Centralized automatic gain control circuit
US4251881A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 1978 |
| Grant date | Feb 17, 1981 |
| Priority date | — |
| Expiry date | Jun 5, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J3/17
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Disclosed is an automatic gain control circuit for a communications system, such as a time assignment speech interpolation system, which equalizes the loss in each of a plurality of transmission facilities by providing a symbol generator at a remote location for generating a test signal of predetermined amplitude. At a near location, the received test signal is applied to a controlled gain circuit for each facility, which is under the control of a central microprocessor provided with a reference signal for comparing the received test signal against the reference signal. The gain of the controlled gain circuit may be increased or decreased in accordance with the comparison of the received test signal with the reference signal. In one embodiment, the sum of the digital samples of the received test signal is compared against a reference value stored in a digital memory. In the preferred embodiment the stored reference value comprises a low and a high value which define an acceptable amplitude range therebetween. The gain of the controlled gain circuit is increased or decreased if the received test signal is outside of the acceptable range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.