Impairment compensation

Patent metadata

Field	Value
Publication number	US-9667358-B2
Application number	US-201113170346-A
Country	US
Kind code	B2
Filing date	Jun 28, 2011
Priority date	Jun 28, 2011
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

A method is provided for compensating for impairment of an electrical signal output from a device under test (DUT), the impairment resulting from an impairment network. The method includes measuring an impaired electrical signal received at an electronic analyzer via the impairment network; applying a coded pulse sequence to the impairment network; estimating an impairment transfer function corresponding to the impairment based on the applied pulse sequence; and correcting the measured electrical signal using the impairment transfer function to determine the electrical signal output from the DUT.

First claim

What is claimed is:

1. A method of compensating for impairment of an electrical signal output from a device under test (DUT), the impairment resulting from an impairment network, the method comprising:
measuring an impaired electrical signal received at an electronic analyzer via the impairment network;
applying a coded pulse sequence to the impairment network, the coded pulse sequence comprising a plurality of pulses;
estimating an impairment transfer function corresponding to the impairment based on the applied coded pulse sequence; and
correcting the measured impaired electrical signal using the impairment transfer function to determine the electrical signal output from the DUT.

2. The method of claim 1 , wherein the impairment network comprises a cable and at least one connector connecting the DUT and the electronic analyzer.

3. The method of claim 2 , wherein the impairment network further comprises at least one internal component of the electronic analyzer that drifts with time or at least one internal component of the DUT.

4. The method of claim 1 , wherein estimating the impairment transfer function comprises inferring the impairment transfer function using S-parameter S 11 of the impairment network.

5. The method of claim 1 , wherein estimating the impairment transfer function comprises directly measuring the impairment transfer function using one of S-parameter S 21 or S 12 of the impairment network.

6. The method of claim 1 , wherein estimating the impairment transfer function comprises:
adjusting a calibration signal to match the electrical signal output from the DUT; and
dividing the measured impaired electrical signal by the adjusted calibration signal.

7. The method of claim 1 , wherein estimating the impairment transfer function comprises:
adjusting a calibration signal to match a negative of the electrical signal output from the DUT; and
mixing the adjusted calibration signal with the electrical signal output from the DUT.

8. The method of claim 1 , wherein the applied coded pulse sequence has variable amplitude so that the impairment transfer function includes nonlinear characteristics of the impairment.

9. The method of claim 1 , wherein the coded pulse sequence comprises one of a pseudorandom bit sequence (PRBS), a prescribed binary sequence, and a prescribed pulse sequence of varying pulse widths and pulse amplitudes.

10. The method of claim 1 , wherein the coded pulse sequence is applied continuously in a background.

11. The method of claim 1 , wherein the coded pulse sequence is applied only during a retrace period or a non-acquisition time of the electronic analyzer.

12. The method of claim 1 , wherein correcting the measured electrical signal comprises:
dividing an estimated response by the impairment transfer function to obtain corrected estimated response of the electrical signal.

13. The method of claim 1 , further comprising:
correcting a subcarrier distortion of a modulated signal, associated with the electrical signal output by the DUT, during post-processing using the impairment transfer function.

14. The method of claim 1 , wherein the electronic analyzer is one of an electronic spectrum analyzer and an electronic signal analyzer.

15. A method of compensating for impairment of an electrical signal output from a signal generator, the impairment resulting from an impairment network, the method comprising:
determining an electrical signal to be provided to a device under test (DUT) via the impairment network;
applying a coded pulse sequence to the impairment network, the coded pulse sequence comprising a plurality of pulses;
estimating an impairment transfer function corresponding to the impairment based on the applied coded pulse sequence; and
correcting the electrical signal using the impairment transfer function prior to the impairment network to provide the electrical signal to the DUT.

16. The method of claim 15 , wherein determining the impairment transfer function comprises determining at least one S-parameter of the impairment network.

17. The method of claim 15 , wherein determining the impairment transfer function comprises adjusting a calibration signal to equal the electrical signal output from the signal generator.

18. A system for compensating for impairment of a test signal transmitted through an impairment network, the system comprising:
a pulse generator configured to apply a coded pulse sequence to the impairment network, the coded pulse sequence comprising a plurality of pulses; and
a processing device configured to measure the test signal after the test signal passes through the impairment network, to estimate an impairment transfer function of the impairment based on a corresponding response to the applied coded pulse sequence from the impairment network, and to determine impairment correction information based on the measured test signal and the estimated impairment transfer function; and
a correction circuit configured to apply the impairment correction information received from the processing device to the test signal after the test signal passes through the impairment network to provide a corrected test signal.

19. The system of claim 18 , wherein the coded pulse sequence applied by the pulse generator includes variable amplitude and variable pulse width.

20. The system of claim 18 , further comprising:
an arbitrary waveform generator configured to generate a calibration signal,
wherein the processing device adjusts calibration signal to match the test signal, and estimates the impairment transfer function by dividing the measured test signal by the adjusted calibration signal.

Assignees

• Baney Douglas
• Keysight Technologies Inc

Inventors

• Baney Douglas

Classifications

• H04B17/11 Primary

  for calibration · CPC title

• H04B17/14

  of the whole transmission and reception path, e.g. self-test loop-back · CPC title