SU1251305A1 - Digital signal regenerator - Google Patents

Description

one

The invention relates to a technique for transmitting digital (discrete) signals but also for communication pins and can be used as terminal and intermediate regenerators of a linear digital signal of multichannel transmission systems with pulse-code or delta modulation.

The aim of the invention is to increase the non-resistance of the regenerator by eliminating the influence of the irregularity of the operating time and reducing the influence of high-frequency noise numbers at the point of the regenerator.

FIG. 1 shows a functional diagram of the regenerator; in fig. 2 - time diagrams of work (or basics) on voltage plots.

The digital signal regenerator consists of the amplifier-corrector 1, the AGC device 2 in the feedback circuit, the analog keys 3-6, the integrator 7, the coincidence element 8, the first 9 and second 10 analog memory cells, the subtraction unit 11, the averager 12 controlled generator 13 phase shifter 14, a short pulse shaper 15, a threshold shaper 16, a threshold averager 17, and an output shaper 18.

Moreover, the amplifier-corrector 1, the AGC device in the feedback circuit 2, the first key 3, the threshold generator 16, the threshold averager 17, the integrator 7, the fourth key 6, the coincidence element 8, the output signal generator 18, form the digital signal regeneration channel, and the second 4 and third 5 analog keys, analog cells 9 and 10 memory, and subtraction unit 11, averager 12, a controlled oscillator 13, a phase divider 14 and a short pulse shaper 15 constitute a device for automatically adjusting the phase of clock pulses, the outputs of which are connected coincidence with the element 8 and to a control input of the second analog switch 4.

In this case, the amplifier-corrector 1 with the AGC circuit 2 in the feedback is cascaded together; with the coincidence element 8, the output of which is connected to the input of the output signal generator 18, with the control unit 1, with the input of the first analog switch 3, whose signal input is connected to the first input of the coincidence element 8, and the output through the torque generator 16 and the averager 17 The threshold is connected to the input control circuit APi 2, and the digital signal regenerator contains the second and third analog switches 4 and 5, the signal inputs of which are connected to the output of the amplifier — corrector 1, and the outputs, respectively, through the 9 k; 1 and 10 memory slots are connected from the entrance The subtractive unit 11, the output of which through the averager 12 is connected to the control input of the controlled generator 13, the direct and inverse outputs of which, respectively

 B

0

connected to the control inputs of the bunks of analog switches 4 and 5, and the short pulse shaper 5 is connected to the second input of the coincidence element 8. In addition, 5 regenerator entered the integrator 7, the fourth analog switch 6 and the phase shifter: 4 so that the input of the integrator 7 is connected to the output of the amplifier-corrector 1, and the output to the first input of the match element 8 and the signal inputs of the first 3 and second 4 analog keys The output of the fourth analog switch 6 is connected to the common NINA, and the control input to the input of the short pulse shaper 15 and the output of the phase shifter 14, the input of which is connected to the direct output of the controlled oscillator 13.

The regenerator works as follows: M.

Corrected and amplified signal

19 (Fig. 2) with the amplifier-corrector 1 (Fig. 1) is fed to the input of the integrator 7, as well as to the inputs of the analog switches 5 and 6. The reference inputs of the keys 4 and 5 receive reference pulses

20 and 21 (FIG. 2) from the direct and inverse: on the outputs of the controlled generator 13. As a result, the outputs of the keys 4 and 5 form pulses 22 and 23 (average energy), which by means of analog cells 9 and 10 of memory These and subtracting units 1 i are constantly c) annihilated. If the sequences 22 and 23 (average energies) are equal, the averager 12 from the output of the subtractor is 11; its block 1 enters an "average zero GOK and the output voltage of the averager 12 does not change the frequency of the controlled oscillator 13. This state corresponds to the coincidence of the fronts of the op () ph1) 1x and pulses 20 and 21 from the moment of maximum information impulses 19 (Fig. 2). In the case of phase shift of the reference pulses 20 and 21, relative to informational 9, the average values of the energy of sequences 22 and 23 will begin to differ, this difference will be highlighted by the subtractive unit 1 1 and through the average} n-1 12 will change the frequency of the controlled | -generator 13 so that the fronts of the reference pulses 20 and 21 are again combined with

Centers - Informa 1ION of ul ulsov 19.

Thus, the operation of the autonodging phase 1e of the variable generator 1 swells as well as in the device-prototype.

The pulses 20 are used. Tl formir () (with the form of a mirovatblYa short pitch) pulse 15) and pulses 26 (fi 1, 2). They are 24 and 26 and are used to control the analog key 6 and the element 8 of the auxiliaries, respectively, which are included in the iiei) regenerator 1i, signal.

The chain .ii works as follows ob5) azo.m.

The corrected impulses arrive at the input of the integrator 7, which, by means of the fourth key 6, is turned on by the PULS 20 for a time of 0.5 Tt, i.e. in the presence of the maximum received current signal.

Thus, as a result of the integration, the average energy of the premise is determined over a time of 0.5 Tt. At the end of this interval, the obtained result is tested by applying to the second input of the element 8 coincidence short pulses 26.

Thus, the method of a single counting of the received signal is replaced by a method of accumulating and analyzing the energy of each parcel. As a result, the dependence of the signal-to-noise ratio on the phase shift between the time of testing and the time of maximum of the signal is eliminated, which reduces the dependence of the noise immunity of the regenerator on the phase jitter and the inaccuracy of the clock selection circuit. In addition, at the output of the integrator 7, there is a gain in the signal-to-interference ratio, which is greater, the wider the interference frequency band at the integrator input. The threshold voltage is formed from the average values of the unit premises of the information signal by closing the key 3 with pulses 27 (Fig. 2), coming from the output of coincidence element 8. The pulses 27 also control the operation of the output signal generator 18, the output signal 28 of which enters the line.

The signal-to-noise ratio at the output of integrator 7 is determined by the following formula:

qsux 2TFqBx,

where qeux is the signal-to-noise ratio at the output of the integrator 7 or at the input of the circuit 8, coincidence;

T is the integration period,, 5Tt;

F is the interference bandwidth;

qex is the signal-to-noise ratio at the input of the integrator 7 or at the output of the amplifier-corrector 1.

This shows that the gain obtained by integrating is the greater, the wider the interference frequency band at the input of the integrator 7.

Thus, compared with the prototype regenerator, the proposed regenerator reduces the effect of non-optimal test times on the regeneration noise immunity; reduces the effect of high-frequency noise present at the output of the amplifier-corrector on the reliability of the decision in the resolver; increases the accuracy of the threshold level selection by reducing the effect of high-frequency noise on the threshold formation circuit.

These advantages can significantly increase the noise immunity of the proposed device in comparison with the prototype.

nineteen

2G

2

LH

fig 2

C () Art; 1vits.1b K- (l dv

Tehrsl I. VeresKorrektor V. But ha

Circulation 816 Subscription

VNIIPI USSR State Committee

for inventions and discoveries

113035, Moscow, F - 35, 4/5 Rauglska nab.

Branch PGSH "Patent, Uzhg-town, ul. Project, 4

Claims (1)

A DIGITAL SIGNAL REGENERATOR containing an amplifier-corrector with an AGC circuit in feedback, cascaded to a coincidence element, the output of which is connected to the input of the output signal shaper and to the control input of the first analog key, the signal input of which is connected to the first input of the coincidence element, and the output through the threshold shaper and the threshold averager are connected to the control input of the AGC circuit, as well as the second and third analog keys, the signal inputs of which are connected to the output of the amplifier-corrector, and the outputs with responsibly, through the memory cells, they are connected to the inputs of the subtracting unit, the output of which through the averager is connected to the control input of the controlled generator, the direct and inverse outputs of which are respectively connected to the control inputs of the second and third analog keys, and a short pulse shaper whose output is connected to the second input of the coincidence element , characterized in that, in order to increase noise immunity, an integrator, a fourth analog switch and a phase shifter are introduced into it, while the input of the integrator is connected to the output of the amplifier-corrector, and the output is to the first input of the matching element and the signal inputs of the first and fourth analog keys, and the output of the fourth analog key is connected to a common bus, and the control input is connected to the input of the short-pulse driver and the output of the phase shifter, the input of which is connected with direct output of a controlled generator.