RFID reader systems detecting pilot tone
US8350665B1 · kind B1 · utility
19Cited by
13References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 28, 2012 |
| Grant date | Jan 8, 2013 |
| Priority date | — |
| Expiry date | Feb 28, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/0008
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
RFID tags are commanded to generate a pilot tone in their backscatter. When the backscattered pilot tone is received in the reader, the pilot tone is used to estimate the tag period/frequency. Then, the estimate is used to seed and lock a symbol timing recovery loop, which provides a detected signal to one or more correlators for detecting the tag preamble. A delayed version of the received tag signal is compared against a baseline signal threshold established from the received signal to detect the pilot tone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.