Apparatus and method for self-interference cancellation

Patent metadata

Field	Value
Publication number	US-10079666-B2
Application number	US-201615269313-A
Country	US
Kind code	B2
Filing date	Sep 19, 2016
Priority date	Mar 20, 2014
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

Embodiments of the present invention provide an apparatus for self-interference cancellation. The apparatus includes: a first splitter, configured to perform splitting processing on a local oscillator signal generated by a local oscillator to separately transmit the local oscillator signal to an up-converter and a delayer; the up-converter, configured to perform up-conversion processing on a baseband transmit signal according to the local oscillator signal to generate a transmit signal; the delayer, configured to perform delaying processing on the local oscillator signal according to a preset target delay; a first down-converter, configured to perform, based on the local oscillator signal obtained after the delaying processing, down-conversion processing on a receive signal to acquire a baseband receive signal, and transmit the baseband receive signal to a self-interference canceller; and the self-interference canceller, configured to perform self-interference cancellation processing on the baseband receive signal.

First claim

What is claimed is:

1. An apparatus for self-interference cancellation, the apparatus comprising:
a local oscillator, configured to generate and transmit a local oscillator signal;
a first splitter, configured to receive the local oscillator signal through an input port and split the local oscillator signal into two signals, wherein one of the two signals is transmitted to an up-converter through a first output port of the first splitter and the other signal is transmitted to a delayer through a second output port of the first splitter, wherein the up-converter is connected to the first output port of the first splitter through a first input port and is configured to perform up-conversion processing on a baseband transmit signal received from a second input port using the local oscillator signal received from the first splitter to generate a radio frequency transmit signal, and wherein the delayer is configured to perform delaying processing on the local oscillator signal received from the first splitter through an input port according to a preset target delay;
a first down-converter, connected to the second output port of the first splitter through a first input port and configured to perform, based on the local oscillator signal received from the first splitter and that is obtained after the delaying processing by the delayer, down-conversion processing on a radio frequency receive signal to acquire a baseband receive signal, wherein a delay value of the delaying processing is a delay between the baseband transmit signal and the baseband receive signal; and
a self-interference canceller, connected to an output port of the first down-converter through a first input port and configured to perform self-interference cancellation processing on the baseband receive signal received from the first down-converter.

2. The apparatus according to claim 1 , wherein the self-interference canceller is connected to a transmit branch through a second input port and is configured to:
acquire, based on the baseband transmit signal received from the transmit branch, an estimation of a baseband self-interference signal in the baseband receive signal received from the first down-converter; and
cancel the baseband self-interference signal in the baseband receive signal using the estimation of the baseband self-interference signal.

3. The apparatus according to claim 1 , wherein the apparatus further comprises:
a second splitter, configured to acquire, from the delayer through an input port, the local oscillator signal obtained after the delaying processing, and split the local oscillator signal obtained after the delaying processing into two signals, wherein one of the two signals is transmitted to the first down-converter through a first output port of the second splitter and the other signal is transmitted to a second down-converter through a second output port of the second splitter; and
a third splitter, configured to acquire the radio frequency transmit signal from the up-converter through an input port and split the radio frequency transmit signal into two signals, wherein one signal is used as a to-be-transmitted signal and is transmitted to a transmit antenna using a first output port of the third splitter; and the other signal is used as a radio frequency reference signal and is transmitted to the second down-converter using a second output port of the third splitter,
wherein the second down-converter is configured to perform, based on the local oscillator signal obtained from the second splitter after the delaying processing, down-conversion processing on the radio frequency reference signal received from the third splitter to acquire a baseband reference signal, and send the baseband reference signal to the self-interference canceller, and
wherein the self-interference canceller is configured to perform, based on the baseband reference signal received from the second down-converter, self-interference cancellation processing on the baseband receive signal received from the first down-converter.

4. The apparatus according to claim 3 , wherein the self-interference canceller is configured to:
acquire, based on the baseband reference signal received from the second down-converter, an estimation of a baseband self-interference signal in the baseband receive signal received from the first down-converter; and
cancel the baseband self-interference signal in the baseband receive signal using the estimation of the baseband self-interference signal.

5. The apparatus according to claim 1 , wherein:
the target delay is determined according to a first delay, a second delay, and a third delay;
the first delay is a processing delay after the up-conversion processing in a transmit branch;
the second delay is a processing delay before the down-conversion processing in a receive branch; and
the third delay is an average delay of a multipath signal from a transmit antenna to a receive antenna.

6. The apparatus according to claim 2 , wherein:
the target delay is determined according to a first delay, a second delay, and a third delay;
the first delay is a processing delay after the up-conversion processing in a transmit branch;
the second delay is a processing delay before the down-conversion processing in a receive branch; and
the third delay is an average delay of a multipath signal from a transmit antenna to a receive antenna.

7. The apparatus according to claim 3 , wherein:
the target delay is determined according to a first delay, a second delay, and a third delay;
the first delay is a processing delay after the up-conversion processing in a transmit branch;
the second delay is a processing delay before the down-conversion processing in a receive branch; and
the third delay is an average delay of a multipath signal from a transmit antenna to a receive antenna.

8. The apparatus according to claim 4 , wherein:
the target delay is determined according to a first delay, a second delay, and a third delay;
the first delay is a processing delay after the up-conversion processing in a transmit branch;
the second delay is a processing delay before the down-conversion processing in a receive branch; and
the third delay is an average delay of a multipath signal from a transmit antenna to a receive antenna.

9. An apparatus for self-interference cancellation, the apparatus comprising:
a local oscillator, configured to generate and transmit a local oscillator signal;
a first splitter, configured to receive the local oscillator signal through an input port and split the local oscillator signal into two signals, wherein one of the two signals is transmitted to a first down-converter through a first output port of the first splitter and the other signal is transmitted to a second down-converter through a second output port of the first splitter, wherein the first down-converter is connected to the first output port of the first splitter through a first input port and is configured to perform, based on the local oscillator signal received from the first splitter, down-conversion processing on a radio frequency receive signal received from a second input port to acquire a baseband receive signal, and send the baseband receive signal to a self-interference canceller; and
a second splitter, connected to a second input port of the second down-converter through a second output port and configured to acquire a radio frequency reference signal according to a radio frequency transmit signal received from an input port, and send the radio frequency reference signal to the second down-converter,
wherein the second down-converter is connected to the second output port of the first splitter through a first input port, configured to perform, based on the lo

Assignees

• Huawei Tech Co Ltd

Inventors

• Liu Sheng
• Chen Teyan
• Cheng Hong

Classifications

• H04L5/14

  Two-way operation using the same type of signal, i.e. duplex · CPC title

• H04L5/1461

  Suppression of signals in the return path, i.e. bidirectional control circuits · CPC title

• H04B1/525 Primary

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

• H04L5/005

  of common pilots, i.e. pilots destined for multiple users or terminals · CPC title

• H04L5/0073 Primary

  Allocation arrangements that take into account other cell interferences · CPC title