Method for determining phase noise in a periodically modulated signal

Patent metadata

Field	Value
Publication number	US-10771098-B2
Application number	US-201816159350-A
Country	US
Kind code	B2
Filing date	Oct 12, 2018
Priority date	Oct 12, 2018
Publication date	Sep 8, 2020
Grant date	Sep 8, 2020

Abstract

A method for determining phase noise in a periodically modulated signal is described. The modulated signal is processed to generate a processed signal from the modulated signal. At least an approximate period of a modulation of the modulated signal is determined from the processed signal. The type of modulation of the modulated signal is determined from the processed signal. The modulated signal is demodulated based on the determined period and the determined type of modulation to generate a demodulated signal, and the phase noise is determined from the demodulated signal. Moreover, a measurement device is described.

First claim

The invention claimed is:

1. A method for determining phase noise in a periodically modulated signal, the method comprising the following steps:
processing the periodically modulated signal to generate a processed signal from the periodically modulated signal;
determining at least an approximate period of a modulation of the periodically modulated signal from the processed signal;
determining a type of modulation of the periodically modulated signal from the processed signal;
demodulating the modulated signal based on the determined period and the determined type of modulation to generate a demodulated signal, wherein the demodulated signal corresponds to a continuous wave signal containing the phase noise to be quantified; and
determining the phase noise from the demodulated signal.

2. The method of claim 1 , wherein the periodically modulated signal is digitized to generate the processed signal.

3. The method of claim 1 , wherein the type of modulation of the periodically modulated signal is assigned to a family of quadrature amplitude modulations.

4. The method of claim 1 , wherein the type of modulation of the periodically modulated signal is assigned to at least one of a family of phase modulations and a family of frequency modulations.

5. The method of claim 1 , wherein the approximate period is determined by an autocorrelation of the processed signal.

6. The method according to claim 5 , wherein at least one local maximum of an autocorrelation function resulting from the autocorrelation of the processed signal is approximated via a model.

7. The method of claim 1 , wherein the demodulated signal is averaged over a time interval being a multiple of the determined approximate period to determine the phase noise.

8. The method of claim 1 , wherein the phase noise is determined for specific samples in the processed signal corresponding to specific frequency offsets.

9. The method of claim 8 , wherein the phase noise is determined for several frequency offsets that are different from each other.

10. The method of claim 1 , wherein the phase noise is visualized together with the periodically modulated signal.

11. The method of claim 1 , wherein the periodically modulated signal is processed using at least one of a radio frequency signal analyzer or an oscilloscope.

12. The method of claim 1 , wherein an amplitude noise is determined from the demodulated signal.

13. A measurement device, comprising: an input channel, a processing unit, a demodulation unit and a noise analysis unit,
the input channel being configured to receive an input signal and to forward the input signal to the processing unit,
the processing unit being configured to process the input signal to generate a processed signal from the input signal and to forward the processed input signal to the demodulation unit,
the demodulation unit being configured to determine a type and a period of a modulation of the input signal to generate a demodulated signal by demodulating the processed signal based on the period and the type of modulation and to forward the demodulated signal to the noise analysis unit, wherein the demodulated signal corresponds to a continuous wave signal containing the phase noise to be quantified, and
the noise analysis unit being configured to determine at least one of a phase noise and an amplitude noise of the demodulated signal.

14. The measurement device of claim 13 , wherein the measurement device is established by at least one of a radio frequency signal analyzer or an oscilloscope.

15. The measurement device of claim 13 , wherein the processing unit comprises an analog-to-digital converter.

16. The measurement device of claim 13 , wherein the demodulation unit is configured to generate an autocorrelation of the processed signal.

17. A method for determining phase noise in a periodically modulated signal, the method comprising the following steps:
processing the periodically modulated signal to generate a processed signal from the periodically modulated signal;
determining at least an approximate period of a modulation of the periodically modulated signal from the processed signal, wherein the approximate period of the modulation of the periodically modulated signal is determined by an autocorrelation of the processed signal;
determining a type of modulation of the periodically modulated signal from the processed signal;
demodulating the modulated signal based on the determined period and the determined type of modulation to generate a demodulated signal; and
determining the phase noise from the demodulated signal.

Assignees

• Rohde & Schwarz

Inventors

• Cirillo Luke
• Lagler Andreas
• Breitenfeld Alexander

Classifications

• H03B2200/009

  Reduction of phase noise · CPC title

• G01S13/343

  using sawtooth modulation · CPC title

• H04L1/206

  for modulated signals · CPC title

• G01S13/345

  using triangular modulation · CPC title

• G01S7/4008 Primary

  of transmitters · CPC title