System and Method for Gaussian Random Noise Generation

• US 20150123721A1
• Filed: 11/05/2013
• Published: 05/07/2015
• Est. Priority Date: 11/05/2013
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Inventors: Midha, Gagan, Joshi, Archit
• Granted Patent: US 9,331,681 B2
• Time in Patent Office: Days
• US Class Current: 327/164
• CPC Class Codes: H03K 3/84 Generating pulses having a predetermined statistical distribution of a parameter, e.g. random pulse generators

Abstract

In accordance with an embodiment, a method of generating noise includes generating, using a hardware-based noise generator, a plurality of periodic waveforms having different frequencies, weighting, using the hardware-based noise generator, amplitudes of the plurality of periodic waveforms based on a predetermined spectral shape to form a plurality of weighted waveforms, and summing the plurality of plurality of weighted waveforms to form an output random noise signal.

Claims

1. A method of generating noise comprising:

generating, using a hardware-based noise generator, a plurality of periodic waveforms having different frequencies;

weighting, using the hardware-based noise generator, amplitudes of the plurality of periodic waveforms based on a predetermined spectral shape to form a plurality of weighted waveforms; and

summing the plurality of plurality of weighted waveforms to form an output random noise signal.

2. The method of claim 1, wherein the output random noise signal has a Gaussian distribution and a spectral shape according to the predetermined spectral shape.

3. The method of claim 1, wherein generating further comprises randomizing an initial phases of the plurality of periodic waveforms.

4. The method of claim 3, wherein determining the initial phases comprises using a pseudo random number generator.

5. The method of claim 1, wherein the hardware-based noise generator comprises a computing device having a processor and a memory.

6. The method of claim 1, wherein the hardware-based noise generator comprises dedicated hardware.

7. The method of claim 1, wherein the plurality of periodic waveforms is sinusoidal.

8. The method of claim 1, wherein generating each of the plurality of periodic waveforms comprises performing a direct digital synthesis.

9. The method of claim 1, wherein generating each of the plurality of periodic waveforms comprises:

incrementing a counter;

determining a first waveform value based on an output of the counter; and

weighting each of the plurality of periodic waveforms comprises scaling the first waveform value.

10. The method of claim 9, wherein incrementing the counter comprises incrementing a modulo counter.

11. The method of claim 9, wherein incrementing the counter comprises using a sigma-delta modulator to increment the counter at a fractional frequency.

12. The method of claim 9, wherein determining the first waveform value comprises using a lookup table.

13. A system for generating random noise comprising:

a hardware-based noise generator configured to

generate a plurality of sinusoidal waveforms having different frequencies,

weight amplitudes of the plurality of sinusoidal waveforms to form weighted waveforms, and

add the weighted waveforms together to form an output random noise signal.

14. The system of claim 13, wherein the hardware-based noise generator is further configured to randomize phases of the plurality of sinusoidal waveforms.

15. The system of claim 14, wherein the hardware-based noise generator comprises a pseudo-random noise generator.

16. The system of claim 14, wherein the hardware-based noise generator comprises:

a plurality of direct digital synthesizers;

a plurality of multipliers coupled to corresponding outputs of the plurality of direct digital synthesizers; and

a summing circuit coupled to outputs of the plurality of direct digital synthesizers.

17. The system of claim 16, wherein at least one of the plurality of direct digital synthesizers comprises:

a modulo counter; and

a lookup table coupled to the output of the modulo counter.

18. The system of claim 17, further comprising a sigma-delta modulator coupled to an input of the modulo counter, wherein the sigma-delta modulator is configured to select between at least two counting ratios to generate a fractional frequency.

19. A method of simulating a circuit comprising:

providing a model of a target circuit having at least one input;

generating, using a hardware-based noise generator, a plurality of periodic waveforms using direct digital synthesis, wherein the plurality of periodic waveforms have different frequencies and randomized phases;

weighting, using the hardware-based noise generator, amplitudes of the plurality of periodic waveforms based on a predetermined spectral shape to form a plurality of weighted waveforms;

summing the plurality of plurality of weighted waveforms to form an output random noise signal; and

simulating the model of the target circuit using a computer, wherein simulating comprises introducing the random noise signal to the at least one input and providing simulation output data.

20. The method of claim 19, wherein the hardware-based noise generator comprises the computer.

21. The method of claim 19, wherein generating each of the plurality of periodic waveforms comprises:

incrementing a counter;

determining a first waveform value based on an output of the counter; and

weighting each of the plurality of periodic waveforms comprises scaling the first waveform value.