NON-LINEAR INTERFERENCE CANCELLATION WITH MULTIPLE AGGRESSORS

• US 20150065058A1
• Filed: 08/29/2013
• Published: 03/05/2015
• Est. Priority Date: 08/29/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wang, Jibing, Rimini, Roberto
• Granted Patent: US 9,100,110 B2
• Time in Patent Office: Days
• US Class Current: 455/63.1
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04B 1/109 by improving strong signal performance of the receiver when strong unwanted signals are present at the receiver input
• CPC Class Codes: H04B 15/00 Suppression or limitation of noise or interference by means associated with receiver H04B1/10

Abstract

Disclosed is non-linear interference cancellation (NLIC) on a victim receiver in a communication system in which there is self-jamming interference from multiple aggressor transmitters. The victim receiver may implement cascaded NLIC operations using multiple interference signals in succession to remove the multiple interference signals from the Rx signal and to cancel or mitigate the self-jamming interference. The reconstruction and removal of the interference signals may be ordered based on the expected level of interference from the interference signals on the desired Rx signal. The victim receiver may first perform NLIC operation using the Tx signal from the transmitter aggressor estimated to generate the strongest interference signal to remove the strongest interference signal from the Rx signal first. The victim receiver may perform NLIC operation on the TX signal from the next strongest transmitter aggressor, and so on, to remove interference signals of multiple aggressor transmitters from the Rx signal.

Claims

1. A method for non-linear interference cancellation (NLIC) by a victim receiver, comprising:

determining an expected level of interference on the victim receiver from each aggressor transmitter of a plurality of aggressor transmitters;

ordering the aggressor transmitters from a strongest aggressor transmitter having a highest expected level of interference to a weakest aggressor transmitter having a lowest expected level of interference;

receiving a composite receive (Rx) signal, wherein the composite Rx signal comprises a desired Rx signal and an interference component, wherein the interference component includes an interference signal from each of the aggressor transmitters;

receiving a transmit (Tx) signal from the strongest aggressor transmitter; and

operating the Tx signal from the strongest aggressor transmitter to perform NLIC of the interference signal from the strongest aggressor transmitter in the composite Rx signal.

2. The method of claim 1, further comprising:

receiving a Tx signal from each aggressor transmitters; and

operating successively the Tx signal from each aggressor transmitter to perform NLIC operation of the interference signal from each aggressor transmitter in the composite Rx signal based on said ordering of the aggressor transmitters.

3. The method of claim 2, wherein said operating successively the Tx signal from each aggressor transmitter to perform NLIC of the interference signal from each aggressor transmitter comprises:

constructing adaptively an estimated interference signal using the Tx signal to approximate the interference signal; and

removing the estimated interference signal from the composite Rx signal.

4. The method of claim 3, wherein said constructing adaptively an estimated interference signal using the Tx signal to approximate the interference signal further comprises:

constructing one or more non-linear components of the interference signal from the Tx signal; and

generating a weighted sum of the non-linear components of the interference signal with corresponding weight estimates in an adaptive filter to generate the estimated interference signal.

5. The method of claim 2, wherein said operating successively the Tx signal from each aggressor transmitter to perform NLIC of the interference signal from each aggressor transmitter comprises generating a Rx signal, wherein the Rx signal comprises the desired Rx signal and a residual of the interference signal from each of the aggressor transmitter.

6. The method of claim 5, further comprising processing the Rx signal to recover the desired Rx signal.

7. The method of claim 2, wherein said operating successively the Tx signal from each aggressor transmitter to perform NLIC of the interference signal from each aggressor transmitter comprises operating on a sample by sample basis the Tx signal from each aggressor transmitter.

8. The method of claim 2, wherein said operating successively the Tx signal from each aggressor transmitter to perform NLIC of the interference signal from each aggressor transmitter comprises operating on a block of samples of the Tx signal from each aggressor transmitter.

9. The method of claim 1, further comprising:

updating said determining of an expected level of interference on the victim receiver from each aggressor transmitter when a number of aggressor transmitters changes;

updating said ordering of the aggressor transmitters from an updated strongest aggressor transmitter to an updated weakest aggressor transmitter; and

operating the Tx signal from the updated strongest aggressor transmitter to perform NLIC of the interference signal from the updated strongest aggressor transmitter in the composite Rx signal.

10. The method of claim 1, wherein said determining an expected level of interference on the victim receiver from an aggressor transmitter comprises:

calibrating antenna isolation data from the aggressor transmitter to the victim receiver;

receiving Tx parameters from the aggressor transmitter; and

determining the expected level of interference on the victim receiver from the aggressor transmitter using the antenna isolation data and the Tx parameters.

11. The method of claim 10, further comprising:

receiving a new Tx parameters from an aggressor transmitter;

updating said determining the expected level of interference on the victim receiver from the aggressor transmitter using the new Tx parameters;

updating said ordering of the aggressor transmitters from an updated strongest aggressor transmitter to an updated weakest aggressor transmitter; and

operating the Tx signal from the updated strongest aggressor transmitter to perform NLIC of the interference signal from the updated strongest aggressor transmitter in the composite Rx signal.

12. An apparatus, comprising:

a memory; and

one or more processors coupled to the memory and configured to;

determine an expected level of interference on the apparatus from each aggressor transmitter of a plurality of aggressor transmitters;

order the aggressor transmitters from a strongest aggressor transmitter having a highest expected level of interference to a weakest aggressor transmitter having a lowest expected level of interference;

receive a composite receive (Rx) signal, wherein the composite Rx signal comprises a desired Rx signal and an interference component, wherein the interference component includes an interference signal from each of the aggressor transmitters;

receive a transmit (Tx) signal from the strongest aggressor transmitter; and

operate on the Tx signal from the strongest aggressor transmitter to perform non-linear interference cancellation (NLIC) of the interference signal from the strongest aggressor transmitter in the composite Rx signal.

13. The apparatus of claim 12, wherein the one or more processors are further configured to:

receive a Tx signal from each aggressor transmitters; and

operate successively the Tx signal from each aggressor transmitter to perform NLIC operation of the interference signal from each aggressor transmitter in the composite Rx signal based on the order of the aggressor transmitters.

14. The apparatus of claim 13, wherein the one or more processors are configured to operate successively the Tx signal from each aggressor transmitter to perform NLIC of the interference signal from each aggressor transmitter by being further configured to:

construct adaptively an estimated interference signal from the Tx signal to approximate the interference signal; and

remove the estimated interference signal from the composite Rx signal.

15. The apparatus of claim 14, wherein the one or more processors are configured to construct adaptively an estimated interference signal from the Tx signal by being further configured to:

construct one or more non-linear components of the interference signal from the Tx signal; and

generate a weighted sum of the non-linear components of the interference signal with corresponding weight estimates in an adaptive filter to generate the estimated interference signal.

16. The apparatus of claim 13, wherein the one or more processors are configured to operate successively the Tx signal from each aggressor transmitter to perform NLIC of the interference signal from each aggressor transmitter by being further configured to generate a Rx signal, wherein the Rx signal comprises the desired Rx signal and a residual of the interference signal from each of the aggressor transmitter.

17. The apparatus of claim 16, wherein the one or more processors are further configured to process the Rx signal to recover the desired Rx signal.

18. The apparatus of claim 13, wherein the one or more processors are configured to operate successively the Tx signal from each aggressor transmitter to perform NLIC of the interference signal from each aggressor transmitter by being further configured to operate on a sample by sample basis the Tx signal from each aggressor transmitter.

19. The apparatus of claim 13, wherein the one or more processors are configured to operate successively the Tx signal from each aggressor transmitter to perform NLIC of the interference signal from each aggressor transmitter by being further configured to operate on a block of samples of the Tx signal from each aggressor transmitter.

20. The apparatus of claim 12, wherein the one or more processors are further configured to:

update the expected level of interference on the apparatus from each aggressor transmitter when a number of aggressor transmitters changes;

update the order of the aggressor transmitters from an updated strongest aggressor transmitter to an updated weakest aggressor transmitter; and

operate the Tx signal from the updated strongest aggressor transmitter to perform NLIC of the interference signal from the updated strongest aggressor transmitter in the composite Rx signal.

21. The apparatus of claim 12, wherein the one or more processors are configured to determine an expected level of interference on the apparatus from each aggressor transmitter by being further configured to:

calibrate antenna isolation data from the aggressor transmitter to the apparatus;

receive Tx parameters from the aggressor transmitter; and

determine the expected level of interference on the apparatus from the aggressor transmitter based on the antenna isolation data and the Tx parameters.

22. The apparatus of claim 21, wherein the one or more processors are further configured to:

receive a new Tx parameters from an aggressor transmitter;

update the expected level of interference on the apparatus from the aggressor transmitter based on the new Tx parameters; and

update the order of the aggressor transmitters from an updated strongest aggressor transmitter to an updated weakest aggressor transmitter; and

operate the Tx signal from the updated strongest aggressor transmitter to perform NLIC of the interference signal from the updated strongest aggressor transmitter in the composite Rx signal.

23. A non-transitory machine-readable medium comprising a plurality of machine-readable instructions which, when executed by one or more processors, are adapted to cause the one or more processors to perform a method for non-linear interference cancellation (NLIC) comprising:

determining an expected level of interference on a victim receiver from each aggressor transmitter of a plurality of aggressor transmitters;

ordering the aggressor transmitters from a strongest aggressor transmitter having a highest expected level of interference to a weakest aggressor transmitter having a lowest expected level of interference;

receiving a composite receive (Rx) signal, wherein the composite Rx signal comprises a desired Rx signal and an interference component, wherein the interference component includes an interference signal from each of the aggressor transmitters;

receiving a transmit (Tx) signal from the strongest aggressor transmitter; and

operating the Tx signal from the strongest aggressor transmitter to perform NLIC of the interference signal from the strongest aggressor transmitter in the composite Rx signal.

24. The non-transitory machine-readable medium of claim 23, wherein the method further comprises:

receiving a Tx signal from each aggressor transmitters; and

operating successively the Tx signal from each aggressor transmitter to perform NLIC operation of the interference signal from each aggressor transmitter in the composite Rx signal based on said ordering of the aggressor transmitters.

25. The non-transitory machine-readable medium of claim 23, wherein the method further comprises:

updating said determining of an expected level of interference on the victim receiver from each aggressor transmitter when a number of aggressor transmitters changes;

updating said ordering of the aggressor transmitters from an updated strongest aggressor transmitter to an updated weakest aggressor transmitter; and

operating the Tx signal from the updated strongest aggressor transmitter to perform NLIC of the interference signal from the updated strongest aggressor transmitter in the composite Rx signal.

26. The non-transitory machine-readable medium of claim 23, wherein said determining an expected level of interference on the victim receiver from an aggressor transmitter comprises:

calibrating antenna isolation data from the aggressor transmitter to the victim receiver;

receiving Tx parameters from the aggressor transmitter; and

determining the expected level of interference on the victim receiver from the aggressor transmitter using the antenna isolation data and the Tx parameters.

27. The non-transitory machine-readable medium of claim 26, wherein the method further comprises:

receiving a new Tx parameters from an aggressor transmitter;

updating said determining the expected level of interference on the victim receiver from the aggressor transmitter using the new Tx parameters;

updating said ordering of the aggressor transmitters from an updated strongest aggressor transmitter to an updated weakest aggressor transmitter; and

operating the Tx signal from the updated strongest aggressor transmitter to perform NLIC of the interference signal from the updated strongest aggressor transmitter in the composite Rx signal.

28. A system, comprising:

means for determining an expected level of interference on the system from each aggressor transmitter of a plurality of aggressor transmitters;

means for ordering the aggressor transmitters from a strongest aggressor transmitter having a highest expected level of interference to a weakest aggressor transmitter having a lowest expected level of interference;

means for receiving a composite receive (Rx) signal, wherein the composite Rx signal comprises a desired Rx signal and an interference component, wherein the interference component includes an interference signal from each of the aggressor transmitters;

means for receiving a transmit (Tx) signal from the strongest aggressor transmitter; and

means for operating the Tx signal from the strongest aggressor transmitter to perform non-linear interference cancellation (NLIC) of the interference signal from the strongest aggressor transmitter in the composite Rx signal.

29. The system of claim 28, further comprising:

means for receiving a Tx signal from each aggressor transmitters; and

means for operating successively the Tx signal from each aggressor transmitter to perform NLIC operation of the interference signal from each aggressor transmitter in the composite Rx signal based on said ordering of the aggressor transmitters.

30. The system of claim 28, further comprising:

means for updating said determining of an expected level of interference on the system from each aggressor transmitter when a number of aggressor transmitters changes;

means for updating said ordering of the aggressor transmitters from an updated strongest aggressor transmitter to an updated weakest aggressor transmitter; and

means for operating the Tx signal from the updated strongest aggressor transmitter to perform NLIC of the interference signal from the updated strongest aggressor transmitter in the composite Rx signal.

31. The system of claim 28, wherein the means for determining an expected level of interference on the system from an aggressor transmitter comprises:

means for calibrating antenna isolation data from the aggressor transmitter to the system;

means for receiving Tx parameters from the aggressor transmitter; and

means for determining the expected level of interference on the system from the aggressor transmitter using the antenna isolation data and the Tx parameters.

32. The system of claim 31, further comprising:

means for receiving a new Tx parameters from an aggressor transmitter;

means for updating said determining the expected level of interference on the system from the aggressor transmitter using the new Tx parameters;

means for updating said ordering of the aggressor transmitters from an updated strongest aggressor transmitter to an updated weakest aggressor transmitter; and

means for operating the Tx signal from the updated strongest aggressor transmitter to perform NLIC of the interference signal from the updated strongest aggressor transmitter in the composite Rx signal.