SU1363524A1 - Receiver of phase=manipulated signals - Google Patents

Abstract

This invention relates to a radio reception technique and improves noise immunity when receiving weak signals. The device contains a synchronization unit 1, a signal parametron 2, a decisive unit 3, a reference parametron 4, a phase detector 5, a switching unit 6, a synchronized generator 8 consisting of a synchronizer 9 and a generator 10. The shaper 7 MODULATED 1X is reintroduced pulses. 4 W1. with O) co. HCHE 4: Rig. i

Description

This invention relates to a radio reception technique and can be used in radio communications and radio measurements.

The purpose of the invention is to improve noise immunity when receiving weak signals.

FIG. 1 shows the structural electrical circuit of the proposed

receiver; in fig. 2 - diagrams for 10 strains of their appearance. So, when transferring

NINs that show his work; FIG. 3 shows a diagram of a modulating pulse generator; in fig. 4 is a diagram of a decision block.

The receiver of the phase-shift keyed signals (Fig. 1) contains a synchronization unit 1, a signal parametron 2, a decisive unit 3, a reference parametron 4, a phase detector p 5, a switching unit 6, a driver 7 modulating clock 20 clock sync pulses. Subpulses, synchronized generator 8, consisting of synchronizer 9 and generator .10.

Shaper 7 modulating pulses (Fig. 3) contains a standby multivibrator 11 and a phase inverter 12.

Decision unit 3 contains (FIG. 4) a reversible counter 13 consisting of a phase inverter 14 and a read unit 15, two valves 16 and 17, an output trigger 18 and a delay line 19.

The receiver works as follows.

A signal phase noise (Fig. 2a) is fed to the input of the signal parameter 2 (Fig. 1). The same oscillation is fed to the synchronization unit 1, which produces the clock sync pulses (Fig. 2b) determining the boundaries of the parcels and their frequency, and to the synchronized generator 8, which is completed with a precision to a phase, the output oscillation of which (Fig. 2c) is used as a pump voltage for the signal parameter 2 and reference oscarter 4.

In the proposed receiver of phase-shifted signals, the noise immunity of the demodulator itself is increased, and the auxiliary devices - the synchronization unit 1, generating clock sync pulses defining the boundaries of the elementary links, and the synchronized generator 8, generating a reference voltage adjusted to change the frequency of the signal, work the same as known device.

Thus, clock sync pulses can be isolated from the previously detected stream of information symbols.

25 The synchronized oscillator 8 is adjusted to the phase according to the received signal using a frequency doubler and a phase locked loop system that includes a B synchronizer 9. The signal from the output of the synchronizer 9 is used to restore in the generator 10 the carrier suppressed by phase 180 °

3g Signal parameter 2 operates in the mode of multiple excitation of subharmonic oscillations during the duration of the signal sending .. This mode is set by subharmonic pulses (Fig. 2d) affecting switching unit 6, which for an appropriate time deduces signal parametron 2 from regeneration, providing quenching (module -

45) subharmonic oscillations.

At the output of the signal parameter 2, a sequence of subharmonic radio pulses is obtained (FIG. 2 e),

50, the filling phase of these radio pulses can take one of two possible opposite values. This sequence is fed to a phase detector 5, to its second input.

55, a continuous reference frequency clamp of the signal (Fig. 2e) is obtained, which is formed from the oscillation of the pump by dividing its frequency by the reference parameter 4.

Tact (symbol-by-symbol) synchronization of the operation of the proposed receiver is carried out either by specially transmitted signals, which may have a different appearance, or by extracting the clock signals from the information flow of symbols. The method of allocating the transmitted sync pulses of certain sync pulses on a separate carrier, they are separated by filtering and detection. When transmitting a subcarrier whose period or half period is equal to the symbol period, the subcarrier transitions through zero exactly correspond to the initial moments of the symbols. Consequently, the differential brought to the form of a meander subcarrier can be a full way of clock sync pulses can be isolated from a pre-detected stream of information symbols.

25 The synchronized oscillator 8 is adjusted to the phase according to the received signal using a frequency doubler and a phase locked loop system that includes a B synchronizer 9. The signal from the output of the synchronizer 9 is used to restore in the generator 10 the carrier suppressed by phase 180 °

3g Signal parameter 2 operates in the mode of multiple excitation of subharmonic oscillations during the duration of the signal sending .. This mode is set by subharmonic pulses (Fig. 2d) affecting switching unit 6, which for an appropriate time takes signal parametron 2 from the regeneration state , providing blanking (module

45) subharmonic oscillations.

At the output of the signal parameter 2, a sequence of subharmonic radio pulses is obtained (Fig. 2d)

50, the filling phase of these radio pulses can take one of two possible opposite values. This sequence is fed to a phase detector 5, to its second input.

55, the continuous frequency reference of the signal frequency (Fig. 2e) is formed, which is formed from the oscillation of the pump by dividing its frequency by the reference parameter 4.

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The output voltage of the phase detector 5 repeats the shape of the radio pulse envelope (Fig. 2g). At the same time, when the filling phase of the radio pulse coincides with the phase of the reference voltage, it is positive, and in opposite phases it is negative. Thus, the polarity of the video pulses at the output of the phase detector 5 alternates in accordance with the alternation of the filling phases of the radio pulses, i.e. the information contained in the filling phase of the radio pulses goes to the polarity of the amplitude of the video pulses. Video pulses from the output of the phase detector 5 are supplied to decision block 3.

The autosuperse mode, in which the number of signal excitations Parameter 2 for the duration of the signal, and therefore the number of informative samples is maximum, is provided by the driver 7 MO

Yuliruyuschih impulses, which is 25 difference between the number of positive

damping pulses (Fig. 2d) when the amplitude of the excited pulses coming from the output

 phase detector 5, a level sufficient to register them. The damping pulses act on the switching unit 6, which outputs the signal parametron 2 from the regeneration state for a time sufficient to fully quench the excited subharmonic. In a quiet state, the waiting multivibrator 1 1 is locked (Fig. 3). It starts when the amplitude of the video pulses of the blocking voltage is exceeded. For this, the pulses from the output of the phase detector 5 are preliminarily passed through the phase inverter 12, which turns the negative pulses into positive and transmits positive ones. After generating the modulating damping pulse, the standby multivibrator 11 returns to its original stable state. the first state before the next video impulse appears at the input of the triggering level.

The static processing of a sequence of video pulses (Fig. 2g) is carried out by the decision block 3. It works according to the principle of direct calculation of the posterior probability and gives a pulse corresponding to the polarity of the pulses received in greater numbers at the input beyond

35

40

45

50

55

and negative pulses, following from the output of the phase detector 5, with the reading block 15 showing the sign of the difference (1 corresponds to a greater number of positive pulses, O - a greater number of negative pulses).

At the time of the end of the signal element from the output of the synchronization unit 1, a pulse arrives, which opens the valves 16 and 17. Consequently, at the same time, the signals corresponding to the indications of the sign trigger 15 of the reversible counter 13 pass to the inputs of the output trigger 18 and set it to the appropriate position. The same pulse from the output of the synchronization unit 1, after passing through the delay line 19, arrives at the installation of the initial initial state of the reversible counter 13 and prepares it for operation during the next signal element.

This provides the algorithm for the operation of the decision block 3, which consists in issuing a pulse corresponding to the polarity of the pulses received in greater numbers during the duration of the signal element.

Claims (1)

Invention Formula Receiver of phase-shift keyed signals containing synchronization unit 0 time divided by the duration of the elementary sending of the phase-shift keyed signal. This time is set by the clock sync pulses coming from the synchronization unit 1 to the controller unit 3 and controlling the operation of the latter. At the output of decision block 3, the binary code (Fig. 2h) is received, corresponding to the transmitted ones. A reversible counter 13 (FIG. 4) counts the current difference between the number of positive and negative pulses following the output of the phase detector 5 to the phase inverter 14. Positive video pulses are passed to one output of the phase inverter 14 connected to the summing input of the readout unit 15 0, and negative, changing its polarity, passes to another output of the phase inverter, connected to the subtracting input of the reading unit 15. Last and shows current five 0 five 0 five 0 five and negative pulses, following from the output of the phase detector 5, the reading block 15 showing the sign of the difference (1 corresponds to a greater number of positive pulses, O - a greater number of negative pulses). At the time of the end of the signal element from the output of the synchronization unit 1, a pulse arrives, which opens the valves 16 and 17. Consequently, at the same time, the signals corresponding to the indications of the sign trigger 15 of the reversible counter 13 pass to the inputs of the output trigger 18 and set it to the appropriate position. The same pulse from the output of the synchronization unit 1, after passing through the delay line 19, arrives at the installation of the initial initial state of the reversible counter 13 and prepares it for operation during the next signal element. This provides the algorithm for the operation of the decision block 3, which consists in issuing a pulse corresponding to the polarity of the pulses received in greater numbers during the duration of the signal element. Invention Formula Receiver of phase-shift keyed signals containing synchronization unit. whose input is connected to the synchronized generator input and to the information input of the signal parametron, the pump input, the control input and the output of which are connected respectively to the output of the synchronized generator, which is connected to the input of the reference parameter, to the output of the switching unit and to the signal input of the phase detector , the reference input and the output of which are connected respectively to the output of the reference parameter and to the signal input of the decision unit, characterized in that, in order to increase noise immunity when receiving weak signals, a modulating pulse driver is inputted, the input and output of which are connected by a corresponding input signal of the unit, to the control input, the output of which is connected to the output of the synchronization unit, and to the input of the switching unit. but FIG. 2 Fig.Z from 5 Fy