RU2477927C1 - Device for signal demodulation with differential phase-shift keying - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: device for signal demodulation with differential phase-shift keying contains band-rejection filter 1, the output of which is connected to the input of rectifier 2, the output of which is connected to the first input of resolver 3 and through synchronising pulses shaping unit 4 to the second input of resolver 3, the output of which is the output of device, the input of band-rejection filter 1 through band pass filter 5 is connected to device input. Resolver 3 contains monostable multivibrator 6, the input of which is the input of resolver 3, and the output of monostable multivibrator 6 is connected to the first input of trigger 7, the second input of which is the second input of resolver 3, and the output of trigger 7 is the output of resolver 3. The proposed device performs signal demodulation with differential phase-shift keying.

EFFECT: simplification of device structure.

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Description

The invention relates to communication technology and can be used in data transmission equipment.

A device for demodulating signals with relative phase shift keying [1], consisting of a band-pass filter, the output of which is connected to the input of the delay line and the first input of the phase detector, the second input of the phase detector is connected to the output of the delay line. The output of the phase detector is connected to the input of the deciding unit, to the other input of which the count pulses from the output of the synchronization circuit are received. The output of the decision block and the output of the synchronization circuit are the outputs of the demodulator. A disadvantage of the known device is the difficulty in implementing the exact elements of the delay line at the carrier frequency.

The closest analogue to the proposed device is a device for demodulating signals with relative phase shift keying [2], containing a phase detector, the first input of which is the input of the device, and the second input of which is connected to the output of the synchronous voltage generator, the input of which is connected to the input of the device, and the output a phase detector is connected to the first input of the decisive block and, through the sync pulse generation block, to the second input of the decisive block, whose output is the output of the device. The synchronous voltage generator comprises a frequency doubler, a bandpass filter, and a frequency divider connected in series. The solving unit contains a series-connected regenerator, a differentiating chain, a rectifier, the output of which is connected to the first input of the trigger and the first input of the matching circuit, the output of which is connected to the second input of the trigger, the output of which is the output of the device, and the second inputs of the regenerator and matching circuit are combined and are the second the input of the decisive block.

A disadvantage of the known device is the need for a synchronous voltage generator, which complicates the device. In order to simplify the device, a notch filter is introduced into it, the output of which is connected to the input of the rectifier, the output of which is connected to the first input of the deciding unit and, through the clock generation unit, to the second input of the deciding unit, whose output is the output of the device, the notch filter input is connected through a band-pass filter with device input. The decision block contains a standby multivibrator, the input of which is the input of the decision block, and the output of the standby multivibrator is connected to the first input of the trigger, the second input of which is the second input of the decision block, and the output of the trigger is the output of the decision block. The trigger is made in the form of a D-trigger.

In Fig.1 shows a structural diagram of a device for demodulating signals with relative phase shift keying, Fig.2 is a structural diagram of a decisive block, and Fig.3 is a timing diagram explaining the operation of the device.

A device for demodulating signals with relative phase shift keying comprises a notch filter 1, the output of which is connected to the input of the rectifier 2, the output of which is connected to the first input of the decision block 3 and, through the clock generation unit 4, to the second input of the decision block 3, the output of which is the output of the device, the input of the notch filter 1 through the bandpass filter 5 is connected to the input of the device. The decision block 3 contains a standby multivibrator 6, the input of which is the input of the decision block 3, and the output of the standby multivibrator 6 is connected to the first input of the trigger 7, the second input of which is the second input of the decision block 3, and the output of the trigger 7 is the output of the decision block 3.

A device for demodulating signals with relative phase shift keying works as follows.

On figa shows the original information sequence. The input signal, phase-manipulated by the initial information sequence, fig.3b, is fed to the input of the bandpass filter 5 and then to the input of the notch filter 1. At the moment of phase change at the output of the notch filter 1 there are damped oscillations, figv, which are rectified by rectifier 2 and start the waiting multivibrator 6, which generates an impulse of a duration equal to approximately half the duration of the information packet, Fig. 3d. The 3D clock pulses generated by the synchronization pulse generating unit 4 are fed to the clock input of the trigger 7, to the D input, which receives pulses from the waiting multivibrator 6. If there are pulses from the waiting multivibrator 6 at the inverted output of the trigger 7, a log.0 is set when the clock pulse arrives at the clock input of the trigger 7, and in the absence of pulses from the standby multivibrator 6 on the inverse output of the trigger 7 is set to log.1 fig.3e. Thus, the signal at the inverse output of trigger 7 repeats the original information sequence, i.e. the proposed device performs demodulation of signals with relative phase shift keying.

Information sources

1. S. Stein, J. Jones. The principles of modern communication theory and its application to the transmission of discrete messages. - M.: Communication, 1971. S. 243.

2. Petrovich N.T. transmission of discrete information in channels with phase shift keying. - M.: Soviet Radio, 1965. S.100.

Claims (2)

1. A device for demodulating signals with relative phase shift keying, comprising a band-pass filter, a rectifier, a clock generating unit, the output of which is connected to the input of the decision unit, the output of which is the output of the device, characterized in that a notch filter is inserted into it, the output of which is connected to the input a rectifier, the output of which is connected to the first input of the decisive block and through the clock generation block with the second input of the decisive block, whose output is the output of the device, input reject molecular filter through a bandpass filter connected to the input device decider comprises a monostable multivibrator, the input of which is the input deciding unit, and the output of monostable multivibrator coupled to the first input of the flip-flop, a second input of which is the second input of the casting unit, and the trigger output is an output deciding unit. 2. A device for demodulating signals with relative phase shift keying according to claim 1, characterized in that the trigger is made in the form of a D-trigger.

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