Patent · US Expired

Frequency of occurrence retraining decision circuit

US4752943A · kind A · utility

1Cited by
3References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 7, 1987
Grant dateJun 21, 1988
Priority date
Expiry dateAug 7, 2007

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L27/38
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

In a system encompassing the transmission of high speed data over a communication channel, a circuit provides information as to whether the modems of the system are in synchronism. The circuit first determines the number of points being received within a given time at a certain inner location in the signal constellation and at another certain outer location in the signal constellation. The circuit includes an up/down counter which is incremented for each inner point received by the circuit and decremented for each outer point received. The counter output is conveyed to a comparator which determines whether the counter output has reached a preselected threshold. At the time that the counter output reaches the preselected threshold, the comparator outputs a signal which is indicative of the fact that the modems of the system are out of synchronism and retraining of the system is required.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.