SU1252954A2 - Autocorrelational meter of parameters of pseudorandom phase-shift keyed signal - Google Patents

Abstract

The invention relates to telecommunications. The purpose of the invention is to increase the measurement accuracy in case of carrier frequency instability. The device comprises a multiplication unit I, a delay element 2, a band-pass filter 3, a nonlinear element 4, low-pass filters 5, 7 and 11, a tuning rate generator 6, frequency meters 8 and 9, an additional multiplication unit 10, a gate 12, a pulse counter 13, the meter 14 base signal meter 15 duration of the parcels, the arithmetic unit 16, the block registration. The goal is achieved by introducing a mixer 18, an IF amplifier 19, a multiplier 20, a low-pass filter 21, a control element 22, a tunable local oscillator 23. 2 Il. 1

Description

The invention relates to telecommunications, in particular, to devices for processing phase-shift keyed (FMN) signals in discrete information transmission systems, in combined communication systems, in radar and is an improvement of the invention in accordance with the author. S 92P04.

The purpose of the invention is to improve the measurement accuracy in case of carrier frequency instability.

FIG. I presents the structural electrical circuit of the proposed meter; in fig. 2 - time diagrams that show his work.

The autocorrelation meter contains a multiplier 1, a delay element 2, a band-pass filter 3, a non-linear element 4, a low-pass filter 5, a tuning tuning generator 6, a second low-pass filter 7, the first 8 and second 9 frequency meters, the additional block 10 multiplying, third low-pass filter, valve 12, pulse counter 13, signal base meter 14, sprinkling meter 15, arithmetic unit 16 recording unit 17, mixer 18, intermediate frequency snubber 19, multiplier 20, fourth low-pass filter 2 ravl guide member 2 and the tunable local oscillator 23.

The meter works as follows.

The received pseudo-random IMH signal arrives at the first input of the mixer 18, the second input of which is supplied with a voltage tunable

a local oscillator 23. At the output of the mixer 18, 40, the frequency meter 9 indicates the voltage of the combination frequencies. The intermediate frequency amplifier 19 extracts the intermediate frequency signal (Fig. 2b).

This signal is fed to the first inputs of the blocks J and 10 multiplying and remainder 20 directly, and to their second inputs through the corresponding taps of the delay element 2. Moreover, the amount of delay generated at the first tap (first output) of the delay element 2 is varied according to the linear law of the tuning rate by means of a generator 6, which produces a periodic sawtooth control voltage. The magnitude of the delay formed on the second tap (second exit) of element 2 for

The holder is set to a constant and shorter elementary dressing length. The amount of delay formed on the third tap (third outlet) of delay element 2 is fixed and less than the delay on the second tap.

Part of the delay element 2, the multiplier 20 and the low-pass filter 21 perform the functions of the frequency discriminator. If the phase advance during the delay formed on the third tap of delay element 2 is equal to or a multiple of "/ 2", the voltage at the output of the filter 21 is zero. The third tap of delay element 2 determines the transition frequency.

If the intermediate frequency of the IMN signal at the input of the delay element 2 is not equal to the transition frequency, then the output of the low-pass filter 21 is the error voltage, which, through the control element 22, affects the frequency of the tunable local oscillator 23 so that these frequencies are equal .

The result of multiplication in multiplication unit 1 is high-frequency-filled beats that pass through a band-pass filter 3 and a non-linear element 4. Low-pass filters 5 and 7 are connected to 8 and 9 frequency meters, to the second inputs of which the output periodically changes the saw-shaped voltage from generator 6. As a result, from the output of the frequency meter 8, information is taken about the value of the clock frequency (Fig. 2c), and from the output

interstitial frequency, which, together with the frequency of the tunable local oscillator 23, allows to determine the carrier frequency of the received FMN signal

The result of multiplication in the additional multiplication unit 10 is also high-frequency stuffing beats, the envelope of which is enlarged by the AND filter of the lower frequencies.

This envelope is the product (Fig. 2e) of two identical modulating functions (Fig. 2a, d), shifted in time by the amount of delay formed on the second tap of delay element 2.

The number of negative pulses in the signal is equal to the number of phase jumps

3

received FMN signal, and the duration of negative pulses is equal to the shift of the modulating functions and does not depend on the duration of the elementary premises. The voltage (Fig. 2d) from the output of the low-pass filter II is fed to the input of the uni-polar valve 12, at the output of which only negative pulses appear (Fig. 2e). These pulses are counted by the counter-m 13. The number of phase jumps during the duration of the received FMN signal by one exceeds the number of its elementary sums.

The number of phase jumps counted by the counter 13 enters the input of the I4 meter of the signal base, where the signal base is determined. Information about the value of the clock frequency from the output of the frequency meter 8 is fed to the meter 15, where the clock pulses are formed (Fig. 2c), by which the duration

Autocorrelation meter for pseudo-random phomanio-poured signal parameters by author. No. 921104, characterized in that, in order to improve the measurement accuracy when the carrier frequency is unstable, a series-connected mixer, an intermediate frequency amplifier, a multiplier, a fourth low-pass filter, a control element and a tunable local oscillator are inputted into it, the first and second inputs the multiplier is connected respectively to the second input and to the third output of the delay element, and the output of the tunable local oscillator is connected to the fifth input of the recording unit and to the first input of the mixer, the second input of which pry is

Elementary toppings. The measured values of -25 by the input of the autocorrelation signal and the measurement of the base of the signal and the duration l of the parameters of the pseudo-random phase maps are fed into the arithmetic and simulated signal.

Compiled by V. Slepakov Editor A. Kozoriz Tehred I. Veres Proofreader A. Zimokosov

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Order 4632/58 Circulation 624 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

and 125295 4

The virtual block 16, where the duration of the received signal is determined.

Claims (1)

Invention Formula Autocorrelation meter for pseudo-random phomanio-poured signal parameters by author. No. 921104, characterized in that, in order to improve the measurement accuracy when the carrier frequency is unstable, a serially connected mixer, an intermediate frequency amplifier, a multiplier, a fourth low-pass filter, a control element, and a tunable local oscillator are inputted into it, the first and second multiplier inputs connected to the second input and to the third output of the delay element, respectively, and the output of the tunable local oscillator is connected to the fifth input of the registration unit and to the first input of the mixer, the second input of which pry is the input of the autocorrelation parameter and the parameters of the pseudo-random phase parameter of the stimulated signal.