Architecture and control of hybrid coupler based analog self-interference cancellation

Patent metadata

Field	Value
Publication number	US-9602149-B1
Application number	US-201514976647-A
Country	US
Kind code	B1
Filing date	Dec 21, 2015
Priority date	Dec 21, 2015
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

An apparatus for interference cancellation in a wireless communication system, includes a cancellation unit configured to receive a transmit (Tx) signal from an output port of a power amplifier and a receive (Rx) signal from an antenna, and generate a cancellation of a primary portion of the Tx signal from the Rx signal at an output thereof, leaving a residual portion as a residual Tx signal, wherein the output of the cancellation unit is coupled to an Rx input port of a transceiver. The apparatus further includes a compensation control unit configured to modify one or more signals within the cancellation unit, based on the residual Tx signal at the output of the cancellation unit.

First claim

The invention claimed is:

1. An apparatus for interference cancellation in a wireless communication system, comprising:
a cancellation unit configured to:
receive a transmit (Tx) signal from an output port of a power amplifier and a receive (Rx) signal from an antenna, wherein due to a coupling of the Tx signal and the Rx signal within the cancellation unit, the Rx signal contains portions of the Tx signal, and
generate a cancellation of a primary portion of the Tx signal from the Rx signal at an output thereof, leaving a residual portion as a residual Tx signal in the Rx signal, wherein the Rx signal that is output from the cancellation unit is coupled to an Rx input port of a transceiver; and

a compensation control unit configured to modify one or more signals within the cancellation unit, based on the residual Tx signal at the output of the cancellation unit, wherein the modification of the one or more signals results in a reduction or an elimination of the residual Tx signal at the output of the cancellation unit,
wherein the cancellation unit comprises:
a first coupling unit configured to:
receive the transmit (Tx) signal from the output port of the power amplifier and generate an in-phase Tx signal in a first signal path and a quadrature Tx signal in a second signal path; and
receive the receive (Rx) signal from the antenna and generate an in-phase Rx signal in the second signal path and a quadrature Rx signal in the first signal path;

a receive filter unit coupled to the first signal path and the second signal path and configured to:
generate an overall quadrature receive signal comprising the quadrature Rx signal and a residual component of the in-phase Tx signal in a third signal path, and
generate an overall in-phase receive signal comprising the in-phase Rx signal and a residual component of the quadrature Tx signal in a fourth signal path; and

a second coupling unit configured to:
receive the overall quadrature receive signal along the third signal path and the overall in-phase receive signal along the fourth signal path, and
generate an overall receive signal comprising an Rx output signal and the residual Tx signal at an output thereof.

2. The apparatus of claim 1 , wherein the compensation control unit comprises,
a feedback receiver unit configured to selectively generate a compensation signal based on a measured power of the residual Tx signal or a signal associated therewith; and
a compensation unit configured to modify the overall in-phase receive signal or the overall quadrature receive signal or both, based on the compensation signal.

3. The apparatus of claim 2 , further comprising a third coupling unit coupled to the first output of the second coupling unit configured to receive the overall receive signal and sample the residual Tx signal from the overall receive signal to generate a residual Tx output signal at a first output thereof and convey the overall receive signal to an Rx input port of a transceiver via a second output thereof.

4. The apparatus of claim 3 , wherein the feedback receiver unit is configured to:
receive the residual Tx output signal from the first output of the third coupling unit, and
generate the compensation signal for compensating the overall in-phase receive signal or the overall quadrature receive signal or both, based on retrieving a value associated with the residual Tx output signal from a memory unit associated therewith.

5. The apparatus of claim 2 , wherein the compensation unit comprises an attenuation unit coupled to the third signal path or the fourth signal path, and configured to provide an attenuation to the overall quadrature receive signal or the overall in-phase receive signal respectively, based on the compensation signal.

6. The apparatus of claim 5 , wherein the compensation unit further comprises a phase shift unit coupled to the third signal path or the fourth signal path, and configured to provide a phase shift to the overall quadrature receive signal or the overall in-phase receive signal respectively, based on the compensation signal.

7. The apparatus of claim 2 , wherein the feedback receiver unit is configured to selectively generate the compensation signal based on a predetermined condition.

8. The apparatus of claim 7 , wherein the predetermined condition comprises the measured power of the residual Tx signal or the signal associated therewith exceeding a predetermined threshold.

9. The apparatus of claim 8 , wherein the feedback receiver unit is configured to operate in:
a correction mode when the measured power of the residual Tx signal or the signal associated therewith exceeds a predetermined threshold, wherein the feedback receiver unit is configured to generate the compensation signal; and
a monitor mode when the measured power of the residual Tx signal or the signal associated therewith falls below the predetermined threshold, wherein the feedback receiver unit is configured to dynamically monitor the power of the residual Tx signal or the signal associated therewith.

10. The apparatus of claim 2 , wherein the compensation unit is further configured to modify a first signal comprising the quadrature Rx signal and the in-phase Tx signal in the first signal path or a second signal comprising the in-phase Rx signal and the quadrature Tx signal in the second signal path or both, based on the compensation signal.

11. The apparatus of claim 10 , wherein the compensation unit comprises an attenuation unit coupled to the first signal path or the second signal path, and configured to provide an attenuation to the first signal or the second signal respectively, based on the compensation signal.

12. The apparatus of claim 11 , wherein the compensation unit comprises a phase shift unit coupled to the first signal path or the second signal path, and configured to provide a phase shift to the first signal or the second signal respectively, based on the compensation signal.

13. An apparatus for interference cancellation in a wireless communication system, comprising:
a cancellation unit configured to:
receive a transmit (Tx) signal from an output port of a power amplifier and a receive (Rx) signal from an antenna, wherein due to a coupling of the Tx signal and the Rx signal within the cancellation unit, the Rx signal contains portions of the Tx signal, and
generate a cancellation of a primary portion of the Tx signal from the Rx signal at an output thereof, leaving a residual portion as a residual Tx signal in the Rx signal, wherein the Rx signal that is output from the cancellation unit is coupled to an Rx input port of a transceiver;

a compensation control unit configured to modify one or more signals within the cancellation unit, based on the residual Tx signal at the output of the cancellation unit, wherein the modification of the one or more signals results in a reduction or an elimination of the residual Tx signal at the output of the cancellation unit; and
a power monitoring unit configured to measure a power of the Tx signal from the output port of the power amplifier and selectively activate the compensation control unit, based on the measured power of the Tx signal.

14. The apparatus of claim 13 , wherein the power monitoring system is configured to activate the compensation control unit when the measured power of the Tx signal exceeds a predetermined power.

15. An apparatus for interference cancellation in a wireless communication system, comprising:
a first coupling unit configured to:
receive a transmit (Tx) signal from an output port of a power amplifier and generate an in-phase Tx signal in a first sign

Assignees

• Intel Ip Corp

Inventors

• Tanzi Nebil
• Chance Gregory

Classifications

• 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

• H04W52/243

  taking into account interferences · CPC title

• H04W52/24

  using SIR [Signal to Interference Ratio] or other wireless path parameters · CPC title

• H04B1/525

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

• H04W52/245

  taking into account received signal strength · CPC title