Silicon photomultiplier receivers and future VLC systems

Presented at the 2020 IEEE Globecom Workshops, with Dr Wajahat Ali as first author. It looks at what future visible light communications (VLC) systems built around SiPMs could look like. Like the rest of my DPhil work, it uses onsemi J-series SiPMs.

Abstract

The performance of a Silicon photomultiplier (SiPM) receiver when used with a 405 nm transmitter is discussed. A comparison of the irradiance available from a low-power transmitter that covers 20 m $^2$ and the performance of the SiPM shows that in an indoor application this combination of transmitter and receiver can support OOK data rates of 1 Gbps. A comparison of the performance of the SiPM and an OEIC highlights the benefits that arise from the relatively large area of the SiPMs. Finally, the potential impact of using SiPMs on future VLC systems is discussed.

Key Findings

The transmitter uses 405 nm light. That choice is justified by the SiPM’s photon detection efficiency and by the spectra of artificial ambient light. At 405 nm there is a blue-light eye hazard, but the transmitter falls in the lowest risk group when assessed against an LED safety standard.

The receiver supports a 1 Gbps link at a BER of $10^{-3}$ . The SiPM is 9 dB more sensitive than a state-of-the-art OEIC that incorporates an APD. Because the SiPM is so much larger, the irradiance it needs is more than two orders of magnitude lower than state-of-the-art APD receivers need.

If a SiPM is used as the up-link receiver, small, low-power, inexpensive LEDs could serve as the transmitter.