Method and device for comparing two variable analogue signals
US5305243A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 1991 |
| Grant date | Apr 19, 1994 |
| Priority date | — |
| Expiry date | Sep 10, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R23/005
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device compares two variable analogue signals, e.g. varying in time, such as audio or video signals. The signals, which are either different or identical but shifted in time, are within a predetermined frequency range. The device includes two parallel channels for processing analogue signals. One of the channels introduces a time shift of one signal with respect to the other, the shift being equal to a 1/4 period at the center frequency of the band. Both channels include in series circuits for transforming the analogue signals into binary logic signals, a logic circuit, a summing circuit for establishing a first and second correlation signal. An adder adds the absolute values of the first and second correlation signals to form a third correlation signal that is substantially independent of any time shift between the analogue signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.