Interference cancellation apparatus and method

Patent metadata

Field	Value
Publication number	US-10084584-B2
Application number	US-201615390257-A
Country	US
Kind code	B2
Filing date	Dec 23, 2016
Priority date	Jun 26, 2014
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

Embodiments of the present invention relate to the field of communications technologies, and provide an interference cancellation apparatus and method, which can avoid being limited by a dynamic range of an ADC/DAC and can cancel a second-type self-interference component effectively. The interference cancellation apparatus includes a main receive antenna, a divider, a first-type interference canceller, a down converter, a filter, a coupler, a digital down-conversion unit, a second-type interference reconstructor, and a local-frequency signal generator. The present invention is used for interference cancellation.

First claim

What is claimed is:

1. An interference cancellation apparatus, comprising:
a main receive antenna, configured to receive a radio frequency signal, and transmit the received radio frequency signal to a first-type interference canceller;
a divider, configured to acquire a radio frequency reference signal generated according to a transmit signal, and transmit the radio frequency reference signal to the first-type interference canceller and a second-type interference reconstructor;
the first-type interference canceller, configured to receive the radio frequency reference signal transmitted by the divider and the received radio frequency signal transmitted by the main receive antenna, and cancel a first-type self-interference component in the received radio frequency signal according to the radio frequency reference signal to acquire a first processed signal, wherein the first-type self-interference component comprises a main-path self-interference component;
a local-frequency signal generator, configured to acquire a self-interference channel parameter acquired by the second-type interference reconstructor, and generate a first local-frequency signal and a second local-frequency signal according to the self-interference channel parameter;
a down converter, configured to receive the first local-frequency signal generated by the local-frequency signal generator and the first processed signal acquired by the first-type interference canceller, and perform frequency mixing processing on the first local-frequency signal and the first processed signal to acquire a second processed signal;
a filter, configured to receive the second processed signal, and perform filtering processing on the second processed signal to acquire a third processed signal;
the second-type interference reconstructor, configured to acquire the second local-frequency signal generated by the local-frequency signal generator and the radio frequency reference signal acquired by the divider, and reconstruct the self-interference signal according to the self-interference channel parameter, the radio frequency reference signal, and the second local-frequency signal;
a coupler, configured to receive the third processed signal acquired by the filter and the reconstructed self-interference signal transmitted by the second-type interference reconstructor, and cancel a second-type self-interference signal in the third processed signal according to the reconstructed self-interference signal to generate a fourth processed signal; and
a digital down-conversion unit, configured to receive the fourth processed signal, convert the fourth processed signal into a digital signal, and perform digital down-conversion processing on the digital signal to acquire a fifth processed signal; wherein
the second-type interference reconstructor is further configured to acquire a digital baseband reference signal, receive the fifth processed signal transmitted by the digital down-conversion unit, and perform self-interference channel estimation according to the fifth processed signal and the digital baseband reference signal to acquire the self-interference channel parameter.

2. The apparatus according to claim 1 , wherein the second-type interference reconstructor comprises:
a self-interference estimation module, configured to acquire the digital baseband reference signal, receive the fifth processed signal transmitted by the digital down-conversion unit, and perform self-interference channel estimation according to the digital baseband reference signal and the fifth processed signal to acquire the self-interference channel parameter; and
a self-interference signal reconstruction module, configured to acquire the second local-frequency signal generated by the local-frequency signal generator, receive the radio frequency reference signal acquired by the divider ( 120 ) and the self-interference channel parameter acquired by the self-interference estimation module, and reconstruct the self-interference signal according to the self-interference channel parameter, the radio frequency reference signal, and the second local-frequency signal.

3. The apparatus according to claim 1 , further comprising a first amplifier, wherein the first amplifier is configured to amplify the fourth processed signal.

4. The apparatus according to claim 1 , further comprising a second amplifier and a third amplifier, wherein:
the second amplifier is configured to amplify the first processed signal; and
the third amplifier is configured to amplify the reconstructed self-interference signal.

5. The apparatus according to claim 1 , further comprising a second amplifier and a fourth amplifier, wherein:
the second amplifier is configured to amplify the first processed signal; and
the fourth amplifier is configured to amplify the radio frequency reference signal received by the second-type interference reconstructor.

6. The apparatus according to claim 2 , wherein the self-interference signal reconstruction module comprises:
a first power divider, a first attenuator group, a first mixer group, a first low-pass filter group, and a first delayer group, wherein:
the first power divider is configured to receive the radio frequency reference signal, and divide the radio frequency reference signal into at least one signal;
the first attenuator group comprises at least one attenuator, wherein the attenuator is configured to perform attenuation processing on one of the at least one radio frequency reference signal according to the self-interference channel parameter;
the first mixer group comprises at least one mixer, wherein the mixer is configured to perform, according to the second local-frequency signal, frequency mixing processing on one of the radio frequency reference signal after attenuation processing;
the first low-pass filter group comprises at least one low-pass filter, wherein the low-pass filter is configured to perform filtering processing on one of the radio frequency reference signal after frequency mixing processing; and
the first delayer group comprises at least one delayer and at least one combiner, wherein: the at least one delayer is connected in series by using a first input end and an output end of a combiner, an input end of a first delayer and a second input end of the combiner are configured to input one radio frequency reference signal after filtering processing, and an output end of a last combiner is configured to output the reconstructed self-interference signal.

7. The apparatus according to claim 2 , wherein the self-interference signal reconstruction module comprises:
a second power divider, a second mixer group, a second low-pass filter group, a second attenuator group, and a second delayer group, wherein:
the second power divider is configured to receive the radio frequency reference signal, and divide the radio frequency reference signal into at least one signal;
the second mixer group comprises at least one mixer, wherein the mixer is configured to perform frequency mixing processing on one of the radio frequency reference signal according to the second local-frequency signal;
the second low-pass filter group comprises at least one low-pass filter, wherein the low-pass filter is configured to perform filtering processing on one of the radio frequency reference signal after frequency mixing processing;
the second attenuator group comprises at least one attenuator, wherein the attenuator is configured to perform, according to the self-interference channel parameter, attenuation processing on one of the radio frequency reference signal after filtering processing; and
the second delayer group comprises at least one delayer and at least one combiner, wherein: the at least one delayer is connected in series by using a first input

Assignees

• Huawei Tech Co Ltd

Inventors

• Liu Sheng
• Chen Teyan
• Cai Yu

Classifications

• H04W72/541

  using the level of interference · CPC title

• H04B1/123 Primary

  using adaptive balancing or compensation means (adaptive filter circuits and algorithms H03H) · CPC title

• H04L25/0224

  using sounding signals · CPC title

• H04L25/0212

  of impulse response · CPC title

• H04W88/08

  Access point devices · CPC title