阅读说明：本技术 用于可配置混合自干扰消除的系统和方法 (System and method for configurable hybrid self-interference cancellation ) 是由 威廉·斯蒂芬·哈恩 阿尔弗雷德·里德尔 厄尼·兰迪 黛·西埃赫 崔正一 马扬克·简恩 于 2019-02-27 设计创作，主要内容包括：一种用于自干扰消除的系统,包括：下变频器,其将采样的RF发射信号分解成同相发射信号和正交发射信号；第一模拟矢量调制器,其缩放发射信号以生成第一缩放的发射信号；第二模拟矢量调制器,其缩放延迟的发射信号以生成第二缩放的发射信号；上变频器,其将缩放的发射信号重新组合成RF自干扰消除信号；以及接收耦合器,其将RF自干扰消除信号与RF接收信号组合以减少自干扰。(A system for self-interference cancellation, comprising: a down-converter that decomposes the sampled RF transmit signal into an in-phase transmit signal and a quadrature transmit signal; a first analog vector modulator that scales a transmit signal to generate a first scaled transmit signal; a second analog vector modulator that scales the delayed transmit signal to generate a second scaled transmit signal; an up-converter that recombines the scaled transmit signals into an RF self-interference cancellation signal; and a receive coupler that combines the RF self-interference cancellation signal with the RF receive signal to reduce self-interference.)

1. A system for self-interference cancellation, comprising:

a transmit coupler communicatively coupled to a Radio Frequency (RF) transmit signal of a communication system, the RF transmit signal sampled to produce a sampled RF transmit signal having an RF carrier frequency;

a first analog self-interference canceller, the first analog self-interference canceller comprising:

a 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 divides 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 separates the orthogonal transmit signal component into a first path orthogonal transmit signal component and a second path orthogonal transmit signal component;

a first analog vector modulator scaling the first path in-phase transmit signal component to generate a first scaled in-phase transmit signal component and scaling 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 delay 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 scaled in-phase transmit signal component and the second scaled in-phase transmit signal component to generate an in-phase self-interference cancellation signal component;

a second combining coupler that combines the first scaled quadrature transmit signal component and the second scaled quadrature transmit signal component to generate a quadrature self-interference cancellation signal component; and

an 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, the RF self-interference cancellation signal and the RF receive signal combined producing 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 delay that delays the second path first delayed in-phase transmit signal component to generate a second delayed in-phase transmit signal component;

a fourth delay 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 orthogonal transmit signal components to generate the orthogonal self-interference cancellation signal component.

3. The system of claim 2, further comprising a first amplifier that amplifies the first path inphase transmit signal component before it is scaled by the first analog vector modulator and a second amplifier that amplifies the first path quadrature transmit signal component before it is scaled 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 before it is combined 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 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.

8. The system of claim 7, 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 product of the first path quadrature transmit signal component, the first amplitude scaling value, and a negative sine of the first phase shift value; and the first analog vector modulator generates the second linear combination by adding a product of the first path in-phase transmit signal component, the first amplitude scaling value, and a sine of the first phase shift value to a product of the first path quadrature transmit signal component, the first amplitude scaling value, and a cosine of the first phase shift value.

9. The system of claim 8, wherein the first analog vector modulator generates the first linear combination and the second linear combination using a differential attenuator circuit.

10. The system of claim 7, wherein the complex signal represented by the first path in-phase transmit signal component and the first path quadrature transmit signal component includes both an intended signal and an image signal; wherein the image signal is a complex conjugate of the desired signal.

11. The system of claim 10, wherein to apply a first amplitude scaling value and a first phase shift value, the first analog vector modulator generates the first linear combination and the second linear combination after detecting, measuring, or estimating the image signal; wherein the first analog vector modulator generates the first linear combination and the second linear combination to reduce the presence of the image signal in the first scaled in-phase transmit signal component and the first scaled quadrature transmit signal component.

12. The system of claim 11, 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, a cosine of the first phase shift value, and 1/(1+ scaling factor) to a product of the first path quadrature transmit signal component, the first amplitude scaling value, a negative sine of the first phase shift value, and 1/(1-the scaling factor); and the first analog vector modulator generates the second linear combination by adding a product of the first path in-phase transmit signal component, the first amplitude scaling value, the sine of the first phase shift value, and 1/(1+ the scaling factor) to a product of the first path quadrature transmit signal component, the first amplitude scaling value, the cosine of the first phase shift value, and 1/(1-the scaling factor).

13. The system of claim 12, wherein the scaling factor is derived from a signal power ratio of the image signal to the expected signal.

14. The system of claim 13, wherein the first analog vector modulator generates the first linear combination and the second linear combination using a differential attenuator circuit.

15. The system of claim 1, wherein the first combining coupler comprises a first amplification stage and a second amplification stage; wherein in a first mode of operation, the first combining coupler amplifies the second scaled in-phase transmit signal component using both the first amplification stage and the second amplification stage; wherein in the first mode of operation 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.

16. The system of claim 15, wherein the first combining coupler further comprises a switch; wherein in a second mode of operation, the first combining coupler amplifies the second scaled in-phase transmit signal component using both the first amplification stage and the second amplification stage; wherein in the second mode of operation the first combining coupler amplifies the first scaled in-phase transmit signal component using both 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.

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

18. The system of claim 17, wherein the first combining coupler further comprises a switch; wherein in a second mode of operation, the first combining coupler amplifies the third scaled in-phase transmit signal component using both the first amplification stage and the second amplification stage; wherein in the second mode of operation 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 mode of operation 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.

19. The system of claim 1, wherein the first analog vector modulator generates the first scaled in-phase transmit signal component and the first scaled quadrature transmit signal component using a differential attenuator circuit having a set of scaling stages, the differential attenuator circuit scaling a signal by an overall scaling factor; wherein the set of scaling stages is connected to the differential attenuator circuit by a set of switches; wherein the overall scale factor is set by the configuration of the states of the set of switches.

20. The system of claim 19, wherein the system generates the state configuration by: calculating a desired scaler output for the differential attenuator circuit and selecting the state configuration that results in an overall scale factor that is closest to the desired scaler output.

21. The system of claim 20, wherein the status configuration is selected from a set of status configurations determined from a mixed thermometer code.

22. The system of claim 7, wherein the first analog vector modulator generates the first linear combination by: scaling the first path in-phase transmit signal component using a first differential attenuator circuit, scaling the first path quadrature transmit signal component using a second differential attenuator circuit, and summing the in-phase transmit signal component and the first path quadrature transmit signal component after scaling; wherein the first analog vector modulator generates the second linear combination by: scaling the first path in-phase transmit signal component using a third differential attenuator circuit, scaling the first path quadrature transmit signal component using a fourth differential attenuator circuit, and summing the in-phase transmit signal component and the first path quadrature transmit signal component after scaling.

23. The system of claim 22, wherein the first differential attenuator circuit having a first set of scaling stages scales the first path in-phase transmit signal component by a first total scaling factor; wherein the first total scale factor is set by a first state configuration of the first set of zoom stages; wherein the second differential attenuator circuit having a second set of scaling stages scales the first path quadrature transmit signal components by a second overall scaling factor; wherein the second overall scale factor is set by a second state configuration of the second set of zoom stages; wherein the third differential attenuator circuit having a third set of scaling stages scales the first path in-phase transmit signal component by a third overall scaling factor; wherein the third overall scale factor is set by a third state configuration of the third set of zoom stages; wherein the fourth differential attenuator circuit having a fourth set of scaling stages scales the first path quadrature transmit signal components by a fourth overall scaling factor; wherein the fourth overall scale factor is set by a fourth state configuration of the fourth set of zoom stages.

24. The system of claim 23, wherein the first state configuration, the second state configuration, the third state configuration, and the fourth state configuration are selected from a set of state configurations determined from a mixed thermometer code.

Technical Field

The present invention relates generally to the field of wireless communications, and more specifically to a new and useful system and method for configurable hybrid self-interference cancellation.

Background

Conventional wireless communication systems are half-duplex; that is, they are not capable of transmitting and receiving signals simultaneously over a single wireless communication channel. Recently, work in the field of wireless communications has brought about advances in developing full-duplex wireless communication systems; these systems, if successfully implemented, can provide significant benefits to the wireless communications field. For example, cellular networks may halve spectrum requirements using full duplex communication. One of the major obstacles to successful implementation of full-duplex communication is the problem of self-interference. Despite advances in this area, many solutions aimed at solving the self-interference problem are still deficient in performance, especially when the self-interference cancellation solution is able to meet the performance without high complexity or high loss. Furthermore, while some of these solutions may perform well if designed and used for a single scenario, they may not be flexible to change operating modes or environments (e.g., moving from 4X4 MIMO to 1X4 SIMO). Accordingly, there is a need in the wireless communications arts to create new and useful systems and methods for configurable hybrid self-interference cancellation. The present invention provides such a new and useful system and method.