SU819939A1 - Generator of pseudorandom time intervals with predetermined moments - Google Patents

Description

(54) the pseudo-random sequence of time intervals of a predetermined TORQUE 3A hydrochloric pospedovatelnrsti controlled by a frequency divider and shaper duration of the output pulses, and also a switch, a first output connected to the second input of the controllable frequency divider, the entrance controlled oscillator clock frequency is connected to the second output switch The drawing shows the functional diagram of the generator. The generator contains a pseudo-random binary sequence generator 1, a controlled frequency divider 2, a shaper 3 of the output pulse duration, a controlled clock frequency generator 4, a switch 5 and the output bus 6. The device operates as follows. Pulse generator 4 clock pulses control the operation of pseudo-random binary sequence generator 1, and at each clock stroke the generator 4 at the output of pseudo-random binary sequence generator 1 a pulse appears (one) with a probability of p. equal, respectively, to the value of 1 - p. Generator 1 can be performed based on shift registers and generates a pseudo-random binary sequence of maximum length. The pseudo-random impulse flow from the output of generator 1 is fed to the input of a controlled frequency divider 2, the target ratio of which can be changed with the help of switch 5. At the same time, switch 4 controls the frequency of the tracking pulse of generator 4. The output pulses of controlled frequency divider 2 are generated for a duration shaper 3 and arrive at the output bus 6 of the generator. The output of the pseudo-random binary sequence generator is practically uncorrelated (with an accuracy of m | - "1, where S is the period of the sequence) a sequence of zeros and ones of Bernoulli type. The fidelity of Re (N) in terms of H pulses per t clocks of the generator 4 is described by the binomial distribution law (Bernutshn distribution) .. eCSU-Ser Ip) 94 At the same time, the probability P (h) of a sequence of h zeros at the output of generator 1, is determined by the product of the probability P h (o) of the fact that for h cycles there is not a single impulse, and P (-t) that per (h + 1) -th cycle there is one impulse, t . P (V) - Pr (0),) p (.p) h Note that the probability of occurrence of a sequence that does not contain zeros is equal to Р J i. probability of occurrence of a unit. The average value of the length of the sequence: vP (v) - p |: M -)) - -2H-p) of the nature of the zeros y, --0.р. - -aui-rL-.L-- p and its variance is v - 2) - () 2 (-p) 3Vp) V ...- (Wl P / P Let M be the division factor (recalculation) of the divider 2. Since each sequence of zeros (including those not containing zeros) ends in a pulse (one), then the appearance of a pulse at the output of divider 2 means that during the registration of M pulses, successive sequences of zeros occurred (including those that are not contain zeros), separated by one. The total duration of M sequences of zeros is a random variable R, and / how many the sequence lengths are statically independent; the average value is .Jo R-., and the variance is Dv- h-- Tr. Since each zero sequence ends with one, the number: generator L ticks 4 required for the appearance of M successive sequences of zeros the total duration of R,

a time interval in which the L cycles of the generator 4 will take place

in - - (R.-vN),

where is the frequency of the clock generator 4. Thus, the average value of the time interval between the output impulses for the injected device

(RtfA) Ya dispersion of this interval

V, J. t N -P

0 and p4

At the same time, change the frequency f of the generator 4 and the ratio of the target M of the divider 2 using the switch 5 in such a way that

e-tf co., t, -D.fj.i | -,

Those. you can change the variance of the interval O with a constant average. By switching f and M in such a way that the -i OMStv can change the average value of the interval at a constant dispersion of o-AL .p

9- G- -pT --- COV1si

Thus, this generator is practically inertia-free, and in its output signal there is no correlation and error caused by the operation of the automatic control system.

Claims (1)

1. USSR author's certificate in application N 2555973/21, 19,12.77.