SU440801A1 - Device for auto-selection of in-phase sequence of synchronization pulses when receiving signals with phase-difference manipulation - Google Patents

Description

one

The invention relates to radio engineering and can be used to receive telemetry information transmitted by the method of phase difference manipulation on a subcarrier frequency, the period of which is equal to the duration of the symbol.

Methods of receiving signals with phase difference manipulation, for example, a correlation receiver of signals with a single phase difference manipulation, are known.

However, using phase difference difference keying signals transmitted on the subcarrier frequency, the period of which is equal to the duration of the manipulating sign, at the output of the sync signal extraction circuit, after correspondingly dividing the synchronization frequency, two grids of synchronization pulses are shifted halfway across the other. For optimal processing of the telemetric signal in the path of the information extraction, only the grid of sync pulses should be used, phased with the ends of the telemetry signal sendings. Thus, it is necessary to solve the problem of choosing a phased synchronization grid in the presence of noise interference.

The purpose of the invention is to increase the interference-noise. the stability of the synchronization system by automating the process of selecting the in-phase sequence of synchronization pulses and optimizing the selection of control voltages when operating in conditions of small signal-to-noise ratios.

For this purpose, the outputs of the comparator are connected to the output adder via keys, the second inputs of which are combined with the discharge inputs of the discharge integrators.

The essence of the proposed device

is that the selection of a phased synchronization pulse grid is performed automatically using a control voltage obtained from the telemetry information signal by interrogating integrators in two channels of one common mode and the other of antiphase grids of sync pulses, differentiating the received signals in each channel while maintaining amplitudes, accumulated by the integrator at the time of the survey,

converting differentiated signals to one polarity, expansion and narrowband filtering.

FIG. 1 shows a diagram of the proposed device; in fig. 2 - depicted diagrams

voltages for the operation of the device. The device contains it: a phase detector (multiplier) and a sync pulse isolation circuit 1, unloadable integrators 2 and 3, differentiating circuits 4 and 5, full-wave diverters 6 and 7, extenders

(logarithm) 8 and 9, narrow-band filters 10 and 11, a decision circuit (comparator) 12, keys 13 and 14 and an output adder 15.

The signal of relative phase telegraphy on the subcarrier, the period of which is equal to the duration of the manipulating sign, is fed to one of the known OFT 1 signal reception circuits 1. From the output of the phase detector of this scheme, the OFT code (plot a) is fed to the inputs of two integrators 2 and 3. From the output of the device synchronization of circuit 1, two grids of synchronization pulses, FZ, one of which is phased with the ends of the OFT code packages (plot c), and the other one shifted by half a beat (plot u), are fed to the bits of the corresponding integrators 2 and 3, as well as to the keys 13 and 14. Cumulative The signals integrated by the integrators are differentiated into chains x 4 and 5 (diagrams m, n), are brought to the same polarity with the help of full-wave rectifiers 6 and 7, are expanded (diagrams o, n) are filtered using filters 10, 11 and the resulting constants These voltages are compared at comparator 12. Greater control voltage, despite the presence of noise, will always be in the channel, due to optimal signal processing, where the integrator is polled by a phased clock wave. This voltage controls the corresponding switch 13 or 14, which passes to the output of the device after the output adder 15 a phased synchronization grid.

Subject invention

A device for auto-selecting an in-phase sequence of synchronization pulses when receiving signals with phase-difference manipulation transmitted on a subcarrier frequency, the period of which is equal to the duration of the manipulating sign, containing two channels, in each of which the discharger integrator, a differentiating circuit, a full-wave rectifier, a extender and a narrowband A filter connected to the comparator, characterized in that, in order to improve noise immunity, the outputs of the comparator are connected to the output th adder via keys, the second inputs of which are combined with the discharge dnymi inputs said integrators.

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