RANDOM PULSE GENERATOR

• US 3,758,873 A
• Filed: 07/14/1972
• Issued: 09/11/1973
• Est. Priority Date: 07/14/1972
• Status: Expired due to Term

• Current Assignee: Herbert E. Miller
• Original Assignee: Herbert E. Miller
• Inventors: Miller, Herbert E.
• Primary Examiner(s): Kominski, John
• Application Number:
  US05/271,704
• Time in Patent Office: 424 Days
• Field of Search: 331/78 328/158
• US Class Current: 331/78
• CPC Class Codes: H03K 3/84 Generating pulses having a predetermined statistical distribution of a parameter, e.g. random pulse generators

Abstract

A system for generating electronic pulses separated by intervals which vary according to a predetermined probability distribution, typically exponential. The predetermined probability distribution is realized through the interaction of two other separately controlled functions. A first probability function statistically governs the selection of a first value and a second time varying function establishes the pulse time interval by relation to the selected first value.

Claims

1. A system for producing a sequence of values with each value governed by a predetermined probability, said system comprising:

means for repeatedly selecting a signal level from within a range of signal levels according to a preset probability function;

means for providing a transformation between a first range of signal values and a second range of signal values whereby each signal value in said first range produces one or more corresponding signal values in said second range;

means responsive to each selected signal level and operatively associated with said transformation providing means for detecting from said transformation providing means a signal value in said second range corresponding to the signal value in said first range represented by each said selected signal level;

a plurality of said output signal values from repeated selections of one of said signal levels providing said sequence of values according to the predetermined probability;

said predetermined probability being determined by coaction of the functions describing the selections of said signal level selecting means and the transformations of said transformation providing means.

2. The system of claim 1 wherein:

said transformation providing means includes means for generating the values in said first range as a function of time within said second range;

said detecting means includes means for comparing said values in said first range with said selected signal level to determine equality therebetween; and

means responsive to a determination of equality for providing a time interval corresponding to the time represented by said generating means at said determined equality.

3. The system of claim 1 wherein said signal level selecting means includes:

a random signal generator; and

means for providing each random signal over a range extending within said first range of values.

4. The system of claim 1 further including:

means for selecting an average value for said sequence of values; and

means responsive to the selected average value and said plurality of output values for regulating the average value of the output values detected from said transformation providing means.

5. The system of claim 1 wherein said transformation providing means includes means for providing a plurality of signal values in said second range corresponding to the signal value in said first range representing the signal level selected.

6. A pulse generator for producing a sequence of electrical output pulses at intervals governed by a predetermined probability distribution, said pulse generator comprising:

means responsive to a first signal for producing a signal amplitude within a range of amplitudes, said produced signal amplitude being governed by a predetermined probability function;

means operative in response to said first signal for generating a predetermined signal waveform as a function of time;

means for comparing said produced signal amplitude and said generated signal waveform and operative to produce a timing signal in response to a predetermined coincidence between said produced signal amplitude and said predetermined waveform;

means operative in response to said timing signal for producing one of said sequence of output pulses; and

means further operative in response to said timing signal for producing said first signal for application respectively to said signal amplitude producing means and said signal waveform generating means to provide recycling thereof in order to permit production of a sequence of output pulses.

7. The pulse generator of claim 6 further including:

means responsive to said sequence of Output pulses for providing a signal representative of the actual average interval between pulses in the pulse output sequence;

means for providing selection of an average interval between pulses; and

means for adjusting said predetermined waveform signal generating means in response to the selected average interval and the actual average interval signal to cause said actual average interval between pulses to approach said selected average interval.

8. A pulse generator for producing output pulses at intervals varying according to a predetermined probability distribution, said generator including:

a shift register operative to shift digital signals therein in response to a clock signal;

means for applying a digital input to said shift register as a predetermined combination of a plurality of the binary states of said shift register;

means for converting the binary states of said shift register to an analog signal representing the magnitude of said binary states;

means for selecting an average pulse interval;

means operative in response to said selected average pulse interval for producing a pulse sequence at a corresponding pulse rate;

a plurality of capacitors;

a plurality of resistors operative to discharge said plurality of capacitors;

means for charging said plurality of capacitors to a predetermined signal level in response to an output pulse;

means operative in response to predetermined ranges in said selected average pulse interval for selectively connecting said plurality of capacitors for discharge through said plurality of resistors;

means for accummulating a digital representation of the difference in rate of pulse occurrence between pulses in said pulse sequence and said output pulses;

means operative in response to each bit of said digital representation for selectively enabling a corresponding one of said plurality of resistors as a discharge path for said plurality of capacitors;

means responsive to said first signal for generating said clock signal for said shift register;

means for comparing the voltage level of said plurality of capacitors during discharge by said plurality of resistors with said analog signal to produce a comparison signal in response to detection of a predetermined relation therebetween; and

means for producing one of said output pulses in response to each said comparison signal.