Transmit and receive combining using circulator with distortion cancellation
First Claim
1. A telecommunications system, comprising:
- a circulator device couplable between (i) an antenna and (ii) a transmit path and a receive path, the antenna positionable in the telecommunications system to transmit downlink signals and receive uplink signals;
directional couplers couplable to the antenna and configured to generate samples of a transmit signal subsequent to the transmit signal being routed to the antenna by the circulator device;
a correction circuit couplable to the directional couplers, wherein the correction circuit is configured to correct imperfections in the samples due to finite directivity of the directional couplers and output a corrected transmit signal;
an adaptive filter coupled to the correction circuit, wherein the adaptive filter is configured to generate an output signal by adjusting a level and a phase of the corrected transmit signal; and
a summer device in the receive path, wherein the summer device is configured to sum the output signal with a receive signal in the receive path to reduce distortion of the receive signal by the transmit signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A telecommunications system may include a distortion cancellation subsystem for use with a circulator device coupling an antenna to a transmit path and a receive path. The distortion cancellation subsystem may include a correction circuit and a cancellation circuit. In some aspects, the correction circuit may include a processing device or adaptive filter to correct imperfections in transmit signal samples generated by directional couplers. The correction circuit may also include a summing device to remove receive signal components from the transmit signal samples. The cancellation circuit may receive the output signal of the correction circuit via an adaptive filter. The output of the adaptive filter may be summed with a receive signal to minimize distortion of the receive signal.
11 Citations
20 Claims
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1. A telecommunications system, comprising:
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a circulator device couplable between (i) an antenna and (ii) a transmit path and a receive path, the antenna positionable in the telecommunications system to transmit downlink signals and receive uplink signals; directional couplers couplable to the antenna and configured to generate samples of a transmit signal subsequent to the transmit signal being routed to the antenna by the circulator device; a correction circuit couplable to the directional couplers, wherein the correction circuit is configured to correct imperfections in the samples due to finite directivity of the directional couplers and output a corrected transmit signal; an adaptive filter coupled to the correction circuit, wherein the adaptive filter is configured to generate an output signal by adjusting a level and a phase of the corrected transmit signal; and a summer device in the receive path, wherein the summer device is configured to sum the output signal with a receive signal in the receive path to reduce distortion of the receive signal by the transmit signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A distortion cancellation subsystem for a telecommunications system, comprising:
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a correction circuit couplable to a first directional coupler and a second directional coupler, wherein the correction circuit is configured to receive a first sample and a second sample of a transmit signal subsequent to the transmit signal being routed to an antenna by a circulator device, the correction circuit including a first adaptive filter couplable to a processing device and a first summer device, wherein the correction circuit is configured to correct imperfections in the first sample and the second sample caused by finite directivity of the first directional coupler and the second directional coupler; and a cancellation circuit couplable to (i) a receive path to receive a receive signal routed to the receive path by the circulator device and (ii) the correction circuit to receive a corrected transmit signal generated by the correction circuit, the cancellation circuit including a second adaptive filter and a second summer device, the second adaptive filter couplable to the correction circuit to generate an output signal using the corrected transmit signal, the second summer device couplable to the receive path and to the second adaptive filter, wherein the second summer device is configured to reduce distortion of the receive signal by transmit signal components. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A method, comprising:
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receiving, from directional couplers, samples of a transmit signal subsequent to the transmit signal being routed to an antenna by a circulator device, wherein the antenna is positionable in a telecommunications system to transmit downlink signals and receive uplink signals; receiving, from the circulator device, a receive signal traversing the receive path; generating, by a correction circuit, a corrected transmit signal by correcting imperfections in the samples due to finite directivity of the directional couplers; generating, by an adaptive filter, an output signal by adjusting a level and a phase of the corrected transmit signal; and summing, via a summer device, the receive signal and the output signal to reduce a distortion of the receive signal by the transmit signal. - View Dependent Claims (17, 18, 19, 20)
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Specification