Comfort noise generation for open discontinuous transmission systems
US6711537B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 21, 2000 |
| Grant date | Mar 23, 2004 |
| Priority date | — |
| Expiry date | Jan 28, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/012
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A Comfort Noise Generation (CNG) system is provided for use in open systems where there is no predefined protocol for transmission of Silence Insertion Descriptor (SID) information from transmitter to receiver. The receiver enters an underrun condition in response to periods of silence, and in response generates comfort noise. According to the present invention, the computation of the level and spectral characteristics of the background of the speech signal is done within the receiver, thereby overcoming the lack of a protocol to transmit the SID information during silence periods. These characteristics are computed as a gain parameter and a set of Linear Prediction Coding (LPC) parameters which are applied to a filter which filters flat-spectrum noise in order to generate noise that sounds like the background noise of the speech signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.