SU1658411A1 - Device for generating minimum-shift frequency-shift-keyed signals - Google Patents

Abstract

The invention relates to radio and can be used in the equipment for the transmission of discrete information. The aim of the invention is to improve the accuracy of the formation. The device comprises a reference frequency signal generator 1, a frequency synthesizer 2, switches 3 and 5, a differential frequency separation unit 4, phase manipulator 6, and an adder 7 modulo two. At the output of the device, a frequency-manipulated signal is formed with a minimum shift (without phase discontinuity), corresponding to the quadrature formation method, but without using quadrature channels, to which high demands on the identity of the characteristics must be presented. This improves the accuracy of signal formation. 3 il.

Description

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The invention relates to the field of radio communication and can be used in the equipment for transmitting discrete information with frequency-manipulated signals.

The aim of the invention is to improve the accuracy of the formation.

FIG. 1 shows a structural electrical circuit of the device; in fig. 2 is a block diagram of a second switch; in fig. 3 - voltage plots showing the operation of the device.

The device contains a reference frequency signal generator 1, a frequency synthesizer 2, a first switch 3, a differential frequency separation block 4, a second switch 5, a phase handler 6 and an adder 7 modulo two, the second switch 5 including a driver 8 clock pulses, an inverter 9 and triggers 10 and 11.

The device works as follows.

The reference frequency signal generator 1 generates a reference signal with a frequency

w - that goes to the synthesizer

2 frequencies. In this case, at its two outputs, signals are formed with frequencies

  oJb + t, (02 Qto --Sf, which

2T

arrive at the first switch 3 and the block 4 of the allocation of the difference frequency. At the output of the latter, a signal is generated with the frequency

The deo that goes to the second switch 5. The signal input of the second switch 5 receives discrete binary information with a 2T symbol duration.

Differential frequency signal

arrives at the second switch 5, where it is converted into a periodic sequence of video pulses in the shaper 8, which arrives at the counting inputs of the triggers 10 and 11 directly and through the inverter 9. The information inputs of the triggers receive discrete information. As a result, the first and second outputs (the first output is the output of the trigger 11, the second output is the trigger 10), respectively, are formed of a sequence of odd and even characters of the original information sequence with a 2T symbol duration.

The sequence of characters from the first and second outputs of the second switch 5 is fed to the adder 7 modulo two, the output of which controls the first switch 3. If the output signal of the adder 7 modulo two takes the value 1, then the first switch 3 passes

output synthesizer signal with frequency

71Л

a - Sho + from: and if 0, then ftJz% - jj.

The output signal of the first switch 3 proceeds to phase manipulator 6. To the first input of which the sequence comes from the second output of the second switch 5. corresponding to the odd characters of the output 10 information sequence. If the symbol from the second output of the second switch 5 takes the value 1, then the signal from the output of the first switch 3 passes through the phase key 6 without turning phase 15, and if 0, the signal phase changes to n.

As a result, a frequency-manipulated signal with a minimum shift (without phase discontinuity) is formed at the output, corresponding to the quadrature formation method, but without using quadrature channels, to which high requirements should be imposed.

25 identity characteristics.

The operation of the device is illustrated by the diagrams shown in FIG. 3, where Fig. 3a shows the law of change of the oscillation phase from the output of a 2 h3030 synthesizer. in fig. 36 is a discrete information sequence; FIG. Sv is a sequence formed from even-numbered symbols of the original information sequence; in FIG. 3g is the sequence of formation of odd symbols of the information sequence; in FIG. HL - adder signal 7 modulo two, in FIG. Ze is the law of phase variation of the frequency-manipulated signal at the turn of the first switch 3; in FIG. ZG is the law of change in the phase of the output frequency-manipulated signal with a minimum shift corresponding to the quadrature formation method.

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Claims (1)

Invention Formula A device for generating a frequency-manipulated signal with a minima shift, containing series-connected reference frequency generator and a frequency synthesizer, the outputs of which are connected to the inputs of a difference frequency extractor and 55 signal inputs of the first switch, characterized in that, in order to improve the formation accuracy, a second switch, a phase manipulator and a modulo two adder, whose output is connected to the control input, are introduced the first switch, and the output of the differential frequency allocation unit is connected to the control input of the second switch, the first output of which is connected to the first input of the modulo two, and the second output to the second input of the modulator 5 FIG. 2 PP PP PP 1-I Two and the first input of the phase switch, the second input of which is connected to the output of the first switch, and the output of the phase switch, is the output of the device, the input of which is the signal input of the second switch. one