Systems and methods for cancelling interferers in a receiver

• US 8,594,603 B2
• Filed: 11/08/2010
• Issued: 11/26/2013
• 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
• Primary Examiner(s): Nguyen, Simon
• Application Number:
  US12/941,777
• Publication Number:
  US 20110124307A1
• Time in Patent Office: 1,114 Days
• Field of Search: 455/63.1, 455/296, 455303-306, 455313-317, 455/278.1, 455/283
• 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;

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

a high-pass filter that filters the alternate baseband or intermediate-frequency signal to produce a high-pass-filtered alternate baseband or intermediate-frequency signal;

a combiner that combines the main baseband or intermediate-frequency signal and the high-pass-filtered alternate baseband or intermediate-frequency signal to form a combined signal; and

a low-pass filter that forms a baseband or intermediate-frequency signal based on the combined 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 high-pass-filtered 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;

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

high pass filtering the alternate baseband or intermediate-frequency signal to produce a high-pass-filtered alternate baseband or intermediate-frequency signal;

combining the main baseband or intermediate-frequency signal and the high-pass-filtered alternate baseband or intermediate-frequency signal to form a combined signal; and

forming a baseband or intermediate-frequency signal based on the combined signal using a low-pass filter,

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 high-pass-filtered 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.