RU2601136C1 - Multifunctional device for generation of telemetry radio signals with angular modulation for transmitting analogue-digital or digital information - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: invention relates to radio telemetry systems and can be used for generation of radio signals with different types of modulation. Multifunctional device for generation of telemetry radio signals with angular modulation for transmitting analogue-digital or digital information includes: two analogue-to-digital converters, ten memory registers, three switches, two multipliers, two adders, phase accumulator, phase-amplitude converter, digital-to-analogue converter, low-pass filter, power amplifier, two FIR (with finite impulse response) filters, synchronisation circuit, clock frequency generator, programming interface.

EFFECT: technical result is broader functional capabilities owing to generation of telemetry radio signals with APM-FM during transmission of analogue-digital information from two sources, with time division of channels or radio signals with PSK, MFM, FSK and PSK, MFM, FSK with pre-modulated filtering, when transmitting digital information.

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Description

The invention relates to radio telemetry systems and can be used to generate radio signals with two-stream amplitude-pulse and frequency modulation (AIM-FM), time division of information channels, phase shift keying (PSK), PSK with pre-modulation filtering, modulation with a minimum frequency shift (MMS) ), MMS with premodulation filtering, frequency shift keying (FMN), FMN with premodulation filtering.

A device for generating telemetric radio signals with angular modulation - phase shift keying (QPSK), with quadrature phase shift keying (CPM), with shift quadrature phase shift keying (SCFM) and with minimal frequency shift keying (MFM) is another name for MMS [RF Patent No. 2378783, H04L 27/12]. This device contains a reference signal generator, a constant voltage source, four switches, a synchronizer, a quadrature encoder, a delay element, a phase manipulator unit, a symbol envelope generator and an adder. However, the known device cannot generate telemetric radio signals from dual-stream AIM-FM for transmitting analog-digital information with time division of information channels, as well as FMN, MMS, FMN with pre-modulation filtering.

A device is known for transmitting signals with frequency modulation and time division of channels, which generates a radio signal from a dual-stream AIM-FM with time division of information channels, that is, information of each channel of the first and second streams is transmitted alternately in time and at its subcarrier frequency, as in FIG. 2 [A.S. USSR No. 777872, H04L 27/10]. This device contains: a frequency-modulated generator, a controlled key, a mixer, a tunable filter, a second driver of control pulses, a synchronizer, a delay unit, a switch, a first driver of control pulses, a frequency divider, phase detector, synthesizer. However, the known device cannot generate telemetric radio signals with FMN, MMS, FMN and FMN, MMS, FMN with premodulation filtering.

A device is known “Digital synthesizer of frequency and phase-shift signals” [RF Patent No. 2358384, H03L 7/18], selected as a prototype, comprising: a reference generator, a delay unit, four memory registers, three digital drives, an adder, a code converter, digital-to-analog a converter, a low-pass filter, a frequency divider with a variable division coefficient, but it cannot generate radio signals with FMN, MMS, FMN with premodulation filtering and dual-stream AIM-FM with time division of information channels.

The technical result of the invention is to expand the functionality of the device due to the possibility of forming telemetric radio signals from dual-stream AIM-FM, when transmitting analog-digital information from two sources (streams), with time division of channels, or radio signals from FMN, MFM, FMN and FMN, MFM, FMN with premodulation filtering, when transmitting digital information.

To achieve this result in a multifunctional device for generating telemetric radio signals with angular modulation for transmitting analog-digital or digital information, containing the fourth memory register 6, the eighth memory register 20, a phase 13 accumulator and a second adder 14 connected in series with the output of the converter phase - amplitude 15, series-connected digital-to-analog converter 17 and low-pass filter 18, series-connected clock generator From 27 and synchronization circuits 26, the first analog-to-digital converter 1 is introduced, the output of which is connected to the input 1 of the first switch 10, the second analog-to-digital converter 2, the output of which is connected to the input 2 of the first switch 10, the first memory register 3, the output of which is connected with input 3 of the first switch 10, the second memory register 4, the output of which is connected to the input 4 of the first switch 10, the first switch 10, the output of which is connected to the first input of the first multiplier 11, the third memory register 5, the output of which is connected to the second the input of the first multiplier 11, the first multiplier 11, the output of which is connected to the first adder 12, the first adder 12, the output of which is connected to the input of the phase 13 accumulator, the fourth memory register 6, the output of which is connected to the input 1 of the second switch 25, the fifth memory register 7, the output of which is connected to the input 2 of the second switch 25, the sixth memory register 8, the output of which is connected to the input 5 of the second switch 25, the seventh memory register 9, the output of which is connected to the input 6 of the second switch 25, the second switch 25, the output 7 of which is connected the input of the first FIR (finite impulse response) filter 24, the first FIR filter 24, the output of which is connected to the first adder 12, the eighth memory register 20, the output of which is connected to the first input of the third switch 21, the ninth memory register 22, the output of which is connected to the second input the third switch 21, the third switch 21, the output of which is connected to the input of the second FIR filter 28, the second FIR filter 28, the output of which is connected to the second input of the second adder 14, the tenth memory register 23, the output of which is connected to the first input of the second multiplier 16, the second multiplier 16, the output of which is connected to the input of the digital-to-analog converter 17 and the first input with the output of the phase-to-amplitude converter 15, a power amplifier 19, the input of which is connected to the output of the low-pass filter 18, the programming interface 29, connected to the inputs of the memory registers 1-9, 20, 22, 23 and FIR filters 24, 28.

In FIG. 1 is a structural diagram of a multifunctional device for generating telemetric radio signals with angular modulation for transmitting analog-digital or digital information. In FIG. 2 shows the structure of the video signal and the radio signal of a dual-stream telemetry system with AIM-FM and time division of information channels.

A multifunctional device for generating telemetric radio signals with angular modulation for transmitting analog-to-digital or digital information (Fig. 1) contains: a first analog-to-digital converter 1, a second analog-to-digital converter 2, the first memory register 3, the second memory register 4, the third register memory 5, fourth memory register 6, fifth memory register 7, sixth memory register 8, seventh memory register 9, first switch 10, first multiplier 11, first adder 12, phase 13 accumulator, second adder 14, transform Phase - amplitude 15, second multiplier 16, digital-to-analog converter 17, low-pass filter 18, power amplifier 19, eighth memory register 20, third switch 21, ninth memory register 22, tenth memory register 23, first FIR filter 24, second switch 25 synchronization circuit 26, clock generator 27, second FIR filter 28, programming interface 29.

The principle of operation of a multifunctional device is as follows.

The type of the generated telemetric radio signal with dual-stream AIM-FM, MMS, FMN, FMN and MMS, FMN, FMN with pre-modulation filtering is selected using the first, second and third switches 10, 25, 21, as well as programming, using the programming interface 29, according to the selected modulation and its characteristics, the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth memory registers 3, 4, 5, 6, 7, 8, 9, 20, 22 and programming the parameters of FIR filters 24, 28 .

The basis of the multifunctional device is a direct synthesis synthesizer, consisting of a phase 13 accumulator, a second adder 14, a phase-to-amplitude converter 15, a second multiplier 16, a digital-to-analog converter 17, a low-pass filter 18. The phase 13 accumulator, which is executed according to the accumulating adder circuit, forms output linearly increasing along the front of the signal ft generator clock 27, a digital code. After 2 ^N cycles ft, the phase 13 accumulator overflows and is reset to its initial state. Such a periodic overflow corresponds to the periodic law of a change in the instantaneous phase of a sinusoidal signal with a period of 2π. The digital code M, coming from the first adder 12 to the phase 13 accumulator, forms an additional additive that regulates the step of the phase increment in one cycle ft, i.e. determines the speed of the battery overflow phase or ultimately the frequency of the output signal according to

where M is the code of the phase increment;

N - phase 13 battery capacity;

ft - the frequency of the clock generator 27.

The code from the output of the phase 13 accumulator, through an additional second adder 14, is fed to the phase-amplitude converter 15, which converts the instantaneous phase code into a digital code for the amplitude of the output signal U (t), which will be converted by a digital-to-analog converter 17 into a real analog a signal consisting of "steps" of duration Tm = 1 / ft and after filtering by a low-pass filter 18 acquires a pure sinusoidal shape and then is amplified by a power amplifier 19. The second total p 14 allows the addition of a discrete number to the phase code from the output of the phase 13 accumulator, thereby allowing phase manipulation (QPSK) of the 0-π radio signal to be generated. Included between the phase-amplitude converter 15 and the digital-to-analog converter 17, the second multiplier 16 allows you to change the amplitude of the output signal from the output of the digital-to-analog converter.

To generate a radio signal from a dual-stream AIM-FM with time division of information channels, a logical “0” code is set at the VM input. The telemetry information flows of FM1 and FM2, as shown in graphs a), b) of FIG. 2, go to the first analog-to-digital converter 1 and the second analog-to-digital converter 2, where the analog waveform is converted to digital codes in proportion to the amplitudes of the signals of FM1, FM2. It is necessary to bring these codes in accordance with the M code necessary to control the phase 13 battery in order to generate the FM signal frequencies according to the formula

where Ch1, Ch2 are digital codes at the outputs of the first analog-to-digital converter 1 and the second analog-to-digital converter 2;

K is a digital code of a coefficient specifying the step of changing the frequency of the signal U (t), determined based on the value of the frequency deviation and the bit depth of the ADC output code, and is programmed into the third memory register 5;

P1 and P2 are codes of the initial frequencies fn1 and fn2 of the AIM-FM modulated signal flows, where fn1 and fn2 are equal to the carrier frequencies of the first and second flows minus the value of the frequency deviation, and are programmed into the fourth and fifth memory registers 6, 7.

Thus, changes in the values of codes Ch1, Ch2, according to the input analog information, form new values of M and accordingly change the frequency of the output signal U (t) of each stream. To select the flow of information that will be transmitted at the current time, to form a temporary separation of the channels of information of each stream, to form the AIM of each stream, the VP control signal is used - the stream selection. Depending on the values of the logical “0” or “1” signal of the VI, the first and second switches 10, 25 alternately change the codes Ch1 and Ch2 and P1 and P2 in the formula (2). In this case, the frequency of the signal U (t) alternately changes from the FM1 stream to the FM2 stream, as shown in graph d) of FIG. 2. Information signals FM1, FM2 can be as analog, ie accept any values of amplitudes within given boundaries, as well as digital, i.e. accept discrete levels.

To generate a radio signal with modulation MMC and MMS with pre-modulation filtering, a logical “1” code is supplied to the VM input. In the first and second memory registers 3, 4, the logic code “0” is programmed. In the sixth register of memory 8, a code corresponding to code M is programmed to generate the frequency of the radio signal fout1, based on the following formula, with a + sign:

where fн is the value of the carrier frequency of the radio signal, MHz;

R - information transfer of information, Mbps;

m - modulation index, for MMS is 0.5;

fout1 is the upper frequency of the radio signal corresponding to the transmission of logical “1” data;

fout0 is the lower frequency of the radio signal corresponding to the transmission of logical “0” data.

In the seventh memory register 9, a digital code corresponding to code M is programmed to generate the frequency of the radio signal fout0, based on formula (3), with a minus sign. An informational digital signal is fed to the input of the VI. In this case, using the second switch 25, the output codes of the sixth and seventh memory registers 8, 9 are switched to the output of the second switch 25, thereby changing the values of P1 (0) at the input of the first adder 12 and, accordingly, M, since in this case M = P1 (0)

where P1 is the code coming from the seventh register of memory 9 and corresponding to the logical transmission “1”;

P0 - code coming from the sixth register of memory 8 and corresponding to the transfer of logical "0".

When generating a radio signal with MMS and pre-modulation filtering, the first FIR filter 24 is programmed for a given duration of the impulse response, while the transition of the codes from P0 to P1 does not occur stepwise, but smoothly, in steps of duration Tm = 1 / ft, which will improve the spectral characteristics of the radio signal.

For the formation of a radio signal with modulation of the FSK and FSK with premodulation filtering, the difference from the formation of a radio signal with modulation of the MMS and MMS with premodulation filtering is that in formula (3) the value of m is chosen to be different from 0.5 and, accordingly, the values of fout1 and fout0 are different, which will require programming other values of the codes P1 (P0) in the sixth and seventh memory registers 8, 9.

To generate a radio signal with modulation of the PSK and PSK with pre-modulation filtering, logical “1” codes are set at the inputs of the VM and VP. In the second register of memory 4, a code with the number 0 is programmed, in the seventh register of memory 9, a code equal to the value of M is programmed to form the carrier frequency of the radio signal. As described previously, for the formation of the phase manipulation of the radio signal between the phase 13 accumulator and the phase-amplitude converter 15, a second adder 14 is included, the input of which, by means of the third switch 21, codes from the eighth and ninth memory register 20, 22 are switched, which, as a result of summing with With the code from the output of the accumulator, the phases lead to an abrupt switching of the instantaneous phase of the signal to 0-π radians. The third switch 21 is controlled by the Inf.FMn signal, which is informational. To generate a radio signal with QPSK modulation with pre-modulation filtering, between the third switch 21 and the second adder 14 there is a second FIR filter 28, which allows, according to the duration of the impulse response, to send codes from the eighth and ninth memory registers 20, 22 to the second adder 14 without a jump, but smoothly, in reality stepwise. Accordingly, in the radio signal, the 0-π phase switching will be smooth, which will improve the spectral characteristics of the radio signal.

Claims (1)

A multifunctional device for generating telemetric radio signals with angular modulation for transmitting analog-digital or digital information, comprising a fourth memory register, an eighth memory register, a phase accumulator connected in series and a second adder, the output of which is connected to the phase-amplitude converter input, a digital-to-analog converter and low-pass filter, serially connected clock generator and synchronization circuit, characterized in that in it introduced the first analog-to-digital converter, the output of which is connected to the input 1 of the first switch, the second analog-to-digital converter, the output of which is connected to the input 2 of the first switch, the first memory register, the output of which is connected to the input 3 of the first switch, the second memory register, output which is connected to the input 4 of the first switch, the output of which is connected to the first input of the first multiplier, the third memory register, the output of which is connected to the second input of the first multiplier, the output of which is connected to the first m adder, the output of which is connected to the input of the phase accumulator, the fourth memory register, the output of which is connected to the input 1 of the second switch, the fifth memory register, the output of which is connected to the input 2 of the second switch, the sixth memory register, the output of which is connected to the input 5 of the second switch, the seventh memory register, the output of which is connected to the input 6 of the second switch, the output of 7 of which is connected to the input of the first filter with a finite impulse response (FIR), the output of which is connected to the first adder, the eighth memory register the tee, whose output is connected to the first input of the third switch, the ninth memory register, the output of which is connected to the second input of the third switch, the output of which is connected to the input of the second FIR filter, the output of which is connected to the second input of the second adder, the tenth memory register, the output of which is connected to the first input of the second multiplier, the output of which is connected to the input of the digital-to-analog converter and the first input - with the output of the phase-amplitude converter, the power amplifier, the input of which is connected to the output of the filter is low their frequencies, a programming interface associated with the inputs of the memory registers and FIR filters.

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