Method and apparatus for cross-polarization compensation
AssigneeRaytheon Company
InventorThomas A. Schonhoff
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Abstract
Methods and apparatus for compensating for polarization loss in communications systems that use orthogonally spaced polarization. In one example, a signal processing method uses a statistical decorrelation process to separate out two orthogonally polarized desired signals from noisy received signals that include these orthogonally polarized desired signals along with their cross-polarized components, thereby compensating for the polarization contamination.
Claims20
A digital signal processor-implemented method of compensating for cross-polarization in a communications system, the method comprising:
- receiving at a receiver of the communications system a first input signal comprising a first transmitted signal and a first cross-polarization component of a second, orthogonally polarized transmitted signal;
- receiving at the receiver a second input signal comprising the second, orthogonally polarized transmitted signal and a second cross-polarization component of the first transmitted signal;
- calculating a two-by-two cross-correlation matrix for the first and second input signals;
- calculating a corresponding decorrelation matrix;
- and
- performing a matrix multiplication of the decorrelation matrix with a first vector comprising the first and second input signals to generate a second vector comprising first and second output signals, wherein the first output signal is representative of the first transmitted signal and the second output signal is representative of the second, orthogonally polarized transmitted signal, the first and second output signals being substantially free of the first and second cross-polarization components.
A communications system receiver comprising:
- a first input configured to receive a first signal including a first transmitted signal having a first polarization and a first cross-polarization component of a second transmitted signal having a second, orthogonal polarization;
- a second input configured to receive a second signal including the second transmitted signal and a second cross-polarization component of the first transmitted signal;
- a digital signal processor configured to receive the first and second signals, the digital signal processor configured to implement a statistical decorrelation separation process separate the first and second transmitted signals from the first and second signals and to provide first and second output signals, the first and second output signals corresponding to the first and second transmitted signals, respectively, and being substantially free of the first and second cross-polarization components.
The communications system receiver as claimed in 11, further comprising a digital storage medium configured to store the plurality of complex samples.
The communications system receiver as claimed in 8, further comprising an antenna including a first antenna element coupled to the first input and configured to receive the first signal and provide the first signal to the first input, and a second antenna element coupled to the second input and configured to provide the second signal to the second input.
A method of compensating for cross-polarization in a communications receiver configured for dual-polarized signaling, the method comprising:
- receiving at the receiver a first input signal including a first carrier signal having a first polarization and modulated with a first data stream, and a first cross-polarization component of a second carrier signal having a second, orthogonal polarization;
- receiving at the receiver a second input signal including the second carrier signal modulated with a second data stream, and a second cross-polarization component of the first carrier signal;
- performing a statistical decorrelation separation process to separate the first and second carrier signals from the first and second input signals;
- based on the statistical decorrelation separation process, providing first and second output signals corresponding to the first and second transmitted signals, respectively, and being substantially free of the first and second cross-polarization components.
Dependencies are inferred from the claim text.