Wideband Residual Sideband Calibration

• US 20180083661A1
• Filed: 09/22/2016
• Published: 03/22/2018
• Est. Priority Date: 09/22/2016
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Emadi, Mohammad, Taghivand, Mazhareddin, Khalili, Alireza
• Application Number:
  US15/273,461
• Publication Number:
  US 20180083661A1
• Time in Patent Office: Days
• CPC Class Codes: H04B 1/1036 with automatic suppression of narrow band noise or interference, e.g. by using tuneable notch filters H04B1/123 takes precedence; filter circuits H03H
• CPC Class Codes: H04B 1/16 Circuits
• CPC Class Codes: H04B 17/0085 using test signal generators
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements
• CPC Class Codes: H04B 17/354 Adjacent channel leakage power

Abstract

Various aspects of this disclosure describe the calibration of residual sideband energy in a receiver, for example estimating gain mismatch and phase mismatch in in-phase (I) and quadrature-phase channels (Q) of a receiver. An input to the receiver is supplied with an input signal generated to comprise a bandwidth including a plurality of frequencies, such as a linear frequency modulation signal. An output signal of the receiver is filtered by a filter programmed to be matched to the input signal, and estimates of gain error and phase error in I and Q channels of the receiver are determined from the filtered outputs.

Claims

1. A method comprising:

generating, with an input signal generator of a device, a calibration test signal comprising a bandwidth including a plurality of frequencies;

driving an input of a receiver of the device with the calibration test signal generated by the device;

obtaining an output signal of the receiver generated from the driving the input of the receiver with the calibration test signal generated by the device;

filtering the output signal of the receiver with a filter matched to the calibration test signal to produce a filtered output signal; and

calibrating the receiver based on the filtered output signal.

2. The method as recited in claim 1, wherein the calibrating comprises determining a gain mismatch and a phase mismatch of I and Q channels of the receiver.

3. The method as recited in claim 2, wherein the determining a gain mismatch and a phase mismatch comprises determining a phase and an amplitude from a peak of the filtered output signal.

4. The method as recited in claim 1, wherein the calibration test signal comprises a linear frequency modulation signal.

5. The method as recited in claim 4, further comprising programming the filter with coefficients representing the linear frequency modulation signal.

6. The method as recited in claim 1, wherein the calibration test signal comprises a plurality of linear frequency modulation signals each with a different center frequency.

7. The method as recited in claim 1, further comprising performing the generating, the driving, the obtaining, the filtering, and the calibrating upon start-up of the receiver.

8. The method as recited in claim 1, further comprising setting the bandwidth according to a desired phase resolution.

9. A system comprising:

an input signal generator configured to generate a test signal comprising a bandwidth including a plurality of frequencies, the test signal generated by increasing a frequency of the test signal over a first duration of the test signal and decreasing the frequency over a second duration of the test signal;

a receiver configured to receive the test signal and generate an output signal; and

a calibration processor comprising;

a filter configured to be matched to the test signal and filter the output signal to produce a filtered output signal; and

a mismatch estimator configured to determine a gain mismatch or a phase mismatch of I and Q channels of the receiver from the filtered output signal.

10. The system as recited in claim 9, wherein the test signal comprises a linear frequency modulation signal.

11. The system as recited in claim 10, wherein the filter is programmed with coefficients representing the linear frequency modulation signal.

12. The system as recited in claim 9, wherein the test signal comprises a plurality of linear frequency modulation signals each with a different center frequency.

13. The system as recited in claim 9, wherein the input signal generator, the receiver, and the calibration processor comprise separate respective devices.

14. The system as recited in claim 9, wherein the input signal generator and the calibration processor comprise part of the receiver.

15. A method comprising:

filtering an output signal of a receiver with a filter configured to be matched to an input signal to the receiver that caused the output signal to be produced; and

determining a gain mismatch or a phase mismatch of I and Q channels of the receiver by solving a system of simultaneous equations constructed from the filtered output signal.

16. The method as recited in claim 15, wherein the input signal comprises a linear frequency modulation signal.

17. The method as recited in claim 16, wherein the filter is configured to be matched to the input signal by programming the filter with coefficients representing the linear frequency modulation signal.

18. The method as recited in claim 15, further comprising performing the filtering and the determining responsive to the receiver being powered on.

19. The method as recited in claim 15, wherein the input signal is real valued and the output signal and the filtered output signal are complex valued.

20. The method as recited in claim 15, wherein the input signal comprises a sequence generated from a Barker code.

21. A device comprising:

means for receiving an output signal of a receiver generated by applying an input signal comprising a bandwidth including a plurality of frequencies to an input of the receiver, the input signal including a first portion over which a frequency of the input signal is increased and a second portion over which the frequency is decreased;

means for receiving configuration parameters to configure a filter to be matched to the input signal;

means for filtering the received output signal with the filter configured according to the configuration parameters to produce a filtered output signal; and

means for calibrating the receiver based on the filtered output signal.

22. The device as recited in claim 21, wherein the means for calibrating comprise means for determining a gain mismatch and a phase mismatch of I and Q channels of the receiver.

23. The device as recited in claim 21, wherein the input signal comprises a linear frequency modulation signal.

24. The device as recited in claim 23, wherein to configure the filter to be matched to the input signal comprises to program the filter with coefficients representing the linear frequency modulation signal.

25. The device as recited in claim 22, wherein the configuration parameters comprise filter coefficients for the filter.