Idle channel noise suppressor for speech encoders
US4323730A · kind A · utility
3Cited by
7References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 13, 1979 |
| Grant date | Apr 6, 1982 |
| Priority date | — |
| Expiry date | Jun 13, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/50
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The idle channel for a speech encoder is detected by the detection, at the encoder comparator output, of zero-level traversals caused by noise transient signals appearing at the analog input of the encoder. In response to the detection of an idle channel, the encoder is caused to output a PCM code sample corresponding to a zero amplitude analog signal. In order that a speech signal passing through zero amplitude during the sampling period not be confused with an idle channel condition, the detection circuit responds only to a plurality of zero-level traversals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.