RU2677261C1 - Satellite control channels radio suppression method - Google Patents

Abstract

FIELD: radio engineering and communications.SUBSTANCE: invention relates to the communication technology, in particular for the artificial radio interference creation, and can be used for radio suppression (RS) of the satellite command-program radio links (CPRL), operating according to the CCSDS standards. For the satellite control channels radio suppression, receiving the radiation source signals in all operation sub-bands of Δf, Δf… Δf, identifying the detected signal as the “spacecraft-to-Earth” (“SC-Earth”) control channels (CC) signal, determining and memorizing the “Earth-SC” CC frequency value, generating the control signals by the transmission mode and emitting the interfering signal at the frequency, corresponding to the “Earth-SC” CC previously stored frequency. Evaluating the CC RS efficiency, for which re-receiving the of the radiation source signal at the “SC-Earth” CC frequency, and recording the information presence therein, transmitted for the purpose of the telecommands handshaking from the ground control station. If this information takes place, then successively increasing the interfering signal effective isotropically radiated power until the transmission of acknowledgments of the telecommands reception on the “SC-Earth” CC frequency is ceased.EFFECT: technical result of the invention consists in the development of the satellite CC RS method, providing the satellite CC RS with previously unknown operating frequencies and the RS efficiency objective monitoring during jamming.3 cl, 4 dwg

Description

The invention relates to the field of radio engineering, and in particular to the technique of creating artificial radio interference, and, in particular, can be used for radio suppression (RP) of satellite command and program radio links (CPRL) operating according to CCSDS (Consultative Committee for Space Data Systems, International Advisory Space Data Transmission Systems Committee) [1].

KPRL is a radio link providing official communication between the spacecraft (SC) and the ground control station (NSU).

A known method of forming radio interference: Paly A.I. Electronic warfare. - M.: Military Publishing House, 1989. - S. 34, Fig. 2.11. The analogue includes receiving a signal from a radiation source, determining the parameters of this signal (carrier frequency, type of modulation and spectrum width), shaping the structure of the modulating interference voltage, modulating the exciter signal with the obtained modulating voltage. Amplification and broadcasting of an interfering radio signal. However, this analogue has the following drawback - it provides radio interference suppression only for radio lines whose subscribers operate at the same frequency in simplex mode (alternating operation of the source and receiver transceivers) and is not able to reliably suppress modern communication systems using effective methods to combat signal fading and interference in the communication channel, based on the frequency diversity of the reception and transmission channels (duplex frequency separation between the channels of forward and reverse transmission).

A known method of forming radio interference: Europatent EP 0293167 A2, published 30.11.88, bull. 88/48, IPC Н04К 3/00. This analogue includes receiving a signal from a radiation source, determining the frequency and structural parameters of this signal (carrier frequency, transmission duration, start and end transmission of an adjacent “friendly” transmitter), shaping the structure of the modulating interference voltage, modulating the carrier vibration with the received modulating voltage, amplifying the modulated interference signal and its broadcasting only after the operation of the adjacent transmitter. However, this analogue does not provide suppression of radio interference modern communication systems using frequency diversity channels for receiving and transmitting messages.

The closest in its technical essence to the claimed is the method of RP communication channels according to the patent of the Russian Federation No. 2104616 C1 of 02/10/98, IPC Н04К 3/00, publ. 02/10/98, bull. Number 4.

The prototype method includes receiving signals from radiation sources, determining their parameters, measuring the total time during which there is no signal reception at the operating frequencies of the radiation sources in a given period of time, distributing the temporary suppression resource between the operating frequencies of the radiation sources subject to RP. The formation of the structure of control signals that specify the operation mode of the transmission control device and the structure of modulating voltages. Modulation of the pathogen signals, their amplification in the interference transmitter and broadcasting in the mode specified by the signal of the transmission control device according to the temporary suppression resource, for an interval equal to the time of no reception at the suppressed frequency.

The disadvantages of the prototype method are:

- the implementation of the RP only those communication systems that use a limited number of operating frequencies and information on the degree of their workload is completely a priori known;

- lack of monitoring of the effectiveness of jamming.

The aim of this invention is to develop a method of RP satellite control channels (KU), providing RP satellite KU with previously unknown operating frequencies and objective monitoring of the effectiveness of RP when jamming.

, где n - условный номер частоты КУ "Земля-КА", k - условный номер частоты КУ "КА-Земля", а величина соотношения

задана предварительно. Формируют сигналы управления режимом передачи, где в качестве параметров используют ширину спектра и вид модуляции сигнала КУ "КА-Земля" f_{КУ"КА-Земля"}. Модулируют, усиливают и излучают помеховый сигнал с уровнем эквивалентной изотропно излучаемой мощности (ЭИИМ), равным максимально заявленному уровню ЭИИМ наземной станции управления (НСУ) на частоте, соответствующей ранее запомненному значению частоты КУ "Земля-КА" f_{КУ"Земля-КА"}. Оценивают эффективность РП КУ, для чего повторно принимают сигнал источника излучения на частоте КУ "КА-Земля" f_{КУ"КА-Земля"}, фиксируют наличие в нем информации, передаваемой в целях квитирования телекоманд с НСУ. При этом, если в сигнале источника излучения информация, передаваемая в целях квитирования телекоманд с НСУ отсутствует, то РП считают эффективным, в обратном случае итеративно на ΔР (%) увеличивают ЭИИМ помехового сигнала и оценивают эффективность РП КУ до тех пор, пока при очередной итерации в принятом сигнале КУ "КА-Земля" f_{КУ"КА-Земля"} не будет отсутствовать информация, передаваемая в целях квитирования телекоманд с НСУ.This goal is achieved by the fact that in the known RP method, they receive signals from a radiation source, determine their parameters, generate control signals for the transmission mode and structure of the modulating voltages, modulate, amplify and emit interference signals. Signals of the radiation source are received in all sub-ranges of operation Δf _1, Δf ₂ ... Δf _i , where i is the number of the sub-range of operation of the radiation source. The detected signal is identified as the signal of the spacecraft - Earth spacecraft ("KA-Earth") f _{KU "KA-Earth"} . Determine and store the frequency value of the KU "Earth-KA" f _{KU "Earth-KA"} , and the frequency value is calculated by the ratio

, where n is the conditional frequency number of the spacecraft KA-Earth, k is the conditional frequency number of the spacecraft KA-Earth, and the ratio

predefined. Generate signals transmission mode control, where the parameters used and the type of the spectrum width modulation signal KU "Earth-spacecraft" f _{KU "KA-Earth".} The interfering signal is modulated, amplified and emitted with an equivalent isotropically radiated power (EIRP) level equal to the maximum declared level of the EIRP of the ground control station (NLM) at a frequency corresponding to the previously stored frequency value of the KU Earth-KA f _{KU Zemlya-KA} . Evaluate the effectiveness of the RP KU, for which they re-receive the signal of the radiation source at the frequency KU "KA-Zemly" f _{KU "KA-Zemly"} , record the presence of information transmitted in it for the purpose of acknowledging telecommands with NSU. At the same time, if the information transmitted for the purpose of acknowledging telecommands with NSIs is not available in the signal of the radiation source, then the RP is considered effective, otherwise the EIRP of the interference signal is iteratively increased by ΔР (%) and the efficiency of the RP KU is evaluated until the next iteration in the received signal of KA-KA-Zemly f _{K KA-Zemly KU} there will be no information transmitted for the purpose of acknowledging telecommands from the NSO.

Thanks to the new set of essential features, in the claimed method, the satellite RP is implemented with previously unknown operating frequencies and objective monitoring of the effectiveness of the RP when jamming is performed.

The claimed method is illustrated in the following figures:

in FIG. 1 reflects the essence of the claimed technical solution;

in FIG. 2 - RP algorithm of satellite KU;

in FIG. 3 - frame structure of the channel level standard CCSDS;

in FIG. 4 - structure of the acknowledgment field of telecommands of the CCSDS standard.

In FIG. 1 numbers indicate: 1 - NSU KA, 1.1 - path for receiving NSU KA, 1.2 - path for transmitting NSU KA, 2 - source of radiation (KA), 2.1 - frequency KU "KA-Zemly", which contains receipts for receiving telecommands with NSU , 2.2 - frequency control unit “Earth-KA” for transmitting control telecommands to the spacecraft, 3 - automatic jamming station (ASA), 3.1 - radiation path of the interfering signal, 4 - monitoring post (PC) ASP, 4.1 - receiving channel of the ASP ASP monitoring the effectiveness of RP satellite KU.

The possibility of implementing the proposed method is explained by the following. It is known, see, for example, pages 330-333 [2], that satellite spacecraft control radars operate as follows. When the spacecraft (object 2 in Fig. 1) enters the radio-visibility zone of the NSU (object 1 in Fig. 1), tracking of the expected satellite movement along the sky begins with the antenna systems of the NSU, and the operating frequencies of the NSU transceivers are set in accordance with the operating frequencies of the onboard spacecraft equipment. At the frequency of the KU Zemlya-KA f _{K KU Zemlya-KA} (channel 1.2 of facility 1 in Fig. 1), telecommands from the NSU are issued to control the spacecraft's onboard equipment and bookmark the flight mission. At the same time, on the frequency of the control channel "KA-Earth" f _{KU "KA-Earth"} (channel 1.1 of object 1 in Fig. 1), receipts are received on the execution of telecommands. Values of receipts for receiving telecommands with NSOs are also available for PC ASP (channel 4.1 of facility 4 in Fig. 1) when equipped with appropriate receivers of signals of the KA-Earth earth.

Since the frequency value of the KU Earth-KA f _{KU Zemlya-KA is} determined based on the frequency of the KU KA-Zemly f _{KU KA-Zemly} , the jamming from the TSA (channel 3.1 object 3 in Fig. 1 ) at a frequency of "f _{KU" Earth-KA "} will lead to the fact that the on-board equipment of the KA will not receive telecommands from the NSU. Accordingly, in the signal of a radiation source at a frequency of KU" KA-Zemlya f _{KU "KA-Zemlya"} (channel 2.1 object 2 in Fig. 1), there will be no information transmitted for the purpose of acknowledging telecoms from the NSO.

These circumstances make it possible to judge the effectiveness of jamming by monitoring the TSA PC (through channel 4.1 of facility 4 in Fig. 1) of the information transmitted for the purpose of acknowledging telecommands from the NSO at the frequency of KA-Zemlya _KU-Zemlya , i.e., the effectiveness of RP satellite CPRL. Thus, the presence of information transmitted for the purpose of acknowledging telecommands from the NSO at the frequency of KA-Zemlya _{KU KA-Zemly} indicates a low efficiency of jamming at the frequency of KA-Zemlya _{K KA-Zemlya} .

In this case, the EIRP of the interfering signal is iteratively increased by ΔР (%), and the ΔР value is selected in the range (5-15)%. The indicated increase is performed until, during the next iteration, the information transmitted for the purpose of acknowledging the telecommands from the NSO is absent in the received signal of the KA-Zemly KU KA- _{Zemly KU} . At full, i.e. effective RP satellite KPRL, at a frequency of KU "spacecraft Earth" f _{KU "spacecraft Earth"} to be completely absent information transmitted in the order acknowledgment telecommand with the NSO.

The proposed method of RP satellite KU is implemented by the following sequence of actions (see algorithm in Fig. 2).

At the initial stage, the signals of the radiation source are received in all subbands of its operation Δf ₁ , Δf ₂ ... Δf _i , where i is the number of the subband of operation of the radiation source. The operating ranges of the radiation source are predefined for a particular CPRL, see, for example, pp. 34-35, 151-162 [6].

To identify the received signal as a signal of the spacecraft KA-Earth, it is compared with the reference signal from the database. The parameters of the reference signal can be both time-frequency characteristics (frequency, type of modulation, clock speed), and the element-wise structure of the data packets of demodulated signals (frame length, control field values, mechanism for calculating packet checksums). For example, as the parameters of the reference signal of the KA-Earth KU in the CCSDS standard, the element-wise structure of the channel layer protocol TM-SDLP (Telemetry Space Data Link Link Protocol, channel level telemetry protocol, Fig. 3) can be used [7].

, где n - условный номер частоты КУ "Земля-КА", k - условный номер частоты КУ "КА-Земля", а величина соотношения

заранее определена для конкретной КПРЛ, см., например, стр. 151-152, 155-156 [6].Next, determine the value of the frequency (KU) of the Earth-KA f _{KU Earth-KA} , and the frequency value is calculated by the ratio

, where n is the conditional frequency number of the spacecraft KA-Earth, k is the conditional frequency number of the spacecraft KA-Earth, and the ratio

predefined for a specific CPRL, see, for example, pp. 151-152, 155-156 [6].

The transmission mode control signals are generated, where the spectrum width and the type of modulation of the signal of the KA-Earth control channel f _{KA KA-Earth} are used as parameters. The interfering signal is modulated, amplified and emitted with an EIRP level equal to the maximum declared level of the EIRP of the NSU at a frequency corresponding to the previously stored value of the frequency of the Earth-KA _{KU of the Earth-KA} (the value of the EIRP is known and determined, see [6 , 8]).

After that, the effectiveness of the RP KU is evaluated, for which they re-receive the signal of the radiation source at the frequency KU-KA-Zemly f _{KU KA-Zemly} , and record the presence of information transmitted in it for the purpose of acknowledging telecoms from the NSU. Such information can be, for example, the values of receipt parameters for receiving CLCW telecommands (Communications Link Control Word, channel control word, Fig. 4) of the channel level protocol TM-SDLP of the CCSDS standard, see pages 53-59 [9]. At the same time, if the information transmitted in order to acknowledge telecommands with NSIs is absent in the signal of the radiation source, then the RP is considered effective, in the opposite case iteratively by ΔР (%), and the ΔР value is selected within (5-15)%, the EIRP of the interference the signal and evaluate the effectiveness of the RP KU until then, in the received signal of the KA-KA-Earth f _{K KA-Zemly, the} transmission of information transmitted for the purpose of acknowledging the telecommands from the NSO is stopped.

Thus, when interfering with the frequency of the KU Earth-KA f of the _{KU Zemlya-KA} and monitoring the information transmitted for the purpose of acknowledging telecommands from the NSU, at the frequency of the KU-Zemlya f _{KU KA-Zemly} , the ability to control the effectiveness of RP satellite CPRL.

These circumstances allow us to judge the achievement of the goal of the proposed technical solution, which is ensured only by the consistent implementation of all of the above actions.

References.

1. Official CCSDS website. Internet link https://public.ccsds.org.

2. Manuylov Yu.S. et al. Control of spacecraft and means of the ground control complex. - SPb .: VKA named after A.F. Mozhaysky, 2010 .-- 609 p.

3. Paly A.I. Electronic warfare. - M.: Military Publishing House, 1989, p. 34, fig. 2.11.

4. Europatent EP 0293167 A2, published 30.11.88, bull. 88/48, IPC Н04К 3/00

5. Volkov V.E., Churovsky S.R., Shishkov A.Ya. The method of radio suppression of communication channels. RF patent No. 2149512 for application No. 95103151/09, dated March 6, 1995.

6. Radio Frequency and Modulation Systems: Part 1. Earth Stations and Spacecraft, CCSDS 401.0-B, October 2016.

7. TM Space Data Link Protocol. Recommendation for Space Data System Standarts, CCSDS 132.0-B-1, September 2003.

8. Nasa System Engineering Processes and Requirements 4. (NPR 723.1A, 03/26/2007).

9. Packet Telecommand Standard. ESA PSS-04-107 Issue 2, April 1992.

Claims (3)

1. The method of radio suppression (RP) of satellite control channels (CC), which consists in receiving signals from a radiation source, determining their parameters, generating control signals for the transmission mode and structure of the modulating voltages, modulating, amplifying and emitting interference signals, characterized in that receive the radiation source signals in all sub-bands of the operation Δf ₁ , Δf ₂ ... Δf _i , where i is the number of the sub-band of the radiation source, identify the detected signal as a signal spacecraft-Earth (KA-Earth) f _{KU ”KA-Earth”} , determine and remember the value of KU “Earth-KA” f _{KU ”3emlya-KA”} , and the frequency value is calculated by the ratio

, where n is the conditional frequency number of the spacecraft KA-Earth, k is the conditional frequency number of the spacecraft KA-Earth, and the ratio

preset, the transmission mode control signals are generated, where the spectrum width and the modulation type of the KA-Earth control channel signal f _{KA “KA-Earth”} are used as parameters, the interference signal is modulated, amplified and emitted with an equivalent isotropically radiated power level (EIRP ), equal to the maximum declared level of the EIRP of the ground control station (NSU) at a frequency corresponding to the previously stored value of the frequency of the KU “Earth-KA” f _{KU “3emlya-KA”} , after which the effectiveness of the RP KU is evaluated, for which it is re-adopted by signal source of radiation at a frequency KU "KA-earth" f _{KU "KA-earth"} fix presence therein of information transmitted in the order acknowledgment telecommand with NSO, wherein if a signal radiation source information transmitted in the order acknowledgment telecommand with NLF is absent, then RP is considered effective; otherwise, it is iteratively increased by ΔР (%) the EIRP of the interfering signal and the effectiveness of the RP KU is estimated until, at the next iteration in the received signal of the KA-Earth _{KU-KA-Earth KU ”} There will be no information transmitted May in order to acknowledge telecommands from the NSO. 2. The method according to p. 1, characterized in that the identification of the detected signal as a signal KU "KA-Earth" is carried out by comparing with the reference values of the signals KU "KA-Earth" from the database. 3. The method according to p. 1, characterized in that the value of ΔP (%) is chosen in the range of ΔP (%) = (5-15)%.

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