Apparatus and method for interference cancellation

Patent metadata

Field	Value
Publication number	US-9847808-B2
Application number	US-201615263885-A
Country	US
Kind code	B2
Filing date	Sep 13, 2016
Priority date	Mar 14, 2014
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

Embodiments of the present invention provide an apparatus and a method for interference cancellation. The apparatus includes: a splitter, configured to acquire a first transmit signal and a second transmit signal; a first circulator, configured to transmit the first transmit signal to an antenna and to send a to-be-processed signal to a combiner, where the to-be-processed signal includes a receive signal component and a self-interference signal component, the self-interference signal component corresponds to an interference signal generated due to that the antenna reflects the first transmit signal; a second circulator, configured to: transmit the second transmit signal to an equivalent load, and acquire a reference signal generated due to that the equivalent load reflects the second transmit signal, where an impedance of the equivalent load corresponds to an impedance of the antenna; and a combiner, configured to cancel the self-interference signal component according to the reference signal.

First claim

What is claimed is:

1. An apparatus for self-interference cancellation, wherein the apparatus comprises:
a splitter, configured to: perform splitting processing on a radio-frequency signal to acquire a first transmit signal and a second transmit signal, transmit the first transmit signal to a first port of a first circulator, and transmit the second transmit signal to a first port of a second circulator;
the first circulator, configured to transmit the first transmit signal to an antenna through a second port;
the antenna, configured to: transmit the first transmit signal, perform receiving processing to acquire a receive signal, and transmit the receive signal to the second port of the first circulator, wherein:
the first circulator is further configured to send a to-be-processed signal through a third port to a combiner, wherein the to-be-processed signal comprises a receive signal component and a self-interference signal component, the receive signal component corresponds to the receive signal, and the self-interference signal component corresponds to an interference signal generated due to that the antenna reflects the first transmit signal;
the second circulator, configured to: transmit the second transmit signal through a second port to an equivalent load, and acquire, through a third port, a reference signal generated due to that the equivalent load reflects the second transmit signal, wherein an impedance of the equivalent load corresponds to an impedance of the antenna; and
the combiner, configured to cancel the self-interference signal component in the to-be-processed signal according to the reference signal; and the apparatus further comprising:
an amplitude and phase regulator, disposed between the second circulator and the equivalent load, and configured to:
regulate, based on the to-be-processed signal, an amplitude and the phase of the second transmit signal, so that an amplitude of the reference signal is opposite to or approximately opposite to an amplitude of the self-interference signal component, and the phase of the reference signal is the same as or approximately the same as a phase of the self-interference signal component; or
regulate, based on the to-be-processed signal, an amplitude and the phase of the second transmit signal, so that an amplitude of the reference signal is the same as or approximately the same as an amplitude of the self-interference signal component, and a difference between the phase of the reference signal and a phase of the self-interference signal component is 180° or approximately 180°; and

the combiner is configured to combine the to-be-processed signal with the reference signal.

2. The apparatus according to claim 1 , wherein a phase of the first transmit signal is the same as or approximately the same as a phase of the second transmit signal; and
the combiner is configured to: perform phase inversion processing on the reference signal, so that a phase of the reference signal changes by 180° or approximately changes by 180°; and combine the reference signal obtained after the phase inversion processing with the to-be-processed signal; or
the combiner is configured to: perform phase inversion processing on the to-be-processed signal, so that a phase of the to-be-processed signal changes by 180° or approximately changes by 180°; and combine the to-be-processed signal obtained after the phase inversion processing with the reference signal.

3. The apparatus according to claim 1 , wherein a difference between a phase of the first transmit signal and a phase of the second transmit signal is 180° or approximately 180°; and
the combiner is configured to combine the to-be-processed signal with the reference signal.

4. An apparatus for self-interference cancellation, wherein the apparatus comprises:
a splitter, configured to: perform splitting processing on a radio-frequency signal to acquire a first transmit signal and a second transmit signal, transmit the first transmit signal to a first port of a first circulator, and transmit the second transmit signal to a first port of a second circulator;
the first circulator, configured to transmit the first transmit signal to an antenna through a second port;
the antenna, configured to: transmit the first transmit signal, perform receiving processing to acquire a receive signal, and transmit the receive signal to the second port of the first circulator, wherein:
the first circulator is further configured to send a to-be-processed signal through a third port to a combiner, wherein the to-be-processed signal comprises a receive signal component and a self-interference signal component, the receive signal component corresponds to the receive signal, and the self-interference signal component corresponds to an interference signal generated due to that the antenna reflects the first transmit signal;
the second circulator, configured to: transmit the second transmit signal through a second port to an equivalent load, and acquire, through a third port, a reference signal generated due to that the equivalent load reflects the second transmit signal, wherein an impedance of the equivalent load corresponds to an impedance of the antenna; and
the combiner, configured to cancel the self-interference signal component in the to-be-processed signal according to the reference signal, wherein the splitter is configured to perform splitting processing on a radio-frequency signal to acquire a first transmit signal and a second transmit signal, wherein a phase of the first transmit signal is the same as or approximately the same as a phase of the second transmit signal; and
the apparatus further comprises:
a phase changer, wherein
the phase changer is disposed between the splitter and the first circulator, and is configured to perform phase inversion processing on the first transmit signal, so that the phase of the first transmit signal changes by 180° or approximately changes by 180°; or
the phase changer is disposed between the splitter and the second circulator, and is configured to perform phase inversion processing on the second transmit signal, so that the phase of the second transmit signal changes by 180° or approximately changes by 180°; or
the phase changer is disposed between the first circulator and the combiner, and is configured to perform phase inversion processing on the to-be-processed signal, so that a phase of the to-be-processed signal changes by 180° or approximately changes by 180°; or
the phase changer is disposed between the second circulator and the combiner, and is configured to perform phase inversion processing on the reference signal, so that a phase of the reference signal changes by 180° or approximately changes by 180°; and
the combiner is configured to combine the to-be-processed signal with the reference signal.

5. The apparatus according to of claim 4 , wherein the apparatus further comprises:
an amplitude and phase regulator, disposed between the second circulator and the equivalent load, and configured to: regulate, based on the to-be-processed signal, an amplitude and the phase of the second transmit signal, so that an amplitude of the reference signal is opposite to or approximately opposite to an amplitude of the self-interference signal component, and the phase of the reference signal is the same as or approximately the same as a phase of the self-interference signal component; or
regulate, based on the to-be-processed signal, an amplitude and the phase of the second transmit signal, so that an amplitude of the reference signal is the same as or approximately the same as an amplitude of the self-interference signal component, and a difference between the phase of the reference signal and a phase of the self-interference signal component is 180° or approximately 180°; and
the combiner is

Assignees

• Huawei Tech Co Ltd

Inventors

• Liu Sheng

Classifications

• H01P1/213

  combining or separating two or more different frequencies (H01P1/215 takes precedence) · CPC title

• H04B1/525 Primary

  with means for reducing leakage of transmitter signal into the receiver · CPC title

• H01P5/12

  Coupling devices having more than two ports (H01P5/04 takes precedence) · CPC title

• H01P1/182

  Waveguide phase-shifters (H01P1/181, H01P1/185, H01P1/19 take precedence) · CPC title

• H03H7/48

  Networks for connecting several sources or loads, working on the same frequency or frequency band, to a common load or source (phase shifters providing two or more output signals H03H7/21) · CPC title