TY - GEN
T1 - A principled design for passive light communication
AU - Ghiasi, Seyed Keyarash
AU - Zamalloa, Marco A.Zúñiga
AU - Langendoen, Koen
PY - 2021
Y1 - 2021
N2 - To take advantage of Visible Light Communication (VLC) for low-power applications, such as IoT tags, researchers have been developing systems to modulate (backscatter) ambient light using LC shutters. Various approaches have been explored for single-pixel transmitters, but without following a principled approach. This has resulted in either relatively low data rates, short ranges, or the need for powerful artificial light sources. This paper takes a step back and proposes a more theoretical framework: ChromaLux. By considering the fundamental characteristics of liquid crystals (birefringence and thickness), we demonstrate that the design space is way larger than previously explored, allowing for much better systems. In particular, we uncover the existence of a transient state where the switching time can be reduced by an order of magnitude without lowering the contrast significantly, improving both range and data rate. Using a prototype, we demonstrate that our framework is applicable to different LCs. Our results show significant improvements over state-of-the-art single-pixel systems, achieving ranges of 50 meters at 1 kbps and with bit-error-rates below 1%.
AB - To take advantage of Visible Light Communication (VLC) for low-power applications, such as IoT tags, researchers have been developing systems to modulate (backscatter) ambient light using LC shutters. Various approaches have been explored for single-pixel transmitters, but without following a principled approach. This has resulted in either relatively low data rates, short ranges, or the need for powerful artificial light sources. This paper takes a step back and proposes a more theoretical framework: ChromaLux. By considering the fundamental characteristics of liquid crystals (birefringence and thickness), we demonstrate that the design space is way larger than previously explored, allowing for much better systems. In particular, we uncover the existence of a transient state where the switching time can be reduced by an order of magnitude without lowering the contrast significantly, improving both range and data rate. Using a prototype, we demonstrate that our framework is applicable to different LCs. Our results show significant improvements over state-of-the-art single-pixel systems, achieving ranges of 50 meters at 1 kbps and with bit-error-rates below 1%.
KW - backscattering
KW - liquid crystal displays
KW - visible light communication
UR - http://www.scopus.com/inward/record.url?scp=85102886691&partnerID=8YFLogxK
U2 - 10.1145/3447993.3448629
DO - 10.1145/3447993.3448629
M3 - Conference contribution
AN - SCOPUS:85102886691
T3 - Proceedings of the Annual International Conference on Mobile Computing and Networking, MOBICOM
SP - 121
EP - 133
BT - ACM MobiCom 2021 - Proceedings of the 27th ACM Annual International Conference On Mobile Computing And Networking
PB - Association for Computing Machinery (ACM)
T2 - 27th ACM Annual International Conference On Mobile Computing And Networking, MobiCom 2021
Y2 - 25 October 2021 through 29 October 2021
ER -