Frequency synchronization apparatus
US5128971A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 14, 1991 |
| Grant date | Jul 7, 1992 |
| Priority date | — |
| Expiry date | Jan 14, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J3/0664
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An improved method and apparatus for synchronizing a receiver oscillator with a transmitter oscillator is provided. The receiver is arranged with a counter driven by the receiver oscillator; and the transmitter is arranged with a counter driven by the transmitter oscillator. The transmitter sends a start signal to the receiver and simultaneously records the current reading of its counter. Later, the transmitter sends a stop signal to the receiver and simultaneously records the current reading of its counter. The transmitter then computes the elapsed count, and sends this value to the receiver as the "transmitter reading". Upon receipt of the start signal, the receiver records the current reading of its counter. Later, upon receipt of the stop signal, the receiver records the current reading of its counter, and then computes the elapsed count. Upon receipt of the "transmitter reading", the receiver is then able to determine the error of its own oscillator relative to that of the transmitter site oscillator as: ##EQU1## where A and B are predetermined constants which may be used to normalize the receiver and transmitter counter speeds to each other or to a third set of units. The tra…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.