Quadrature error correction using polynomial models in tone calibration

• US 9,281,907 B2
• Filed: 05/20/2013
• Issued: 03/08/2016
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: An, Wei, Schubert, Richard P., Stein, Yosef
• Primary Examiner(s): Le, Lana N
• Application Number:
  US13/897,719
• Publication Number:
  US 20140273902A1
• Time in Patent Office: 1,023 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements
• CPC Class Codes: H04B 17/391 Modelling the propagation channel

Abstract

One example embodiment provides a system, apparatus, and method for using polynomial models in tone calibration for quadrature error correction in I/Q receivers. In one example embodiment, method for calibrating an I/Q receiver is provided and includes receiving a first mismatch parameter indicating a mismatch between I and Q channels of the I/Q receiver; and estimating a second mismatch parameter from the first mismatch parameter using a polynomial model.

Claims

1. A method for calibrating an I/O. receiver, comprising:

receiving, from a tone calibration estimator, a first set of mismatch parameters indicating a mismatch between I and Q channels of the I/O. receiver, wherein the first set of mismatch parameters includes a total gain mismatch parameter and a total phase mismatch parameter, and wherein the tone calibration estimator is to inject test tones at frequencies within a test spectrum into the I/O. receiver; and

estimating, by a polynomial calibration estimator, a second set of mismatch parameters from the first set of mismatch parameters using a polynomial model, wherein the second set of mismatch parameters includes a frequency-dependent gain mismatch parameter, a frequency-dependent phase mismatch parameter, and a frequency-independent phase mismatch parameter.

2. The method of claim 1, wherein estimating the second set of mismatch parameters comprises applying a third or fourth order polynomial to estimate the second set of mismatch parameters.

3. The method of claim 1, wherein the first set of mismatch parameters comprises a first plurality of frequency dependent mismatch parameters at frequencies over a test spectrum, and wherein estimating the second set of mismatch parameters comprises estimating a second plurality of frequency dependent mismatch parameters over negative and positive frequency pairs in the test spectrum.

4. The method of claim 1, wherein estimating the second set of mismatch parameters comprises minimizing a matrix using least squared error (LSE) calculations.

5. The method of claim 1, further comprising:

generating, by the tone calibration estimator, N tone signals over a test spectrum;

providing, by the tone calibration estimator, the tone signals to the I/Q receiver;

performing, by the tone calibration estimator, tone calibration to generate the first set of mismatch parameters; and

providing the first set of mismatch parameters to the polynomial calibration estimator.

6. The method of claim 5, wherein estimating the second set of mismatch parameters comprises estimating a parameter mismatch over negative and positive frequency pairs in the test spectrum.

7. An apparatus for calibrating an I/O. receiver, the apparatus comprising:

a polynomial estimator to;

receive a first mismatch parameters, from a tone calibration estimator, wherein the first mismatch parameter indicates a mismatch between I and Q channels of the I/Q. receiver, and

estimate a second mismatch parameter from the first mismatch parameter estimation using a polynomial model;

a tone generator to generate N tone signals over a test frequency spectrum and input the tone signals into analog paths of the I/O. receiver;

a transform block, coupled to an end of a particular analog path, to transform a signal received at the end of the particular analog path from a time domain signal to a frequency domain signal and to output the frequency domain signal; and

the tone calibration estimator, coupled to the transform block and the polynomial estimator, to receive the frequency domain signal from the transform block, perform tone calibration on the frequency domain signal to generate the first mismatch parameter, and provide the first mismatch parameter to the polynomial estimator.

8. The apparatus of claim 7, wherein the polynomial estimator is to estimate the second mismatch parameter from the first mismatch parameter by applying a third or fourth order polynomial.

9. The apparatus of claim 8, wherein the polynomial estimator is to estimate the second mismatch parameter from the first mismatch parameter by applying a fourth order polynomial.

10. The apparatus of claim 7, wherein the first mismatch parameter comprises a first plurality of frequency dependent mismatch parameters at frequencies of a test spectrum, and wherein the polynomial estimator is to estimate the second plurality of frequency dependent mismatch parameters over negative and positive frequency pairs of the test spectrum.

11. The apparatus of claim 7, wherein the polynomial estimator is to estimate the second mismatch parameter using a polynomial with a matrix and uses least squared error (LSE) calculations.

12. The apparatus of claim 7, wherein the first mismatch parameter received by the polynomial estimator comprises a total gain mismatch and a total phase mismatch.

13. The apparatus of claim 7, wherein the second mismatch parameter comprises a total gain mismatch parameter and a total phase mismatch parameter for each frequency of the N tone signals.

14. An apparatus for calibrating an I/O. receiver, comprising:

a tone calibration estimator to inject test tones at frequencies within a test spectrum into the I/O. receiver, estimate a first set of mismatch parameters comprising a total gain mismatch parameter and a total phase mismatch parameter, and output the first set of mismatch parameters; and

a polynomial calibration estimator coupled to the tone calibration estimator, the polynomial calibration estimator to receive the first set of mismatch parameters from the tone calibration estimator and estimate a second set of mismatch parameters from the first set of mismatch parameters using a polynomial model, the second set of mismatch parameters comprising a frequency-dependent gain mismatch parameter, a frequency-dependent phase mismatch parameter, and a frequency-independent phase mismatch parameter.

15. The apparatus of claim 14, wherein the polynomial calibration estimator is to estimate the second set of mismatch parameters over negative and positive frequency pairs in the test spectrum.

16. One or more non-transitory computer readable media having instructions thereon that, in response to execution by one or more processing devices of an apparatus, cause the apparatus to provide a polynomial calibration estimator to:

receive, from a tone calibration estimator, a first set of mismatch parameters indicating a mismatch between I and Q channels of the I/O. receiver, wherein the first set of mismatch parameters includes a total gain mismatch parameter and a total phase mismatch parameter, and wherein the tone calibration estimator is to inject test tones at frequencies within a test spectrum into the I/O. receiver; and

estimate a second set of mismatch parameters from the first set of mismatch parameters using a polynomial model, wherein the second set of mismatch parameters includes a frequency-dependent gain mismatch parameter, a frequency-dependent phase mismatch parameter, and a frequency-independent phase mismatch parameter.

17. The one or more non-transitory computer readable media of claim 16, wherein the first set of mismatch parameters comprises a first plurality of frequency dependent mismatch parameters at frequencies over a test spectrum, and wherein estimation of the second set of mismatch parameters comprises estimation of a second plurality of frequency dependent mismatch parameters over negative and positive frequency pairs in the test spectrum.

18. The one or more non-transitory computer readable media of claim 16, wherein generate the second set of mismatch parameters comprises generate the second set of mismatch parameters jointly over multiple frequency pairs from the first set of mismatch parameters using the polynomial model.

19. The one or more non-transitory computer readable media of claim 16, wherein the instructions are further to, upon execution by the one or more processing devices of the apparatus, cause the apparatus to provide the tone calibration estimator to:

generate N tone signals over a test spectrum;

provide the tone signals to the I/Q receiver;

perform tone calibration in the tone calibration estimator to generate the first set of mismatch parameters; and

provide the first set of mismatch parameters to the polynomial calibration estimator.

20. The one or more non-transitory computer readable media of claim 16, wherein the instructions are further to, upon execution by the one or more processing devices of the apparatus, cause the apparatus to:

correct for mismatch represented by the second set of mismatch parameters in the I/O receiver.