SU1432743A1 - Device for shaping random signals - Google Patents

Abstract

The invention relates to a pulse technique. The purpose of the invention is to enhance the functionality by allowing the formation of signals with a given spectrum. The reference signal with a given spec; The fundamental power density is formed by the shaper 3 of the reference signal. The output driver 4 converts this signal by approximating the power spectral density curve with a step curve) into a random process with a given power spectral density (for example, 1 / R, with). To do this, taking into account the constant value of the relative error of approximation, the necessary ratio of the transmission ratios of the 11.1-11.6 low-pass filters of the output shaper 4 is established, the output of which is set to the adder {2, that provides calibration of the output signal. The operation of the device blocks is coordinated by the control unit 1. The control unit 5 performs the counting and indication of h; the clock pulses per device operation cycle, i.e. for the period of the sequence formed by the shaper 3 of the reference signal. 3 hp f-ly, 1 ill. tC (L 4 00 to h 4 CO

Description

The invention relates to a pulse technique and can be used in metrology and in testing automatic control systems and radio systems.

The aim of the invention is to extend the functionality by providing the possibility of generating signals with a given spectrum.

The drawing shows a functional diagram of a device for generating random signals.

The device contains control BLK1 (consists of parts 1.1 and 1.2), the input of which is connected to the generator output 2 clock pulses, the driver 3 of the reference signal, the output of which is connected to the input of the output driver 4, the control unit 5, whose input connected to the first output of control unit 1 and to the synchronization input of the driver 3 of the reference signal, the first and second inputs of which are connected respectively to the second and third codes of the control unit 1, the group of inputs of which is connected to the corresponding outputs of the driver 3 supports signal.

Control unit 1 contains the first and second triggers 5 and 7, the element AND S decoder 9 and the element OR 10, the first input of which is the second output of control unit 1 and connected to the reset input of the first trigger 6, the output of which is the third output of control unit 1 The first output of which is connected to the output of the AND element 8, the first input of which is connected to the synchronization input of the first trigger 6 and is the input of the control unit 1, the group of inputs of which is connected to the corresponding inputs of the decoder 9, the output of which is connected to the second input element OR 10, the output of which is connected to the input of the installation of the second trigger 7, the output of which is connected to the second input of the element AND 8.

The output coil 1 and 4 contains a group of 11 parallel-connected low-pass filters 11.1-11.6, the inputs of which are the input of the output coder 4, and the outputs are connected to the input of the adder 12.

The control unit 5 contains a series-connected counter 13 pulses and a decoder 14, outputs to

with

5 0 5 About

. „,

.

five

0

five

This is connected to the inputs of the indicators 15. The synchronization input of the counter of 13 pulses is connected to the input of the control unit 5.

The reference signal generator 3 can be implemented, for example, on shift register 16 with modulo 17 adder in the feedback circuit.

A device for generating random signals operates as follows.

Shaper 3 reference signal forms the original random process with a spectral density of power, 3in 2lFfT .1

bones of the form (-2fff. sequence of maximum length. The block 1 controls the signal at the first input of the shaper 3 of the reference signal sets the register 16 of the latter to the initial (nonzero) state.

The pseudo-random signal from the outputs of the reference signal generator 3 is fed to the input of the output generator 4, which forms a random process with a spectral power density of the form at o / 2) from the original M-sequence. This uses the power spectral density curve approximation method. Based on the selected relative magnitude of the relative error of approximation of the logarithmic amplitude characteristic (LFH), a constant ratio of the transmission coefficients of the 11.1-11.6 low-pass filters (CF.1) C5.1 / C0 1 is established, where it corresponds to the low-pass filter at the lower boundary of the formed LHH, - on the upper border. From where, 1, where fg is the cut-off frequency, S-ro low-pass filter (S 1,2, ..., 6). For f f) 2 / s (the upper limit frequency of the generated LAH, which lies within the Sin .1 spectra of the spectrum (.-: j ---.) Of the original M sequence. When set to 1, the required number of low-pass filters 11.1-11.6 is determined by

n (- lgi) 4g | th 4. 1.

For example, for 1 /-noise, i.e. with c 1j with a spectrum limited by frequencies f 10 Hz and 10,000 Hz, having received,

Consequently, the number of components of the low-pass filter. Respectively f, 10 Hz,

f, 10 2 40 Hz, f3 160 Hz, f 640 Hz,

f 2560 Hz, f 10240 Hz, C, 32,

WITH,

C, 1.

16, Cz 8, C 4, Su 2,

At the output of the output shaper 4, an adder 12 is installed, by means of which a level-calibrated output voltage of 1 / f noise is established.

When a single signal arrives at the input (Record 1) of the bis trigger, by arriving at its other input clock pulses from the generator 2 clock pulses at the output of the trigger 6, a single signal goes to the second Input of the shift register 16

When a single signal arrives at the input (start) of trigger 7 on. the output signal appears allowing the signal that arrives at the second input of the element 8. At the first input of the element 8 comes the clock pulses from the generator 2 clock pulses, From the output of the cell And 8 the clock pulses go to the clock input of the shift register 16 - | Furnace the formation of the M-sequence in the imaging unit 3 of the reference signal. In the process of its formation from the output of the element And 8, the clock pulses also arrive at the input of the control unit 5. From the output of the imaging unit 3 of the reference signal, the M-sequence is fed to the input of the output imaging device 4.

When a certain combination is created at the inputs of the decoder 9, the outputs of the driver 3 of the support of the signal at the output of the decoder 9 appear to be a signal through the OR 10 element to the input of the trigger setup 7, which prohibits the passage of the AND 8 clock pulses through the element on block 5 of the control, the number of clock pulses is fixed during the period of the M-sequence

t

 during the same period T ,, on

An analog voltage of a calibrated low-frequency noise with a power spectral density of 1 / f at about 2 is generated at the output of the device.

Claims (4)

1. A device for shaping random signals comprising a clock pulse generator, a reference signal former and an output driver, characterized in that, in order to extend the functionality by providing the possibility of generating signals with a given spectrum, a control unit and a control unit are introduced into it whose input is connected to the first output of the control unit, the second third and first outputs of which are connected respectively to the first, second inputs and to the synchronization input of the driver reference signal, the corresponding outputs of which are connected to the group of inputs of the control unit, the input of the output shaper is connected to the corresponding output of the shaper of the reference signal, the output of the clock generator is connected to the input of the control unit. 2. The device according to claim 1, wherein the control unit contains two triggers, an AND element, a decoder and an OR element, the first input of which is the second output of the control unit and is connected to the reset input of the first trigger The output of which is the output of the control unit, the first output of which is connected to the output of the element I, the first input of which is connected to the synchronization input of the first trigger and is the input of the control unit, the group of inputs of which is connected to the corresponding inputs of the decoder, the output is connected to torym input OR gate whose output is connected to the input for setting the second flip-flop, whose output is connected to the second input element I. 3. The device according to claim 1, characterized in that the output driver contains a group of parallel-connected low-pass filters, the inputs of which are the input of the output driver, and the outputs are connected to the input of the adder. 4. The device according to claim 1, characterized in that the control unit comprises a pulse counter connected in series and a decoder, the outputs of which are connected to the inputs of the respective indicators, the pulse counter clock input is connected to the input of the control unit