Systems and Methods for Cancelling Interferers in a Receiver

• US 20110124307A1
• Filed: 11/08/2010
• Published: 05/26/2011
• Est. Priority Date: 11/08/2009
• Status: Active Grant

• Current Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: Balankutty, Ajay, Kinget, Peter
• Granted Patent: US 8,594,603 B2
• Time in Patent Office: Days
• US Class Current: 455/296
• CPC Class Codes: H04B 1/12 Neutralising, balancing, or compensation arrangements

Abstract

In some embodiments, systems and methods for cancelling interferers in a receiver, comprise: a first mixer in a main path that downconverts a first RF signal to form a main baseband or intermediate-frequency signal; and a second mixer in an alternate path that downconverts a second RF signal to form an alternate baseband or intermediate-frequency signal, wherein the first RF signal and the second RF signal are both based on a third RF signal, and wherein the main baseband or intermediate-frequency signal and the alternate baseband or intermediate-frequency signal, when combined, cancel out an interferer in the third RF signal.

Claims

1. A system for cancelling interferers in a receiver, comprising:

a first mixer in a main path that downconverts a first RF signal to form a main baseband or intermediate-frequency signal; and

a second mixer in an alternate path that downconverts a second RF signal to form an alternate baseband or intermediate-frequency signal,

wherein the first RF signal and the second RF signal are both based on a third RF signal, and wherein the main baseband or intermediate-frequency signal and the alternate baseband or intermediate-frequency signal, when combined, cancel out an interferer in the third RF signal.

2. The system of claim 1, wherein the first RF signal, the second RF signal, and the third RF signal are the same signal.

3. The system of claim 1, wherein the first mixer downconverts the first RF signal using a first local oscillator signal, the second mixer downconverts the second RF signal using a second local oscillator signal, and the first local oscillator signal and the second local oscillator signal are phase shifted with respect to each other.

4. The system of claim 3, wherein at least one of the first local oscillator signal and the second local oscillator signal are phase shifted with respect to each other by a phase shifter.

5. The system of claim 4, further comprising an interface for controlling phase shifter.

6. The system of claim 1, further comprising an amplifier in one of the main path and the alternate path for amplifying a corresponding one of the main baseband or intermediate-frequency signal and the alternate baseband or intermediate-frequency signal to match the other of the main baseband or intermediate-frequency signal and the alternate baseband or intermediate-frequency signal.

7. The system of claim 6, wherein the amplifier is a programmable gain amplifier.

8. The system of claim 6, further comprising an interface for controlling the gain of the amplifier.

9. A method for cancelling interferers in a receiver, comprising:

downconverting a first RF signal to form a main baseband or intermediate-frequency signal; and

downconverting a second RF signal to form an alternate baseband or intermediate-frequency signal,

wherein the first RF signal and the second RF signal are both based on a third RF signal, and wherein the main baseband or intermediate-frequency signal and the alternate baseband or intermediate-frequency signal, when combined, cancel out an interferer in the third RF signal.

10. The method of claim 9, wherein the first RF signal, the second RF signal, and the third RF signal are the same signal.

11. The method of claim 9, wherein the downconverting of the first RF signal is performed using a first local oscillator signal, the downconverting of the second RF signal is performed using a second local oscillator signal, and the first local oscillator signal and the second local oscillator signal are phase shifted with respect to each other.

12. The method of claim 11, further comprising phase shifting at least one of the first local oscillator signal and the second local oscillator signal.

13. The method of claim 12, further comprising controlling the amount of the phase shifting.

14. The method of claim 9, further comprising amplifying one of the main baseband or intermediate-frequency signal and the alternate baseband or intermediate-frequency signal to match the other of the main baseband or intermediate-frequency signal and the alternate baseband or intermediate-frequency signal.

15. The method of claim 14, further comprising controlling the gain of the amplifying.

16. A method for cancelling interferers in a receiver, comprising:

a) providing a radio frequency test tone to a main path and an alternate path in a receiver;

b) enabling the main path and disabling the alternate path and then measuring a downconverted signal amplitude produced at the output of the main path;

c) enabling the alternate path and disabling the main path and then measuring a downconverted signal amplitude produced at the output of the alternate path;

d) adjusting a gain setting in at least one of the main path and the alternate path to match the downconverted signal amplitude of the main path and the downconverted signal amplitude of the alternate path;

e) enabling the main path and the alternate path and then measuring a signal power produced at a combined output of the main path and the alternate path; and

f) adjusting a phase control setting in at least one of the main path and the alternate path to minimize the signal power produced at the combined output.

17. The method of claim 16, further comprising storing the gain setting and the phase control setting.

18. The method of claim 16, further comprising performing a) through f) for a plurality of test tone frequencies.

19. A system for cancelling interferers in a receiver, comprising:

at least one hardware processor that;

a) provides a radio frequency test tone to a main path and an alternate path in a receiver;

b) enables the main path and disables the alternate path and then measures a downconverted signal amplitude produced at the output of the main path;

c) enables the alternate path and disables the main path and then measures a downconverted signal amplitude produced at the output of the alternate path;

d) adjusts a gain setting in at least one of the main path and the alternate path to match the downconverted signal amplitude of the main path and the downconverted signal amplitude of the alternate path;

e) enables the main path and the alternate path and then measures a signal power produced at a combined output of the main path and the alternate path; and

f) adjusts a phase control setting in at least one of the main path and the alternate path to minimize the signal power produced at the combined output.

20. The system of claim 19, wherein the at least one hardware processor also stores the gain setting and the phase control setting.

21. The system of claim 19, wherein the at least one hardware processor performs a) through f) for a plurality of test tone frequencies.

22. A computer-readable medium containing computer-executable instructions that, when executed by a processor, cause the processor to perform a method for cancelling interferers in a receiver, the method comprising:

a) providing a radio frequency test tone to a main path and an alternate path in a receiver;

b) enabling the main path and disabling the alternate path and then measuring a downconverted signal amplitude produced at the output of the main path;

c) enabling the alternate path and disabling the main path and then measuring a downconverted signal amplitude produced at the output of the alternate path;

d) adjusting a gain setting in at least one of the main path and the alternate path to match the downconverted signal amplitude of the main path and the downconverted signal amplitude of the alternate path;

e) enabling the main path and the alternate path and then measuring a signal power produced at a combined output of the main path and the alternate path; and

f) adjusting a phase control setting in at least one of the main path and the alternate path to minimize the signal power produced at the combined output.

23. The medium of claim 22, wherein the method further comprises storing the gain setting and the phase control setting.

24. The medium of claim 22, wherein the method further comprises performing a) through f) for a plurality of test tone frequencies.