Code modulation using narrow spectral notching
US6631165B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 1999 |
| Grant date | Oct 7, 2003 |
| Priority date | — |
| Expiry date | Sep 1, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/00
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method (100) and apparatus (400) for encoding and decoding data in a signal using notch depth modulation. The method (100) of data to be encoded in the signal. The method then notch filters (125) the signal according to the frequency notch representation of the data. The apparatus (400) for encoding data comprises an digitizer (405) to digitize the signal. A code former (420) provides the data to be encoded in the signal. A notch filter (430) notch filters the signal according to the data. Decoding the data converts the signal into a frequency domain representation (520) and determines the notch spectral content (525) of the signal at selected notch frequencies. The method (500) establishes notch thresholds (534) at each of the selected notch frequencies, then decodes the data (540) from the signal by comparing the notch spectral content to the notch thresholds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.