The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 26, 2019
Filed:
Feb. 03, 2017
Massachusetts Institute of Technology, Cambridge, MA (US);
Hemonth Rao, Lexington, MA (US);
Andrew Fletcher, Westford, MA (US);
Scott Hamilton, Lexington, MA (US);
Nicholas Hardy, Wellesley, MA (US);
Marvin Scheinbart, Chelmsford, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
A multi-rate, burst-mode, photon-counting receiver can communicate at data rates up to 10.416 Mb/s over a 30-foot water channel. With added attenuation, the maximum link loss is 97.1 dB at λ=517 nm. In clear ocean water, this equates to link distances up to 148 meters. For λ=470 nm, the achievable link distance in clear ocean water is 450 meters. The receiver incorporates soft-decision forward error correction (FEC) that supports multiple code rates to achieve error-free performance. A burst-mode receiver architecture provides robust performance with respect to unpredictable channel obstructions. The receiver can detect the data rate on-the-fly and adapts to changing levels of signal and background light. The receiver updates its phase alignment and channel estimates every frame, allowing for rapid changes in water quality as well as motion between transmitter and receiver.