Adaptive noise reduction in a signal analyzer

Patent metadata

Field	Value
Publication number	US-10145877-B1
Application number	US-201615163856-A
Country	US
Kind code	B1
Filing date	May 25, 2016
Priority date	May 25, 2016
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

In an exemplary embodiment of the disclosure, a signal analyzer includes at least one noise reduction system in the form of an adaptive noise reduction system. The adaptive noise reduction system executes an adaptive noise floor extension (NFE) procedure that includes determining a predicted standard deviation of a response by the signal analyzer to intrinsic noise in the signal analyzer when various signal processing parameters desired by a user are applied to an input signal. The predicted standard deviation is then used in the signal analyzer to select and apply various noise subtraction values upon the input signal before displaying of a signal spectrum of the input signal upon a display of the signal analyzer. The adaptive NFE procedure is directed at reducing or eliminating various ambiguities and/or errors in the displayed signal spectrum.

First claim

What is claimed is:

1. A signal analyzer comprising:
an input port for coupling a signal into the signal analyzer;
one or more controls operable to set one or more signal processing parameters for processing the signal;
a non-transitory memory containing a set of computer-executable instructions;
a processor configured to access the memory and execute the set of computer-executable instructions to at least:
determine, based at least in part on the one or more signal processing parameters set via the one or more controls, a predicted standard deviation of a response by the signal analyzer to intrinsic noise in the signal analyzer;
select from a set of noise subtraction values, at least a first noise subtraction value that is based on the predicted standard deviation;
execute an adaptive noise floor extension (NFE) procedure upon the signal to provide a signal having reduced noise, the adaptive NFE procedure based at least in part on the first noise subtraction value; and

a display for displaying a spectrum of the reduced noise signal after execution of the adaptive NFE procedure.

2. The signal analyzer of claim 1 , further comprising one or more selectors for selecting one of the adaptive NFE procedure or a fixed-mode NFE procedure, the fixed-mode NFE procedure comprising use of a fixed noise subtraction relationship in a non-linear subtractor.

3. The signal analyzer of claim 2 , wherein the fixed-mode NFE procedure is directed at providing a fixed amount of noise subtraction irrespective of visual interpretation ambiguities associated with the signal displayed on the display.

4. The signal analyzer of claim 1 , wherein the one or more signal processing parameters set via the one or more controls of the signal analyzer comprises one or more of a resolution bandwidth, a video bandwidth, a sweep time, a detector type, and an amount of signal trace averaging.

5. The signal analyzer of claim 4 , wherein the adaptive NFE procedure is further based on use of one of a power scale, a logarithmic scale, or a voltage scale.

6. A method comprising:
determining, based at least in part on one or more signal processing parameters set via one or more controls of a signal analyzer, a predicted standard deviation of a response by the signal analyzer to intrinsic noise in the signal analyzer;
selecting from a set of noise subtraction values, at least a first noise subtraction value that is based on the predicted standard deviation;
receiving a signal via an input port of the signal analyzer;
executing an adaptive noise floor extension (NFE) procedure upon the signal, the adaptive NFE procedure based at least in part on the selected first noise subtraction value to provide a signal having reduced noise;
selecting one of the adaptive NFE procedure or a fixed-mode NFE procedure to be executed upon the signal, the fixed-mode NFE procedure comprising use of a fixed noise subtraction relationship in a non-linear subtractor, to provide a signal having reduced noise; and
displaying a spectrum of at least one of the reduced noise signals.

7. The method of claim 6 , wherein the one or more signal processing parameters set via the one or more controls of the signal analyzer comprises one or more of a resolution bandwidth, a video bandwidth, a sweep time, a detector type, and an amount of signal trace averaging.

8. The method of claim 7 , wherein selecting from the set of noise subtraction values comprises selecting an amount of improvement in decibels when executing the adaptive NFE procedure.

9. The method of claim 6 , wherein determining the predicted standard deviation is based on at least one of: a) a ratio between a video bandwidth setting and a resolution bandwidth setting on the signal analyzer, b) a trace average setting on the signal analyzer, and c) a detector type setting on the signal analyzer.

10. A signal analyzer comprising:
a display;
an input port;
a resolution bandwidth (RBW) filter;
a trace averaging subsystem;
a user interface comprising a first control for setting one or more operating parameters of the RBW filter and a second control for setting one or more operating parameters of the trace averaging subsystem; and
an adaptive noise floor extension (NFE) system configured to:
determine, based at least in part on a setting of an operating parameter of the RBW filter and a setting of an operating parameter of the trace averaging subsystem, a predicted standard deviation of a response by the signal analyzer to intrinsic noise in the signal analyzer;
select from a set of noise subtraction values, at least a first noise subtraction value that is based on the predicted standard deviation;
execute an adaptive noise floor extension (NFE) procedure upon an input signal coupled into the signal analyzer via the input port to provide a signal having reduced noise, the adaptive NFE procedure based at least in part on using the first noise subtraction value; and
display a spectrum of the reduced noise signal on the display after execution of the adaptive NFE procedure.

11. The signal analyzer of claim 10 , wherein the operating parameter of the RBW filter is a resolution bandwidth and the operating parameter of the trace averaging subsystem is a sweep time.

12. The signal analyzer of claim 10 , further comprising a video bandwidth (VBW) filter and wherein determining the predicted standard deviation is based at least in part on the setting of the operating parameter of the RBW filter, the setting of the operating parameter of the trace averaging subsystem, and a setting of an operating parameter of the VBW filter.

13. The signal analyzer of claim 12 , wherein the operating parameter of the VBW filter is a video bandwidth.

14. The signal analyzer of claim 13 , further comprising one or more detectors and wherein determining the predicted standard deviation is based on at least one of: a) a ratio between the video bandwidth setting of the VBW filter and a resolution bandwidth setting of the RBW filter, and b) a characteristic of a selected one of the one or more detectors.

15. The signal analyzer of claim 12 , further comprising one or more detectors, wherein determining the predicted standard deviation is based at least in part on the setting of the operating parameter of the RBW filter, the setting of the operating parameter of the trace averaging subsystem, the setting of the operating parameter of the VBW filter, and a characteristic of a selected one of the one or more detectors.

16. The signal analyzer of claim 10 , further comprising one or more selectors for selecting one of the adaptive NFE procedure or a fixed-mode NFE procedure to be executed upon the input signal, the fixed-mode NFE procedure characterized at least in part by use of a fixed noise subtraction relationship in a non-linear subtractor.

17. The signal analyzer of claim 16 , wherein the fixed-mode NFE procedure is directed at providing a fixed amount of noise subtraction.

18. The signal analyzer of claim 16 , wherein the fixed-mode NFE procedure is directed at providing a fixed amount of noise subtraction irrespective of visual interpretation ambiguities associated with the signal displayed on the display.

19. The signal analyzer of claim 16 , wherein the one or more selectors are settable by a user via the user interface.

20. The signal analyzer of claim 10 , wherein the adaptive NFE procedure is further based on use of one of a power scale, a logarithmic scale, or a voltage scale.

Assignees

• Keysight Technologies Inc

Inventors

• Gorin Joseph Michael
• Mclaughlin John Francis

Classifications

• G01R23/173 Primary

  Wobbulating devices similar to swept panoramic receivers · CPC title

• G01R23/16

  Spectrum analysis; Fourier analysis · CPC title

• G01R29/0892 Primary

  Details related to signal analysis or treatment; presenting results, e.g. displays; measuring specific signal features other than field strength, e.g. polarisation, field modes, phase, envelope, maximum value · CPC title