METHOD AND APPARATUS FOR IN-CHANNEL INTERFERENCE CANCELLATION

• US 20130337761A1
• Filed: 06/19/2012
• Published: 12/19/2013
• Est. Priority Date: 06/19/2012
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: Kyperountas, Spyros, Correal, Neiyer S., Shi, Qicai, Sobchak, Charles L.
• Granted Patent: US 9,031,526 B2
• Time in Patent Office: Days
• US Class Current: 455/307
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04B 1/12 Neutralising, balancing, or compensation arrangements
• CPC Class Codes: H04J 11/0066 of narrowband interference narrowband interference reduction H04B1/1036

Abstract

A communication device includes a receiver that is capable of canceling in-channel interference. The receiver includes an antenna for receiving a wireless signal comprising in-channel components and an out-of-channel component, wherein the in-channel components comprise a desired component and an in-channel interference component. A first filter of the receiver filters the wireless signal by blocking at least a portion of the out-of-channel component to produce a first signal comprising the in-channel components, and at least a second filter of the receiver filters the wireless signal by blocking at least a portion of the in-channel components to produce a second signal comprising the out-of-channel component. An in-channel interference estimator of the receiver generates an in-channel interference estimation signal based on the second signal. And a combiner of the filter combines the first signal and the second signal to at least partially cancel the in-channel interference component of the first signal.

Claims

1. A method for canceling in-channel interference comprising:

receiving a wireless signal comprising in-channel components and an out-of-channel component, wherein the in-channel components comprise a desired component and an in-channel interference component;

performing a first filtering of the wireless signal that blocks at least a portion of the out-of-channel component to produce a first signal comprising the in-channel components;

performing a second filtering of the wireless signal that blocks at least a portion of the in-channel components to produce a second signal comprising the out-of-channel component;

generating an in-channel interference estimation signal based on the second signal; and

combining the first signal and the second signal to at least partially cancel the in-channel interference component of the first signal.

2. The method of claim 1, further comprising:

mixing the wireless signal with a first reference signal to produce a first mixed signal;

mixing the wireless signal with a second reference signal to produce a second mixed signal;

wherein performing a first filtering comprises performing a first filtering of the first mixed signal that blocks at least a portion of the out-of-channel component to produce the first signal comprising the in-channel components; and

wherein performing a second filtering comprises performing a second filtering of the second mixed signal that blocks at least a portion of the in-channel components to produce the second signal comprising the out-of-channel component.

3. The method of claim 2, wherein mixing the wireless signal with the first reference signal produces the first mixed signal at an intermediate frequency and wherein mixing the wireless signal with the second reference signal produces the second mixed signal at the intermediate frequency.

4. The method of claim 2, wherein mixing the wireless signal with the first reference signal produces the first mixed signal at a baseband frequency and wherein mixing the wireless signal with a second reference signal produces the second mixed signal at the baseband frequency.

5. The method of claim 1, wherein each of performing a first filtering of the wireless signal and performing a second filtering of the wireless signal comprises filtering the wireless signal with a Wiener filter.

6. The method of claim 1, wherein the second signal comprises an out-of-channel sidelobe of a non-desired out-of-channel signal.

7. The method of claim 6, wherein generating an in-channel interference estimation signal based on the second signal comprises generating an in-channel version of the out-of-channel sidelobe and wherein the in-channel interference component of the first signal comprises an in-channel sidelobe of the non-desired out-of channel signal

8. The method of claim 1, wherein performing a second filtering of the wireless signal that blocks at least a portion of the in-channel components to produce a second signal comprising the out-of-channel component comprises performing a plurality of filterings of the wireless signal to produce a plurality of out-of-channel components, and wherein generating an in-channel interference estimation signal based on the second signal comprises generating an in-channel interference estimation signal based on the plurality of out-of-channel components.

9. The method of claim 8, wherein generating an in-channel interference estimation signal based on the second signal comprises:

weighting each out-of-channel component of the plurality of out-of-channel components to produce a plurality of weighted out-of-channel components; and

combining the plurality of weighted out-of-channel components.

10. The method of claim 9, wherein combining the first signal and the second signal comprises combining the first signal and the second signal to at least partially cancel the in-channel interference component of the first signal and produce an in-channel-interference-canceled in-channel signal and wherein the method further comprises:

determining an error signal based on the in-channel-interference-canceled in-channel signal; and

adjusting the weightings of the plurality of out-of-channel components based on the error signal.

11. A receiver comprising:

an antenna for receiving a wireless signal comprising in-channel components and an out-of-channel component, wherein the in-channel components comprise a desired component and an in-channel interference component;

a first filter that filters the wireless signal by blocking at least a portion of the out-of-channel component to produce a first signal comprising the in-channel components;

at least a second filter that filters the wireless signal by blocking at least a portion of the in-channel components to produce a second signal comprising the out-of-channel component;

an in-channel interference estimator that generates an in-channel interference estimation signal based on the second signal; and

a combiner that combines the first signal and the second signal to at least partially cancel the in-channel interference component of the first signal.

12. The receiver of claim 11, further comprising:

a first mixer that mixes the wireless signal with a first reference signal to produce a first mixed signal;

a second mixer that mixes the wireless signal with a second reference signal to produce a second mixed signal;

wherein the first filter filters the first mixed signal by blocking at least a portion of the out-of-channel component to produce the first signal comprising the in-channel components; and

wherein the at least a second filter filters the second mixed signal by blocking at least a portion of the in-channel components to produce the second signal comprising the out-of-channel component.

13. The receiver of claim 12, wherein mixing the wireless signal with the first reference signal produces the first mixed signal at an intermediate frequency and wherein mixing the wireless signal with the second reference signal produces the second mixed signal at the intermediate frequency.

14. The receiver of claim 12, wherein mixing the wireless signal with the first reference signal produces the first mixed signal at a baseband frequency and wherein mixing the wireless signal with the second reference signal produces the second mixed signal at the baseband frequency.

15. The receiver of claim 11, wherein each of the first filter and the at least a second filter comprises a Wiener filter.

16. The receiver of claim 11, wherein the second signal comprises an out-of-channel sidelobe of a non-desired out-of channel signal.

17. The receiver of claim 16, wherein the in-channel interference estimator generates an in-channel interference estimation signal based on the second signal by generating an in-channel version of the out-of-channel sidelobe and wherein the in-channel interference component of the first signal comprises an in-channel sidelobe of the non-desired out-of channel signal

18. The receiver of claim 11, wherein the at least a second filter comprises a plurality of filters, wherein each filter of the plurality of filters performs a filtering of the wireless signal to produce an out-of-channel component, wherein the out-of-channel component produced by each filter of the plurality of filters is different than the out-of-channel component produced by the other filter of the plurality of filters, and wherein the in-channel interference estimator generates an in-channel interference estimation signal by combining the out-of-channel components produced by the plurality of filters.

19. The receiver of claim 18, wherein the in-channel interference estimator generates an in-channel interference estimation signal generates an in-channel interference estimation signal based on the second signal by:

weighting the plurality of out-of-channel components to produce a plurality of weighted out-of-channel components; and

combining the plurality of weighted out-of-channel components.

20. The receiver of claim 19, wherein combining, by the in-channel interference estimator, of the first signal and the second signal at least partially cancels the in-channel interference component of the first signal and produces an in-channel-interference-canceled in-channel signal, wherein receiver further comprises a feedback circuit that determines an error signal based on the in-channel-interference-canceled in-channel signal and routes the error signal to the in-channel interference estimator, and wherein the in-channel interference estimator adjusts the weightings of the plurality of out-of-channel components based on the error signal.