RU2611606C1 - Method of adaptation of modes of transmitting information over satellite communication channels in conditions of atmospheric disturbances and device for its implementation - Google Patents

Abstract

FIELD: communication.

SUBSTANCE: invention relates to satellite radio communication and can be used to organize a higher quality satellite communication under atmospheric disturbances. For this purpose the method of adaptation of the modes of transmitting information over satellite communication channels in the conditions of atmospheric disturbances and the device implementing it used is adaptive evaluation and adaptive prediction of the signal-to-noise ratio in a satellite communication channel, receiving a prediction error, transmitting to a central Earth station the status information and the prediction error data for each radio channel in the network, making a decision and (or) its correction on the central Earth station on setting parameters of transceiving information for active satellite communication network terminals.

EFFECT: technical result is increasing capacity of a satellite communication channel (network).

2 cl, 7 dwg

Description

The inventions are united by a single inventive concept, relate to radio communications technology, and in particular to methods and devices for adapting information transmission modes via satellite communication channels under the influence of atmospheric disturbances, and can be used to organize higher quality communications under conditions of atmospheric disturbances.

As an alternative to backbone transport and access networks, which provide the unification of a large number of interactive applications within the framework of a single IP / MPLS network platform (high-quality digital telephony, video conferencing, file data exchange, Internet access services) multiservice satellite communication networks are used. These networks make it possible to reserve large-scale telecommunication networks of state structures and provide services regardless of the location of users and the state of terrestrial communication channels.

Modern multiservice satellite networks operate via C-, Ku-, Xa-band transponders within the TCP / IP protocol stack and multiple access technologies defined by the international standards DVB-S (S2), DVB-RCS and in-house recommendations. Due to the high frequency loading of C-band transponders (4/6 GHz), satellite networks are built using the frequency capacitance of the transponders in the Ku (11-12 / 14 GHz) and Ka (20/30 GHz) bands. However, these ranges are characterized by an increased influence of atmospheric disturbances (rain, snow, clouds, tropospheric scintillations) on the attenuation of the energy of relayed radio signals, as a result of which a number of satellite technologies implement methods for adapting channels to changing the propagation conditions of radio waves based on a change in the type of modulation and noise-resistant coding, and also the level of transmission in power (radiation). With any adaptation methods used that compensate for attenuation, energy redundancy is provided, which is determined by recommendations for calculating long-term attenuation (Recommendation ITU-R P.618-10 (10/2009) “Propagation data and prediction methods necessary for system design Earth-to-space communications ”) and guaranteeing the required reliability of receiving information in the worst weather conditions.

A known method of a multi-parameter adaptive radio system for transmitting discrete information (A.S. No. 1585902 (SU). A multi-parameter adaptive radio system for transmitting discrete information / A.G. Salikov et al. // BI. 08.15.1990), in which In order to increase the reliability of information reception in the KB and VHF radio communication systems, according to the results of the reception quality assessment and depending on the noise situation in the communication channel, the following parameters are reconstructed: the carrier frequency of the radio station, radiation power, and information transmission speed character symbols, as well as the type of modulation and coding method.

The disadvantage of this method is the lack of an adaptive system for assessing the state of the channel and the threshold nature of the adjustment of the channel parameters that do not take into account the statistical characteristics of the interference effects and the time taken to adapt. Under conditions of uncertainty regarding the nature of the interference effect, energy redundancy is necessary and, as a result, a decrease in the potential throughput of the communication channel.

A known method of adapting spread spectrum modulation and coding (Patent No. EP 2360855 (US). Adaptive spreading, modulation, and coding / Gilat Satellite Networks, Ltd. // DP. 08.24.2011), in which the signals from the transmitting station to the receiving are presented a stream of data blocks transmitted with a specific value of the coefficient of expansion, the type of modulation and coding rate. In addition, neighboring blocks of information transmitted through the same channel may differ in the indicated parameters depending on the signal-to-noise ratio, thereby increasing the throughput of the communication channel.

The disadvantage of this method is the lack of an adaptive assessment of the quality of the communication channel and, as a result, limited bandwidth due to the input information redundancy to ensure a given accuracy of information reception (retransmission requests for erroneously received blocks).

Closest to the claimed technical solution is the method of organizing adaptive satellite communications (Patent No. 2373647 (RU). The method of organizing adaptive satellite communications / L.V. Kognovitsky et al. // BI. 20.11.2009), in which the signals from workstations to the base the station and from the base station to the workstations are transmitted after analyzing the state of each radio channel and the parameters of the information transmitted through it at the base station, the results of which are multi-parameter sequential adaptation of the type of separation of channels, coding method, modulation type, transmission speed, carrier frequency value, transmission power and position of the operating point of the power amplifier to the state of the radio channel and the parameters of the transmitted information.

The disadvantage of the prototype method is the lack of an adaptive assessment system for the state of the communication channel during the period of quasistationary channel and forecasting on the adaptation interval. Also, the prototype method does not involve the correction of the decision based on the results of evaluating the error in predicting the state of the communication channel. The absence of this system does not allow to effectively realize the potential bandwidth of the communication channel without realizing the estimation of the communication channel in dynamics and without reducing the energy and information redundancy for a given reliability of information reception.

Known adaptive information transfer systems that implement known adaptation methods:

1) Frequency-adaptive radio link described in the article "Adaptive radio communication in communication systems for special purposes" authors Antonyuk L.Ya., Semisoshenko MA in the journal "Telecommunication" No. 5, 2007;

2) Automated complex of technical means for adaptive decameter radio lines of the authors A. Buzova, S. Eliseeva, Yu. I. Kolchugina and others described in the Bulletin of SONIIR, No. 1 (11), 2006, pp. 27-32.

The disadvantage of these complexes is that they are supposed to introduce information redundancy in the structure of the transmission cycle for constant sounding (channel estimation) at operating frequencies in order to obtain information about the channel status and, as a result, the potential bandwidth of the communication channel is not realized.

Closest to the invention is a device for adapting radio channels using artificial intelligence (Patent No. 2405265 (RU) "Method for adapting radio channels using artificial intelligence and a device for its implementation" / S.I. Beda, A.A. Katanovich and others. // November 27, 2010), which periodically measures the quality of the communication channel, compares it with an acceptable level, exchanges data with the correspondent about new adaptation parameters, namely, changing the operating frequency, type of modulation and coding, using wherein the artificial intelligence system to gain experience successful operation of the communication channel. The device consists of a series-connected control electronic computer with special adaptation mode software, a signal conversion device, a driver, a power amplifier, an antenna matching device and a transmitting antenna, as well as a series-connected receiving antenna, an antenna switch and a receiver, the output of which is connected to an analog input signal conversion device. The output of the signal conversion device is in turn connected to the input of the terminal switch equipment. In this case, the control outputs of the control electronic computer are connected to the control inputs of the receiver, pathogen, power amplifier, antenna matching device, and terminal equipment switch. The device also includes an electromagnetic environment control unit, the input of which is connected to one of the outputs of the antenna switch, and an artificial intelligence system as part of the control electronic computer. This system consists of a database of the external environment, a database of adaptation parameters, a matrix of priorities and special software for self-training and the definition of new adaptation parameters. At the same time, the digital output of the electromagnetic environment monitoring unit is connected to the first input of the external environment database, the second and third inputs of which supply data from the common time system and the general object information exchange system. The output of the database of the external environment is connected to the first input of the priority matrix, and the input of the database of adaptation parameters is connected to the output of special adaptation software, and the output of the database of adaptation parameters is connected to the second input of the priority matrix.

The disadvantage of this adaptation device is the low realized bandwidth of the satellite communication channel, which can be achieved by minimizing the energy and information redundancy of the satellite channel. This drawback is a consequence of the lack of a system for adaptive dynamic estimation of a communication channel, a system for predicting the state of a communication channel over the inertia interval of the adaptation process control cycle, and also a correction system for decisions made when setting parameters of modem equipment transceiver based on the results of an analysis of the prediction error of the state of satellite communication channels.

The objective of the patented group of inventions is a method for adapting information transmission modes via satellite communication channels under the influence of atmospheric disturbances and implementing it, which allows to increase the throughput of a satellite communication channel (network) for transmitting user information by minimizing the energy redundancy introduced to compensate for short-term attenuation of the radio signal when exposed to atmospheric disturbances, as well as minimizing the information redundancy introduced for ostovernoy evaluation and prediction of satellite channel status, providing the required level of reliability of data reception and readiness of the communication channel.

The problem is solved in that in the known method of organizing adaptive satellite communications, in which multiple access signals are received at a satellite interactive terminal (CIT) (workstation), amplified by a satellite communications repeater, from the central earth station (CSC) (base station) and from DSS, reinforced by a satellite communications repeater, to the SIT after analyzing the status of each radio channel and parameters of information transmitted through it at satellite interactive terminals of the network, based on the result which carry out a multi-parameter sequential adaptation of the encoding method, type of modulation, transmission speed and position of the operating point of the power amplifier (RT UM) depending on the state of the radio channel and the parameters of the transmitted information. The method also introduced a system of adaptive assessment of the communication channel (with or without the use of test signals). This system is designed to reduce the amount of service information (information redundancy) about the state of the communication channel, thereby increasing the throughput of the communication channel. Additionally, a system for predicting the state of the communication channel taking into account the inertia of the control cycle, as well as a correction system for the configuration of modem equipment to increase the throughput of the communication channel (network) due to the analysis of the forecast error of the state of the channel after the inertia of the control cycle, was introduced. The received radio signal at the SIT is analyzed (evaluated by the method without a test or with a test sequence) and data is accumulated to realize the prediction of the signal-to-noise ratio. Next, information about the state of the communication channel is transmitted to the central earth station. At the DSC, this information is analyzed and a decision is made on the purpose of the operating modes of the network terminals, namely by the type of modulation and coding, and the transmission powers are redistributed (change the position of the RT UM) between the DSC carrier frequencies for various radio directions (SIT) depending on the signal-to-noise ratio in each of the radio directions in order to increase the throughput as communication channels (networks). After receiving service information on the operating mode of the terminal at the CIT, the operating mode set at the previous adaptation step is adjusted. Then, the prediction error is calculated as the difference between the current signal-to-noise ratio and the predicted value. According to the magnitude of the forecasting errors, the channel estimation method is determined to increase the forecasting accuracy, forecasting parameters, form and transmit requests from the SIT to the CZS to correct the operating modes of the network equipment.

The problem is solved in that in a known device containing: a control electronic computer (computer) SIT and a read-only memory (ROM) included thereto with software for managing adaptation modes, the output of which is connected to the input of the ROM with installation software new adaptation parameters and with ROM input with a database of adaptation parameters; serially connected signal conversion device and quality control device; antenna post of satellite interactive terminal; a satellite router with the functions of a switch of terminal equipment, while the control output of the control computer CIT is connected to the control inputs of the satellite router and the quality control device, characterized in that it also includes a receiving path and a series-connected demodulator, decoder and decoder, and the input the reception path is connected to the output of the SIT antenna post, the first output of the reception path is connected to the input of the signal conversion device, and the second output is connected to the input satellite router; a transmission path and sequentially connected modulator, encoder and encoder, wherein the input of the transmission path is connected to the output of the satellite router, and the output of the transmission path is connected to the input of the SIT antenna post; a prediction unit, a random access memory of a programmable logic integrated circuit and a prediction error determination unit, connected in series with the quality control device; moreover, the output of the prediction error determination unit is connected to the first input of the SIT control computer, the output of the quality control device is connected to the second input of the forecast error determination unit, the output of the forecasting unit is connected to the second input of the SIT control computer; as part of the control computer CIT, read-only memory with user interface software, the output of which is connected to the second input of ROM with software for managing adaptation parameters, and a read-only memory with software for managing communication channel estimation and forecasting, the output of which is connected to the first input of ROM with software for managing adaptation modes; wherein the control output of the control computer SIT is connected to the control inputs of the reception path, transmission path, prediction unit and random access memory of a programmable logic integrated circuit; a central earth station for making decisions and correcting the operating modes of satellite interactive network terminals and an associated DSP antenna post, as well as a DSS central storage computer with read-only memory with software for setting new adaptation parameters and an associated ROM with the base data adaptation parameters.

According to the patented group of inventions, multiple access radio signals are generated at the DSC, amplified and relayed to the network terminals, and in each active SIT, the current channel estimation is carried out by the method with or without a test sequence. The choice of the communication channel estimation mode depends on the accuracy of the forecast and the analysis of the forecast error after the lag time of the control cycle. Then, information on the status of satellite communication channels from all active satellite terminals is transmitted via the reverse control channel. At the DSC, this information is analyzed and a decision is made to set the operating modes of the terminals, namely, by the type of modulation and coding, and the transmission power is redistributed (change the position of the RT UM) between the DSC carrier frequencies for different radio directions (SIT) depending on the signal-to-noise ratio in each from radio directions. After receiving service information on the operating mode of the terminal at the SIT, the operating mode established at the previous step of the adaptation cycle is adjusted.

Thanks to a new set of essential features in the method and device that implements it, the throughput of satellite communication channels (networks) is increased by minimizing the energy redundancy introduced to compensate for short-term attenuation of the radio signal when exposed to atmospheric disturbances, as well as information redundancy introduced for reliable assessment and predicting the status of the satellite channel, providing the required level of reliability of information reception and availability of the communication channel and. The analysis of the prior art made it possible to establish that analogues that are characterized by a combination of features that are identical to all the features of the claimed technical solution are absent, which indicates the compliance of the claimed method and device that implements it with the patentability condition of "novelty".

Search results for known solutions in this and related fields of technology in order to identify features that match the distinctive features of the prototype of the claimed method showed that they do not follow explicitly from the prior art.

The prior art also did not reveal the fame of the distinctive essential features that determine the same technical result, which is aimed at solving the problem, therefore, the claimed invention meets the condition of patentability "inventive step".

The possibility of implementing the inventive method on modern computing processors, for example, using programmable logic integrated circuits (FPGAs) allows us to claim its "industrial applicability".

The claimed method is illustrated by drawings, which show:

FIG. 1 - structure of a multimedia satellite communications network;

FIG. 2 - a generalized sequence of actions to adapt the modes of information transfer in satellite communication channels;

FIG. 3 - sequence of actions for adaptive assessment of a communication channel;

FIG. 4 - a sequence of actions to correct the assessment and prediction of the state of the communication channel;

FIG. 5 - sequence of actions for correction of information transmission modes;

FIG. 6 - dependence of the current and predicted values of the signal-to-noise ratio with respect to time;

In FIG. 7 shows a device for adapting information transmission modes via satellite communication channels to the conditions of atmospheric disturbances.

The possibility of implementing the claimed method is illustrated as follows. In FIG. Figure 1 shows multimedia networks for satellite communication of interactive access, where: 101 - CZS, 102 - communication relay located on board the spacecraft in a geostationary orbit, 103 - SIT, 106 - variant of atmospheric disturbances in the direction of the communication relay - SIT N. In the direct satellite channel 104 from the DSC 101 through the communication relay 102, data streams for all satellite interactive terminals of the network 103 (CIT 1, CIT 2, ..., CIT V) are transmitted in a single multiplexed high-speed digital stream on several carriers. According to the generalized adaptation flowchart of FIG. 2, before the start of the satellite communication session, data are input for the transceiver equipment on the SIT, namely: the frequency of reception and transmission, the modulation mode, coding and position of the RT UM (transmit power level) in accordance with the calculated data of the attenuation of the radio signal for a long period, availability the communication channel K _g (for example, from 0.95 to 0.9999) and the minimum value of the forecast error ε _min .

The inertia time is determined by forming a test sequence. After the sequence has passed through the communication channel to the DSC, its return to the SIT, and also taking into account the signal processing in the SIT and DSC equipment, this inertia time is recorded and transmitted as a binary code signal to the adaptation control system, where this value is stored in the memory cells for the period of the communication session.

Multiple access radio signals are generated at the central locking station, amplified and relayed to each SIT network, where they subsequently receive these radio signals and analyze the state of the radio channel based on the evaluation results.

The channel estimation procedure 203 is explained in more detail in FIG. 3.

, где k=1, 2, …, ∞, Т_е - период оценки (период накопления выборочных значений для получения оценки). На СИТ осуществляется демодуляция M-позиционного радиосигнала фазовой или амплитудно-фазовой манипуляции (MPSK, APK) в приемной части модемного оборудования. Процесс оценки канала по методу максимального правдоподобия связан с обработкой поступающих из приемного тракта (синфазной и квадратурной ветви демодулятора) комплексных коэффициентов

, n=1, 2, ..., N и опорной последовательности N пилот-символов

(Wang Kun+, Research on SNR Estimation of Signals in Galileo SAR System, Wu Si-liang and Zhu Sheng-yu, Radar Technology Institute, Beijing Institute of Technology, Beijing 100081, P.R. China).The noise immunity state of a satellite channel is estimated by the ratio of the signal energy per symbol to the noise power spectral density

, where k = 1, 2, ..., ∞, T _e is the evaluation period (the period of accumulation of sample values to obtain an estimate). At the SIT, the M-position radio signal of phase or amplitude-phase manipulation (MPSK, APK) is demodulated in the receiving part of the modem equipment. The process of channel estimation by the maximum likelihood method is associated with the processing of complex coefficients coming from the receiving path (in-phase and quadrature branches of the demodulator)

, n = 1, 2, ..., N and the reference sequence N pilot symbols

(Wang Kun +, Research on SNR Estimation of Signals in Galileo SAR System, Wu Si-liang and Zhu Sheng-yu, Radar Technology Institute, Beijing Institute of Technology, Beijing 100081, PR China).

Assuming that the reception conditions are characterized by the effect on the useful signal m _{k of} additive white Gaussian noise z _k with zero mathematical expectation and unit dispersion, the signal at the output of the demodulator can be represented by the sum:

,

- синфазная и квадратурная составляющие принятой суммы сигнала и шума,Where

,

- in-phase and quadrature components of the received sum of the signal and noise,

P _S - signal power,

P _N - noise power.

301 и опорной последовательность N пилот-символов

303, полученных путем стробирования (аналого-цифрового преобразования) демодулированных сигналов с синфазной и квадратурной ветвей демодулятора. Проверку на наличие команды управления по выбору метода оценки осуществляют в 302 (по умолчанию определен метод без использования тестирующей последовательности). Количество получаемых значений комплексных коэффициентов

и

определяют частотой дискретизации сигнала

. Причем значение частоты дискретизации фиксировано и получено на основе многочисленных экспериментальных данных по анализу характера интенсивности ослаблений радиосигнала в Ku-, Ka-диапазоне «ясного неба» (под влиянием тропосферных сцинтилляций) и воздействия осадков (дождя) (Илюхин А.А., Вдовин А.В. «Математическое моделирование динамики ослабления радиосигнала в спутниковом канале Ku-диапазона с заданными статистическими свойствами», Издательство «Радиотехника», «Электромагнитные волны и электронные системы» №3 2015 г. стр. 4-10).The communication channel estimation procedure (Fig. 3) involves synchronization and accumulation of complex coefficients in the memory cells

301 and the reference sequence of N pilot symbols

303 obtained by gating (analog-to-digital conversion) of demodulated signals from the in-phase and quadrature branches of the demodulator. Checking for the presence of a control command for choosing an evaluation method is carried out in 302 (by default, a method is defined without using a testing sequence). The number of obtained values of complex coefficients

and

determine the sampling rate of the signal

. Moreover, the value of the sampling frequency is fixed and obtained on the basis of numerous experimental data on the analysis of the nature of the intensity of radio signal attenuation in the Ku-, Ka-band of “clear sky” (under the influence of tropospheric scintillations) and the effect of precipitation (rain) (Ilyukhin A.A., Vdovin A .V. “Mathematical modeling of the dynamics of attenuation of a radio signal in a Ku-band satellite channel with specified statistical properties”, Radiotechnika Publishing House, Electromagnetic Waves and Electronic Systems No. 3 of 2015 (4–10).

After submitting a control command to read the values from the memory cells in the microprocessor device, the estimated signal-to-noise ratios are determined by the maximum likelihood method without testing signals 304. Using the automatic gain control system for the receiving path, the signal mixture with the additive noise is normalized and evaluated the signal-to-noise ratio of each N report relative to the normalized value, thereby increasing the throughput of the communication channel due to spelling of service information symbols (reduce information redundancy) and increase the information part of the information transfer cycle (frame):

(эталонные сигналы, известные на стороне приема, в виде немодулированной несущей на фиксированных временных позициях цикла передачи). Данные значения, помимо записываемых

, также записываются в ячейки оперативной памяти. После подачи управляющей команды на считывание значений из ячеек памяти в микропроцессорном устройстве определяют оценочные показатели отношения сигнал-шум по методу максимального правдоподобия с применением тестирующих сигналов 305 (A. Aroumont. A study on SNR estimation algorithms for channel state estimation in Communication Satellite Systems employing Fade Mitigation Techniques. Space Communications 22 (2009), 31-40):Under the influence of atmospheric disturbances, in case of deterioration of the estimated performance of the satellite communication channel, leading to an increase in the error in predicting the state of the channel, a request is made for the central locking system via the reverse communication channel to change the state estimation mode — the operation mode based on pilot signals

(reference signals known on the receiving side, in the form of an unmodulated carrier at fixed temporary positions of the transmission cycle). These values, in addition to recorded

are also written to the memory cells. After submitting a control command to read the values from the memory cells in the microprocessor device, the estimated signal-to-noise ratios are determined using the maximum likelihood method using test signals 305 (A. Aroumont. A study on SNR estimation algorithms for channel state estimation in Communication Satellite Systems employing Fade Mitigation Techniques. Space Communications 22 (2009), 31-40):

- действительная часть произведения значения комплексно-сопряженного г_n и значений пилот-символов m_n.Where

- the real part of the product of the value of the complex conjugate g _n and the values of the pilot symbols m _n .

At the end of the process of evaluating the communication channel, the procedure for predicting the signal-to-noise ratio 204 with the forecast horizon equal to the inertia time of the transmission mode control cycle is carried out. Prediction is carried out by the method of exponential moving average (L. A. Safonova, G. N. Smolovik. Methods and decision-making tools. / Siberian State University of Telecommunications and Informatics // 2012, pp. 14-17). The smoothing parameter α determines the number of estimated values of the signal-to-noise ratio indicators read from the random access memory cells obtained in the previous step 203. By default, the value of this coefficient is specified as α _min , and the change step Δ _α is determined in the adaptation control system:

where α is the smoothing parameter;

Y (kT _e ) - the actual value of the signal-to-noise ratio of the measured process for the period preceding the predicted;

- экспоненциально взвешенная средняя для периода, предшествующего прогнозируемому.

- an exponentially weighted average for the period preceding the forecast.

The step of configuring the parameters for transmitting information to the CZS 205 for satellite terminals of the network is based on obtaining the predicted signal-to-noise ratios for the next control step and data on forecast errors for the current moment from all network terminals. The value of the modulation and coding mode (MODCOD) and the corresponding threshold value of the signal-to-noise ratio are selected from the condition that it should be smaller and closest to the value whose threshold value is determined at the forecast stage. Taking these factors into account, the transmission mode to the DSC changes and a control command is formed to change the parameters of the transceiver for satellite terminals via control channels.

Evaluation of the decision is carried out after the inertia time has elapsed since the receipt of the forecast estimate at the SIT in two parallel branches 207, 209 and 208, 210.

The inertia time includes the propagation time of the signal in the channel, satellite communications, and the time for processing the signals and control commands on the DSC and in the transmission and reception paths of the CIT.

The prediction error 206 is determined in the processor device as the difference between the current signal-to-noise ratio and the predicted:

where T _cor = T _e + T _in - correction time.

The correction procedure for the decision on the channel estimation mode and forecast parameters 207 and 209, namely, the implementation of adaptive estimation and adaptive forecasting, is explained in more detail in FIG. 4. The minimum value of the forecast error corresponds to ε _min specified at the data entry stage. Depending on the currently used method for estimating the communication channel and analyzing the signal-to-noise ratio prediction error obtained at the kth step, it is possible to implement an adaptive channel estimation system (using the maximum likelihood method with or without pilot signals), to which is to increase the throughput of the communication channel by reducing the symbols of the service information of the transmission cycle. For each channel estimation method used, a change in the smoothing coefficient α is provided within the interval α _min ... α _max . Finding the optimal coefficient α, they reduce the time it takes to perform the forecasting operation (reduce the computational complexity of the processes), being able to obtain a more efficient and accurate forecast in conditions of worsening signal-noise situation, that is, respond faster to its change without going beyond the period of inertia of the control cycle , and thereby increase the bandwidth of the communication channel.

The correction of the decision to set the MODCOD mode and the position of the RT UM 208, 2.10 is explained in more detail in FIG. 5, 6. For the implementation of this correction procedure, some restrictions are adopted:

1) the rate of change of the attenuation of the radio signal should not exceed a predetermined value, that is, after the inertia time has elapsed, the signal-to-noise ratio should be within the range of threshold values MODCOD _{W ± 1} relative to the set MODCOD _W (501, 508, points b and ν of Fig. 6 );

2) the MODCOD configuration is selected so that their threshold values differ by equal Δ values (Fig. 6).

Obtaining an estimate of the signal-to-noise ratio at time t and possible variants of the values of estimates at time t + T _in (points c, d, e, ƒ, m, h, s of Fig. 6), namely, the current estimate (for example, a point d of Fig. 6), a predictive estimate (for example, the point of Fig. 6) and the difference between them (forecast errors) e, allow you to generate and send requests from terminals to the DSC to correct information transceiver modes. These requests are generated by checking the conditions 502, 503, 504, 505, 506, 509, 510 in the implemented software stored in the memory cells of the permanent storage device, and exchanging data with the database of threshold values MODCOD and Δ. In turn, after receiving requests from all network terminals on the DSC, control commands are generated to set the operating mode for all SIT networks and to redistribute the transmit power level of the DSC between the carrier frequencies: for satellite interactive terminals on the carrier frequency operating in a clear sky environment, set the transmission level less by the value of the total energy redundancy of a given radio direction. At the same time, radio directions operating in conditions of atmospheric disturbances provide a large (by the value of the total energy redundancy from other radio directions) power transmission level, thereby providing conditions for the functioning of a more efficient operation mode (MODCOD) of terminals in terms of bandwidth. Then, in the transmission cycles for each SIT, control commands are formed for the operation mode of the network terminals (modulation, coding, and channel estimation mode). Thus, the redistribution of the energy potential of the DSS between the SIT and the assignment of operating modes for the SIT, operating within the framework of one leased frequency-energy resource of a satellite repeater, makes it possible to increase the throughput of the communication channel (network).

The effectiveness of the new adaptation method is confirmed by modeling the satellite communications network as part of the central earth station and 60 active satellite terminals, as well as taking into account the specified modulation and coding modes (FM2, FM2 with BCH, FM4, FM8 with BCH), the ratio of the average power at the receiver input to the input saturation power equal to -9 dB and the requirements for the reliability of reception (the probability of error per symbol is at least 10 ^-5 ). The simulation showed that as a result of a dynamic analysis of the state of satellite communication channels subject to atmospheric disturbances and without disturbances, namely, an adaptive assessment and adaptive forecasting of the state of communication channels with a forecast horizon equal to the inertia time of the control cycle, the stage of processing information on the DSC from the terminals about the state of each communication channel and stages of correction of decisions made, the adaptation process fixed the FM8 mode with BCH for the current value of the ratio of the average power at the receiver input to an apparent saturation power of -9 dB at 10% of the time of a simulated satellite communications session. Thus, the channel capacity in this mode of operation is increased by 5-8% per session period.

In FIG. 7 shows a device for adapting information transmission modes via satellite communication channels to the conditions of atmospheric disturbances. It consists of the following elements:

701 - control computer SIT;

702 - signal conversion device (OOPS);

703 — radio signal transmission path;

704 — a radio signal receiving path;

705 — satellite router with terminal equipment switch functions;

706 - quality control device (UKK);

707 - prediction block (BP);

708 - random access memory FPGA (RAM FPGA);

709 — prediction error determination unit (BOOP);

710 - SIT antenna post consisting of an antenna, a low-noise amplifier and a power amplifier;

711 - an antenna post of the central locking station as part of an antenna, a low-noise amplifier and a power amplifier;

712 - CZS;

713 - managing computer CZS;

714 - ROM with software (software) for the management of adaptation modes (CIT, CZS);

715 - ROM with a database of adaptation parameters (ROM BDPA);

716 - demodulator;

717 - decoder;

718 - decoder;

719 - encoder;

720 - encoder;

721 - modulator;

722 - ROM with user interface software;

723 - ROM with software for the installation of new adaptation parameters SIT;

724 - ROM with control software channel estimation and forecasting on SIT;

725 - satellite communication channel;

726 - system bus.

Control computers 701, 713 automatically control all the technical means included in the adaptation device using the software for managing adaptation modes 714, which is stored in ROM cells (ROM option: EP Ugryumov Digital circuitry. 3rd edition . / SPb: BVH-Petersburg // 2010, p. 307-316). The receiving path SIT 704 consists of at least a series-connected demodulator 716, a decoder 717 and a decoder 718. The transmitting path SIT 703 consists of at least a series-connected encoder 719, encoder 720 and a modulator 721 (V. B. Steshenko FPGA ALTERA firms: element base, design system and hardware description languages / M: Publishing House Dodeka XXI // 2007, p. 485-500). The first output of the SIT 704 receiving path is connected in series with UPS 702, UKK 706, BP 707, and BOOP 709. UKK 706, BP 707, and BOOP 709 can be implemented on FPGAs (K. Maxfield. FPGA Design. Architecture, Tools, and Methods . / Translation from English, Moscow: Publishing House Dodeka XXI // 2007, pp. 120-153).

To implement the adaptation process, the receiving and transmitting paths are used to generate and receive service information, as well as to obtain estimated indicators of the communication channel.

Before establishing a communication session on the SIT through the user interface software 722 stored in the ROM cells of the control computer 701, the data are entered: receive and transmit frequencies, modulation mode, coding, and transmit power (position of the RT UM) in accordance with the calculated data of the attenuation of the radio signal for long-term period, availability factor of the communication channel K _g , the minimum value of the forecast error ε _min . This information is recorded in the cells of RAM 701.

The inertia time is determined by generating a control command in the software 714 of the host computer 701 to transmit and receive a test sequence. After passing the test sequence through the communication channel to the DSC, its return to the SIT, as well as taking into account the signal processing in the SIT and CZS equipment, this inertia time is recorded and transmitted as a binary code signal on the system bus 726 to the power supply unit 707 and RAM of the control computer 701 where this value is stored in the memory cells for the duration of the communication session.

Multiple access radio signals are generated at the central locking station, amplified and relayed to each SIT network, where they subsequently receive these radio signals and analyze the state of the radio channel based on the evaluation results.

и

поступают на вход УКК 706, где определяют оценочные показатели отношения сигнал-шум (3, 4). Каждую оценку формируют после накопления в ячейках оперативной памяти ПЛИС N отчетов

(3) или N отчетов

и

(4). На второй вход УКК 706 поступает управляющая команда на выбор режима работы адаптивной оценки канала связи (без тестирующих или с тестирующими сигналами). В случае оценки канала без тестирующих сигналов в ПО 714 формируют управляющую команду, которая поступает в приемный тракт и активизирует работу системы автоматической регулировки усиления смеси сигнала и шума для получения их нормированного значения. В случае ухудшения сигнально-помеховой обстановки в ПО 714 формируется запрос на ЦЗС для перехода на оценку канала по пилот-символам и команда управления для смены режима оценки оборудования СИТ по истечении времени инерционности. Поступающие тестсигналы

также записываются в ячейки оперативной памяти. С выхода УКК 706 значения оценок отношения сигнал-шум в виде двоичного кода поступают на вход БП 707. В соответствии с начальным значением коэффициента сглаживания α_min в ячейках оперативной памяти ПЛИС накапливают значения оценок отношения сигнал-шум. Далее в БП 707 методом экспоненциального скользящего среднего (5) определяют прогнозное значение отношения сигнал-шум с горизонтом прогноза равным времени инерционности. С выхода БП 707 прогнозная оценка в виде сигнала двоичного кода поступает на вход ОЗУ ПЛИС 708 (вариант реализации: Е.П. Угрюмов Цифровая схемотехника. 3-е издание. / СПб: БВХ-Петербург // 2010, стр. 346-352), а также на второй вход управляющей ЭВМ 701. В управляющей ЭВМ 701 формируют запрос на ЦЗС с информацией о прогнозном значении оценки отношения сигнал-шум, передают ее по системной шине 726 в спутниковый маршрутизатор 705, где служебную информацию инкапсулируют в цикл передачи (кадр) обратного канала. На ЦЗС в управляющей ЭВМ 713 после обработки информации со всех СИТ сети в ПО 714 и обмена данными с ПЗУ БДПА 715 формируют команду управления (принимают решение) по режиму работы ЦЗС и режимам работы СИТ сети, а именно перераспределение мощности передачи между несущими частотами в соответствии с условиями распространения сигналов в каналах связи 725 в направлении терминалов сети и установку режимов модуляции, кодирования и оценки канала связи для каждого СИТ. Информация о смене режимов работы СИТ поступает с ЦЗС в слотах служебной информации цикла передачи прямого канала 114.UPS 702 (implementation option: a system consisting of AMBEX8, ADMDPC5016 and IS-RL-101A modules) provides analog-to-digital conversion of the in-phase and quadrature branches of the demodulator with a sampling frequency F _∂ and synchronization of the estimation procedure. Complex coefficients obtained as a result of transformations

and

enter the UKK 706 input, where the estimated signal-to-noise ratios are determined (3, 4). Each estimate is formed after accumulating N reports in FPGA RAM cells

(3) or N reports

and

(four). At the second input of UKK 706, a control command is received to select the operating mode of the adaptive assessment of the communication channel (without testing or with testing signals). In the case of channel estimation without testing signals, a control command is generated in software 714, which enters the receive path and activates the system of automatic gain control of the signal-noise mixture to obtain their normalized value. In the event of a deterioration of the signal-noise situation, software 714 generates a request for a central locking system to switch to channel estimation by pilot symbols and a control command to change the evaluation mode of the SIT equipment after the inertia time has elapsed. Incoming test signals

also written to RAM cells. From the output of UKK 706, the values of the estimates of the signal-to-noise ratio in the form of a binary code are sent to the input of the BP 707. In accordance with the initial value of the smoothing coefficient α _{min, the} values of the estimates of the signal-to-noise ratio are accumulated in the FPGA random access memory cells. Next, in BP 707, the predicted value of the signal-to-noise ratio with the forecast horizon equal to the inertia time is determined by the method of exponential moving average (5). From the output of BP 707, a predictive estimate in the form of a binary code signal is fed to the input of the FPGA 708 RAM (implementation option: EP Ugryumov Digital circuitry. 3rd edition. / SPb: BVH-Petersburg // 2010, p. 346-352) as well as to the second input of the control computer 701. In the control computer 701, a request is made to the central control center with information about the predicted value of the signal-to-noise ratio estimate, transmit it via the system bus 726 to the satellite router 705, where service information is encapsulated in a transmission cycle (frame) return channel. After processing information from all SIT networks in software 714 and exchanging data with BDPA 715 ROMs at the central control center in the host computer 713, they form a control command (make a decision) regarding the central control center operating mode and the CIT network operating modes, namely, the redistribution of transmit power between carrier frequencies in accordance with the conditions of signal propagation in the communication channels 725 in the direction of the network terminals and setting modulation modes, coding and evaluation of the communication channel for each SIT. Information about changing the operating modes of the CIT comes from the DSC in the service information slots of the forward channel 114 transmission cycle.

In the receiving path 704, the control command is decrypted and then transmitted via the system bus 726 to the third control input of the control computer 701. In the ROM with software 714, 723, 724 and after data exchange with the BDPA 715 ROM, the control command is formed to change the operating mode of the CIT equipment: the system bus is transferred to the reception path 704 and transmission 703. At the first stage of adaptation, the energy redundancy, which was introduced when setting the operating modes of the equipment in accordance with the calculated data of the attenuation of the radio signal for a long period, is reduced (data entry ).

Thus, the time of one control cycle is equal to the time of inertia: the time of signal propagation in the satellite communication channel and the time to process the signals and control commands on the CZS and in the SIT reception and transmission paths.

A predicted estimate in the form of a binary code signal from the output of the FPGA FPGA 708, delayed by the inertia time, is supplied to the first input of the BOOP 709. The second value of the estimate from the output of the BCC 706 is received to the second input of the BOOP 709. The forecast error ⎜ε⎜ is determined in BOOP 709 as the difference between the current score value and

predicted. At the second and subsequent stages of adaptation, depending on the value of ⎜ε⎜, in ROM with software 714, 723, 724 and data exchange with ROM BDPA 715 implement adaptive channel estimation, adaptive forecasting and correction of the decision on the position of the PM of the amplifier, modulation and coding, thereby increasing the efficiency of the adaptation device and, as a result, the throughput of the satellite communication channel (network).

, повышают точность прогноза за счет увеличения коэффициента сглаживания от α_min до α_max с шагом Δ_α. Эти действия позволяют отслеживать состояние канала связи в динамике, принимать решения и корректировать установленные параметры оборудования с интервалом инерционности цикла управления. Если значение ⎜ε⎜ на очередной итерации не превышает ε_min, ПО 714, хранящееся в ПЗУ, формирует команду управления для минимизации информационной избыточности, переходя на оценку канала связи без тестирующей последовательности. При этом также уменьшают коэффициент сглаживания для процесса прогнозирования с целью сокращения времени на обработку полученных оценок отношения сигнал-шум в БП 707 и как следствие повышения эффективности работы блока.If ⎜ε⎜ exceeds the minimum permissible value of the forecast error ε _min in ROM with software 714, the following step-by-step actions are provided: increase the accuracy of the estimate by using the testing sequence

, increase the accuracy of the forecast by increasing the smoothing coefficient from α _min to α _max with a step of Δ _α . These actions allow you to monitor the status of the communication channel in dynamics, make decisions and adjust the set parameters of the equipment with an inertia interval of the control cycle. If the value of ⎜ε⎜ at the next iteration does not exceed ε _min , the software 714 stored in the ROM generates a control command to minimize information redundancy, proceeding to the evaluation of the communication channel without a testing sequence. At the same time, the smoothing coefficient for the forecasting process is also reduced in order to reduce the processing time of the obtained estimates of the signal-to-noise ratio in BP 707 and, as a result, increase the efficiency of the unit.

If the forecast error exceeds ε _min and the current signal-to-noise ratio does not go beyond the threshold interval MODCOD _{W ± 1} relative to MODCOD _{W of the} previous adaptation step (i.e., the rate of change of attenuation in the communication channel is within the limits), then requests either to reduce energy redundancy, or to increase the energy of the radio link to switch to a more efficient modulation and coding mode in terms of bandwidth. After receiving requests from all network terminals on the DSC, control commands are generated to set the operation mode for all SIT networks and to redistribute the transmission power level of the DSC between the carrier frequencies. Redistribution of transmission power is carried out at the central locking station: for satellite interactive terminals on a carrier frequency operating in a clear sky environment, the transmission level is set lower by the amount of total energy redundancy for this radio direction. At the same time, radio directions operating in conditions of atmospheric disturbances provide a large (by the value of the total energy redundancy from other radio directions) power transmission level, thereby providing conditions for the functioning of a more efficient operation mode of terminals from the point of view of bandwidth. Thus, the efficiency of the satellite communications network within one leased frequency and energy resource is increased.

The effectiveness of the new adaptation method is confirmed by modeling the satellite communications network as part of the central earth station and 60 active satellite terminals, as well as taking into account the specified modulation and coding modes (FM2, FM2 with BCH, FM4, FM8 with BCH), the ratio of the average power at the receiver input to the input saturation power equal to -9 dB and the requirements for the reliability of reception (the probability of error per symbol is at least 10 ^-5 ). The simulation showed that as a result of a dynamic analysis of the state of satellite communication channels subject to atmospheric disturbances and without disturbances, namely, an adaptive assessment and adaptive forecasting of the state of communication channels with a forecast horizon equal to the inertia time of the control cycle, the stage of processing information on the DSC from the terminals about the state of each communication channel and stages of correction of decisions made, the adaptation process fixed the FM8 mode with BCH for the current value of the ratio of the average power at the receiver input to an apparent saturation power of -9 dB at 10% of the time of a simulated satellite communications session. Thus, the channel capacity in this mode of operation is increased by 5-8% per session period.

Claims (2)

1. A method of adapting information transmission modes via satellite communication channels, in which satellite interactive terminals receive multi-station access signals generated at a central earth station and amplified by a satellite relay, analyze the state of each radio channel and the parameters of information transmitted through it, according to which a multi-parameter sequential adaptation is carried out coding method, type of modulation, transmission speed, position of the operating point of the power amplifier with respect to bandwidth criterion for a given reliability of information reception, characterized in that data is input for the adaptation system to work on the satellite interactive terminal, the inertia time is determined, the signal-to-noise ratio is predicted taking into account the inertia time, and requests for the central earth station with forecast information are generated the value of the signal-to-noise ratio in the satellite communication channel, determine the communication channel estimation mode and forecast parameters, determine the forecast error after and the time lag and make requests to the central earth station for the next stages of adaptation, taking into account information about the prediction error. 2. A device for adapting information transfer modes via satellite communication channels under atmospheric disturbances for the implementation of the method according to claim 1, comprising: a control electronic computer of the satellite interactive terminal and a read-only memory device with adaptation mode management software included in it, output which is connected to the input of read-only memory with software for setting new adaptation parameters and to the input of read-only memory ablation device with a database of adaptation parameters; serially connected signal conversion device and quality control device; antenna post of satellite interactive terminal; a satellite router with the functions of a switch of terminal equipment, while the control output of the control electronic computer of the satellite interactive terminal is connected to the control inputs of the satellite router with the functions of a switch of terminal equipment and a quality control device, characterized in that it also includes a receiving path and those included in it serially connected demodulator, decoder and decoder, the input of the receiving path being connected to the output of the satellite antenna post an interactive interactive terminal, the first output of the receiving path is connected to the input of the signal conversion device, and the second output is connected to the input of the satellite router; a transmission path and sequentially connected modulator, encoder and encoder, wherein the input of the transmission path is connected to the output of the satellite router, and the output of the transmission path is connected to the input of the antenna post of the satellite interactive terminal; a prediction unit, a random access memory of a programmable logic integrated circuit and a prediction error determination unit, connected in series with the quality control device; moreover, the output of the prediction error determination unit is connected to the first input of the control computer of the satellite interactive terminal, the output of the quality control device is connected to the second input of the forecast error determination unit, the output of the prediction unit is connected to the second input of the satellite interactive terminal control computer; as part of the control electronic computer of the satellite interactive terminal, a read-only memory with user interface software, the output of which is connected to the second input of a read-only memory with adaptation parameter management software and a read-only memory with communication channel estimation and prediction control software, the output of which is connected to the first input of read-only memory from software software for managing adaptation modes; wherein the control output of the control electronic computer of the satellite interactive terminal is connected to the control inputs of the reception path, transmission path, prediction unit and random access memory of a programmable logic integrated circuit; the central earth station for making decisions and correcting the operating modes of satellite interactive network terminals and the associated antenna post of the central earth station, as well as the control earth computer with the central earth station with permanent storage device with software for installing new ones, which are part of the central earth station adaptation parameters and the associated read-only memory with a database of adaptation parameters.

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