METHOD AND APPARATUS FOR NOISE CANCELING

• US 20140370822A1
• Filed: 06/13/2013
• Published: 12/18/2014
• Est. Priority Date: 06/13/2013
• Status: Active Grant

• Current Assignee: Xueshan Technologies Inc. (Wi-LAN Inc.)
• Original Assignee: MStar Semiconductor Incorporated (MediaTek, Inc.)
• Inventors: MAHONEY, Dennis, AL-QAQ, Wael
• Granted Patent: US 9,160,387 B2
• Time in Patent Office: Days
• US Class Current: 455/73
• CPC Class Codes: H04B 1/126 having multiple inputs, e.g. auxiliary antenna for receiving interfering signal aerials in general H01Q

Abstract

Aspects of the disclosure can provide a circuit to be used in a device. The circuit includes a first receiver circuit, a second receiver circuit and a processing circuit. The first receiver circuit is configured to receive a first signal from an antenna that captures a combination of a target signal transmitted from another device to the device and an output signal driven by a transmitter in the device. The second receiver circuit is configured to receive a second signal generated based on to the output signal. The processing circuit is configured to cancel from the first signal noise due to the output signal based on the second signal.

Claims

1. A circuit in a device, comprising:

a transceiver circuit, comprising;

a first receiver path, configured to receive a first signal from an antenna that captures a combination of a target signal transmitted from outside the device and an output signal driven by a transmitter outside the transceiver in the device;

a second receiver configured to receive a second signal generated based on to the output signal; and

a processing circuit configured to cancel from the first signal noise due to the output signal based on the second signal.

2. The circuit of claim 1, further comprising:

another transceiver circuit, comprising the transmitter configured to transmit the output signal;

a coupler that couples the second signal to the output signal.

3. The circuit of claim 2, wherein the coupler comprises a directional coupler with different coupling factors for different signal directions.

4. The circuit of claim 1, further comprising:

a controller configured to turn on the second receiver circuit when a received signal strength indication (RSSI) of the first receiver circuit is lower than a threshold.

5. The circuit of claim 1, wherein:

the first receiver circuit is configured to down-convert the first signal into baseband;

the second receiver circuit is configured to down-convert the second signal into baseband; and

the processing circuit is configured to perform baseband processing to cancel the noise from the first signal.

6. The circuit of claim 5, wherein the first receiver circuit and the second receiver circuit have matching filters.

7. The circuit of claim 5, wherein the first receiver circuit and the second receiver circuit are configured to down-convert the first signal and the second signal based on a same local oscillation signal.

8. A method for a device to receive a wireless signal, comprising:

receiving a first signal from an antenna that captures a combination of the wireless signal transmitted from outside the device and an output signal transmitted by the device;

receiving a second signal generated based on the output signal; and

cancelling from the first signal noise due to the output signal based on the second signal.

9. The method of claim 8, further comprising:

receiving the second signal via a coupler that couples the second signal to the output signal.

10. The method of claim 9, further comprising:

receiving the second signal via a directional coupler with different coupling factors for different signal directions.

11. The method of claim 8, further comprising:

detecting a received signal strength indication (RSSI) of the wireless signal in the first signal; and

receiving the second signal when the RSSI is lower than a threshold.

12. The method of claim 8, further comprising:

down-converting the first signal into a first baseband signal;

down-converting the second signal into a second baseband signal; and

processing the first baseband signal and the second baseband signal to cancel the noise.

13. The method of claim 12, further comprising:

down-converting the first signal and the second signal based on a same local oscillation signal.

14. The method of claim 12, further comprising:

filtering the first signal and the second signal with matching filters.

15. An apparatus, comprising:

a transmitter configured to transmit an output signal;

a first receiver path configured to receive a first signal from an antenna that captures a combination of a target signal transmitted from another apparatus to the apparatus and the output signal;

a coupler configured to generate a second signal based on the output signal;

a second receiver path configured to receive the second signal; and

a noise cancelation module configured to cancel from the first signal noise due to the output signal based on the second signal.

16. The apparatus of claim 15, wherein the coupler is a directional coupler with different coupling factors for different signal directions.

17. The apparatus of claim 15, further comprising:

a controller configured to turn on the second receiver path when a received signal strength indication (RSSI) of the first receiver path is lower than a threshold.

18. The apparatus of claim 15, wherein:

the first receiver path is configured to down-convert the first signal into baseband;

the second receiver path is configured to down-convert the second signal into baseband; and

the noise cancelation module is configured to perform baseband processing to cancel the noise from the first signal.

19. The apparatus of claim 18, wherein the first receiver path and the second receiver path are designated to a transceiver circuit and the transmitter configured to transmit an output signal is designated to another transceiver circuit.

20. The apparatus of claim 18, wherein the first receiver path and the second receiver path are configured to down-convert the first signal and the second signal based on a same local oscillation signal.