Cancellation system for frequency reuse in microwave communications
First Claim
1. A method of providing frequency rate in a communication system, the method including:
- receiving a plurality of transmission signals with a plurality of receiver elements wherein said plurality of transmission signals are transmitter by a transmitter having a plurality of transmitting elements, the receiver elements capable of providing a plurality of received signals having known ratios of co-channel interference, providing the received signals with algebraically unique ratios of co-channel interference, and separating at least one desired signal from the received signals.
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0 Petitions
Accused Products
Abstract
Substantial improvements in frequency reuse in microwave communications systems is achieved by canceling co-channel interference and transmitter leakage. Interferometric beam-narrowing reduces beamwidth without reducing preak magnitude of the beam pattern. Frequency-dependent beam-shaping compensates for frequency-dependent distortions of the beam pattern thereby improving bandwidth. A spatial demultiplexing technique utilizes spatial gain distributions of received signals to separate signals, even from co-located transmit sources, and uses microwave lensing to enhance received spatial gain distributions. Predetermined cross-polarization interference is used to separate differently polarized receive signals. A reference branch provides a cancellation signal to a receiver to cancel transmitter leakage signals. An error signal controls an impedance-compensation circuit that is responsive to changes in antenna impedance but not to receive signals. A dc bias magnetic field applied to a magnetic permeable material adjusts non-linear distortion in a cancellation circuit for canceling distortion in a transmitter leakage signal. Discreet impedance elements approximate a circuit having distributed impedance.
54 Citations
21 Claims
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1. A method of providing frequency rate in a communication system, the method including:
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receiving a plurality of transmission signals with a plurality of receiver elements wherein said plurality of transmission signals are transmitter by a transmitter having a plurality of transmitting elements, the receiver elements capable of providing a plurality of received signals having known ratios of co-channel interference, providing the received signals with algebraically unique ratios of co-channel interference, and separating at least one desired signal from the received signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method of bandwidth-efficient communications that achieves frequency reuse, the method including:
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transmitting a plurality of transmission signals from a transmitter having a plurality of transmitting element wherein the plurality of transmission signals have at least one common frequency channel, receiving the plurality of transmitted signals with a plurality of receiver elements for providing a plurality of received signals, the received signals having known ratios of co-channel interference, providing the received signals with algebraically unique ratios of co-channel interference, and separating at least one desired signal from the received signals.
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20. A method of array processing that enables simultaneous frequency use of a plurality of transmitted signals from a transmitter having a plurality of transmitter elements, the method including steps of:
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determining a plurality of ratios of co-channel interference occurring between the transmitted signals received at each of a plurality of receivers, receiving the transmitting signals at the receivers, the receivers capable of being responsive to the received transmitted signals for providing a plurality of received signals, the received signals having known ratios of co-channel interference, providing the received signal with algebraically unique ratios of co-channel interference, and separating the transmitted signals from the received signals.
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21. A method of bandwidth-efficient communications that achieves frequency reuse, the method including steps of:
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providing transmission by a transmitter having a plurality of transmitter elements of a plurality of transmission signals having at least one common frequency channel, providing determination of a plurality of ratios of co-channel interference occurring between the transmitted signals received by a plurality of receivers, receiving the transmitted signals, with the receivers, the receivers capable of being responsive to the received transmitted signals for providing a plurality of received signals having known ratios of co-channel interference, providing the received signals with algebraically unique ratios of co-channel interference, and providing separation of the transmitted signals from the received signals.
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Specification