Digital automatic gain control with lookahead, adaptive noise floor sensing, and decay boost initialization
US5267322A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 13, 1991 |
| Grant date | Nov 30, 1993 |
| Priority date | — |
| Expiry date | Dec 13, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G3/001
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An automatic gain controller for a digitized audio signal, comprising a buffer with a plurality of subframes. Each subframe contains digitized data samples of the signal, the subframes including at least one future subframe and a current subframe. Signal processing means (such as a DSP) is coupled to the memory for controlling gain of the audio signal represented by the current subframe in the buffer. The signal processing means includes means to control gain of the data samples using a stored program for computing a plurality of mean signal level values from the plurality of subframes, each mean signal level value in the plurality corresponding to one of the subframes. The program includes means for causing decay of gain on the signal represented by the current subframe when a first set of the mean values are each below a low threshold signal level. The program also has means for causing gain attack on the audio signal represented by the current subframe when a second set of the mean values are each above a high threshold signal level. The program also comprises means for shifting the data samples in one subframe in the future group into the current subframe for controlling gain o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.