Digital signal transmission system having frame synchronization operation
US4849995A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jul 25, 1986 |
| Grant date | Jul 18, 1989 |
| Priority date | — |
| Expiry date | Jul 25, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/048
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A digital signal transmission system includes a synchronization pattern detection circuit for detecting a synchronization pattern in response to a received transmitted digital signal, a pseudo synchronization detection circuit for detecting a pseudo synchronization pattern in the form of cyclic redundancy code in response to a received transmitted digital signal, and a synchronization protection circuit for counting the synchronization pattern detection signals produced when synchronization patterns are detected in response to a synchronization pattern detection signal from the synchronization pattern detection circuit. The synchronization protection circuit includes a main synchronization counter circuit and an auxiliary synchronization counter circuit. The count of protection steps for the confirmation of synchronization recovery of the auxiliary synchronization counter circuit in accordance with synchronization or asynchronization of the main synchronization counter circuit is variable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.