Process of synchronizing a receiving modem after a training on data
US5058134A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1989 |
| Grant date | Oct 15, 1991 |
| Priority date | — |
| Expiry date | Aug 24, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J3/0605
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In data transmission wherein a transmitting modem transmits data signals to a receiving modem via a telephone line, the process of rotating, in the transmitting modem, the phase of the point of the constellation resulting from a group of data bits by a predetermined phase value, and then rotating, after a predetermined delay in the receiving modem, the phase of the estimated point resulting from the transformation of the analog signal by the opposite of said predetermined phase value, and calculating the mean-squared error between the rotated point and the estimated point of the constellation the error being used to determine whether the receiving modem is out of synchronization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.