RU2576628C1 - Device for coordinated reception of information in tropospheric communication lines - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: invention relates to radio engineering, particularly to devices designed for matched information receiving in tropospheric communication lines, and can be used to create over-the-horizon communication systems. Device comprises receiving antenna, band-pass filters, connected in parallel, switches, mixers, filters, adders, clock generator, shift register, delay lines, heterodynes, synchroniser and common adder. Using the matched information receiving devices in tropospheric communication lines can significantly reduce the loss of information channels to 50 % and, consequently increase the noise immunity and speed of information transmission, which in practice allows using transmitters with lower input power, antennas with a smaller aperture, to reduce the number of receiving antennas, as well as to increase the distance between transmitter and receiver, which generally increases the economic benefit from the use of mentioned device.

EFFECT: technical result consists in reducing the fading effect when receiving information in tropospheric communication lines, higher information transmission speed and noise-immunity of communication with a minimum amount of signal generating and processing channels.

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Description

The invention relates to radio engineering, and more specifically to devices for coordinated reception of information in tropospheric communication lines, and can be used to create systems for horizontal communication.

Over-the-horizon communication - communication beyond the line of sight, in which no active or passive repeaters are used. The horizontal propagation of radio waves is due to the effects of diffraction, refraction and reflection from various layers of the atmosphere.

Currently, in connection with the intensive development and widespread introduction of digital transmission systems, ever higher information transfer rates via tropospheric communication channels are required.

The advantages of tropospheric communication lines are the increased communication range and a sufficiently large bandwidth (120 channels of tonal frequency or the transmission of digital information at a speed of up to 8 Mbit / s).

The possibility of stable reception of radio signals at a considerable distance from the horizon is based on the reflection and scattering of radio waves by the dielectric inhomogeneities of the troposphere, but the attenuation of radio signals increases sharply. In addition, the signal at the receiving end of the line has a multipath structure and is therefore subject to interference fading.

Achieving an increase in the transmission rate of information, noise immunity and reducing the attenuation process due to the multipath propagation of radio waves is an urgent task.

Known devices for transmitting and receiving modulated in phase and frequency signals [AS No. 684750, 7 IPC Н04В 7/165, 1979; H04J 1/20, Japanese application No. 49-25043, IPC Н04В, 1974], which contain on the receiving side a linear matching unit, the output of which is connected to the input of the delay unit and to the inputs of the bandpass filters, the outputs of which are connected through corresponding amplitude detectors to the inputs of the maximum signal detector, the outputs of which through integrators are connected to the trigger inputs, as well as the frequency modulator and the reference signal generating unit, the output of which is connected to the first input of the phase detector, the output of the corresponding integrator being connected to the input of the frequency modulator.

The disadvantages of these devices are low noise immunity and large attenuation due to the multipath propagation of radio waves and, as a result, a decrease in the information transfer rate.

The closest in technical essence and the achieved result is a device for transmitting and receiving information using LFM signals (Patent for the invention of the Russian Federation No. 2013014, 06/11/1991), containing on the receiving side the first, second matched LFM filters, the first, second detectors , comparator, first, second adders, first, second time gating blocks, clock synchronizer, first, second pulse expansion blocks, receiver linear path, delay line, multiplier, low-pass filter. An additional modulation stage of relative phase modulation is introduced on the transmitting side, which allows the generation of a continuous chirp signal, phase-manipulated by an information message from a second source.

The disadvantages of the device are its low noise immunity and high attenuation due to the multipath propagation of radio waves, in addition, the device does not have blocks on the receiving side that equalize signals during multipath propagation of radio waves along the path time, as well as a low information transfer rate.

The tasks that are solved by the claimed device for coordinated reception of information in tropospheric communication lines are to reduce the effect of fading when receiving information in tropospheric communication lines, increase the speed of information transfer and noise immunity of the communication with a minimum number of signal generation and processing channels.

The specified technical result is achieved due to the fact that the inventive device for coordinated reception in tropospheric information transmission lines contains a receiving antenna, n bandpass filters connected in parallel, n-1 switches, n-1 mixers, n-1 filters, n-1 adders , a clock generator, a shift register, n delay lines, n-1 local oscillators, a synchronizer and a common adder, while the receiving antenna is connected to a clock generator and to the inputs of n bandpass filters connected in parallel, the output the first n bandpass filter is connected to the first input of the first n-1 switch, and the first output n-1 of the switch is connected to the input of the first n delay line, the output of which is connected to the input of the common adder, and the second output of the first n-1 switch is connected to the second input of the first n-1 adder, the first input of which through the first n-1 mixer and the first n-1 filter is connected to the output of the second n band-pass filter, the output of the first n-1 adder is connected to the first input of the second n-1 switch, the first output of which is connected to the input second n delay line and, the output of which is connected to the second input of the common adder, the outputs of the next n bandpass filters of n frequency positions are connected to the first inputs of the next n-1 mixers, the outputs of which are connected to the inputs of the next n-1 filters, and the outputs of n-1 filters are connected to the second inputs subsequent adders, the outputs of which are connected to the first inputs of the subsequent n-1 switches, the first outputs of which are connected to the inputs of the next of n delay lines, and the outputs of n delay lines are connected to the corresponding inputs of the common adder, when The second inputs of the n-1 mixers are connected to the outputs of the corresponding n-1 local oscillators, the inputs of which are connected to the synchronizer, and the second inputs of the control switches are connected to the corresponding outputs of the shift register, the input of which is connected to the output of the clock generator.

In addition, in the device for coordinated reception in tropospheric information transmission lines, the first outputs of n switches are connected to n delay lines through n attenuators, the inputs of which are connected to the control device.

In FIG. 1 is a functional diagram of a device for coordinated reception of information in tropospheric communication lines.

In FIG. 2 is a functional diagram of a device for coordinated reception of information in tropospheric communication lines with controlled channels.

The device for coordinated reception of information in tropospheric communication lines in accordance with FIG. 1 includes: a receiving antenna - 1, n bandpass filters - 2, n-1 switches - 3, n-1 mixers - 4, n-1 filters - 5, n-1 adders - 6, a clock generator - 7, a shift register - 8, n delay lines - 9, n-1 local oscillators - 10, synchronizer - 11, where n is the number of frequency positions, 6N is the total adder.

The principle of operation of the device is as follows: assume that n is the number of frequency positions emitted sequentially in time with an interval Δt, and in the device for coordinated reception of information in tropospheric information transmission lines, the sequence of emitted signals is taken into account, transferred to one frequency and combined in time.

The operation of the device for coordinated reception of information in tropospheric communication lines is as follows:

A signal is received at the receiving antenna 1 of the device for coordinated reception of information in tropospheric communication lines, consisting of n is the number of frequency positions emitted sequentially in time with an interval Δt, formed as a result of re-reflection of inhomogeneities in the scattering volume of the troposphere.

Further, a signal from n number of frequency positions is fed to n filters - 2/1, 2/2, 2/3, ... 2 / n, and each filter passes a signal of the corresponding frequency position, determined by the filter transmission frequency. The incoming input signal also starts the clock generator 7, which, through the shift register 8, sequentially with the interval Δt, switches the n-1 switches 3/1, 3/2, 3/3, ... 3 / n-1 to the position corresponding to the signal transmission to n-1 adders 6/1, 6/2, ... 6 / n-1. The signal of the first frequency position through the switch 3/1 enters the delay line 9/1, where it is shifted by the interval nΔt, and then goes to the corresponding input of the total adder 6 / N. The signal of the second frequency position enters the 4/1 mixer, where it is shifted to the frequency of the first frequency position, then, passing through the 5/1 filter, in which it is selected and the unwanted components are suppressed, it goes to the adder 6/1, where it is summed with the offset time due to the reflection by inhomogeneities in the scattering of the troposphere by the Δt value by the signal of the first frequency position, and through the 3/2 switch it enters the delay line 9/2, where it is shifted by the time interval (n-1) Δt, after which it goes to the corresponding input general About the adder 6 / N. Each subsequent frequency position is transferred to the frequency of the previous one, filtered, summed with these signals, delayed by the corresponding value of each frequency position, aligned in time in the delay lines with the previous signals and synchronously fed to the corresponding inputs of the total adder 6 / N. Moreover, the phase alignment of signals in n-1 mixers is carried out using phase-synchronized n-1 local oscillators 10 controlled by a synchronizer 11.

The inventive device is new, because from publicly available information are not known devices that allow for its simplest implementation to effectively reduce the effect of fading on the quality of reception.

The device for coordinated reception of information in tropospheric communication lines is used to reduce the effect of fading when receiving information in tropospheric communication lines, to increase the transmission rate of information and to increase the noise immunity of communication with a minimum number of signal generation and processing channels.

However, to enhance the effects of noise immunity, reduce attenuation in the information transmission channels and, as a result, increase the information transfer rate, it is advisable to use the functional diagram of the device of FIG. 1 add channel management function.

To this end, in each of the n channels in front of the delay line in FIG. 1 include an attenuator, which allows to reduce the effect of attenuation on the received signal in a particular channel, obtaining a functional diagram of a device for coordinated reception of information in tropospheric communication lines with controlled channels.

The device for coordinated reception of information in tropospheric communication lines in accordance with FIG. 2 includes: a receiving antenna - 1, n bandpass filters - 2, n-1 switches - 3, n-1 mixers - 4, n-1 filters - 5, n-1 adders - 6, a clock generator - 7, a shift register - 8, n delay lines - 9, n-1 local oscillators - 10, synchronizer - 11, n attenuators - A1, A2, A3, ... An, control device for attenuators - 12A, where n is the number of frequency positions, 6N is the total adder.

The device of FIG. 2 operates similarly to the device of FIG. 1, but the signal from the first outputs of n-1 switches 3/1, 3/2, 3/3, ... 3 / n-1 goes to the inputs of the corresponding n attenuators A1, A2, A3, ... An and then to the inputs of the corresponding n lines delays 9/1, 9/2, 9/3, ... 9 / n, and the attenuators are controlled by the control unit 12A.

The need to use the devices of FIG. 1, FIG. 2 is determined by the fact that tropospheric information transmission lines are characterized by a strong signal attenuation, which occurs both during signal propagation through the atmosphere and due to the scattering of a part of the signal reflected from the troposphere, therefore transmitters with a power of up to 10 kW and large aperture antennas are used for stable radio communication (up to 30 × 30 m ² ), which means a high gain, as well as highly sensitive receivers with low-noise elements.

Also, tropospheric communication lines are characterized by the constant presence of fast, slow, and selective fading of the radio signal. Reducing the effect of fast fading on the received signal is achieved by using diversity frequency and spatial reception. Therefore, to reduce the influence of the above factors, it is necessary to use several receiving antennas. The solution of these problems is directed to the use of the claimed device.

Using a device for coordinated reception of information in tropospheric communication lines can significantly reduce losses in data transmission channels by up to 50% using the inventive device of FIG. 1 and up to 70% of FIG. 2 and, as a result, increase the noise immunity and information transfer rate, which in practice allows the use of transmitters with lower output power, antennas with a smaller aperture, reduce the number of receive antennas, and also increase the distance between the receiver and transmitter, which in general allows to increase the economic effect from using the inventive device.

Despite the widespread and growing use of satellite-based devices in communication networks and systems and the development of wired networks, it can be assumed that the inventive device used using tropospheric horizontal communication is promising for use in both special and commercial networks, especially in inaccessible terrain.

In special-purpose networks, the advantage of the inventive device for coordinated reception of information in tropospheric communication lines over the use of satellite communications is higher reliability in armed conflicts and anti-terrorist events.

In commercial networks, the use of such devices may be more economically feasible than the use of satellite. The use of the claimed device is also possible in communication lines in high northern latitudes, where the use of satellite communication devices via geostationary satellites is very difficult.

Claims (2)

1. A device for coordinated reception of information in tropospheric communication lines containing a receiving antenna, n band-pass filters connected in parallel, n-1 switches, n-1 mixers, n-1 filters, n-1 adders, clock, shift register, n delay lines, n-1 local oscillators, a synchronizer and a common adder, while the receiving antenna is connected to a clock generator and to the inputs of n parallel bandpass filters, while the output of the first n bandpass filter is connected to the first input of the first n-1 switch atelier, and the first output of the n-1 switch is connected to the input of the first n delay line, the output of which is connected to the input of the common adder, and the second output of the first n-1 switch is connected to the second input of the first n-1 adder, the first input of which is through the first n- 1 mixer and the first n-1 filter are connected to the output of the second n band-pass filter, the output of the first n-1 adder is connected to the first input of the second n-1 switch, the first output of which is connected to the input of the second n delay line, the output of which is connected to the second input of the common adder outputs after blowing n band-pass filters of n frequency positions are connected to the first inputs of subsequent n-1 mixers, the outputs of which are connected to the inputs of subsequent n-1 filters, and the outputs of n-1 filters are connected to the second inputs of subsequent adders, the outputs of which are connected to the first inputs of subsequent n- 1 switches, the first outputs of which are connected to the inputs of the next of n delay lines, and the outputs of n delay lines are connected to the corresponding inputs of the common adder, while the second inputs of n-1 mixers are connected to the outputs of the corresponding n-1 terodyne, the inputs of which are connected to the synchronizer, and the second inputs of the control switches are connected to the corresponding outputs of the shift register, the input of which is connected to the output of the clock generator. 2. The device for coordinated reception of information in tropospheric communication lines according to claim 1, characterized in that the first outputs of n switches are connected to n delay lines through n attenuators, the inputs of which are connected to the control device.

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