Precise amplitude correction circuit
US6625286B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 1999 |
| Grant date | Sep 23, 2003 |
| Priority date | — |
| Expiry date | Jun 18, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04S1/00
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Amplitude is corrected by subtracting a component signal from a composite signal to produce a remainder signal, correlating the remainder signal with the component signal to produce a product signal, averaging the product signal, and adjusting the magnitude of the component signal in accordance with the averaged product signal to minimize the product signal. The amplitude of the component signal is adjusted in a programmable gain amplifier controlled by an up-down counter. The up-down counter is part of a digital control loop including a pseudo-multiplier for multiplying the remainder signal with the component signal. The output of the multiplier controls the direction of the count, which is generally continuous except that it cannot roll over or roll under. The remainder signal is the received signal with the echo removed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.