SU1061278A2 - Automatic discriminator of periodic pulse sequences - Google Patents

Abstract

AUTO SELECTOR OF PERIODIC SEQUENCE OF IT- PULSES by author. St. No. 824470, differing in that, in order to increase the speed in terms of the change in the signal-to-noise ratio, a control signal shaper is introduced, the first input of which is connected to the input of the strobe unit, the second input is connected to the output of the control unit; the third input is connected to the output of the gate driver, the auxiliary output of which is connected to the fourth input of the driver of the gate, their signals, the output of which is connected to the auxiliary input of the narrowband analyzer. (L o to 00

Description

The invention relates to telecommunications, in particular to synchronization devices, can be used in systems for transmitting information, in monitoring and control devices. According to the main author. St. No. 824470 is known a periodic pulse sequence autoselector containing a serially connected gating cascade, a narrowband analyzer, a matching cascade, a controlled comparator, a delay element, and a gate driver, the output of which is connected to the second input of the gating cascade, between the output of the controlled comparator and the input of the gating cascade , a circuit for tracking and automatic phase adjustment is included, consisting of the second element of a series of delays of $ 1 and a half-body and a pulse-phase detector, the output of which is connected to the second input of a controlled comparator, are connected in series by an additional controlled comparator, an additional delay element, an additional driver of half-strobes and an additional pulse-phase detector whose output is connected to another input of the narrowband analyzer, and the input of an additional controlled the comparator is combined with the input of the controlled comparator, and the other input of the additional pulse-phase detector is about combined with another input of the pulse-phase detector, serially connected control unit and extension, the input and output of which are combined respectively with the first input and output of the gate stage, and the input of the control unit is combined with the inputs of the first and second delay elements 1. The disadvantage of this auto-selector is a periodic pulse sequence This is a low response rate in a noisy environment. This leads to the fact that the auto-selector of a periodic sequence of pulses irrationally uses its dynamic characteristics, which under certain conditions, especially when the signal-to-noise ratio h changes towards an increase, can lead to an unjustified deterioration in the quality of the transient process, decrease in speed. The purpose of the invention is to increase the speed in terms of measuring the signal-to-sound ratio. This goal is achieved by the fact that the auto-selector of a periodic pulse sequence, which contains a serially connected gating cascade, a narrowband analyzer, a matching cascade, a controlled comparator, a delay element and a gate driver, the output of which is connected to the second input of the gating cascade, between the output of the controlled comparator and an entrance for the gating cascade is included a circuit for tracking and automatic phase adjustment consisting of the second element connected in series a delay detector, a half-shaper, and a pulse-phase detector, the output of which is connected to the second input of a controlled comparator, an additional controlled comparator connected in series, an additional delay element, an additional half-shaper former, and an additional pulse-phase detector, whose output is connected to another input of the narrowband analyzer , with the input of an additional controlled comparator combined with the input of a controlled comparator, and the other input of an additional impulse The blue phase detector is combined with another input of the pulse phase detector, the control unit and extension cable connected in series, the input and output of which are combined respectively with the first input and output of the gating stage, and the input of the control unit are combined with the inputs of the first and second delay elements , the first input of which is connected to the input of the gate unit, the second input is connected to the output of the control unit, the third input is connected to the output of the gate driver. the auxiliary output of which is connected to the fourth input of the control signal generator, the output of which is connected to the auxiliary input of the narrowband analyzer. I FIG. Figure 1 shows the structural electrical diagram of the auto-selector of a periodic pulse sequence; in fig. 2 - structure-electric circuit of the control signal generator; in fig. 3 - diagrams explaining the operation of the auto-selector of a periodic pulse sequence. The autoselector of a periodic sequence of pulses contains a gating cascade 1, a narrowband analyzer 2, a matching cascade 3, controlled comparators 4 and 5, delay elements 6-8, shapers 9 and 10 half-gates, pulse-phase detectors 11 and 12, shaper 13 gates, extension cable 14 , control unit 15, driver 16 control signals. The control signal generator 16 includes keys 16-1, 16-2, 16-3, averaging blocks 16-4, 16-5, subtraction block 16-6, division block 16-7, voltage generator 16-8. Autoselector periodic sequence of pulses works as follows.

At the initial moment of operation, narrowband analyzer 2 is in the unexcited state, the control signal to the gate cascade 1 is not applied, and it passes the entire mixture of signal and interference from the input of the auto-selector to a periodic pulse sequence, and to the input of the narrowband analyzer 2 is fed through an extension cable 14. Control The signal at the second input of the narrowband analyzer 2 is such that its central tuning frequency exactly corresponds to the frequency of received pulses. Narrowband analyzer 2, when excited, selects the first harmonic of the tracking frequency through the mixture arriving at its input, which, acting through the matching stage 3 on the control comparator 4, is converted into a sequence of clock pulses.

The sequence of clock pulses from the output of the controlled comparator 4 is fed to the delay element 6, which establishes the phase relations necessary for normal operation between the received sequence of clock pulses at the output of the controlled comparator 4 and then goes to the gate generator 13, which converts the input sequence of clock pulses into a sequence of strobe pulses used for control of the gating cascade 1, which is activated and begins to pass narrowly to the input band analyzer 2 received the mixture only in the time intervals of the expected arrival of the useful signal.

This sequence of gating pulses is also used to control the keys 16-2 and 16-3 of the control signal generator 16, and the sequence of gating pulses arriving at the second input of the key 16-3 is generated with some delay in relation to the pulses arriving at the second key input 16-2 (Fig. 3.2 and 3.3).

To more accurately determine the moment of arrival of the useful signal, a circuit is used for tracking and automatic adjustment of small phase fluctuations, for which the signal from the output of the controlled comparator 4 is fed through delay element 7 and shaper 9 half-strokes to the pulse-phase detector 11, to the second input. which receives a signal from the input of the strobe cascade 1. The pulse-phase detector 11 compares the energy of the parts of the input pulses belonging to each of the half-strobes and generates a control signal proportional to the phase error of the sequence of pulses input to the auto-selector, 5 of a periodic pulse train and a sequence of clock pulses generated by a controlled comparator 4.

This control signal changes the moment of fixation of the alternating voltage transition from the output of the narrowband analyzer 2 through the level set by the control signal in the direction of decreasing the phase error.

A change in the frequency of the received sequence causes the appearance of an additional phase shift, which cannot be compensated by a change in the comparison threshold in the controlled comparator 4.

The output signal from the matching stage 3 is fed through a controlled comparator 5, a delay element 8 and a shaper of 10 half-strokes to a pulse-phase detector 12. The latter compares the energy of the parts of the input pulses belonging to each of the half-strobes, and generates a control signal proportional to the phase mismatch of the pulse sequence at the output of the controlled comparator 5 and the pulse sequence fed to the input of the auto-selector of the periodic pulse sequence. This control signal changes the resonance frequency of the narrowband analyzer 2 in the direction of decreasing the error. Since the inertia of the narrowband analyzer 2 is high when the center frequency changes, the circuit for tracking and auto-tuning of phases monitors the slow fluctuations of the frequency of the received signal, eliminating the possibility of out-of-band control of the circuit for tracking small fluctuations in phase.

In the case of synchronization failure (absence of gating pulses at the control input of the gating circuit YES 1) the signal and interference mixture from the input of the auto-selector of the periodic pulse sequence to the input of the narrowband analyzer 2 does not pass, however, this mixture of signal and interference enters the input of the narrowband analyzer 2 through the extension 14.

In the established mode, the control signal from the output of the control unit 15 simultaneously enters the second input of the extender 14, sets the division factor K accordingly, and the second input of the key 16-1 of the control signal generator 16, which turns on and starts to pass the received mixture of periodic signal and noise (Fig. 3.1) From the input of the auto-selector of a periodic pulse sequence to the first inputs are keys 16-2 and 16-3, which pass this mixture only during the time intervals of the gating x pulses on their second inputs. Thus, at the output of the switch 16-2, a sequence of useful pulses is formed in mixture with the noise inside the interval of existence of these DC + Urn pulses (Fig. 3.4). At the exit

The key 16-3 forms a periodic sequence of noise segments at intervals of the existence of gating pulses Um (Fig. 3.5). Formed sequences of pulses go to the inputs of the averaging blocks 16-4 and 16-5, respectively, at the output of which signals Uc -f Uid and Uiu are formed (Fig. 3.6 and 3.7). The signals from the outputs of the averaging blocks 16-4 and 16-5 are fed to the inputs of the subtraction block 16-6, the output of which forms a signal corresponding to the average value of the useful component Uc (Fig. 3.8). The signal from the output of block 16-6 of the subtraction is fed to the first input of block 16-7 division, the second input of which receives a signal from 1 output of block 16-5 averaging, i.e. the average value of the noise component of the received signal. A dividing unit 16-7 thus measures the ratio between the usable and the noise components of the received signal. The signal from the output of dividing block 16-7 (Fig. 3.9) is fed to the input of voltage generator 16-8.

The technical and economic efficiency of the auto-selector of a periodic pulse sequence is to increase the speed with a change in the signal-to-noise ratio.

Claims (1)

AUTO SELECTOR OF PERIODIC SEQUENCE OF IM- j PULSE according to ed. St. No. 824470, characterized in that, in order to improve performance in terms of changing the signal-to-noise ratio, a driver of control signals is introduced, the first input of which is connected to the input of the gating unit, the second input is connected to the output of the control unit; the third input is connected to the output of the gate generator, the additional output of which is connected to the fourth input of the driver of control signals, the output of which is connected to the additional input of the narrow-band analyzer.