Reconstructing light-based communication signals using an alias frequency
US9564966B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 2015 |
| Grant date | Feb 7, 2017 |
| Priority date | — |
| Expiry date | Sep 30, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W4/023
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Methods and systems are described for sampling an LCOM message signal at a rate less than the Nyquist rate (i.e., an “alias frequency”) and accurately reconstructing the entire LCOM message using a light receiver (e.g., digital camera) of a typical mobile computing device, such as a smartphone, tablet, or other mobile computing device. The described methods and system take advantage of the repetition of LCOM signals, sampling an LCOM signal at a frequency less than the Nyquist frequency over at least two repetitions of a signal waveform, thereby collecting sufficient samples to accurately reconstruct the signal. The samples of each successive signal waveform repetition are offset from one another so that different points on the waveform are sampled, thus facilitating reconstruction of the signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.