RU149476U1 - RADIO SIGNAL SIMULATOR - Google Patents

Abstract

A radio signal simulator comprising a series-connected signal generator, a frequency multiplier, a digital-to-analog converter and a low-pass filter, a control device and a memory device connected in series, and a permanent memory device, the output of which is connected to the second input of the digital-to-analog converter, characterized in that a switching device, a valcoder, an indicator and an accumulating adder are introduced into it, the first input of which is connected to the output of the storage device, and the output with the input of the permanent storage device, the indicator input and the second input of the switching device are combined and connected to the second output of the control device, the first input of the switching device, the output of which is the output of the radio signal simulator, is connected to the output of the low-pass filter, the input of the control device is connected to the output of the encoder, the second the input of the accumulating adder is combined with the first input of the digital-to-analog converter.

Description

The utility model relates to the field of radio engineering, in particular, to means for simulating radio signals with programmed adjustment of the operating frequency (MHF), and can be used to create means of radio monitoring at the test stage, as well as training operators of such tools.

Currently, radio communication with frequency hopping devices has become widespread. Such signals can be used with various types of modulation at a tuning speed from units of jumps per second to several thousand. To create means of radio monitoring and training operators of such tools, it is necessary to use radio communication means with frequency hopping as sources of radio emission. The high cost of radio communication with frequency hopping, as well as the wide range of such devices makes it difficult to use them as a means of playing along with the development of radio monitoring equipment and operator training. Therefore, to solve these problems, it is promising to replace real means of radio communication with frequency hopping, their simulators, which form various types of signals with specified parameters and have a lower cost.

Known simulator of navigation signals [Russian Patent No. 123976, G01S 7/40, 2013] of navigation spacecraft designed to generate radio signals of the same type similar in structure to the signals emitted by such devices.

A device for simulating periodic signals of variable frequency [patent EP No. 030053, G01S 7/40, 1981]. It consists of a clock generator of a predetermined frequency, a control device, a controlled divider, a computer and a digital-to-analog converter (DAC). The disadvantage of this device is that it provides the formation of a signal only in a sinusoidal form and does not allow the formation of signals of various types of modulations and parameters.

Closest to the claimed model is a radio signal simulator [Russia, patent No. 2207586, G01S 7/02, 2001], adopted as a prototype.

The radio signal simulator comprises a reference frequency signal generator, a frequency multiplier, read-only memory (ROM), a digital-to-analog converter, a low-pass filter (LPF), a storage device (memory), and a control device. This device provides a simulation of several specified types of radio signals with various parameters.

The disadvantages of the device are the inability to form signals with frequency hopping.

The technical result consists in expanding the types of radio signals generated in the simulator due to the implementation of signals with frequency hopping.

This result is achieved by the fact that in the simulator of radio signals containing a series-connected signal generator, frequency multiplier, DAC and low-pass filter, as well as a series-connected control device and memory, as well as ROM, the output of which is connected to the second input of the DAC, an additional switching device, a valcoder , the indicator and the accumulating adder, the first input of which is connected to the memory output, and the output with the ROM input, the indicator input and the second input of the switching device are combined and connected to the second output of the control device the first input of the switching device, the output of which is the output of a radio signal simulator, connected to the output of the low-pass filter, the input of the control device is connected to the output of the encoder, the second input of the accumulating adder is combined with the first input of the DAC.

In FIG. 1 shows a block diagram of a device.

In FIG. 2 is a structural diagram of a control device.

The radio signal simulator consists of the following functional units:

1 - signal generator;

2 - frequency multiplier;

3 - control device;

4 - memory;

5 - accumulating adder;

6 - ROM;

7 - DAC;

8 - low-pass filter;

9 - switching device;

10 - valcoder;

11 - indicator.

The inventive model contains serially connected signal generator 1, frequency multiplier 2, DAC 7 and low-pass filter 8, as well as serially connected control device 3 and memory 4, as well as ROM 6, the output of which is connected to the second input of the DAC 7, characterized in that introduced a switching device 9, a valcoder 10, an indicator 11 and an accumulating adder 5, the first input of which is connected to the output of the memory 4, and the output with the input of the ROM 6, the input of the indicator 11 and the second input of the switching device 9 are combined and connected to the second output of the control device 3, the first the input of the switching device 11, the output of which is the output of the radio signal simulator, is connected to the output of the low-pass filter 8, the input of the control device 3 is connected to the output of the encoder 10, the second input of the accumulating adder 5 is combined with the first input of the DAC 7.

The control device 3 can be made in the form of a device (Fig. 2), comprising three adapters 12.1-12.3, a public channel (CPC) 13, a programmable read-only memory (EPROM) 14 and a controller 15.

In this case, the adapters 12.1-12.3 provide communication as follows:

12.1 - communication of the CPC 13 with the encoder 10;

12.2 - communication of the CPC 13 with the switching device 9 and the indicator 11;

12.3 - communication of KOP 13 with memory 4.

PROM 14 is intended for storing the values of the frequency codes of the generated radio signal with frequency hopping, modulation type codes, frequency tuning step codes and tuning range.

The controller 15 is designed to supply at certain points in time, determined by the program algorithm of the program, control commands to the ROM for supplying to the input of the memory 4 values of the frequency codes of the generated radio frequency signal with frequency hopping, modulation type codes, frequency tuning step codes and tuning range through the CPC 13 and adapter 12.3.

The control program for the control device 3 can be created using an object-oriented approach and should provide the solution to the following tasks:

- carry out a survey of the state of the encoder 10 about the switched on operating mode and the corresponding parameters of the generated signal (the center frequency of the group dial, the type of modulation, the number of frequencies in the group dial, the frequency tuning step and the tuning range);

- transmit frequency codes of the generated radio signal with frequency hopping, modulation type codes, frequency tuning step codes, signal generation duration at one frequency and tuning range in memory 4;

- transmit for display on the indicator 11 information about the on mode of operation and the corresponding parameters of the generated signal;

- to manage the state of the switching device 9 (open or closed).

Valkoder 10 is designed to transmit to the control device 3 the code of the operating mode and information about the corresponding parameters of the generated radio signal.

The radio signal simulator operates as follows.

с выхода умножителя частоты 2 одновременно поступает на второй вход накапливающего сумматора 5 и первый вход ЦАП 7. С выхода валкодера 10 на вход устройства управления 3 поступает код для включения соответствующего режима работы и соответствующих ему параметров формируемого сигнала. После этого со второго выхода устройства управления 3 информация о выбранном режиме работы и, соответствующих ему параметрах сигнала поступает на индикатор 11, кроме того, на индикатор 11 поступает информация о состоянии устройства коммутации 9 (закрыто или открыто). Синтез сигнала с ППРЧ заключается в формировании выходного колебания на различных частотах f_i с ограниченным временем излучения на данной частоте, определяемой заданной скоростью перестройки по частотам. После окончания интервала времени отведенного для излучения на первой частоте f₁ из заданного списка частот осуществляется формирование колебания на другой частоте f_j по псевдослучайному закону. При этом последовательность смены частот определяется устройством управления 3 программно. Формирование колебания на конкретной частоте f_i в заданный момент времени заключается в формировании на выходе имитатора радиосигналов последовательности дискретных отсчетов, соответствующих определенным значениям фазовых сдвигов, с последующим цифроаналоговым преобразованием при помощи ЦАП 7 и фильтрацией с помощью ФНЧ 9.From the output of the signal generator 1, the clock signal of the reference frequency F _{T is} fed to the input of the frequency multiplier 2, in which it is multiplied by a coefficient k, determined by a particular implementation of the frequency multiplier. After that, the clock signal with frequency

from the output of the frequency multiplier 2 simultaneously enters the second input of the accumulating adder 5 and the first input of the DAC 7. From the output of the valcoder 10, a code is received at the input of the control device 3 to enable the corresponding operating mode and the corresponding parameters of the generated signal. After that, from the second output of the control device 3, information about the selected operating mode and corresponding signal parameters is supplied to the indicator 11, in addition, the indicator 11 receives information about the status of the switching device 9 (closed or open). The synthesis of the signal with frequency hopping is the formation of the output oscillation at different frequencies f _i with a limited radiation time at a given frequency, determined by a given frequency tuning frequency. After the end of the time allotted for radiation at the first frequency f ₁ from a given list of frequencies, oscillation is generated at another frequency f _j according to the pseudo-random law. In this case, the sequence of frequency changes is determined by the control device 3 programmatically. The formation of oscillations at a specific frequency f _i at a given point in time consists in the formation at the output of the radio signal simulator of a sequence of discrete samples corresponding to certain values of phase shifts, followed by digital-to-analog conversion using DAC 7 and filtering using low-pass filter 9.

For this, from the first output of the control device 3 to the memory 4, a frequency code K _{ω of} synthesized oscillations is supplied. From the output of the memory 4, the frequency code K _{ω of the} synthesized oscillations is fed to the input of the accumulating adder 5 and is recorded in it at the first clock cycle. At the following clock cycles, the frequency code K _{ω (i + 1) of the} synthesized oscillations arriving at the first input of the accumulating adder 5 is added to the value of the previous frequency code K _{ω (i + 1)} = K _{ω (i)} + K _{ω (i-1)} . Each subsequent clock cycle will increase the binary number written in the accumulating adder 5 by a constant addition K _ω . After exceeding the volume of the accumulating adder 5, the duty cycle is repeated.

, где Δφ_d=1, 2, … 2ⁿ, n - разрядность накапливающего сумматора 5 [http://www.wubblick.com].Thus, the output code of the accumulating adder 5 is the code of the instantaneous phase Δφ _{d of the} output oscillation. The earlier the overflow of accumulating adder 5 occurs, the faster the phase changes in time and the greater the frequency f _{i of the} generated oscillation. The relationship of the frequency of the generated oscillations f _i and the instantaneous phase value Δφ _d is determined by the following expression

, where Δφ _d = 1, 2, ... 2 ⁿ , n is the bit depth of the accumulating adder 5 [http://www.wubblick.com].

After that, from the output of the accumulating adder 5, the generated frequency code K _ω , which is simultaneously the corresponding phase value Δφ _d , is fed to the input of the ROM 6, in which the digital values of the amplitudes of the function sin are recorded. In this case, the frequency code K _ω is the address for ROM 6, and, accordingly, the argument of the function sin. Thus, the output code of the ROM 6 is equal to the value of the function sin for this argument y = sin (Δφ _d ). From the output of the ROM 6, the code of the value of the function sin for a given argument is fed to the second input of the DAC 7, at the output of which the selected values of the function sin are converted to analog voltage. From the output of the DAC 7, the sequence of amplitude-modulated pulses is fed to the low-pass filter 8, which selects the first harmonic. Thus, at the output of the low-pass filter 8, a signal of a given frequency f _{i is formed} . After that, the signal from the output of the low-pass filter 8 through the second input of the switching device 9 passes to the output of the radio signal simulator. At the end of the time interval allotted by the control program of the control device 3 for generating a signal at a frequency f _i, the signal generation process for the next time interval is repeated for frequency f _j . Thus, the formation of the signal with frequency hopping occurs.

The switching device 9 can be implemented on the basis of an electromagnetic high-frequency reed switch controlled by a push button switch, for example RES-18.

The valcoder 10 can be made in the form of a mechanical incremental valcoder of the PEC 11 series from BOURNS [http://www.stas633.narod.ru/ProVse/Valcoder/Encoder.html].

The control device 3 can be made on the basis of a microcontroller, for example ATmega16 [http://www.atmel.com/devices/atmega16.aspx].

Frequency multiplier 2, memory 4, accumulating adder 5, ROM 6 and DAC 7 can be made in the form of a direct digital synthesis frequency synthesizer, for example AD9851 [http: //www.analogxom/ru/rfif-components/direct-digital-synthesis- dds / ad9851 / products / product.html].

The signal generator 1 can be implemented on the basis of a generator, for example KXO-V97 [http://www.compel.ru/infosheet/GEYER/KXO-V97%2050.0%20MHz/].

The low-pass filter 8 is a low-pass filter with a cutoff frequency of 70 MHz and can be implemented on the basis of an 11-order Chebyshev filter.

The indicator 11 is designed to display the parameters of the generated signals and the status of the switching device 10, and can be performed on the basis of the LCD indicator WH1602B [http://www.compel.ru/infosheet/WINSTAR/WH1602B-YGK-CTK/].

Thus, the simulator of radio signals allows you to synthesize based on direct digital synthesis signal with frequency hopping.

Claims (1)

A radio signal simulator comprising a series-connected signal generator, a frequency multiplier, a digital-to-analog converter and a low-pass filter, a control device and a memory device connected in series, and a permanent memory device, the output of which is connected to the second input of the digital-to-analog converter, characterized in that a switching device, a valcoder, an indicator and an accumulating adder are introduced into it, the first input of which is connected to the output of the storage device, and the output with the input of the permanent storage device, the indicator input and the second input of the switching device are combined and connected to the second output of the control device, the first input of the switching device, the output of which is the output of the radio signal simulator, is connected to the output of the low-pass filter, the input of the control device is connected to the output of the encoder, the second the input of the accumulating adder is combined with the first input of the digital-to-analog converter.

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