a) Schematic of clock drift; (b) schematic of waveform

Fig. 3. Flow chart of signal generation process

Fig. 4. Statistical results of signal parameters. (a) Linearity analysis for data block size and mean time; (b) distribution fitting of data block with size of 4 Kbit

Fig. 5. Actual waveform modulated by PWLSK

Fig. 6. Mean value and variance value of photons. (a) Mean value; (b) variance value

Fig. 7. Average data rate and BER of each data block selection scheme

Fig. 8. Performance comparison between OOK scheme and PWLSK scheme

Fig. 9. BER of PWLSK scheme and OOK scheme under different λ₀

Fig. 10. Achievement exhibiting of terminal interface. (a) Sending terminal; (b) receiving terminal