Communication mode identification technique
US5444712A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1993 |
| Grant date | Aug 22, 1995 |
| Priority date | — |
| Expiry date | Aug 30, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/34
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A technique for use in communications systems utilizing busy and idle modes. In the busy mode, symbols representative of data are transmitted to system end users. In the idle mode, during which no data is communicated to end users, idle mode symbols are transmitted. Such idle mode symbols are not used to represent data and are only transmitted during the idle mode. Advantageously, such idle mode symbols maintain adaptive apparatus, such as AGC circuits, NEXT cancellers and equalizers, in their properly converged state. In the disclosed embodiment, the idle mode symbols are the innermost symbols in a signal constellation and transition from the idle to busy mode is represented by the transmission of a predetermined number of outermost symbols in the signal constellation. Use of such symbols for idle-to-busy mode transitions advantageously provides ready detection of such transitions. In addition, use of the innermost symbols for the idle mode reduces spectral emission and crosstalk.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.