SU449453A1 - Method of integrated reception of signals of frequency telegraphy - Google Patents

Description

(54) METHOD FOR INTEGRATED RECEIVING SIGNALS OF FREQUENCY TELEGRAPHY

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This invention relates to a radio receiver; technology.

Known methods of integrated reception of the signals of frequency telegraphy, based on the integration of the send and from. compressed by two identical channels, and the formation of output pulses after comparing the results of integration.

The circuit of the invention — an increase in the noise immunity of the integral reception with deep selective fading — is achieved in that according to the proposed method, this and the preceding premises are additionally compared in the pressing and pressing channels and the sign of the transmission is determined by the result.

If Tdin channel, for example, works, press), which corresponds to the complete closure of the second channel (release), the decision to change the noiCbinica sign (the transition from the click frequency to the release frequency is taken due to the absence of a signal from this package).

; FIG. 1 shows a block diagram of an apparatus for integrated reception of frequency telegraphy signals by the proposed method in FIG. Figure 2 shows the diagrams of signals at different points of the channel (in the canape of the release, the signals are similar).

The diagram contains the receiving device 1

, and two channels, in i of each of which there are electronic terminals 2 and 3, integrating circuits 4 and 5, trigger 6, differentiating elements 7 and 8, the circuits coincide WII 9-12, circuits OR 13 and 14, trig, ger 15, matching circuit 16 and circuit, NO 17.

The signal of the intermediate frequency of the receiving device 1 is fed to the inputs of the channels 11azhati and release. In each channel, alternately, via keys 2 to 3, controlled triggers 6 are connected to the output of the receiver IF 6 integrating circuits 4 and 5. Each circuit is in the integration mode for one message and in the next message in; free swing mode, remember

until the end of this sending, the amplitude value of the signal of the previous sending. The oscillations are extinguished by pulses that are produced by the output of differentiating elements 7 and 8. In coincidence circuits 9-12 (they receive signals from the detectors integrating general circuits 4 and 5), the signal is cut. At the output of the OR 13 circuit, the data signals of the parcels are collected, which arrive at the output trigger 15. In the OR 14 circuit, the signals of the anticipated (delayed by one parcel) parcels are collected. These signals through the coincidence circuit 16 and the NET circuit 17 are fed to the second input of the output trigger 15. When receiving a long parcel equal to several elementary parcels, in the device consisting of the coincidence circuit 16 and the NET circuit 17, pulses that coincide with the pulses of the parcels are crossed out .

The operation of the click channel described in the description corresponds to the case of a deep press of the channel. Thus, when the parcel enters the channel, pressing the cut from the detected

the signal of the integrating circuits 4 and 5 switch the output trigger 15 to the position corresponding to the pressing. When pauses in the channel are pressed, the held pulse of the previous parcel switches the trigger to the position corresponding to the release. The channel also works wring out.

Thus, information is received even with deep selective fading, leading to the disappearance of one of the signals.

Subject invention

The method of integrated reception of signals of frequency telegraphy, based on integ. Generating press and release packages sent to two identical channels, followed by comparison of the results of integration, characterized in that, in order to increase noise immunity during deep selective fading, the given and previous packages are additionally compared and the sign of the package is compared by results .

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