RU2779079C1 - Radio communication system with mobile objects - Google Patents

Abstract

FIELD: communication technology.

SUBSTANCE: invention relates to a high-frequency radio communication system and is intended for data transmission between mobile and stationary subscribers. The result is achieved through the introduction of a computational communication module (CCM), which provides procedures for spatial and frequency separation of channels that implement the retransmission of undelivered receipts for a correctly received message using the CCM of mobile objects and ground-based communication complexes located in a stable communication zone relative to the source and recipient of information.

EFFECT: increase in the noise immunity of the system and reduction in the reliable information delivery time.

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Description

The invention relates to a high-frequency (HF) radio communication system and is intended for data transmission between mobile and fixed subscribers.

A known radio communication system [1], the principle of operation of which is that from each RF ground station (NS) emit marker signals in the first slot of each frame of the TDMA channel access protocol at all frequencies, which are periodically assigned and activated in the control center of the RF system RF communications. To implement the FDMA protocol for accessing communication channels, according to which different HF ground stations have different sets of active operating frequencies, each HF airborne station is registered at the corresponding HF ground station at the best HF communication frequency selected by the HF airborne station based on the results of its assessment of the quality of reception of marker signals . Then, between the HF ground station and the HF aircraft station registered on it, packet data is exchanged until the quality of the Air-to-Ground channel of the HF band allows. If the quality of the Air-Ground channel of the HF band deteriorates below the permissible level, a new channel is selected at the HF onboard station and registered on this channel at the new or old HF ground station, but at a new operating frequency. Through the terrestrial communication subsystem, packet data is exchanged between each HF ground station and air traffic control and airline control centers, as well as the control point of the HF communication system. At each RF ground station, the best frequency for receiving messages from each other RF ground station is selected based on the results of assessing the quality of marker signal reception using additional RF ground-to-ground receivers and ground-to-ground demodulators of a single-tone multi-position phase shift keying signal. The audibility table is formed based on the results of the selection of the best reception frequencies, in which they indicate the sign of their availability (inaccessibility) for the terrestrial communication subsystem, the identifiers of the ground stations and the corresponding numbers of the best reception frequencies with the codes of the recommended maximum allowable data transfer rates. On each frequency channel, one channel access frame slot is allocated for transmitting messages in the Ground-to-Ground direction. The audibility table is transmitted simultaneously by N RF transmitters in slots that are allocated for ground-to-ground reporting. Then receive tables of audibility from other RF ground stations at pre-selected best reception frequencies using additional RF receivers and demodulators "Earth-to-Earth" single-tone multi-position phase-shift keying signal. The Earth-to-Earth network connectivity table is formed on the basis of the received audibility tables, which indicate the identifiers of ground stations with signs of their availability (unavailability) for the terrestrial communication subsystem and the corresponding numbers of the best reception and transmission frequencies with codes of recommended maximum allowable data transfer rates. The Earth-to-Earth network connectivity table is used to select communication frequencies (receive and transmit) with other HF NS. A data packet received at an inaccessible HF ground station from an HF on-board station registered on it is transmitted simultaneously with the audibility table via the HF radio channel in the "Ground-to-Ground" slot to another available HF NS, from which it is broadcast to the ATC control center or UAL or to the control point of the HF communication system through the terrestrial communication subsystem. A data packet from an ATC or ATC control tower or from a CCP destined for an HF aircraft station that is registered to an inaccessible HF ground station is transmitted through the ground communication subsystem to an accessible HF NS, from which it is then broadcast over the HF ground-to-ground radio channel range to an inaccessible HF ground station, and from which it is then transmitted via the HF air-to-ground radio channel to the HF airborne station. The data packet from the CCP, addressed to the inaccessible HF ground station, is transmitted through the terrestrial subsystem to the accessible HF ground station, from where it is broadcast over the HF ground-to-ground radio channel to the inaccessible HF ground station.

The disadvantages of analog are as follows:

- it is impossible to improve the efficiency of the information transmission system without a significant change in the operation algorithms and software and hardware;

- the time of information delivery is long;

- due to the need to organize multi-channel work, the implementation of this method requires dozens of ground stations, communications between them and the corresponding computing resources, which makes it difficult to use such equipment in mobile objects.

There is a known method for protecting narrow-band data transmission channels in conditions of multipath propagation of radio signals and a set of tools for its implementation [2], in which on the transmitting side of the data transmission channel there is a message packet generator and serially connected modulator, power amplifier and transmitting antenna, as well as a module for forming and conversion of bit packets, containing a generator of bit packets with guard intervals before the packets, the input of which is connected to the generator of message packets, and the output is connected to the first input of the code modulator, to the second input of which the generator of expanding signals is connected, the output of the code modulator is connected to the input of the bit duration converter, the output of which is connected to the input of the multiplexer, the output of the multiplexer is connected to the input of the modulator, and on the receiving side of the data transmission channel, a receiving antenna, an amplifier and a demodulator, an inverse conversion module and a processing module are connected in series. ducts of received signals, containing a signal duration converter, the input of which is connected to the output of the demodulator, and the output is connected to the first input of the multi-channel code decoder of packets, the second input of which is connected to the output of the shaper of copies of expanding signals, the output of the multi-channel code decoder of packets is connected to the input of the multi-channel solver, the output of which is connected to the input of the signal delay converter, the output of which is the output of the module for inverse conversion and processing of received signals.

The disadvantages of analog should include:

- lack of mutual synchronization between the transmitting and receiving parties, which worsens the reliability of information transmission and increases the time of message delivery;

- in moving objects, the communication range always changes, which affects the delay of radio signals in time, and for time-shifted and not synchronized signals, the cross-correlation may not be equal to zero. They can interfere with each other, which is why Walsh coding and corresponding decoding must be synchronized [3, p. 86].

A complex of means of protecting narrow-band radio communication systems in a complex radio-electronic environment is known, which, by most significant features, is taken as a prototype [4]. The complex on the transmitting side of the radio communication system contains a message source connected in series, a discrete signal generator, an encoder, a phase generator, a phase modulator, a power amplifier and a transmitting antenna. On the receiving side, the complex contains a receiving antenna connected in series, a microwave amplifier and a phase demodulator, as well as a threshold decision device, the first input of which is connected to the output of the threshold shaper. The output of the deciding threshold device is connected to the input of the converter of discrete message signals, from the output of which information is supplied to consumers. On the transmitting side of the radio communication system, an initial PM signal generator of the transmitting side is additionally introduced, the outputs of which are connected to the corresponding inputs of the adder of the original PM signals, the outputs of the adder of the original PM signals are connected to the corresponding inputs of the encoder. On the receiving side of the radio communication system, a generator of the initial PM signals of the receiving side, a series-connected analog-to-digital signal converter, a signal scaler for compressing the PM video packet of the message in time, an impulse noise compensation device, an interpolation device, an amplitude normalizing device and a decoder with correlation processing are additionally introduced. PM of the message signals, the outputs of which are connected to the corresponding inputs of the adder of discrete signals, the output of the adder of discrete signals is connected to the second input of the decision threshold device, the outputs of the shaper of the initial PM signals of the receiving side are connected to the corresponding inputs of the decoder with correlation processing of the PM of the message signals, while the analog input digital signal converter is connected to the output of the phase demodulator.

The prototype has the following disadvantages:

- the specifics of the organization of ground-air communications are not taken into account, namely, the fact that, due to compliance with the requirements for electromagnetic compatibility of onboard equipment, the power of the onboard HF transmitter should not exceed a certain value (usually 400 W), and the radiation pattern of the onboard HF antenna from - due to the possibility of finding the respondent in any direction in azimuth - circular - the communication channel "air-to-ground" has a low energy potential compared to ground-based means, to exclude mutual influence, the transmitting and receiving radio centers of the ground-based communication complex (NCS) are geographically separated;

- not using all the advantages of diversity reception;

- the low energy potential of the on-board-to-ground channel reduces the quality of the received signals and often leads to the impossibility of detecting them, this phenomenon is especially undesirable if a positive receipt is not received (in the case of reliable reception of the correspondent's message), because due to the specifics of the implementation of the IR method, this leads to to the re-implementation of the finishing procedure for packages that are actually already finished.

The technical task is to increase noise immunity and reduce the delivery time of reliable information by organizing the retransmission of a positive receipt not delivered to the correspondent through the computing communication modules (CCMs) of neighboring software and / or NCS, which are currently located in the zone of stable communication with the correspondent and with the respondent. A zone of stable communication is an area of airspace in which the required signal-to-noise ratio is provided at the current time [4, 5, 6].

The specified technical result is achieved by the fact that a radio communication system with mobile objects (software) containing transmitting equipment, which includes a message source, a discrete signal generator, an encoder, a generator of the original FM signals of the transmitting side, an adder of the original FM signals, a phase shaper, a modulator, an amplifier power and transmitting antenna, and receiving equipment, which includes a receiving antenna, a microwave amplifier, a demodulator, a threshold generator, a threshold solver, a discrete signal adder, a generator of the initial PM signals of the receiving side, a decoder with correlation processing, an amplitude normalizing device, an interpolation device, an impulse noise compensation device, a signal scaler, a discrete message signal converter and an analog-to-digital converter (ADC) of signals, includes territorially separated terrestrial communication complexes, each of which contains more than non-line-of-sight transmitting and receiving radio centers connected by two-way communications between themselves by a terrestrial data transmission network and over the air, if located in a stable communication zone, connected with computing communication modules of mobile objects that are currently in the stable communication zone, and each naval software contains a calculator to which a group of n modems and a group of (m-n) modems are connected by two-way connections, with m>n, transmitting channel-forming equipment of n channels, the first receiving channel-forming equipment of n channels, the second receiving channel-forming equipment of (m-n) channels , a module for generating message packets with guard intervals before packets and a scheme for generating a pilot signal (preamble), a module for generating a time scale based on the marks of the receiver of signals from global navigation satellite systems, a module for scanning frequencies for the presence of ringing signals in them, a module for monitoring the quality of communication channels , automatic selection ora probabilistically optimal at a given time for a given correspondent of the operating frequency from the list of assigned and automatic compilation of a communication channel, a module for controlling the coding and decoding procedure, adapting to the current signal-interference situation in terms of data transfer rate by sequentially increasing redundancy, a module for message acknowledgment and automatic re-request packets received with errors, a module for relaying receipts for his message to a certain correspondent, a module for hardware control and generation of messages to the recipient of information, while the input/output of the calculator is the input/output of the system.

The module for generating message packets with guard intervals before the packets and the pilot signal generation circuit (preamble) includes a discrete signal generator and a message source connected by two-way connections to the calculator, the inputs of which are the system inputs, while the outputs of the information message source are connected to the corresponding inputs of the generator discrete signals.

The module for hardware control and generation of messages to the recipient of information includes a distributor of discrete signals of messages connected in series and a converter of discrete signals of messages, the outputs of which are the outputs of the system, while the control and control buses of the computer are connected by two-way connections to the corresponding inputs/outputs of the distributor and the converter of discrete signals, and the input of the distributor of discrete message signals is connected to the information output of the calculator.

The module for controlling the coding and decoding procedure, adapting to the current signal-interference situation in terms of data transfer rate by sequentially increasing redundancy and reducing the information transfer rate includes an encoder connected by two-way communications through a calculator, a generator of initial PM signals of the transmitting side, the outputs of which are connected to the inputs of the encoder , adder of initial PM signals, phase shaper, signal scaler, impulse noise compensation device, interpolation device, amplitude normalizing device, decoder with correlation processing, source PM signal generator of the receiving side, the outputs of which are additionally connected to the corresponding inputs of the decoder with correlation processing of PM signals messages, a discrete signal adder, a threshold generator, a threshold decision device, the input of which is additionally connected to the output of the threshold generator.

The structure of the transmitting channel-forming equipment of n channels includes n parallel chains, each of which consists of a power amplifier and a transmitting antenna connected in series, while the inputs of the power amplifiers are connected through a group of n modems to the corresponding information outputs of the computer, the control and monitoring buses of which are connected by two-way connections to the corresponding inputs/outputs of power amplifiers and a group of n modems.

The composition of the first receiving channel-forming equipment of n channels includes n parallel chains, each of which consists of a receiving antenna and a microwave amplifier connected in series, while the outputs of the microwave amplifiers are connected through a group of n modems to the corresponding information inputs of the computer, the control and monitoring buses of which are connected two-way connections to the corresponding inputs/outputs of microwave amplifiers and a group of n modems.

The composition of the second receiving channel-forming equipment from (m-n) channels includes (m-n) parallel chains, each of which consists of a receiving antenna and a microwave amplifier connected in series, while the outputs of the microwave amplifiers through a group of (m-n) modems are connected to the corresponding information inputs of the calculator, the control and monitoring buses of which are connected by two-way connections to the corresponding inputs / outputs of microwave amplifiers and a group of (m-n) modems.

The essence of the system will be clear from the application materials and the presented figures. In FIG. 1 shows a block diagram of a radio communication system with mobile objects, where the designations are introduced:

1 - ground communication complex (NKS);

2 - computational communication module (CCM) of a moving object;

3 - terrestrial data transmission network;

4 - transmitting radio center NKS;

5 - receiving radio center NKS;

6 - outputs of the terrestrial network 3 for data transmission for connecting other NCSs;

7 - conditionally shows the traffic of an undelivered receipt for a sent and correctly received message from the remote BMC 2 PO.

In FIG. 2 shows a block diagram of the Navy 2, where the designations are introduced:

8 - calculator;

9 - group of n modems;

10 - a group of (m-n) modems, while m>n;

11 - transmitting channel-forming equipment of n channels;

12 - the first receiving channel-forming equipment of n channels;

13 - the second receiving channel-forming equipment from (m-n) channels;

14 - a module for generating message packets with guard intervals before packets and a pilot signal (preamble) generating circuit, the inputs of which are system inputs;

15 - module for generating a time scale based on the marks of the receiver of signals from global navigation satellite systems;

16 - module for scanning frequencies for the presence of ringing signals and markers NKS 1;

17 - module for monitoring the quality of communication channels, automatic selection of the probabilistically optimal at a given time for a given correspondent of the operating frequency from the list of assigned ones and automatic compilation of a communication channel;

18 - module for controlling the coding and decoding procedure, adapting to the current signal-interference situation in terms of data transfer rate by successively increasing redundancy and reducing the information transfer rate;

19 - module for acknowledging messages and automatically re-requesting packets received with errors;

20 - relaying module to a certain correspondent of receipts for his message;

21 - module for hardware control and generation of messages to the recipient of information;

22 - input / output of the system.

In FIG. Figure 3 shows a block diagram of the module for generating message packets with guard intervals before packets, a scheme for generating a pilot signal (preamble), the inputs of which are the inputs of the system, and the following notation is introduced:

23 - message source;

24 - discrete signal generator.

In FIG. 4 shows a block diagram of the module for hardware control and the formation of messages to the recipient of information 21, the outputs of which are the outputs of the system, and the following designations are introduced:

25 - converter of discrete signals of messages; 44 - distributor of discrete message signals.

In FIG. 5 shows a block diagram of the module for controlling the coding and decoding procedure, adapting to the current signal-interference situation in terms of data transfer rate by sequentially increasing redundancy and reducing the information transfer rate 18, and the following notations are introduced:

26 - encoder;

27 - generator of the original FM signals of the transmitting side;

28 - adder of the original FM signals;

29 - phase shaper;

30 - analog-to-digital converter (ADC) of signals;

31 - signal scale converter;

32 - impulse noise compensation device;

33 - interpolation device;

34 - amplitude normalizing device;

35 - decoder with correlation processing;

36 - generator of the initial FM signals of the receiving side;

37 - adder of discrete signals;

38 - decisive threshold device;

39 - threshold former.

In FIG. 6 shows a block diagram of the transmitting radio frequency paths of the system and introduced the notation:

40 - power amplifier and;

41 - transmitting antenna.

In FIG. 7 shows a block diagram of the receiving radio frequency paths of the system and introduced the notation:

42 - microwave amplifier;

43 - receiving antenna.

The radio communication system operates as follows.

Before organizing a communication session, all subscribers participating in the information exchange must know the communication plan and numbers assigned to all subscribers of the frequency channel system with reference to a specific subscriber and to a single time in the system.

Before communication sessions, all available frequency channels in the communication plans are evenly distributed among the ground communication complexes and information about them is entered into the Navy 2 of mobile objects so that the zones of single-hop routes of the NCS 1 with the same frequencies do not overlap. At the same time, models of zones of single-hop radio wave propagation paths of moving naval forces 2 as part of moving objects should be taken into account.

Before the start of the transmission of radio signals during a specified time interval, a sequence consisting of a specified number of symbols is emitted on the air, designed to configure the automatic gain control system, tune the transmitter, antenna matching device and stabilize transients that occur in radio equipment when receiving / transmitting radio signals.

The connection is established by sending ringing signals at the frequency of the selected i-th channel.

If at the time of connection establishment the calling modem from group 9 of BMC 2 does not have information about the quality of frequency channels, then i is taken equal to 1, otherwise the value of i is set equal to the serial number of the channel with the best quality, determined by the results of its testing using modules 16 and 17 and calculator 8.

The reason for moving to the next value i with the repetition of the connection establishment procedure on another frequency channel are:

- detection by the modem from groups 9 and 10 of occupancy of the transmission and (or) reception frequency during the time interval preceding the sending of the ringing signal;

- no response signal from the called modem of group 9. Having received the ringing signal, the modem from groups 9 or 10 of BMC 2 issues a receipt

to establish a connection and is configured to receive a signal using the expected communication protocol. If at the expected time determined by the duration of the preamble, the protocol signal is not received by the modem from groups 9 or 10 of the BMC 2, then it switches to the frequency channel scanning mode using module 16 and calculator 8.

The waiting time for a receipt for a ringing signal is determined by the receiver's tuning time to the receive frequency and the duration of the message (the duration of the preamble and data). A longer interval is used for the modem from group 9 to tune the transmitting device and the antenna matching device to the radiation frequency to transmit a response message, after which the remote modem from groups 9 or 10 of the Navy 2 proceeds to bring information using one of the protocols.

In the protocol for data exchange between spaced VMS 2 with a low energy potential of the received radio signal, a mechanism of sequential redundancy increase is implemented, which implies joint decoding of packet repetitions [6]. The relative rate of the error-correcting code is reduced by a multiple of the packet repetition number. The BMC data protocol 2 adapts to the interference environment in terms of the data rate.

The message contains a number of packets determined by the exchange protocol, as well as a receipt for it. Subsequent messages from the correspondent, sent after receiving the receipt, will contain repetitions of unfinished packets and newly sent packets. The procedure continues until positive receipts for all packages are received.

If no receipt is received within the specified time after re-requests, then the modem from group 9 of BMC 2 stops the information exchange and starts the connection establishment procedure on a frequency channel different from the current one [4, 5, 6]. After a connection is established on the other channel, the guaranteed forwarding process resumes.

The use of receiving several modems from groups 9 and 10 in each of the spaced Navy 2 allows you to increase the reliability (noise immunity) of delivery and reduce the time of data delivery.

In each of the calling messages, the total number of the frequency channel is indicated, on which a response signal is expected to be received (the receiving channel of the first i-th modem from group 9 BMC 2, corresponding to its transmission channel. After enumeration of all frequency channels, the j-ro receiving channel of the modem of the remote BMC is indicated .

If the BMC has one transmitter and several receivers, then the receivers with the corresponding modems are tuned to the same receive channel frequency, the modems perform independent signal processing (detection, synchronization, reliability assessment) followed by a “soft” addition of the demodulator decisions and their decoding in module 18 using calculator 8 [6].

The communication protocol defines the order of sequential data transmission on a single carrier frequency, in which an automatic retransmission request scheme is used in combination with a sequential redundancy method based on, for example, a turbo code [6] to ensure packet delivery. On the transmitting side, each information block is supplemented with a checksum, after which it is encoded, for example, at a rate of ¼ in such a way that it is converted into a sequence of four code blocks. Data transmission is carried out by the transmitting side by alternating transmission of information frames by the transmitting side and receipts confirming the quality of message reception by the receiving side. Code blocks are transmitted sequentially, which allows you to change the information rate depending on the propagation conditions (from no redundant - with successful transmission on the first attempt to ¼ of the technical one - for four repetitions of the message).

After performing these procedures in the BMS 2, where there is information at its input, a ringing radio signal with the address of the respondent is formed and radiated into the air. A remote mobile object with BMC 2, located in the zone of stable communication, receives a ringing radio signal, analyzes it and, if the address in it matches the address of its own BMC 2, then a response receipt is generated in it - confirmation. If the calling subscriber authentically accepted the receipt, then it is considered that the communication channel has been created and the communication session can be started.

After composing the channel on the transmitting side in the module 14 of the BMC 2 of the corresponding moving object, from the information available at the output of the source 23 of information messages in the shaper 24 of discrete signals, packets of messages are formed that are converted to a form convenient for the following operations, for example, if necessary, they are converted into digital form using analog-to-digital conversion and pulses of a single time scale in the system from module 15, reduce its redundancy, form packets of a given duration with guard intervals, pilot signals (preambles), information. The pilot signal is needed to indicate the beginning of the packet on the receiving side. It must differ in structure from information, be noise-immune, orthogonal to it, and carry data, for example, about the address, the exact (system) time of data transmission, etc. Therefore, the pilot signal and information are formed, for example, by multiplying them by different orthogonal sequences in module 14 [6, 7].

Then, in module 18, the symbols in the packets are encoded at a given data rate, modulated in the corresponding modem from group 9, converted into radio signals that enter one of the n channels of equipment 11, where, for example, they are amplified and, after passing through the antenna matching device and transmitting antenna are radiated into space. A modem is a device that combines a modulator and a demodulator that perform the corresponding functions.

The exact (system) frame transmission time is provided by synchronizing the time scale of the module 15, for example, by one-second marks from the output of the receiver of global navigation satellite systems with an antenna [8].

The width of the spectrum and other parameters of the output radio signal at the output of the modulator from the group of modems 9 is formed by the filtering method and match it with the bandwidth of the radio channel to implement the optimal information transfer rate.

On the receiving side of the communication channel, multipath radio signals reflected from the ionosphere, through the corresponding channel of the equipment 12 or 13, consisting, for example, of serially connected receiving antenna and microwave amplifier, where the transmitted radio signals are distinguished from others, are fed to the input of the corresponding modem from group 9 or 10 , are demodulated and sampled to simplify further digital signal processing [6]. The threshold level when sampling the received signals (the number of quantization levels) is determined by the maximum level of noise and interference at the output of the microwave amplifier. Then, in module 15, for example, a strobe is formed in the time interval where the pilot signal is expected to appear, for example, using a timing circuit with advanced and late gating [6, Fig. 10.13 sheet 648]. The efficiency of pilot signal extraction is determined, for example, by the autocorrelation function of the signal selected during its formation, for example, a Barker code with a low level of its side lobes [2, 5, 6, 8]. When extracting a pilot signal from the received signals, for example, correlation processing is carried out by multiplying them by a copy of the transmitted pilot signal, generated, for example, in accordance with the Barker code [2, 5, 6, 8] in module 15. At the same time, the embedded in information on the exact (system) time of transmission of the packet and the signal delay time in the radio channel is determined, which is very important when exchanging data between naval forces of 2 moving objects, since even with a single-hop radio signal propagation path over a distance of 3000 km, the delay value can be up to 10 ms. This information is necessary to set to zero the nodes that carry out the procedures for generating prototype codes of source codes in order to accurately reproduce the received messages and increase their reliability. The pilot signal synchronizes the time scale of module 15 for reception, with the help of which, after sampling the received signals in module 12 or 13, they are decoded in module 18 with the selection of the preamble and information, together with the calculator 8, are checked for validity and, in case of correct reception, at the output of module 21 messages are formed to the recipient of information of the required form.

When decoding in module 19, for example, correlation processing of the received signals is carried out by multiplying the signals by copies of the signal system, for example, Walsh and Barker, coming from the calculator 8 [2, 6, 7].

In the process of checking the reliability in the calculator 8 solves the problem of choosing the level of the threshold, which is determined by the maximum level of interference in the channel.

During the movement of moving objects using the module 16 and the calculator 8 is scanning known to all subscribers of the system frequencies ground communication complexes 1. This procedure allows, for example, by the value of the signal-to-noise ratio, using module 17 and calculator 8, to select a channel with a probabilistically optimal frequency at a given time and take it into account in further communication sessions. In case of receiving a message with its address in BMC 2, it is processed in accordance with the procedures discussed above. If the receipt of the correct reception of the message of the Navy 2 of another mobile object is not received, then the receipt is considered not delivered, the addresses of the source and recipient of information are recorded in the memory of the calculator 8, a repeated communication session is organized with this recipient of information at the frequency of the received receipt, which allows during the waiting time allocated for receiving receipts to rebroadcast it, to exclude repetitions of correctly received messages and thereby increase the noise immunity of the system. The waiting time for a receipt about the correct reception of a message can be equal, for example, to the total time of triple the duration of the receipt plus the delay time in the paths for receiving, processing, transmitting messages and broadcasting them over the ground network 3 data transmission with inputs/outputs 6 for other NCS 1. To increase noise immunity provides that the duration of the receipt does not exceed the stationarity time of the communication channel.

To reduce the delivery time of messages, for example, high noise immunity of the preamble can be provided due to additional coding, which significantly exceeds the noise immunity of information packets.

During a communication session, modulators from modem group 9, transmitters and transmitting antennas of equipment 11 in BMC 2 are considered elements of the forward channel, and receiving antennas and receivers of equipment 12 and 13, demodulators in modem groups 9 and 10 are elements of the reverse channel for receiving messages from another remote BMC 2.

The implementation of individual modules of the system is as follows. When transmitting messages from the discrete signal converter 25 to the nodes 26-29 connected to the calculator 8 to perform noise-correcting coding operations, the outputs of the generator of the initial PM signals of the transmitting side 27 are connected to the corresponding inputs of the encoder 26 [4].

To take advantage of frequency diversity, radio signals are transmitted in different bands over n channels. The implementation of frequency diversity procedures is carried out using n transmitting antennas 41 and n power amplifiers 40, which are part of the transmitting channel-forming equipment of n channels 11. Each of the transmitting antennas 41 is connected to a group of n modems of the transmitting radio center through the corresponding power amplifier 40.

A feature of receiving radio signals is that the first receiving channel-forming equipment 12 of n channels includes n receiving antennas 43 and n microwave amplifiers 42, and the second receiving channel-forming equipment 13 of (m-n) channels includes (m-n) receiving antennas 43 and ( m-n) microwave amplifiers 42. Each of the n receiving antennas 43 of the first receiving channel-forming equipment 12 is connected to a group of n modems of the receiving radio center through the corresponding microwave amplifier 42. And each of the (m-n) receiving antennas 43 of the second receiving channel-forming equipment 13 is connected to a group of (m-n) modems of the receiving radio center through the corresponding microwave amplifier 42.

The receiving antennas 43 and the microwave amplifiers 42 in the channel-forming apparatuses 12 and 13 are identical. The number of channels per reception should always be greater than m>n, since in order to take advantage of the frequency and space diversity, radio signals are received from different sources in different bands.

When receiving messages after the ADC 30, the nodes connected by two-way connections to the calculator 8: the signal scaler 31, the impulse noise compensation device 32, the interpolation device 33, the amplitude normalizer 34, the decoder with correlation processing 35, the shaper of the initial PM signals of the receiving side 36, the adder discrete signals 37, the threshold decision device 38, the threshold shaper 39, convert the discrete signals to the form required for processing by the calculator 8 [4]. To perform the required procedures when performing noise-immune decoding operations, the input of the decision threshold device 38 is additionally connected to the output of the threshold generator 39, and the outputs of the generator of the original PM signals of the receiving side 36 are connected to the corresponding inputs of the decoder with correlation processing 35. After processing by the calculator 8, the signals are transmitted to the distributor 44 discrete message signals are bred through the appropriate channels using converters 25 of discrete message signals, from the outputs of which information of the required form is supplied to consumers.

The buses (inputs/outputs) of the calculator 8, connected with the nodes of the system, are divided into information ones, indicated in Fig. 3 - fig. 7 with one-way links, and the command and control indicated in FIG. 3 - fig. 7 two-way connections.

Naval Forces 2 can also be used in the ground communications complex 1, since it is similar in structure and functions to the Naval Forces 2 of the airborne communications complex. The only difference is that the number of transmitting and receiving facilities and the radiation power in the NCS 1 is greater than on board, the transmitting radio center 4 is removed from the receiving center beyond the line of sight and in the retransmission mode of the receipt of the correct reception of the message from the Navy 2 to the recipient of the information receiving radio center 5 is broadcast to the transmitting radio center 4 over the terrestrial data network 3. The computational communication module as part of the onboard or ground communication complexes of the HF range provides data exchange in the operating mode with automatic selection of the optimal radio channel by frequency from a list of predefined ones and adaptation by information transfer rate.

To improve noise immunity, methods of frequency and spatial diversity of channels are used. In the first case, the number of receiving means in the Navy 2 is always greater than that of transmitting ones, which makes it possible to receive a message from a larger number of means and then carry out appropriate processing, for example, voting, learn the gain in the signal-to-noise ratio, and, consequently, improve noise immunity. In the second case, the message on the terrestrial data network 3 with inputs/outputs 6 is transmitted to several NCS 1 and radiated into space. Due to the different propagation paths and operating frequencies in the VMS 2, the radio signals arrive uncorrelated, and after appropriate processing, the best signal can be selected [4].

VMS 2 supports operation on both the same and different transmit and receive frequencies, which is important for providing communication with long-haul aircraft. The BMC 2 can provide, from the user's point of view, a single-responder co-op mode that allows them to redistribute the available radio paths. The use of one or more Naval Forces 2 modems in the joint operation mode allows the use of territorially separated transmitting and receiving ground communication complexes as repeaters for a certain correspondent of radio signals from Naval Forces 2 having a low energy potential, including receipts of the correct reception of the message sent by this correspondent.

The calculator 8 together with the module 17 VMS 2 provides quality control of the communication channels, on the basis of which the selection of the probabilistically optimal frequency at a given point in time is carried out. Channel quality control is carried out by means of one-sided and two-sided probing both in automatic mode and on command. In modems 9 and 10 BMC 2 signal-code constructions are used, built on the basis of using, for example, a turbo code and Walsh and Barker sequences [3, 6, 7].

In the standby mode, the modems 9, 10 and the equipment 11, 12, 13 of the Navy 2, together with the calculator 8, scan their receiving frequencies of each of the available channels for the presence of ringing signals of other system subscribers.

The module 21 together with the calculator 8 implements the hardware control of the HUD 2 with the output of the received data to its output or through the calculator 8 and input/output 22 to external systems.

The technical result of the invention consists in increasing the noise immunity of the HF radio communication system due to diversity in frequency and space, the use of orthogonal signals and turbo codes that are closest to the Shannon limit [6], ensuring the timeliness of message delivery by reducing the number of re-requests of invalid data over reverse communication channel. The reliability of message transmission and their reproducibility with a given accuracy for information recipients are increased by introducing pilot signal processing procedures, taking into account the constantly changing delay time of radio signals in the communication channel, and ensuring mutual synchronization between the transmitting and receiving sides of the system.

The radio communication system can be implemented in software and on modern serial hardware and software and serial integrated circuits. VMS 2 can be implemented using the "programmable radio" (SDR) technology and is a hardware platform, made, for example, on the basis of the domestic VLSI 1892 VM14Ya with external modules.

It is possible to use BMC 2 at various communication objects, for example, when interacting with external control equipment via interfaces (input/output 22): MKIO, Ethernet, RS-232, ARINC-429 and via interfaces: S1-TCH GOST 23578-79 and Ethernet - for connection to channel-forming equipment.

When exchanging data between computing communication modules, not only re-request of a receipt is used, but also retransmission of receipts through the NCS or Navy of mobile objects located in the stable communication zone (where the signal-to-noise ratio exceeds the specified value), relative to the correspondent and the respondent located in the stable communication zone at the same time with the respondent and with the correspondent, which ensures its guaranteed completion and the exclusion of repeated inquiries.

Frequency diversity reception and the transition to a more powerful noise-correcting coding scheme and its integration into the procedures of the successive redundancy enhancement method can reduce the number of repetitions required for reliable packet delivery, and, as a result, increase the noise immunity and information rate in the communication channel. In addition to increasing the speed, the use of turbo coding makes it possible to increase the range of acceptable signal-to-noise ratios, in which it remains possible to ensure high-quality and timely delivery of data to the selected subscriber.

Literature:

1. RF patent for invention No. 2286030, publication date 10/20/2006 Bull. No. 29.

2. RF patent for invention No. 2663240, publication date 08/03/2018 Bull. No. 22.

3. Berlin A.N. Digital cellular communication systems. - M.: Eco-Trends, 2007. - 296 p.

4. RF patent for invention No. 2720215, publication date 04/28/2020 Bull. No. 13 (prototype).

5. M.V. Ratynsky. Fundamentals of cellular communications / Ed. D. B. Zimina - M.: Radio and communication, 1998. 248 p.

6. Sklyar, Bernard. Digital communication. Theoretical foundations and practical application. Ed. 2nd, corrected: Per. from English. - M.: Publishing house "William", 2003. 1104 p.

7. H.F. Harmut. Information transfer by orthogonal functions. Per. from English. N.G. Dyadyunova and A.I. Senina, M., "Communication", 1975. 272 p.

8. GPS - global positioning system. - M.: PRIN, 1994, 76 p.

Claims (9)

A radio communication system with mobile objects (software) containing a message source, a discrete signal generator, an encoder, a generator of initial PM signals of the transmitting side, an adder of initial PM signals, a phase shaper, a power amplifier, a transmitting antenna, a receiving antenna, a microwave amplifier, a threshold shaper, a decisive threshold device, adder of discrete signals, generator of initial PM signals of the receiving side, decoder with correlation processing, amplitude normalizing device, interpolation device, impulse noise compensation device, signal scaler, message discrete signal converter and analog-to-digital converter (ADC) of signals, different because includes territorially separated terrestrial communication complexes, each of which contains transmitting and receiving radio centers remote from each other at a distance of more direct visibility, connected by two-way connections between themselves by a terrestrial data transmission network and over the air, if located in a stable communication zone, associated with computing communication modules (Navy) mobile objects currently in the zone of stable communication, and each VMS software contains a computer to which are connected by two-way connections: a group of n modems and a group of (m-n) modems, with m>n, transmitting channel-forming equipment of n channels, the first receiving channel-forming equipment of n channels, the second receiving channel-forming equipment from (m-n) channels, an analog-to-digital converter, a module for generating message packets with guard intervals before packets and a pilot signal generation scheme, a module for generating a time scale based on the marks of the receiver of signals from global navigation satellite systems, a module for scanning frequencies for the presence of ringers in them signals, a module for monitoring the quality of communication channels, automatic selection of the probabilistically optimal operating frequency for a given correspondent at a given time from the list of assigned ones and automatic compilation of a communication channel, a module for controlling the encoding and decoding procedure, adapting to the current signal-interference situation in terms of speed data transmission by successively increasing redundancy, a module for acknowledging messages and automatically re-requesting packets received with errors, a module for relaying receipts to a certain correspondent for his message, a module for hardware control and generating messages to the recipient of information, while the input / output of the calculator is the input / output of the system, the module for generating message packets with guard intervals before the packets and the pilot signal generation circuit includes a discrete signal generator and a message source connected by two-way connections to the calculator, the inputs of which are the system inputs, while the outputs of the information message source are connected to the corresponding inputs of the discrete signal generator, the module for hardware control and generation of messages to the recipient of information includes a distributor of discrete signals of messages connected in series and a converter of discrete signals of messages, the outputs of which are the outputs of the system, while the control and control buses of the calculator are connected by two-way connections to the corresponding inputs/outputs of the distributor and the converter of discrete signals, and the input of the distributor of discrete message signals is connected to the information output of the calculator, the module for controlling the coding and decoding procedure, adapting to the current signal-interference situation in terms of data transfer rate by sequentially increasing redundancy and reducing the information transfer rate includes two-way communications connected through a calculator: an encoder, an ADC of signals, a generator of the initial PM signals of the transmitting side, the outputs of which connected to the encoder inputs, an adder of initial PM signals, a phase shaper, a signal scaler, an impulse noise compensation device, an interpolation device, an amplitude normalizer, a decoder with correlation processing, a shaper of the initial PM signals of the receiving side, the outputs of which are additionally connected to the corresponding inputs of the decoder with correlation processing of PM message signals, a discrete signal adder, a threshold generator, a threshold decision device, the input of which is additionally connected to the output of the threshold generator, the transmitting channel-forming equipment of n channels includes n parallel chains, each of which consists of a power amplifier and a transmitting antenna connected in series, while the inputs of the power amplifiers are connected through a group of n modems to the corresponding information outputs of the calculator, the control and monitoring buses of which are connected by two-way connections to the corresponding inputs/outputs of power amplifiers and a group of n modems, the first receiving channel-forming equipment of n channels includes n parallel chains, each of which consists of a series-connected receiving antenna and a microwave amplifier, while the outputs of the microwave amplifiers are connected through a group of n modems to the corresponding information inputs of the computer, the control and monitoring buses of which are connected two-way connections to the corresponding inputs / outputs of microwave amplifiers and a group of n modems, the composition of the second receiving channel-forming equipment from (m-n) channels includes (m-n) parallel chains, each of which consists of a receiving antenna and a microwave amplifier connected in series, while the outputs of the microwave amplifiers through a group of (m-n) modems are connected to the corresponding information inputs of the calculator, the control and monitoring buses of which are connected by two-way connections to the corresponding inputs / outputs of microwave amplifiers and a group of (m-n) modems.

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