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Signal Correlator

IP.com Disclosure Number: IPCOM000097881D
Original Publication Date: 1961-Aug-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Backman, FF: AUTHOR [+2]

Abstract

The signal correlator produces, in real time, a cross-correlation function between two input functions or signals. It is designed for detecting whether or not a specific audio signal is present in a highnoise environment. The inputs are a known and an unknown signal given as functions of time. It produces the auto-correlation function, when the inputs are the same functions of time, one input signal being delayed by a known increment of time.

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Signal Correlator

The signal correlator produces, in real time, a cross-correlation function between two input functions or signals. It is designed for detecting whether or not a specific audio signal is present in a highnoise environment. The inputs are a known and an unknown signal given as functions of time. It produces the auto- correlation function, when the inputs are the same functions of time, one input signal being delayed by a known increment of time.

The input signals A, B enter transformers and are added and subtracted from one another. The A+B and the A-B signals are each impressed across incandescent lamps which perform the necessary multiplication of the signals and their integration in order to generate the correlation function. The difference in brightness detected by photocells and measured by a meter is an indication of the cross correlation between the two input signals. Any periodicity greater than the thermal time constant of the lamps is disregarded. The limits of the integral may be changed by taking lamps of another time constant.

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