Methods and apparatus for free-space undersea communications
US10491309B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 2017 |
| Grant date | Nov 26, 2019 |
| Priority date | — |
| Expiry date | Jan 7, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/564
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.