System for compensating polarization errors
First Claim
1. A method for compensating for the cross coupling interference in first channel signals having a first sense of polarization as received at a first antenna pick-up means by second channel signals of a second opposite sense of polarization in a frequency reuse by polarization diversity system wherein signals in each of said first and second opposite sense polarizations are in given channels or frequency bands separated by a guard band and said channels in said first polarization are offset in frequency from said channels in said second polarization such that each channel center frequency of the second polarization is provided at the guard band between channels of the first polarization, said compensating method comprising the steps of:
- sensing the second channel signals by second pick-up means adapted to receive said second opposite sense polarization;
sensing the ratio of the amplitudes of the second polarization signals at the guard band frequencies adjacent said first channel as received at said second and first antenna pick-up means;
reducing the amplitude of the second channel signals sensed by the second antenna pick-up means in proportion to said ratio; and
differentially summing said reduced amplitude second channel signals with said first channel signals received by said first antenna pick-up means.
2 Assignments
0 Petitions
Accused Products
Abstract
A method and system is described for use with or in a satellite for compensating for cross coupling of satellite feeder link signals from a first channel of a first linear polarization as received by a first linearly polarized satellite antenna element with adjacent signals from a second channel. The second channel signals are at a generally orthogonal linear polarization. The system includes a second linearly polarized antenna element oriented orthogonal to the first antenna element for sensing the second channel signal, a gain controlled amplifier for reducing the gain of the second channel signal received at the second antenna element in inverse proportion to the sensed amount of cross coupling (depolarization) and adding the reduced gain signals that have been inverted to the first channel signals from said first antenna element.
-
Citations
18 Claims
-
1. A method for compensating for the cross coupling interference in first channel signals having a first sense of polarization as received at a first antenna pick-up means by second channel signals of a second opposite sense of polarization in a frequency reuse by polarization diversity system wherein signals in each of said first and second opposite sense polarizations are in given channels or frequency bands separated by a guard band and said channels in said first polarization are offset in frequency from said channels in said second polarization such that each channel center frequency of the second polarization is provided at the guard band between channels of the first polarization, said compensating method comprising the steps of:
-
sensing the second channel signals by second pick-up means adapted to receive said second opposite sense polarization; sensing the ratio of the amplitudes of the second polarization signals at the guard band frequencies adjacent said first channel as received at said second and first antenna pick-up means; reducing the amplitude of the second channel signals sensed by the second antenna pick-up means in proportion to said ratio; and differentially summing said reduced amplitude second channel signals with said first channel signals received by said first antenna pick-up means. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A system for compensating for cross coupling interference in first channel signals having a first sense of polarization as received by a first antenna pick-up means by second channel signals having a second opposite sense of polarization in a frequency reuse by polarization diversity system wherein signals in each of said first and second opposite sense polarizations are in given channels or frequency bands separated by a guard band and said channels in said first polarization are offset in frequency from said channels in said second polarization such that each channel center frequency of the second polarization is provided at the guard band between channels of the first polarization, said compensating system comprising, in combination:
-
means including a second antenna pick-up means adapted to receive said second opposite sense polarization for sensing the second channel signals; means coupled to said first and second antenna pick-up means for providing a gain control signal proportional to the ratio of the second channel signals at the guard band frequencies adjacent said first channel as received at said second and first antenna pick-up means, means coupled to said first and second mentioned means for reducing the amplitude of the second channel signals sensed by the second antenna pick-up means in proportion to said ratio; and means for differentially summing said reduced amplitude second channel signals with said first channel signals received by said first antenna pick-up means. - View Dependent Claims (8, 9, 10, 11, 12, 13)
-
-
14. A system for compensating for cross coupling interference in first channel signals having a first sense of polarization as received by a first antenna pick-up means at a satellite by second channel signals having a second opposite sense of polarization in a frequency reuse by polarization diversity feeder link system wherein each of said first and second opposite sense polarized signals are in given channels or frequency bands separated by a guard band and said channels in said first polarization are offset in frequency from said channels in said second polarization such that the channel center frequency of the second polarization is provided at the guard band of said first polarization, said compensating system comprising in combination:
-
means including a second antenna pick-up means adapted to receive said second opposite sense polarization for sensing the second channel signals; means coupled to said first and second antenna pick-up means for providing a gain control signal proportional to the ratio of the second channel signals at the guard band frequencies adjacent said first channel as received at said second and first antenna pick-up means; means coupled to said first and second mentioned means for reducing the amplitude of the second channel signals sensed by the second antenna pick-up means in proportion to said ratio; and means for differentially summing said reduced amplitude second channel signals within said first channel signals received by said first antenna pick-up means. - View Dependent Claims (15, 16, 17, 18)
-
Specification