Method for generating an output signal having predetermined jitter characteristics

Patent metadata

Field	Value
Publication number	US-10972331-B2
Application number	US-202016776256-A
Country	US
Kind code	B2
Filing date	Jan 29, 2020
Priority date	Jan 31, 2019
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

A method for generating an output signal having predetermined jitter characteristics is disclosed. A first signal is generated via a first signal generator module. A second signal is generated via a second signal generator module. The first signal is pulse position modulated by the second signal, thereby generating a modulated signal having predetermined jitter characteristics. An output signal having predetermined jitter characteristics is generated based on the modulated signal. Moreover, a signal generator for generating an output signal having predetermined jitter characteristics is disclosed.

First claim

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method for generating an output signal having predetermined jitter characteristics, comprising the following steps:
generating a first signal via a first signal generator;
generating a second signal via a second signal generator;
pulse-position modulating the first signal by the second signal, thereby generating a modulated signal having predetermined jitter characteristics; and
generating an output signal having predetermined jitter characteristics based on the modulated signal.

2. The method of claim 1 , wherein the first signal is PAM-n coded.

3. The method of claim 2 , wherein the first signal is generated with rising edges having predefined rising slopes between pairs of different signal levels and with falling edges having predefined falling slopes between pairs of different signal levels in order to obtain a predefined duty cycle distortion in the modulated signal.

4. The method of claim 2 , wherein the first signal comprises at least one of a predefined symbol sequence and a pseudo-random symbol sequence.

5. The method of claim 2 , wherein the pulse position of each signal edge of the first signal is modulated, wherein the modulation of the first signal by the second signal is kept constant within each symbol.

6. The method of claim 1 , wherein the modulated signal is filtered via a filter in order to generate the output signal, thereby generating predefined inter-symbol interferences in the output signal.

7. The method of claim 6 , wherein the filter is a finite impulse response filter.

8. The method of claim 6 , wherein the modulated signal is filtered with a filter sampling rate being equal to or larger than a data rate of the first signal.

9. The method of claim 8 , wherein the periodic signal is generated as a superposition of several sine-shaped signals.

10. The method of claim 1 , wherein the second signal comprises at least one of a periodic signal and white Gaussian noise in order to generate periodic jitter and random jitter in the modulated signal, respectively.

11. The method of claim 1 , wherein a perturbation signal being uncorrelated with the first signal, the second signal and the modulated signal is at least one of generated and received, wherein the perturbation signal is added to at least one of the first signal, the second signal and the modulated signal in order to generate other bounded uncorrelated jitter in the output signal.

12. Method according to claim 11 , wherein the perturbation signal is multiplied with a predetermined weighting factor before being added to the at least one of the first signal, the second signal and the modulated signal.

13. The method of claim 1 , wherein at least the modulated signal is established as a digital signal, and wherein the modulated signal is converted to an analog signal in order to generate the output signal.

14. A signal generator for generating an output signal having predetermined jitter characteristics, comprising a first signal generator circuit, a second signal generator circuit, and a modulation circuit,
the first signal generator circuit being configured to generate a first signal and to forward said first signal to the modulation circuit;
the second signal generator circuit being configured to generate a second signal and to forward said second signal to the modulation circuit; and
the modulation circuit being configured to pulse-position modulate the first signal by the second signal, thereby generating a modulated signal having predetermined jitter characteristics.

15. The signal generator of claim 14 , wherein the first signal generator circuit is configured to generate the first signal as a PAM-n coded signal with rising edges having predefined rising slopes between pairs of different signal levels and with falling edges having predefined falling slopes between pairs of different signal levels in order to obtain a predefined duty cycle distortion in the modulated signal.

16. The signal generator of claim 14 , wherein the second signal generator circuit is configured to generate the second signal with at least one of a periodic signal and white Gaussian noise.

17. The signal generator of claim 14 , comprising a finite impulse response filter module downstream of the modulation circuit.

18. The signal generator of claim 14 , comprising a perturbation circuit being configured to at least one of generate and receive a perturbation signal that is uncorrelated with the first signal, the second signal and the modulated signal, wherein the perturbation module is configured to add the weighted perturbation signal to at least one of the first signal, the second signal and the modulated signal.

19. The signal generator of claim 14 , wherein at least one of the first signal generator circuit and the second signal generator circuit is established as a digital signal generator.

20. The signal generator of claim 19 , comprising a digital-to-analog converter downstream of the modulation circuit.

Assignees

• Rohde & Schwarz

Inventors

• Herbordt Wolfgang
• Wollinger Martina
• Freidhof Markus

Classifications

• H04L27/362 Primary

  Modulation using more than one carrier, e.g. with quadrature carriers, separately amplitude modulated (H04L27/366 takes precedence) · CPC title

• G01R31/31709

  Jitter measurements; Jitter generators (measuring jitter, noise figure or signal-to-noise ratio per se G01R29/26; analysis of tester signals G01R31/31901) · CPC title

• H03K7/04 Primary

  Position modulation, i.e. PPM · CPC title