METHOD AND APPARATUS FOR ADAPTIVE NON-LINEAR SELF-JAMMING INTERFERENCE CANCELLATION

• US 20110149714A1
• Filed: 12/20/2010
• Published: 06/23/2011
• Est. Priority Date: 12/21/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Burke, Joseph P., Heidmann, Peter D., Rimini, Roberto
• Granted Patent: US 8,744,377 B2
• Time in Patent Office: Days
• US Class Current: 370/201
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver

Abstract

Certain embodiments of the disclosure propose a method for cancelling co-channel interference (self-jamming) generated by nonlinearities in the radio-frequency (RF) front-end devices. The proposed method utilizes an adaptive non-linear filter to generate a distorted version of the transmitted signal. The self-jamming interference may be mitigated utilizing the distorted signal through adaptive cancellation.

Claims

1. A method, comprising:

generating a signal to be transmitted on a first frequency band;

constructing an additional distorted version of the generated signal by applying a non-linear distortion to a baseband portion of the generated signal;

transmitting the generated signal on the first frequency band;

receiving a signal on a second frequency band, the received signal being corrupted by self-jamming interference, wherein where the self-jamming interference is caused by any type of non-linearities generated by transmit and receive chains; and

subtracting the additional distorted version of the generated signal from the received signal to remove the self-jamming interference.

2. The method of claim 1, wherein constructing the additional distorted version of the generated signal comprises:

applying one or more non-linear filter operators to the baseband portion of the generated signal.

3. The method of claim 2, further comprising applying frequency shifting at an output of the one or more non-linear filter operators for self-jamming interference which is not DC centered.

4. The method of claim 2, wherein coefficients of the non-linear filter operators are generated by minimizing a MSE (Minimum Square Error) cost function.

5. The method of claim 4, wherein the cost function is minimized by utilizing at least one of a least mean square (LMS) or a recursive least squares (RLS) algorithm.

6. The method of claim 5, wherein an error signal is generated by subtracting output of the non-linear filter operators from the received signal.

7. The method of claim 6, where the error signal is generated by subtracting output of the non-linear filter operators, after frequency shifting and low-pass filtering, from the received signal.

8. The method of claim 1, wherein the self-jamming interference comprises a p-order inter-modulation distortion where p>

1.

9. The method of claim 8, wherein even-order non-linear filter operators are applied to the baseband portion of the generated signal.

10. The method of claim 8, wherein odd-order non-linear filter operators are applied to the baseband portion of the generated signal.

11. The method of claim 8, wherein even-order and odd-order non-linear filter operators are applied to the baseband portion of the generated signal.

12. The method of claim 8, wherein memory related effects are taken into account by augmenting the non-linear filter operators with digital memory elements and applying non-linear filter operators and the digital memory elements to the baseband portion of the generated signal.

13. The method of claim 1, wherein the transmitted and received signals are wireless signals.

14. The method of claim 1, wherein the transmitted and received signals are wired signals.

15. The method of claim 1, wherein multiple signals transmitted simultaneously in a multi-mode or multi-carrier transceiver may result in reciprocal intermodulation products.

16. An apparatus, comprising:

means for generating a signal to be transmitted on a first frequency band;

means for constructing an additional distorted version of the generated signal by applying a non-linear distortion to a baseband portion of the generated signal;

means for transmitting the generated signal on the first frequency band;

means for receiving a signal on a second frequency band, the received signal being corrupted by self-jamming interference, wherein where the self-jamming interference is caused by any type of non-linearities generated by transmit and receive chains; and

means for subtracting the additional distorted version of the generated signal from the received signal to remove the self-jamming interference.

17. The apparatus of claim 16, wherein the means for constructing the additional distorted version of the generated signal comprises:

means for applying one or more non-linear filter operators to the baseband portion of the generated signal.

18. The apparatus of claim 17, further comprising means for applying frequency shifting at an output of the one or more non-linear filter operators for self-jamming interference which is not DC centered.

19. The apparatus of claim 17, wherein coefficients of the non-linear filter operators are generated by minimizing a MSE (Minimum Square Error) cost function.

20. The apparatus of claim 19, wherein the cost function is minimized by utilizing at least one of a least mean square (LMS) or a recursive least squares (RLS) algorithm.

21. The apparatus of claim 20, wherein an error signal is generated by subtracting output of the non-linear filter operators from the received signal.

22. The apparatus of claim 21, where the error signal is generated by subtracting output of the non-linear filter operators, after frequency shifting and low-pass filtering, from the received signal.

23. The apparatus of claim 16, wherein the self-jamming interference comprises a p-order inter-modulation distortion where p>

1.

24. The apparatus of claim 23, wherein even-order non-linear filter operators are applied to the baseband portion of the generated signal.

25. The apparatus of claim 23, wherein odd-order non-linear filter operators are applied to the baseband portion of the generated signal.

26. The apparatus of claim 23, wherein even-order and odd-order non-linear filter operators are applied to the baseband portion of the generated signal.

27. The apparatus of claim 23, wherein memory related effects are taken into account by augmenting the non-linear filter operators with digital memory elements and applying non-linear filter operators and the digital memory elements to the baseband portion of the generated signal.

28. The apparatus of claim 16, wherein the transmitted and received signals are wireless signals.

29. The apparatus of claim 16, wherein the transmitted and received signals are wired signals.

30. The apparatus of claim 16, wherein multiple signals transmitted simultaneously in a multi-mode or multi-carrier transceiver may result in reciprocal intermodulation products.

31. An apparatus, comprising:

at least one processor configured to;

generate a signal to be transmitted on a first frequency band, construct an additional distorted version of the generated signal by applying a non-linear distortion to a baseband portion of the generated signal, transmit the generated signal on the first frequency band, receive a signal on a second frequency band, the received signal being corrupted by self-jamming interference, wherein where the self-jamming interference is caused by any type of non-linearities generated by transmit and receive chains, and subtract the additional distorted version of the generated signal from the received signal to remove the self-jamming interference; and

a memory coupled with the at least one processor.

32. A computer-program product comprising a computer-readable medium having instructions stored thereon, the instructions executable by a processor for:

generating a signal to be transmitted on a first frequency band;

constructing an additional distorted version of the generated signal by applying a non-linear distortion to a baseband portion of the generated signal;

transmitting the generated signal on the first frequency band;

receiving a signal on a second frequency band, the received signal being corrupted by self-jamming interference, wherein where the self-jamming interference is caused by any type of non-linearities generated by transmit and receive chains; and

subtracting the additional distorted version of the generated signal from the received signal to remove the self-jamming interference.