Carrier synchronization type demodulator for PSK signal
US6765972B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 2000 |
| Grant date | Jul 20, 2004 |
| Priority date | — |
| Expiry date | Feb 14, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2275
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A proximity IC card (PICC) which relates to and provides a carrier synchronization type demodulator, which is able to stably receive a PSK signal from a PICC and is enhanced in noise immunity, and which is realized at a low cost and in such a way as to have a small size. The carrier synchronization type demodulator is adapted to receive and demodulate PSK-modulated subcarrier signals to be synchronized with and superposed onto a sent carrier signal. This demodulator includes a carrier detecting device for detecting the subcarrier signals successively received in a predetermined time, a phase-change-point detecting device for detecting a phase change point of the subcarrier signal after the subcarrier signal is detected, and a data reception control device for controlling the reception of data of a predetermined format by employing a moment, at which the phase change point is detected, as a synchronization start point for receiving data, and by using an internal clock that is synchronized with the sent carrier signal by using the moment as a starting point of synchronization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.