US 12,323,184 B2
Visible light communications technology for inter-vehicular use
Russell Andres, Riverview, MI (US); Michael William Putty, Grosse Pointe Woods, MI (US); and Sridhar Lakshmanan, Belleville, MI (US)
Assigned to The Regents of The University of Michigan, Ann Arbor, MI (US)
Filed by THE REGENTS OF THE UNIVERSITY OF MICHIGAN, Ann Arbor, MI (US)
Filed on Aug. 29, 2022, as Appl. No. 17/897,319.
Claims priority of provisional application 63/238,704, filed on Aug. 30, 2021.
Prior Publication US 2023/0065439 A1, Mar. 2, 2023
Int. Cl. H04B 10/69 (2013.01); H04B 10/116 (2013.01); H04B 10/60 (2013.01); H04L 7/04 (2006.01)
CPC H04B 10/116 (2013.01) [H04B 10/6931 (2013.01); H04B 10/697 (2013.01); H04L 7/048 (2013.01); H04B 10/60 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method of preprocessing an optical signal so as to filter out ambient light and accommodate for differences in signal level to enhance Visible Light Communication (VLC) operation, the method comprising:
detecting a light input via a photodetector and amplifying an output of the photodetector via a first amplifier and outputting an amplified detected signal representative of the light input, the light input having both the optical signal and the ambient light;
filtering out the ambient light of the amplified output of the photodetector and outputting a filtered signal, wherein the filtering removes portions of the detected signal that are not at a same modulation frequency as the optical signal; and
increasing an amplitude of the filtered signal in a second amplifier, the second amplifier being a variable amplifier that is controlled at variable gain settings by a controller based upon an an amplitude capture stage that captures an amplitude of the filtered signal.