SU896789A1 - Quasicoherent demodulator of phase telegraphy signals - Google Patents

Description

(54) QUASNIC-GERTAIN DEMODULATOR SIGNALS

one

The invention relates to communication technology and can be used in a discrete communication system with phase shift manipulation.

A quasi-coherent demodulator of phase telegraphy signals is known, containing serially connected input regenerator, front-edge selector of pulses and phase discriminator, the outputs of which are connected to the control inputs of the add-exclusion unit, the signal input of which is connected to the output of the master oscillator, and the output through control the divider is connected to another input of the phase discriminator and to the counting input of a binary counter, the output of which is connected to one of the signal inputs of the output o phase detector p.

However, the known demodulator has a low noise immunity. PHASE TELEGRAPHY

The purpose of the invention is to increase the noise immunity by compensating for the parasitic phase signal.

To achieve this goal, in a quasi-coherent demodulator of phase telegraphy signals containing series-connected input regenerator, front-edge selector pulses and phase discriminator, the outputs of which are connected to the control inputs of the pulse-exclusion unit, the signal input of which is connected to the output of the master oscillator output through controlled divider connected to another input

15 phase discriminator and to the counting input of a binary counter, the output of which is connected to one of the signal inputs of the output phase detector, the output phase detector is made in

20 as a parallel register, the other signal inputs of which are connected to the additional outputs of the binary counter, and the synchronization inputs are connected to the output of the selector in front of it of the pulse edge. The drawing shows a structural electrical circuit of the proposed demodulator. A quasi-coherent demodulator of phase telegraphy signals contains a Vrg I regenerator, a front-of-the-pulse detector 2, a control divider 3, a binary counter 4, a phase discriminator 5, a master generator 6, an add-exclusion pulse unit 7, and an output phase detector, a master oscillator 6, an add-exclusion pulse 7 unit, and an output phase detector, a master oscillator 6, an add-exclusion pulse 7, and an output phase detector parallel register 8. The demodulator operates as follows. From the input to the input regenerator 1 of a phase-manipulated sinusoidal signal, rectangular pulses are generated at its output, reflecting the time distribution of the signal’s polarity, which are converted by the selector 2 of the leading edge of pulses into ultrashort pulses corresponding to the leading edge of the original pulses applied to its input and the instants of time tj, at which the phase of the demodulated signal reaches a multiple of 2πH, - These ultrashort pulses are fed to the input of a discrete signal phase-locked loop (PLL) designed to receive a pulse signal of a frequency 2 times higher than the frequency of the demodulated signal, where n is the multiplicity of phase manipulation and consisting of controlled divider 3, block 7, generator 6 and the phase disc of the discriminator 5. By entering the input of the phase discriminator 5, they ensure the formation of impulses at its output that correspond to the rule for determining the sign of the phase mismatch of the AH-i signfu, (chg; where H is 0; 1 - the value of the signal at the output of the controlled divider 3 at time t. Trimming pulses are fed to the control inputs of block 7, which realizes them, by changing the phase of the signal at the output of the controlled divider to

Claims (1)

Phase-mismatch compensation. A pulse signal from the control output is connected to the additional outputs of the binary counter, and the synchronizing inputs are connected to the output of the divider 3, the dynamic input (state change on the leading edge) of the counting input of the binary counter 4 ensures that at the output of its higher bit of a signal, which differs from a quasi-coherent only by a constant positive phase shift equal to half a step of manipulation, which causes The state of binary counter 4, corresponding to) the maximum likelihood of the phase of the demodulated phase telegraphy (FT) signal, which is impulse from the output of the leading edge of the pulses 2 is written to the parallel register 8. Thus, since the phase shift in the front-end regenerator-selector circuit the pulse front, which is characterized by slow drift, caused by changes in the working conditions of the elements and their natural aging, is monitored by a discrete PAL ring, then between signals, upayuschimi to parallel inputs of the register which performs the function of the phase detector will not occur parasitic phase shift, reducing the noise immunity quasi-coherent signal demodulation CFT torus. The claims quasi-coherent demodulation torsignalov phase telegraphy comprising serially coupled an input regenerator extractor leading edge pulse and a phase discriminator which outputs are connected to the control inputs of the exclusion pulse adding unit, a signal input coupled to an output of the master oscillator, and an output via controllable divider connected to another input of the phase discriminator and to the counting input of a binary counter, the output of which is connected to one of the signal inputs in the output phase detector, characterized in that, in order to increase noise immunity by compensating for parasitic phase shift, the output phase detector is made in the form of a parallel register, other signal inputs 5896789 home of the front-end distinguisher 1. 1. Buhviner V.E. Discrete circuits Information sources. Connection 1969. p. 88-95 (taken into account in the examination of the type). in phase radio communication systems, and.,