Arrangement for the suppression of signal interference

Claim 2

An arrangement for the suppression of signal interference comprising: two transmission networks which electrically connect an electric signal source to a processing circuit, the transmission networks arranged to have different sensitivities to interference signals of unspecified characteristics, a processing ciruit for computing an interference-free useful signal from two composite signals supplied by the two transmission networks, the two transmission networks each providing a different response to a respective interference signal, the processing circuit including means for deriving the useful signal from the composite signals at the inputs of the processing circuit by computation and elimination of the interference signals which influence each transmission network.

Claim 3

An arrangement for the suppression of signal interference produced in two transmission networks which electrically connect an electric signal source to a processing circuit, the transmission networks having different sensitivities to interference signals, wherein the processing circuit comprises, an input subtracting circuit connected to the transmission networks formed by two transmission lines so as to supply the difference between the interference signals (Z 1 -Z 2 ) which influence the transmission lines to a correlation network connected to the transmission lines, said correlation network computing the interference-signal ratio (Z 1 /Z 2 ), a reduction network connected to the correlation network to derive a signal (Z 1 /Z 2 )-1, a divider connected to the reduction network and to the input subtracting circuit thereby to compute the interference signal (Z 2 ) from the difference between the interference signals (Z 1 -Z 2 ), as the dividend, and the signal (Z 1 /Z 2 )-1 representing the interference-signal ratio minus 1, as the divisor, and an output subtracting circuit connected to the divider and to the transmission line which is influenced by Z 2 thereby to compute an undisturbed useful signal by subtracting the interference signal Z 2 from the disturbed signal having the interference component Z 2 .

Claim 4

An arrangement for the suppression of signal interference produced in two transmission networks which electrically connect an electric signal source to a processing circuit, the transmission networks having different sensitivities to interference signals, wherein the processing circuit comprises, an input subtracting circuit connected to the transmission networks formed by two transmission lines so as to supply the difference between the interference signals (Z 1 -Z 2 ) which influence the transmission lines to a correlation network connected to the transmission lines, said correlation network computing the interference-signal ratio (Z 1 /Z 2 ), a reduction network connected to the correlation network to derive a signal (Z 1 /Z 2 )-1, a divider connected to the reduction network and to the input subtracting circuit thereby to compute the interference signal (Z 2 ) from the difference between the interference signals (Z 1 -Z 2 ), as the dividend, and the signal (Z 1 /Z 2 )-1 representing the interference-signal ratio minus 1, as the divisor, and an output subtracting circuit connected to the divider and to the transmission line which is influenced by Z 2 thereby to compute an undisturbed useful signal by subtracting the interference signal Z 2 from the disturbed signal having the interference component Z 2 .

Claim 5

An arrangement as claimed in claim 2, wherein the correlation network comprises two cross-correlators connected to the input subtracting circuit and to a respective one of said two transmission lines and which operate with a delay time τ=0, a further divider coupled to said two cross-correlators for computing the interference-signal ratio (Z 1 /Z 2 ) from output quantities supplied by said correlators.

Claim 6

An arrangement as claimed in claim 2, wherein the correlation network comprises two auto-correlators connected to a respective one of said two transmission lines and one auto-correlator connected to the input subtracting circuit, said correlators operating with a delay time τ=0, an arithmetic network coupled to said auto-correlators for computing the interference-signal ratio (Z 1 /Z 2 ) from output quantities supplied by said correlators in accordance with the relationship ##EQU3## wherein Φ 1 is the output quantity of the autocorrelator connected to the transmission line which is influenced by the interference signal (Z 1 ) Φ 2 is the output quantity of the autocorrelator which is connected to the transmission line which is influenced by the interference signal (Z 2 ), and Φ 3 is the output quantity of the autocorrelator which is connected to the input subtracting circuit.

Claim 7

In an apparatus for suppressing signal interference received via first and second transmission networks which couple an electric signal source at a first location to a signal processing circuit at a second location remote from the first location, said first and second transmission networks supplying, in addition to a useful signal, first and second interference signals Z 1 and Z 2 , respectively, wherein Z 1 ≠Z 2 , a processing circuit comprising: a subtracting circuit having input means coupled to said first and second networks and having first and second outputs for supplying signals equal to the difference of the interference signals (Z 1 -Z 2 ), a correlation network having a first input coupled to the first output of the subtracting circuit and a second input coupled to said first and second networks, said correlation network being operative to derive an interference-signal ratio (Z 1 /Z 2 ) at an output thereof, a reduction network coupled to the output of the correlation network to supply at its output a signal (Z 1 /Z 2 )-1, a divider network having first and second inputs coupled to the output of the reduction network and the second output of the subtracting circuit, respectively, and operative to derive at its output a signal (Z 1 -Z 2 )/((Z 1 /Z 2 )-1), and a second subtracting circuit having a first input coupled to the output of the divider network and a second input coupled to the second transmission network thereby to derive at an output terminal thereof a signal comprising the useful signal from the electric signal source relatively free of said interference signals of the transmission networks.

Claim 8

In an apparatus for suppressing signal interference received via first and second transmission networks which couple an electric signal source at a first location to a signal processing circuit at a second location remote from the first location, said first and second transmission networks supplying, in addition to a useful signal, first and second interference signals Z 1 and Z 2 , respectively, wherein Z 1 ≠Z 2 , a processing circuit comprising: a subtracting circuit having input means coupled to said first and second networks and having first and second outputs for supplying signals equal to the difference of the interference signals (Z 1 -Z 2 ), a correlation network having a first input coupled to the first output of the subtracting circuit and a second input coupled to said first and second networks, said correlation network being operative to derive an interference-signal ratio (Z 1 /Z 2 ) at an output thereof, a reduction network coupled to the output of the correlation network to supply at its output a signal (Z 1 /Z 2 )-1, a divider network having first and second inputs coupled to the output of the reduction network and the second output of the subtracting circuit, respectively, and operative to derive at its output a signal (Z 1 -Z 2 )/((Z 1 /Z 2 )-1), and a second subtracting circuit having a first input coupled to the output of the divider network and a second input coupled to the second transmission network thereby to derive at an output terminal thereof a signal comprising the useful signal from the electric signal source relatively free of said interference signals of the transmission networks.

Claim 9

A circuit for processing a useful signal (X) transmitted over first and second transmission networks arranged to have different sensitivities to interference signals and in a manner so as to suppress interference signals Z 1 and Z 2 produced in the first and second transmission networks, respectively, the processing circuit comprising: a subtraction circuit for subtracting the composite signals X+Z 1 and X+Z 2 received from the first and second transmission networks, respectively, to derive a difference quantity (Z 1 -Z 2 ) which is the difference between the interference signals Z 1 and Z 2 on the first and second transmission networks, respectively, means responsive to said difference quantity and including at least a correlation network for deriving an electric quantity determined by the interference signal received from one of said transmission networks, and means for combining said electric quantity with the composite signal from said one transmission network so as to produce a useful output signal (X) substantially free of the interference signal.

Claim 10

A circuit for processing a useful signal (X) transmitted over first and second transmission networks arranged to have different sensitivities to interference signals and in a manner so as to suppress interference signals Z 1 and Z 2 produced in the first and second transmission networks, respectively, the processing circuit comprising: a subtraction circuit for subtracting the composite signals X+Z 1 and X+Z 2 received from the first and second transmission networks, respectively, to derive a difference quantity (Z 1 -Z 2 ) which is the difference between the interference signals Z 1 and Z 2 on the first and second transmission networks, respectively, means responsive to said difference quantity and including at least a correlation network for deriving an electric quantity determined by the interference signal received from one of said transmission networks, and means for combining said electric quantity with the composite signal from said one transmission network so as to produce a useful output signal (X) substantially free of the interference signal.

Claim 11

A processing circuit as claimed in claim 6 wherein said derived electric quantity is determined by the interference signal Z 2 on the second transmission network and said one transmission network is the second transmission network with one composite signal X+Z 2 , and wherein said combining means comprises a second subtraction circuit which subtracts an electric quantity signal Z 2 from the composite signal X+Z 2 to produce said useful output signal X.

Claim 12

A processing circuit as claimed in claim 6 wherein said electric quantity deriving means comprises, a correlation network having input means coupled to said first and second transmission networks and an input coupled to an output of the subtraction circuit to derive a first intermediate signal equal to the interference signal ratio (Z 1 /Z 2 ), a reduction network coupled to the correlation network to derive a second intermediate signal (Z 1 /Z 2 )-1, a divider having input means coupled to the reduction network and to the subtraction circuit to produce said electric quantity equal to interference signal Z 2 by dividing the difference quantity (Z 1 -Z 2 ) by the second intermediate signal (Z 1 /Z 2 )-1, and a second subtraction circuit having input means coupled to the divider output and the second transmission network to produce said interference-free useful output signal (X) at an output of the second subtraction circuit.

Claim 13

A processing circuit as claimed in claim 8 wherein the correlation network comprises first and second cross-correlator devices each having an input connected to the first subtraction circuit and a second input connected to a respective one of the first and second transmission networks, each cross-correlator device operating with a delay time τ=0, and a further divider having input means coupled to said first and second cross-correlator devices for deriving said first intermediate signal (Z 1 /Z 2 ).

Claim 14

A processing circuit as claimed in claim 8 wherein the correlation network comprises first, second and third auto-correlator devices coupled to the first transmission network, the second transmission network and the output of the first subtraction circuit, respectively, each of the auto-correlator devices operating with a delay time τ=0, and an arithmetic network having input means coupled to outputs of said first, second, and third auto-correlator devices and means for deriving the first intermediate signal (Z 1 /Z 2 ) at an output thereof.