RU1805550C - System for transmission of tetrad-coded radio signals - Google Patents

Abstract

Usage: radio engineering. SUMMARY OF THE INVENTION: the system comprises a clock generator, a D code generator, a phase modulator, a radio frequency generator, a matched two-channel filter, a subtractor, a multiplier, a reference oscillator, a low-pass filter, a solver unit, a polarization modulator, and a polarization selector. 1 ill.%

Description

The invention relates to radio engineering and can be used in information transmission and synchronization systems using electromagnetic wave propagation.

The aim of the invention is to increase the accuracy of reception in conditions of uncertainty of the initial phase of the radio frequency generator.

The drawing shows a structural diagram of a system for transmitting Quaternary-coded radio signals.

The quadruple-coded radio signal transmission system comprises a transmitting part 1, consisting of a radio frequency generator 2, a clock pulse generator 3, a 4 D-code generator, a phase modulator 5 and a polarization modulator 6, a communication channel 7, a receiving part 8 consisting of a polarization selector 9, a matched two-channel filter 10, a subtractor 11, a reference oscillator 12, a multiplier 13, a low-pass filter 14 and a decision block 15.

In this case, in the transmitting part 1, a clock pulse generator 3, a driver of 4 D-codes are connected in series,

a phase modulator 5 and a polarization modulator 6, the second input and output of which are respectively connected to the output of the clock generator 3 and is the output of the transmitting part 1, the second input of the phase modulator 5 is connected to the output of the radio frequency generator 2, the output of the transmitting part 1 is connected via communication channel 7c. the input of the receiving part 8, which at the same time is the input of the polarization selector 9, both outputs of which are connected to the corresponding inputs of the matched two-channel filter 10, the first and second outputs of which are connected to the corresponding inputs of the subtractor 11, the output of which is connected to the second input of the multiplier 1.3, the first input and the output of which is connected respectively by the output of the reference oscillator 12 and the input of the low-pass filter 14, the output of which is connected to the input of the decision unit 15, the output of which is the output at part of me.

The system for transmitting quaternary-coded radio signals works as follows.

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When you turn on the transmission system in the transmitting part 1, the clock generator 3 generates a sequence of clock pulses with a duty cycle equal to one. Each element of this sequence with a high level (1) will be considered odd, and with a low level (UJ - even. In shaper 4 D-codes, this sequence is converted into a D-code with a period (where n is an integer greater than 2.) In the phase modulator 5, the harmonic oscillation coming from the output of the radio frequency generator 2 undergoes binary phase manipulation of the D-code (0, 1 ). the output of the phase modulator 5, the phase-manipulated (FM) radio frequency sequence is fed to the first input of the polarization modulator 6, in which it is converted into a quaternary-coded radio signal - the odd and even elements of the FM sequence are transmitted to communication channel 7 by orthogonal polarization , for example, left and right circular, then the following elements will be in the quaternary-encoded radio signal:

“- the left circular polarization, the initial phase - 0;

R-left circular polarization, the initial phase - L,

y — rights of circular polarization; initial phase — 0;

d - rights circular polarization, the initial phase - l.

The operation of the polarization modulator can be described by the following rule:

VBBIX a., If phase VBxi 0, a VBx2 1 VB.UX /, if phase VBX1 l :, a VBx2 1 VBBIX Y, if phase VBxi 0, a V8x2 О VBbix b, if phase VBX1 lg, a VBx2 О

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In the receiving part, the quaternary-encoded sequence from the communication channel 7 is fed to the input of the polarization sector 9, which selects two FM sequences (one of the odd elements of the D code and the other from the even elements of the Code). Since the polarization selector unambiguously separates electromagnetic waves with orthogonal polarization, at its outputs we have a complete certainty of the channel numbers - on one output is a sequence of even elements of the radio signal (transmitted by one type of polarization), and on the other - odd elements (transmitted by another, orthogonal type of polarization). These two FM radio frequency sequences are fed to the corresponding inputs.

matching the Velty filter 10, the voltage proportional to the ACF of these sequences with period N appears at its outputs. Due to the fact that the sequences of even and odd elements of the D-code are additional sequences, in the subtractor 11 the lateral emissions of their ACF are compensated, and the main peaks add up in phase. In this way,

at the output of the subtractor 11 there will be a voltage proportional to the ACF of the four-coded radio signal. Using a multiplier 13, a reference oscillator 12, and a low-pass filter 14, coherent demodulation of the ACF of a four-coded radio signal is performed. In decisive

block 15, a transfer decision is made

a quad-coded radio signal,

4 D code generator can be

made as in the prototype. The polarization modulator 6 and the polarization selector 9 can be made of two polarizers emitting electromagnetic waves with orthogonal polarization. Communication channel 7 is in particular a radio broadcast. A matched two-channel filter 10 can be performed on the delay elements on surface acoustic waves. 15v decider

the simplest case is a threshold element.

Thus, the proposed system of transmitting Quaternary-encoded radio signals provides higher accuracy of receiving Quaternary-encoded radio signals than the prototype under conditions of uncertainty of the initial phase of the radio frequency generator, by eliminating the uncertainty of the number of transmission channels

radio signal during its demodulation.

Claims (1)

SUMMARY OF THE INVENTION A quadruple-coded radio signal transmission system, comprising the transmitting part, a clock pulse generator, a D-code generator, a phase modulator, the second input of which is connected to the output of the radio frequency generator, connected in series the transmitting part is connected through a channel. in connection with the input of the receiving part, which consists of a matched two-channel filter, a subtractor, a multiplier, the first input of which is connected to the output of the reference generator, a low-pass filter, the output of which is connected to the input of the decision unit, the output of which is the output receiving part, characterized in that, in order to increase the accuracy of reception under conditions of uncertainty of the initial phase of the radio frequency regulator, a polarization modulator is introduced into the transmitting part, while the output of the phase modulator a is connected to the first input of the polarization modulator, the second input of which is connected to the output of the clock generator, and the output is the output of the transmitting part, a polarization selector is introduced in the receiving part, both outputs which is connected to the corresponding inputs of a matched two-channel filter, the first and second outputs of which are connected to the corresponding inputs of the subtractor, the output of which is connected to the second input of the multiplier, the output of which is connected to the input of the low-pass filter, the input of the polarization selector is the input of the receiving part.