SYSTEM FOR TWO OR MORE COMBINED COMMUNICATION CHANNELS REGULATED IN ACCORDANCE WITH LINEAR RELATIONSHIPS

• US 3,835,392 A
• Filed: 03/28/1973
• Issued: 09/10/1974
• Est. Priority Date: 12/03/1970
• Status: Expired due to Term

• Current Assignee: Helmut Mahner, Karl Kammerlander
• Original Assignee: Helmut Mahner, Karl Kammerlander
• Inventors: Mahner, Helmut, Kammerlander, Karl
• Primary Examiner(s): Mayer, Albert J.
• Application Number:
  US05/345,774
• Time in Patent Office: 531 Days
• Field of Search: 325/60,301-306,346,351,366-372,378,387,388,398,404,405,409,431,435,444,474,476 179/15R 329/50,178,179 328/155,163,166 343/1PE,1CS,1CL,1LE
• US Class Current: 455/138
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity

Abstract

Two or more communication channels containing coherent signals of respectively different amplitudes and phases aside from respective uncorrelated spurious signals of mutually equal intensities, are combined to a channel of optimal signal-to-noise ratio. This is done by transforming the original signals in a combiner network to an equal number of linear combinations, and regulating the respective transformations by controlling real parameters thereof so as to eliminate correlation between the linear combinations. As a result, the combined signal of the output channel exhibits the desired optimum of signal-to-noise ratio.

Claims

1. A communication channel combiner network having an output channel for a combined signal and having two communication input channels containing respective input signals composed of mutually coherEnt signals of respectively different amplitudes and phases aside from respective uncorrelated spurious signals of mutually equal intensities, said combiner network interconnecting said two input channels and having first circuit means for forming two linear combinations of said input signals and thus performing a linear transformation of said intput signals, one of said linear combinations forming said combined signal;

two regulating circuits controlling said first circuit means and providing two control parameters for said first circuit means, said regulating circuits being connected and said circuit means being constructed so that said linear transformation is maintained as a unitary transformation, said first circuit means comprising phase shifters determining the mutual phase shift of the two input channels, said phase shifters being controllable by one of the control parameters, multipliers connected to the ouput of said phase shifters said multipliers being adapted to multiply each of the output signals of said phase shifters by the sine and simultaneously by the cosine of the other control parameter thus forming four output signals, and adders adapted to form the sum of the sine-multiplied output of the first multiplier and the cosine-multiplied output of the second multiplier, and to form the difference of the cosine-multiplied output of the first multiplier and the sine-multiplied output of the second multiplier, the output of said adders forming said linear combinations, said combiner network further comprising second circuit means connected to said linear combinations to determine mutual correlation between said linear combinations, and said regulating circuits being actuatable so as to eliminate said mutual correlation, said second circuit means comprising two correlation detector networks one of which being preceded by a 90* phase shifter, the outputs of said correlation detector networks being feedback-connected to the inputs of said regulating circuits, and said regulating circuits providing said control parameters.

2. A communication channel combiner network having an output channel for a combined signal and having two communication input channels containing respective input signals composed of mutually coherent signals of respectively different amplitudes and phases aside from respective uncorrelated spurious signals of mutually equal intensities, said combiner network interconnecting said two input channels and having first circuit means for forming two linear combinations of said input signals and thus performing a linear transformation of said input signals, one of said linear combinations forming said combined signal;

two regulating circuits controlling said first circuit means and providing two control parameters for said first circuit means, said regulating circuits being connected and said circuit means being constructed so that said linear transformation is maintained as a unitary transformation, said first circuit means comprising two cascade connected transformation circuit means, each of which is adapted to perform a linear transformation of input signals applied thereto, and each of which is dependent upon only one of said two control parameters, one of said two regulating circuits being connected to a first one of said two transformation circuit means for controlling the parameter of the first one of said two transformations to provide a pregiven correlation between the two linear combinations the second one of said regulating circuits being connected to said other transformation circuit means for controlling the parameter of the second transformation so that the correlation of the two linear combinations vanishes upon said second transformation, said first transformation circuit means comprising a phase shifter controllable by said first regulating circuit for phase shifting said two input channels relative to each other so as to reduce to zero the imaginary portion of the correlation product of the two phase shifted channels, said secoNd transformation circuit means comprising multipliers for multiplying each of said phase shifted channels by the sine and simultaneously by the cosine of the other control parameter, thus forming four output signals, said first circuit means further comprising adders for forming the sum of the sine-multiplied output of the first multiplier and the consine-multiplied output of the second multiplier and for forming the difference of the cosine-multiplied output of the first multiplier and the sine-multiplied output of the second multiplier, the output of said adders forming said linear combinations said other control parameter being controllable by said second regulating circuit to reduce to zero the correlation product of the two resulting linear combinations said combiner network further comprising second circuit means connected to said linear combinations, and said regulating circuits being actuatable so as to eliminate said mutual correlation.

3. A communication channel combiner network having an output channel for a combined signal and having two communication input channels containing respective input signals composed of mutually coherent signals of respectively different amplitudes and phases aside from respective uncorrelated spurious signals of mutually equal intensities, said combiner network interconnecting said two input channels and having first circuit means for forming two linear combinations of said input signals and thus performing a linear transformation of said input signals, one of said linear combinations forming said combined signal;

two regulating circuits controlling said first circuit means and providing two control parameters for said first circuit means, said regulating circuits being connected and said circuit means being constructed so that said linear transformation is maintained as a unitary transformation, said first circuit means comprising two cascade-connected transformation circuit means, each of which is adapted to perform a linear transformation of input signals applied thereto, and each of which is dependent upon only one of said two control parameters, one of said two regulating circuits being connected to a first one of said two transformation circuit means for controlling the parameter of the first one of said two transformations to provide a pregiven correlation between the two linear combinations, the second one of said regulating circuits being connected to said other transformation circuit means for controlling the parameter of the second transformation so that the correlation of the two linear combinations vanishes upon said second transformation, and first transformation circuit means comprising multipliers for multiplying each of the input channels by the sine and simultaneously by the cosine of the first control parameter, thus forming four output signals, adders for forming the sum of the sine-multiplied output of the first multiplier and the cosine-multiplied output of the second multiplier and for forming the difference of the cosine-multiplied output of the first multiplier and the sine-multiplied output of the second multiplier, the output of said adders forming the output of the first transformation circuit means, the control parameter of said first transformation circuit means being controllable by said first regulating circuit to reduce to zero the real portion of the correlation product of the two signals resulting from the transformation, said second transformation circuit means comprising 90* phase shift means for 90* phase-displacing said two latter signals relative to each other, multipliers for multiplying each of said phase-displaced signals by the sine and simultaneously by the cosine of the second control parameter, thus forming four output signals, and adders for forming the sum of the sine-multiplied output of the first multiplier and the cosine-multiplied output of the second multiplier and for forming the difference of the cosine-multiplied output of the first multiplier and the sine-mulTiplied output of the second multiplier, the output of said adders forming the output of the second transformation circuit means, the control parameter of said second transformation circuit means being controllable by said second regulating circuit to reduce to zero the correlation product of the signals resulting from the latter transformation, said combiner network further comprising second circuit means connected to said linear combinations to determine mutual correlation between said linear combinations and said regulating circuits being actuatable so as to eliminate said mutual correlation.