Method, system and apparatus for initiating and maintaining synchronization of a pulse position modulation (PPM) decoder with a received PPM signal
US6700931B1 · kind B1 · utility
39Cited by
5References
23Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 6, 2000 |
| Grant date | Mar 2, 2004 |
| Priority date | — |
| Expiry date | Feb 24, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/4902
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A radio frequency identification (RFID) tag device having a pulse position modulation (PPM) decoder circuit which calculates a relative frequency relationship between an internal clock-oscillator of the RFID tag device and an external PPM source such as a RFID tag reader, and then synchronizes the RFID tag device PPM decoder circuit to the required precision for reliable PPM symbol decoding. The PPM decoder is synchronized by measuring the “counts per pulse” (CPP) from a calibration cycle having a plurality of pulses in a single symbol frame.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.