SU1054923A1 - Phase-manipulated signal demodulation device - Google Patents

Abstract

i. A DEVICE FOR DAMPLATING A PHASE-MANIPULATED SIGNA-LA containing a trigger connected in series to an fi ltr limiter, an inverter, a nepetxtt key and the first counter; , oVT l and I am sure that, with the aim of raising; Noise immunity strings, a comparison block was introduced, 1111 and a Frastf f & Element And, pulse shaper,; two elements SHS and a level detector, the output of the limiter is connected; to the INPUT level detector and pulse generator / pulse generator, the first output of which through the first element OR is connected to the second inputs of the counters whose outputs are connected to the inputs of the comparator unit, the outputs of which are connected to the first inputs And elements and to the inputs of the remote analyzer, the output of which is connected to the second inputs of the elements AND, the output of the detector uOv is connected to the second input of the first element OR and to the first input. The second element OR, the second input and output of which They are connected respectively with the output of one ele- ment (Lent I and with the first input of the trigger, the second input of which is connected to the OT yrOkro outputs of the I element, and the second, the output of the pulse former is connected to the control input of the comparison unit sd s N5 M

Description

2. The device of claim 1, which is tactile, is that the level detector consists of a series-connected threshold unit, an inverter and a trigger, the second input of which is connected to the output of the threshold unit, the input of which is the input of the level detector whose output is trigger output.

The invention relates to radio and wired telegraph communication and can be used to transmit discrete information.

A device for modulating a phase-shift keyed signal containing a series-connected band-pass filter and a limiter, a deciding unit and a synchronization unit, a reference signal generating unit whose output is connected to the input of a phase comparison unit, a differentiating circuit, a phase determination unit and a reference signal adjustment unit I.

A disadvantage of the known device is low noise immunity. due to the possibility of a loss of synchronization by it of false synchronization in the chain of creating a reference signal.

The closest to the invention according to the technical solution is a device for demodulating a phase-shift keyed signal containing a trigger and a series-connected filter, limiter, inverter, first key and first counter, while the output of the limiter through the second key is connected to the first input of the second counter, and the output of the pulse generator is connected. to the second inputs 1M of the first and second keys 2J,

A disadvantage of this device is low noise immunity due to an abrupt change in the phase of the carrier oscillation only at zero crossing of the carrier oscillation, which, when transmitting information through channels with a higher noise level, leads to the appearance of phase discontinuities in the received signal not compensated by the low-pass filter. The reduction in noise immunity also occurs due to false formations of fronts under the influence of interfering signals with a frequency that is an Integer number of times lower than the frequency of the working signal and due to the absence of the trigger setting in the initial state.

The purpose of the invention is to improve noise immunity.

The goal is achieved by the fact that a device for demodulating a phase-shift keyed signal containing a trigger and a series-connected filter, limiter, inverter,

the first key and the first counter, with: THIS OUTPUT is limited through the second key is connected to the first input of the second counter, and the generator output

Q pulses are connected to the second inputs of the first and second keys, a comparison block, a decoder, two AND elements, a driver, pulses, two OR elements, and a level detector are input, with the output of the limiter connected to the detector inputs. level and pulse former, the first output of which through the first element OR is connected to the second input. I will give the meters whose outputs are connected to the inputs of the comparison unit, the outputs of which are connected to the first inputs of the AND element and to the inputs of the decoder, the output of which is connected to the second inputs of the elements AND,

5, the output of the level detector is connected to the second input of the first OR element and to the first input of the second OR element, the second input and output of which are connected respectively to the output

0 of one element And with the first input of the trigger, the second input of which is connected to the output of another element And, and the second output of the driver and pulses is connected to the control input

5 remote control units compare.

In addition, the level detector consists of a series-connected threshold unit, an inverter and a trigger, the second input of which is connected to the output of the threshold unit, the input of which is the input of the level detector, the output of which is the output of the trigger.

FIG. 1 shows an electrically functional diagram of the device; in fig. 2 - stress diagrams for his work.

A device for demodulating a phase-shift keyed signal contains a filter 1, a limiter 2,

the first and second counters 3 and 4, the pulse generator 5, the first and second keys 6 and 7, the inverter 8, the trigger 9, the comparison block 10, the decrypt-. a rator 11, two elements 12 and 13 AND, a driver of 14 pulses, the first and second elements 15 and 1b of OR, and a level detector 17, which consists of a threshold unit 18, a trigger 19 and an inverter 20.

Device - works as follows.

The input phase-shift keyed signal (Fig. 2a) after filtering in filter 1 is fed to limiter 2. The received rectangular pulse sequence is fed directly to the first input of the second key 7 (Fig. 26i, the first input of the first key b through the inverter 8 (Fig. 2c), as well as to the inputs of the imaging unit 14 and A1pulses and the level detector 17. At the same time, the signal that held the elements 15 and 16 OR trigger 9 and counters 3 and 4 in the initial state is output from the output of the level detector 17. When the first inputs of keys b and 7 are affected sequence to them pulses from the output of the limiter 2 are provided by pulses from the output of the generator 5 pulses by counters 3 and 4. In the absence of phase jumps in the generated pulse train, the counting time of both counters 3 and 4 is the same and equals half of the period of the pulses. 4, in this case, also coincide. Pulse shaper 14 generates two control pulses, the first of which corresponds to the end of the pulse sequence period, and the second one has a time shift tnositelno first. The first control pulse is sent to the control input of the comparison unit 10 (Fig. 2d, allowing determination of the degree of mismatch of states. (Calculation 4Hcejjl of the first and second counters 3 and 4, idetection of the sign of this difference and decryption of the difference value by the decoder 11. In case of coincidence The ria states of the corresponding outputs of counters 3 and 4 do not form signals at the outputs of elements 12 and 13, since the comparison unit 10 gives a zero value of the difference.

The phase jump in the pulse train is reflected as a violation of the pulse and pause correlation attributable to the period of the sequence. The consequence of this is a mismatch of states (violation of equality of numbers) on the corresponding outputs of the first and second counters 3 and 4, the appearance at the outputs of the comparator block 10 at the time of the first impulse of the signal control, which uniquely corresponds to a certain difference the numbers of the first and second counters are 3 and 4, and the signal at one of its additional outputs, fixing in which counter the number is greater. Decoder

0 11 at certain values of the signal fed to it from comparison unit 10, i.e. at certain values of the phase jump, it generates an output signal, which, depending on the signal at the additional outputs of the comparator unit 10, is supplied either through element 12 AND to the second input of the second element 16. OR (Fig. 2e) or through element 13 AND

Q to the second input of the trigger 9 (fig.2zh). These signings form the fronts of the transmitted information parcels and according to them the trigger 9 performs the registration of information (Fig. 2h).

e At the end of the first control pulse, the pulse shaper 14 forms a second control pulse, which is supplied through the first element 15 OR to the second I inputs of the first and second counters.

 s and 4 (fig. 2d). This pulse returns the counters 3 and 4 to the initial state and the cycle of operation of the device is repeated.

At the end of the exchange process

5 (with no input signal), the level detector 17, consisting of a threshold unit 18, trigger 19 and inverter 20, generates at its output a signal that holds

0 counters 3 and 4 and trigger 9 in the initial state before the start of the next exchange.

The technical and economic effect 5 of the invention consists in increasing the noise immunity due to the continuous operation of the counters, which is equivalent to synchronous phase detection. In addition, as a result of the formation of fronts of transmitted information packets, by detecting the duty cycle of the pulses formed from the source signals, failures in the formation of the SII of the fronts of the transmitted messages occur when the appearance of phase discontinuities at the moments of phase discontinuities of the carrier wave. The device also provides with: information with a variety of often-. tami carrier oscillation due to the detection of the complexity of the pulses with counters l block comparison.

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Claims (2)

1. DEVICE FOR DEMODULATION OF THE PHASOMANIPULATION SIGNAL, containing a trigger and serially connected filter, limiter, inverter, first key and first counter, while the output of the limiter through the second key is connected to the first input of the second count-. the output of the pulse generator is connected to the second inputs of the first and second keys, except that in order to increase the noise immunity, a comparison unit, a decoder, two elements And, a pulse shaper, are introduced; two elements OR and a level detector, and the limiter output is connected; to the inputs of the level detector and the pulse generator, the first output of which through the first OR element is connected to the second inputs of the counters, the outputs of which are connected to the inputs of the comparison unit, the outputs of which are connected to the first inputs of the AND elements and to the inputs of the decoder, the output of which is connected to the second inputs of AND elements, the output of the level detector is connected to the second input of the first OR element and to the first input of the second OR element, the second input and output of which are connected respectively to the output of one AND element and to the first input of the trigger , the second input of which is connected to the output of another AND element, and the second, the output of the pulse shaper, is connected to the control input of the comparison unit. SU .... 1054923 2. The device according to π. 1, wherein the level detector consists of a threshold block, an inverter and a trigger connected in series, the second input of which is connected to the output of the threshold block, the input of which is the input of the level detector, the output of which is the trigger output.