Systems and methods for configurable hybrid self-interference cancellation

Patent metadata

Field	Value
Publication number	US-10425115-B2
Application number	US-201916288033-A
Country	US
Kind code	B2
Filing date	Feb 27, 2019
Priority date	Feb 27, 2018
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

A system for self-interference cancellation includes a frequency downconverter that decomposes a sampled RF transmit signal into an in-phase transmit signal and a quadrature transmit signal; a first analog vector modulator that scales the transmit signals to generate first scaled transmit signals; a second analog vector modulator that scales delayed transmit signals to generate second scaled transmit signals; a frequency upconverter that recomposes the scaled transmit signals into an RF self-interference cancellation signal; and a receive coupler that that combines the RF self-interference cancellation signal with a RF receive signal to reduce self-interference.

First claim

We claim:

1. A system for self-interference cancellation comprising:
a transmit coupler, communicatively coupled to a radio frequency (RF) transmit signal of a communication system, that samples the RF transmit signal to create a sampled RF transmit signal having an RF carrier frequency;
a first analog-self-interference canceller comprising:
a frequency downconverter that decomposes the sampled RF transmit signal into an in-phase transmit signal component and a quadrature transmit signal component;
a first sampling coupler that splits the in-phase transmit signal component into a first-path in-phase transmit signal component and a second-path in-phase transmit signal component;
a second sampling coupler that splits the quadrature transmit signal component into a first-path quadrature transmit signal component and a second-path quadrature transmit signal component;
a first analog vector modulator that scales the first-path in-phase transmit signal component to generate a first scaled in-phase transmit signal component and scales the first-path quadrature transmit signal component to generate a first scaled quadrature transmit signal component;
a first delayer that delays the second-path in-phase transmit signal component to generate a first delayed in-phase transmit signal component;
a second delayer that delays the second-path quadrature transmit signal component to generate a first delayed quadrature transmit signal component;
a second analog vector modulator that scales the first delayed in-phase transmit signal component to generate a second scaled in-phase transmit signal component and scales the first delayed quadrature transmit signal component to generate a second scaled quadrature transmit signal component;
a first combining coupler that combines the first and second scaled in-phase transmit signal components to generate an in-phase self-interference cancellation signal component;
a second combining coupler that combines the first and second scaled quadrature transmit signal components to generate a quadrature self-interference cancellation signal component; and
a frequency upconverter that generates an RF self-interference cancellation signal from the in-phase self-interference cancellation signal component and the quadrature self-interference cancellation signal component; and

a receive coupler, communicatively coupled to an RF receive signal of the communication system, that combines the RF self-interference cancellation signal with the RF receive signal, resulting in an RF composite receive signal; wherein the RF composite receive signal contains less self-interference than the RF receive signal.

2. The system of claim 1 , wherein the first analog-self-interference canceller further comprises:
a third sampling coupler that splits the first delayed in-phase transmit signal component into a first-path first delayed in-phase transmit signal component and a second-path first delayed in-phase transmit signal component; wherein the second analog vector modulator is coupled to the first-path first delayed in-phase transmit signal component;
a fourth sampling coupler that splits the first delayed quadrature transmit signal component into a first-path first delayed quadrature transmit signal component and a second-path first delayed quadrature transmit signal component; wherein the second analog vector modulator is coupled to the first-path first delayed quadrature transmit signal component;
a third delayer that delays the second-path first delayed in-phase transmit signal component to generate a second delayed in-phase transmit signal component;
a fourth delayer that delays the second-path first delayed quadrature transmit signal component to generate a second delayed quadrature transmit signal component; and
a third analog vector modulator that scales the second delayed in-phase transmit signal component to generate a third scaled in-phase transmit signal component and scales the second delayed quadrature transmit signal component to generate a third scaled quadrature transmit signal component;

wherein the first combining coupler combines the first, second, and third scaled in-phase transmit signal components to generate the in-phase self-interference cancellation signal component; wherein the second combining coupler combines the first, second, and third scaled quadrature transmit signal components to generate the quadrature self-interference cancellation signal component.

3. The system of claim 2 , further comprising a first amplifier that amplifies the first-path in-phase transmit signal component prior to scaling by the first analog vector modulator and a second amplifier that amplifies the first-path quadrature transmit signal component prior to scaling by the first analog vector modulator.

4. The system of claim 3 , further comprising a third amplifier that amplifies the RF self-interference cancellation signal prior to combination with the RF receive signal.

5. The system of claim 2 , wherein the in-phase transmit signal component and the quadrature transmit signal component both have an intermediate frequency (IF) carrier frequency; wherein the IF carrier frequency is less than the RF carrier frequency.

6. The system of claim 5 , wherein the IF carrier frequency is 0 Hertz.

7. The system of claim 2 , wherein the first combining coupler comprises a first amplification stage and a second amplification stage; wherein, in a first operating mode, the first combining coupler amplifies the third scaled in-phase transmit signal component using both of the first amplification stage and the second amplification stage; wherein, in the first operating mode, the first combining coupler amplifies the second scaled in-phase transmit signal component using both of the first amplification stage and the second amplification stage; wherein, in the first operating mode, the first combining coupler amplifies the first scaled in-phase transmit signal component using only one of the first amplification stage and the second amplification stage.

8. The system of claim 7 , wherein the first combining coupler further comprises a switch; wherein, in a second operating mode, the first combining coupler amplifies the third scaled in-phase transmit signal component using both of the first amplification stage and the second amplification stage; wherein, in the second operating mode, the first combining coupler amplifies the second scaled in-phase transmit signal component using only one of the first amplification stage and the second amplification stage; wherein, in the second operating mode, the first combining coupler amplifies the first scaled in-phase transmit signal component using only one of the first amplification stage and the second amplification stage; wherein the switch switches the first combining coupler from the first operating mode to the second operating mode.

9. The system of claim 1 , wherein the first analog vector modulator generates the first scaled in-phase transmit signal component from a first linear combination of the first-path in-phase transmit signal component and the first-path quadrature transmit signal component; wherein the first analog vector modulator generates the first scaled quadrature transmit signal component from a second linear combination of the first-path in-phase transmit signal component and the first-path quadrature transmit signal component.

10. The system of claim 9 , wherein to apply a first amplitude scaling value and a first phase shift value, the first analog vector modulator generates the first linear combination by adding a product of the first-path in-phase transmit signal component, the first amplitude scaling value, and a cosine of the first phase shift value to a

Assignees

• Kumu Networks Inc

Inventors

• Hahn Wilhelm Steffen
• Riddle Alfred
• Landi Ernie
• Sieh Dai
• Choi Jung-Il
• Jain Mayank

Classifications

• H04B1/525 Primary

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

• H04B1/10 Primary

  Means associated with receiver for limiting or suppressing noise or interference · CPC title

• H04B1/40

  Circuits · CPC title

• H04L5/14

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