Data transmission synchronization system
US6611538B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 1999 |
| Grant date | Aug 26, 2003 |
| Priority date | — |
| Expiry date | May 27, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2007/045
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for providing synchronization in a data transmission system via the use of a short cyclic synchronization sequence inserted in the header of cells to be transmitted. A 2-bit sync sequence is inserted at the beginning of the header in each cell. At the receiving end, a pair of state machines search for and track the sync sequence. A feedback signal is generated that is used by the receiver to adjust its framing so as to align the received data with the boundaries of the cells. To aid in detecting the sync sequence, the two sync bits are rotated each cell cycle. To avoid confusion with data that mimics the sync sequence, the transmitter transmits idle cells containing all ones except for the 2-bit sync sequence field during the period that the receiver is attempting to sync up with the transmitter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.