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The effectiveness of spatial processing largely depends on the spatial structure of the antenna system - the number of antennas, their location in space. Optimization of the spatial structure makes it possible to increase the efficiency of radio systems operating under conditions of spatially correlated interference. The spatial structure determines the spatial correlation matrix of interference, the correlation properties of the channel coefficients of MIMO radio systems, as well as the matrix of mutual impedances of the receiving and transmitting antenna systems. The spatial structure affects a whole range of characteristics of the MIMO radio system, which is especially noticeable when the size of the antenna system is reduced. The dependence of capacity on the number and location of antennas in the transmitting and receiving antenna systems in the presence of interference are investigated. The capacity of the MIMO communication system is calculated when transmitting uncorrelated messages, the action of spatially uncorrelated interference, noise and the channel matrix. To construct a channel matrix using the angular spectrum and spatial structure of the antenna system in the antennas of the receiving or transmitting antenna systems. The article mentions the mutual influence of signal and interference in the antenna system using a matrix transmission coefficient, which is calculated by the matrix of mutual antenna impedances, the diagonal matrix of the load impedances of the receiving path. The article uses a linear filter to convert correlated interference into uncorrelated interference. The capacity of the system increases with an increase in the number of transmitting and receiving antennas, especially when the numbers of transmitting and receiving antennas are the same. Under the action of spatially correlated interference, the capacity decreases several times with a given number of transmitting and receiving antennas. Interference compensation depends on the number of receiving antennas. The capacity also depends on the distance between the antenna elements. With a sufficient value of the distance between the elements (greater than or equal to half the wavelength), it is possible to achieve the maximum value of the capacity and the interference compensation coefficient. The simulation results allow us to justify the choice of the number of antennas to obtain a given capacity in wireless MIMO systems. 2. Monzingo, R.A., Miller, T.W.: Introduction to Adaptive Arrays. John Wiley, New York, 1980. 448 p. 3. Telatar I.E. Capacity of multi-antenna Gaussian channels. European transactions on tele-communication, 1999, vol. 10, no 6b pp. 585-595. 4. Volker Kuhn. Wireless communications over MIMO channels: Applications to CDMA and multiple antenna systems. John Wiley & Sons, 2006. 5. Grachev M.V., Parshin Yu.N. Analysis of the bandwidth of the MIMO communication system taking into account the mutual influence of the channels of the receiving tract. Radar, navigation, communications: Proceedings of the XXV International Scientific and Technical Conference (April 16-18, 2019). In 6 volumes. Voronezh State University; JSC Concern Constellation. Voronezh: Publishing House VSU, 2019. Vol. 5. pp. 242-248. 6. Parshin Yu.N., Ksenzov A.V. The influence of spatial correlation on the efficiency of optimizing the spatial structure of a multi-antenna system with a spaced reception. Bulletin of the Ryazan State Radio Engineering Academy. Ryazan: RGRTU, issue 19, 2006. pp. 54-62 7. Parshin Yu.N., Gusev S.I. Determination of the optimal spatial structure of the signal processing system by the criterion of maximum likelihood. Bulletin of the Ryazan State Radio Engineering Academy. Vol.2. Ryazan: RGRTA, 1997.pp.5-11. 8. Kolupaeva A.S., Parshin Yu.N. The bandwidth of the MIMO system in the presence of spatially correlated interference. Radar, navigation, communication: Proceedings of the XXVI International Scientific and Technical Conference. Voronezh: VSU Publishing House, 2020, Vol. 5. pp. 156-161. 9. Sosulin Yu.G., Kostrov V.V., Parshin Yu.N. Evaluation and correlation signal processing and interference compensation. M.: Radio Engineering, 2014. 632 p. 10. Parshin Yu.N., Grachev M.V. Multi-stage reconfigurable signal processing in a spatially distributed radio system. Bulletin of the Ryazan State Radio Engineering University Ryazan: RGRTU, 2019, No. 67 p. 3-10. 11. Parshin Yu.N., Gusev S.I. The influence of the signal-interference situation on the optimal spatial structure of the antenna system. Bulletin of the Ryazan State Radio Engineering Academy. Vol.4. Ryazan: RGRTA, 1998. pp. 117-120. 12. Sazonov D. M. Antennas and microwave devices: Textbook for radio engineering specialties of universities. M.: Higher School, 1988. 432 p. 13. Parshin Yu.N. Space time signal processing and interference compensation. M.: COURSE, 2021. 200 p.
2. Klochko V.K., Usachev A.N. Mathematical model and methods for estimating angular coordinates of air targets using Doppler radar // Bulletin of the Ryazan State Radio Engineering University. 2014. No. 47. pp. 41 – 46. (in Russian) 3. Klochko V.K., Kuznetsov V.P., Levitin A.V. and others. Algorithms for determining the coordinates of moving targets based on multichannel Doppler radar // Bulletin of the Ryazan State Radio Engineering University. 2015. No. 53. pp. 3-10. (in Russian) 4. Marpl.-ml. S.L. Digital spectral analysis and its applications: trans. from English M.: Mir, 1990. 584 p. (in Russian) 5. Methods and algorithms of digital spectral analysis of signals: textbook / V. I. Koshelev. — M.: COURSE, 2021. — 144 p. (in Russian) 6. Klochko V. K. An algebraic approach to the direction finding of objects in a multi-position system of receivers // Digital signal processing. 2022. ¹ 1. Pp. 28 - 33. (in Russian) 7. Klochko V. K., Wu Ba Hung. Algorithms for increasing the resolution of the additional frequency in the system of radio receivers // Radio engineering and telecommunications systems. 2022. No. 47. pp. 31 – 42. (in Russian) 8. Klochko V. K., Wu Ba Hung. Detection of mobile sources by a system of radio receivers // Digital signal processing. 2022. ¹ 4. Pp. 50 - 55. (in Russian) 9. F. Hlawatsch, G. Matz, H. Kirchauer, and W. Kozek , Time-frequency formulation, design, and implementation of time-varying optimal filters for signal estimation, IEEE Trans. Signal Proc-ess., 48, 1417-1432, May 2000. 10. K. Ghartey , A. Papandreou-Suppappola, and D. Cochran, On the Use of Matching Pursuit Time-Frequency Techniques for Multiple-Channel Detection, in Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing, 5, 3201-3204, May 2001. 11. Papandreou-Suppappola, Antonia, Applications in time-frequency signal processing (Elec-trical engineering and applied signal processing series), New York, 2002, 397 p. 12. Klochko V. K., Kuznetsov V. P., Wu Ba Hung. Estimation of parameters of radio signals from mobile low-altitude objects // Bulletin of the Ryazan State Radio Engineering University. 2022. No. 80. pp. 12-23. (in Russian) 13. Mathematical methods of space-time signal processing in radio and optoelectronic systems: monograph / V. K. Klochko. Ryazan: IP Konyakhin A.V. (Book Jet), 2020. 164 p. 14. Models of uncertainty in theory and applications: studies. manual / V. K. Klochko. M.: COURSE. 2022. 204 p. (in Russian) 15. Kuznetsov V. P., Churakov E. P. Kalman filter system for estimating the parameters of the reflected signal // Bulletin of the Ryazan State Radio Engineering University. 2015. No. 1 (Issue 51). pp. 9-14. (in Russian)
An algorithm for estimating the Doppler phase is synthesized by the method of maximum law-similarity. A block diagram implementing synthesized algorithms is given. To expand the range of one-digit estimation of the Doppler frequency (phase) while maintaining an unambiguous estimation of the delay time (range), it is proposed to use a non-equidistant sequence of pulses – in the simplest case with alternating periods of intrusion. The corresponding detection algorithm has been synthesized, on the basis of which a modified algorithm has been obtained. By solving a system of truthfulness equations with respect to Doppler phase shifts in alternating repetition periods, an algorithm for estimating the difference Doppler phase and an algorithm for unambiguous estimation of the radial velocity of the target are obtained. The block diagrams of detectors-meters of non-equidistant signals based on the algorithms of synthesized and modified detectors and algorithms for unambiguous measurement of the Doppler phase and radial velocity are presented. The analysis of the detector-meters showed that the use of the modified detection algorithm compared with the use of the synthesized algorithm provides significant gains in the value of the threshold signal-to-noise ratio and leads to losses in the accuracy of the Doppler phase measurement. 2. Richards M.A., Scheer J.A., Holm W.A. (Eds.). Principles of Modern Radar: Basic Principles. New York: SciTech Publishing, IET, Edison. 2010. – 924 p. 3. Melvin W. L., Scheer J.A. (Eds.). Principles of Modern Radar: Advanced Techniques. New York: SciTech Publishing, IET, Edison, 2013. – 846 p. 4. Radar Handbook / Ed. by M.I. Skolnik. 3rd ed. McGraw–Hill, 2008. 1352 p. 5. Popov D.I. Adaptacija nerekursivnyh rezhektornyh fil'trov // Izvestija vuzov. Ra-diojelektronika. 2009. vol. 52. no. 4. P. 46-55. (in Russian). 6. Popov D.I. Autocompensation of the Doppler phase of clutter // Cifrovaja obrabotka signalov. 2009. no 2. pp. 30–33. (in Russian). 7. Popov D.I. Avtokompensacija doplerovskoj fazy mnogochastotnyh passivnyh pomeh // Vestnik Rjazanskogo gosudarstvennogo radiotehnicheskogo universiteta. 2018. no. 65. pp. 32–37. 8. Popov D.I. Adaptive suppression of clutter // Cifrovaja obrabotka signalov. 2014. no. 4. pp. 32-37. (in Russian). 9. Popov D.I. Adaptivnije regektornjie filtrij kaskadnogo tipa // Cifrovaya obrabotka signalov. 2016. no. 2. pp. 53-56. (in Russian). 10. Popov D.I. Adaptive notch filter with real weights // Cifrovaya obrabotka signalov. 2017. no. 1. pp. 22-26. (in Russian). 11. Popov D.I. Optimizacja nerekursivnjih regektornjie filtrov s chastichnoj adaptaciej // Cifrovaya obrabotka signalov. 2018. no. 1. pp. 28-32. (in Russian). 12. Popov D.I. Optimizacija rezhektornyh fil'trov po verojatnostnomu kriteriju // Cifrovaja obrabotka signalov. 2021. no. 1. P. 55-58. (in Russian). 13. Kuz'min S.Z. Cifrovaja radiolokacija. Vvedenie v teoriju (Digital radar. Introduction to Theory). Kiev: KViC, 2000. 428 p. (in Russian). 14. Cifrovaja obrabotka signalov v mnogofunkcional'nyh radiolokatorah. Metody. Algoritmy. Apparatura: monografija (Digital signal processing in multifunctional radars. Methods. Algorithms. Equipment: monograph) / pod red. G.V. Zajceva. M.: Radiotehnika, 2015. 376 p. (in Russian). 15. Klochko V.K., Kuznecov V.P., Levitin A.V. i dr. Algoritmy opredelenija koordi-nat dvizhushhihsja celej na baze mnogokanal'noj doplerovskoj RLS // Vestnik Rjazanskogo gosudarstvennogo radiotehnicheskogo universiteta. 2015. no. 53. pp. 3-10. (in Russian). 16. Klochko V.K., Kuznecov V.P., Vu Ba Hung. Ocenivanie parametrov radiosignalov ot podvizhnyh malovysotnyh ob#ektov // Vestnik Rjazanskogo gosudarstvennogo radioteh-nicheskogo universiteta. 2022. no. ¹ 80. pp. 12-23. (in Russian).
In conditions of a limited frequency resource, it is advisable to synthesize radio signals to adapt SDR systems to interference when using, among other things, non-standard types of modulation. Optimization by a single quality indicator leads to uncontrolled deterioration of other indicators, therefore, for more efficient use of radio channel resources, it is advisable to apply multi-criteria signal synthesis. With the consistency of the used coding and modulation procedures, according to a certain criterion, signal-code constructions are obtained, which provide additional improvement in the characteristics of the RCS. These procedures have their own characteristics, advantages and disadvantages. A comparative analysis of the synthesized radio signals of different positioning has been carried out in the interests of adapting RCS to the current interference environment. When choosing the positioning of the synthesized radio signals in order to adapt the RCS to the interference environment, it is advisable to use a multi-criteria approach that takes into account at the current time: noise immunity to the action of AWGN and signal-to-interference conditions, the required hardware costs for signal synthesis, as well as the implemented compromise on other important quality indicators (energy efficiency, out-of-band radiation, correlation characteristics). At the same time, the development of a unified block diagram of adaptive software-defined generator and detector of radio signals, corresponding to the developed procedures for multi-criteria signal synthesis and signal-code structures [3, 5, 6], is paramount importance. This is necessary for the implementation of a universal transceiver that covers a relatively wide class of radio signals that provide effective adaptation to interference under various external conditions.
2. Hu F., Chen B., Zhu K. Full spectrum sharing in cognitive radio networks toward 5G: A survey //IEEE Access. 2018. vol. 6. pp. 15754-15776. 3. Lisnichuk A.A., “Multi-criteria synthesis procedure of DSSS signals for cognitive radio systems adaptation to complex interference environment,” Vestnik RGRTU, No. 66-1, 2018, pp. 9-15. (In Russ.). DOI: 10.21667/1995-4565-2018-66-4-1-9-15 4. Lisnichuk À.À. The procedure for multi-criteria synthesis of OFDM radio signals to reduce the crest factor and increase the structural secrecy of information transmission systems // Vestnik RGRTU. 2021. ¹ 77. p. 17-28. (In Russ.). DOI: 10.21667/1995-4565-2021-77-17-28 5. Kirillov S.N., Lisnichuk A.A., “The multi-criteria synthesis of signal-code sequence based on dependent signals to adapt data communication radio system to narrow-band interference,” Vestnik RGRTU, No. 4, 2017, pp. 3-12. (In Russ.). 6. Lisnichuk A.A., Kirillov S.N., “Analysis of cognitive radio systems characteristics adapting to narrow-band interference effect based on synthesized four-position radio signals,” Vestnik RGRTU, No. 66-1, 2018, pp. 3-8. (In Russ.). DOI: 10.21667/1995-4565-2018-66-4-1-3-8 7. S. N. Kirillov, A. A. Lisnichuk, “Multi-criteria signal synthesis procedure for adapting cognitive radio systems to the influence of interfering factors in the Arctic,” IOP Conf. Series: Earth and Environmental Science. Vol. 302, No. 1, p. 012059. DOI: 10.1088/1755-1315/302/1/012059 8. Sosulin Yu. G., Kostrov V. V., Parshin Yu. N. Estimated-correlation processing of signals and noise compensation. M: Radio engineering. 2014. 632 p. (In Russ.). 9. Bischl H. et al. Adaptive coding and modulation for satellite broadband networks: From theory to practice //International Journal of Satellite Communications and Networking. – 2010. – Ò. 28. – ¹. 2. – Ñ. 59-111. 10. S. N. Kirillov, A. A. Lisnichuk, and others. Multi-criteria approach to the choice of coding procedure for telemetric radio signals of complex technical objects // Vestnik RGRTU. 2021. ¹75. p. 3-14. (In Russ.). 11. Gutkin L.S., Optimization of radio-electronic devices. M.: Sov. radio. 1975. 368 p. (In Russ.).
Yury Parshin, e-mail: parshin.y.n@rsreu.ru Bui Quoc Vuong, e-mail: herapkm@gmail.com The Ryazan State Radio Engineering University (RSREU), Russia, Ryazan Keywords:
The article investigates the impact of broadband interference suppression algorithms on the spectral characteristics of narrowband interference and proposes a modified method for broadband interference suppression, testing its effectiveness. In the modified interference suppression algorithm based on Shchapov Y.M.'s interference suppression algorithm, the values of terminal phases are selected from a set of optimal phases through specific adaptation cycles. New initial phases are set before each adaptation cycle. Initial phase values can be random or uniformly distributed with a predefined step. The simulation results presented in the article show that during the phased adaptation of the antenna radiation pattern for broadband interference suppression, distortion of the narrowband interference spectrum occurs, leading to the appearance of spectral peaks at certain frequencies and an increase in the spectral level between them. The positions of these peaks depend on the interference measurement time, the number of antenna array elements, and the number of adaptation cycles. By tuning adaptation parameters, a balance between narrowband interference suppression and preserving valuable signals can be achieved. The implementation of the modified algorithm contributes to aligning the output interference power towards the global minimum. Furthermore, the improvement compared to the basic algorithm amplifies with an increase in the number of adaptation cycles, resulting in a gain of 5...7 dB.
2. Sosulin Yu. G., Kostrov V. V., Parshin Yu. N. Evaluation and correlation signal processing and interference compensation. Ì.: Radiotechnika, 2014. 632 p. 3. Parshin Yu. N. Chaotic dynamics of an adaptive compensation system for a complex of point and extended interference // Radio Engineering and Electronics. 1988. Vol. 43. No. 11. Pp. 1336–1342. 4. Maltsev A. A., Zimina S. V. Spectral-correlation characteristics of the output signal of adaptive antenna arrays considering fluctuations of the weight vector // Radio Engineering and Electronics. 2001. Vol. 46. No. 11. Pp. 1350–1355. 5. Morgan D. R. Effect of gradient noise on the adaptive cancellation of a sinusoid in white noise // IEEE Transactions on Acoustics, Speech, and Signal Processing. 1983. Vol. ASSP-31. No. 4. Pp. 1043–1045. 6. Zimina S. V. Spectral characteristics and radiation pattern of an adaptive antenna array configured according to the LMS algorithm with a quadratic constraint, taking into account fluctuations of the weight vector // Antennas. 2014. No. 9. Pp. 64–69. 7. Parshin Yu. N., Gusev S. I. Determination of the optimal spatial structure of the signal processing system by the criterion of maximum likelihood // Bulletin of the Ryazan State Radio Engineering Academy. Vol.2. – Ryazan: RSREA. 1997. Pp. 5–11. 8. Parshin Yu. N., Gusev S. I. Formation of zeros of the antenna array radiation pattern by the maximum likelihood method // Bulletin of the Ryazan State Radio Engineering Academy. Issue3. Ryazan: RSREA. 1997. Pp. 9–15. 9. Parshin Yu. N., Lavrov A. M., Gusev S. I. Synthesis of robust spatial structures of radio systems using regularization // Bulletin of the Ryazan State Radio Engineering Academy. Issue 6. Ryazan: RSREA. 2000. Pp. 11–14. 10. Parshin Yu. N., Grachev M. V. Multi–stage reconfigurable signal processing in a spatially distributed radio system // Bulletin of the Ryazan State Radio Engineering University. Ryazan: RSREU. 2019. No. 67. Pp. 3–10. 11. Shchapov Yu. M. Algorithm of phase adaptation of antenna arrays of arbitrary geometry // News of Universities of the USSR. Radio electronics. 1990. Vol. 33. No. 9. Pp. 30–34. 12. Kurganov V. V., Djigan V. I. Phaseless antenna array calibration algorithms with minimal number of output power measurements // Radiotekhnika. 2021. Vol. 85. No. 3. Pp. 96–108. 13. Parshin Yu. N., Bui. Q. V. Spatial suppression of interference complex using phase adaptation algorithms // 25th International Conference on Digital Signal Processing and its Applications (DSPA). 2023. Pp. 1–4. 14. Bui Q. V., Parshin Yu. N. Spatial interference suppression using a modified phase adaptation algorithm // Radar, Navigation, Communication: Proceedings of the XXIX International Scientific and Technical Conference. 2023. Vol.5. Pp. 21–25.
The multichannel construction of systems when detecting a target at an unknown speed leads to separate detection in each frequency channel. The use of the matrix eigenvalue method made it possible to transform the characteristic function of the output (decisive) statistics to a form convenient for integration and obtain calculated expressions for the probabilities of false alarm and correct detection, with the help of which the desired detection characteristics are determined. In particular, the gains in the signal-to-noise threshold ratio of the multi-frequency signal detection system, invariant in each frequency channel to Doppler phase shifts, are established in comparison with the known detection system and in comparison with the multi-channel Doppler frequency system. At the same time, energy gains are achieved in comparison with single-frequency interperiod processing systems. The analysis of the effectiveness of optimal systems makes it possible to establish the maximum detection capabilities of the target signal for this class of systems. A comparative analysis of multichannel detection systems shows that the proposed quasi-optimal detection system based on single-channel coherent accumulation, although inferior in threshold signal-to-noise ratio to the optical system, but unlike it is technically feasible.
2. Richards M.A., Scheer J.A., Holm W.A. (Eds.). Principles of Modern Radar: Basic Principles. New York: SciTech Publishing, IET, Edison. 2010. – 924 p. 3. Melvin W. L., Scheer J.A. (Eds.). Principles of Modern Radar: Advanced Techniques. New York: SciTech Publishing, IET, Edison, 2013. – 846 p. 4. Radar Handbook / Ed. by M.I. Skolnik. 3rd ed. McGraw–Hill, 2008. 1352 p. 5. Popov D.I. Adaptacija nerekursivnyh rezhektornyh fil'trov // Izvestija vuzov. Ra-diojelektronika. 2009. vol. 52. no. 4. P. 46-55. (in Russian). 6. Popov D.I. Autocompensation of the Doppler phase of clutter // Cifrovaja obrabotka signalov. 2009. no 2. pp. 30–33. (in Russian). 7. Popov D.I. Avtokompensacija doplerovskoj fazy mnogochastotnyh passivnyh pomeh // Vestnik Rjazanskogo gosudarstvennogo radiotehnicheskogo universiteta. 2018. no. 65. pp. 32–37. 8. Popov D.I. Adaptive suppression of clutter // Cifrovaja obrabotka signalov. 2014. no. 4. pp. 32-37. (in Russian). 9. Popov D.I. Adaptivnije regektornjie filtrij kaskadnogo tipa // Cifrovaya obrabotka signalov. 2016. no. 2. pp. 53-56. (in Russian). 10. Popov D.I. Adaptive notch filter with real weights // Cifrovaya obrabotka signalov. 2017. no. 1. pp. 22-26. (in Russian). 11. Popov D.I. Optimizacja nerekursivnjih regektornjie filtrov s chastichnoj adaptaciej // Cifrovaya obrabotka signalov. 2018. no. 1. pp. 28-32. (in Russian). 12. Popov D.I. Optimizacija rezhektornyh fil'trov po verojatnostnomu kriteriju // Cifrovaja obrabotka signalov. 2021. no. 1. P. 55-58. (in Russian). 13. Kuz'min S.Z. Cifrovaja radiolokacija. Vvedenie v teoriju (Digital radar. Introduction to Theory). Kiev: KViC, 2000. 428 p. (in Russian). 14. Cifrovaja obrabotka signalov v mnogofunkcional'nyh radiolokatorah. Metody. Algoritmy. Apparatura: monografija (Digital signal processing in multifunctional radars. Methods. Algorithms. Equipment: monograph) / pod red. G.V. Zajceva. M.: Radiotehnika, 2015. 376 p. (in Russian). 15. Klochko V.K., Kuznecov V.P., Levitin A.V. i dr. Algoritmy opredelenija koordi-nat dvizhushhihsja celej na baze mnogokanal'noj doplerovskoj RLS // Vestnik Rjazanskogo gosudarstvennogo radiotehnicheskogo universiteta. 2015. no. 53. pp. 3-10. (in Russian). 16. Klochko V.K., Kuznecov V.P., Vu Ba Hung. Ocenivanie parametrov radiosignalov ot podvizhnyh malovysotnyh ob#ektov // Vestnik Rjazanskogo gosudarstvennogo radioteh-nicheskogo universiteta. 2022. no. ¹ 80. pp. 12-23. (in Russian). 17. Popov D.I., Belokrylov A.G. Sintez obnaruzhitelej-izmeritelej mnogochastotnyh signalov // Izvestija vuzov. Radiojelektronika. 2001. v. 44. no. 11. pp. 33-40. (in Russian). 18. Middlton D. Vvedenie v statisticheskuju teoriju svjazi (Introduction to the statistical theory of communication): v 2 t. per. s angl. M.: Sov. Radio, 1961. v. 1. 782 p.; 1962. v. 2. 832 p. (in Russian).
It is shown that the use of a modification of the Khurgin-Yakovlev algorithm with separate coding of signal samples and derivative allows to increase the quality of the restored speech by 0.5 ... 1.2 points according to GOST R 50840-95 compared to similar non-adaptive codecs based on V.A. . Kotelnikov or the possibility of reducing the required transmission rate by 15 ... 30% for software-defined radio systems for receiving, transmitting and processing information. 2. ITU-T: Recommendation G.729. C source code and test vectors for implementation verification of the G.729 8 kbit/s CS-ACELP speech coder. – Geneva, 1996. 3. ITU-T Recommendation G.729 Annex A. Reduced complexity 8 kbit/s CS-ACELP speech codec, 1996. 4. Jean-Marc Valin Speex: A Free Codec For Free Speech. [Electronic resource]. URL: https://arxiv.org/pdf/1602.08668.pdf 5. Basov O.O., Rybolovlev A.A. Analysis of the degree of adaptation of the modern fleet of speech codecs. // Digital signal processing and its application. Reports of the 9th international conference. - pp. 157-160. 6. Afanasiev A.A., Basov O.O., Bogachev G.V. Features of a system with a variable structure for coding speech signals. 6th International Conference and Exhibition "Digital signal processing and its application". Reports - 1. - M: 2004. - pp.76-79. 7. Khurgin Ya.I., Yakovlev V.P. Finite functions in physics and technology. M.: Science. 1971. - 408 p. 8. Kirillov S.N., Dmitriev V.T. Implementation capabilities and noise immunity of the signal recovery procedure based on the Khurgin-Yakovlev algorithm // Radio engineering. 2003. No. 1. - pp. 73-75. 9. Babkin V.V., Lanne A.A., Shantala V.S. Optimization problem of choice of speech and channel coding. // Materials of the international conference DSPA-2005. Moscow 2005. - pp. 345-347. 10. Noise-immune codecs - the future of digital telephony [Electronic resource]. URL: https://www.osp.ru/nets/1997/10/142940/ 11. Kirillov S.N., Dmitriev V.T., D.E. Krysyaev, S.S. Popov Investigation of the quality of transmitted speech information with various combinations of source and communication channel coding algorithms under interference conditions. Vestnik RGRTU 2008 No. 1 (Issue 23). - PP. 53-56. 12. GOST R 50840-95. Speech transmission over communication paths. M.: Gosstandart of Russia, 1995. - 180 p. 13. Dmitriev V.T., Konstantinova Algorithm for a comprehensive assessment of the quality of speech in a communication channel. // Vestnik RGRTU. 2016. No. 56 - pp. 42-47. 14. Kirillov S.N., Dmitriev V.T. A complex algorithm for objective assessment of the quality of a decoded speech signal under the action of acoustic interference. // Proceedings of SPIIRAS 2018. No. 1. - pp. 34 -55. 15. Kirillov S.N., Dmitriev V.T., Kartavenko Ya.O. Algorithm for an objective assessment of the quality of a decoded speech signal based on the change in the spectral dynamics of the critical bands of the spectrum. Vestnik RGRTU. 2011. No. 37. pp. 3-7. 16. Dmitriev V.T. Noise immunity of speech codecs based on the Khurgin-Yakovlev algorithm / Vestnik RGRTA No. 12, 2003 - pp. 133-136. 17. Kirillov S.N., Dmitriev V.T. Stability of primary codecs of speech signals based on the representation of Khurgin-Yakovlev to the action of acoustic noise.// Vestnik RGRTU. 2019. No. 3 - pp.17-25.
The results of the study conducted in this article show that reducing the speed does not provide a fundamental gain in distance, except that the characteristics of a channel with a split video stream have a relationship in clear and turbid water. However, it is possible to use both branches of the two-color channel to increase the data transfer rate and, as is done in China, increase the resolution of professional video images. In combination with other methods of increasing the communication range, for example, using noise-resistant coding, this method may be more effective, but this issue requires separate research. In the case of low water turbidity, the 473 nm channel, close to the “clear sea” type, can play the role of a service channel for transmitting additional telemetry and service information, and it is also possible to use it as a reverse service channel. This requires minimal hardware costs when introducing light filters, which also leads to a reduction in the energy budget by approximately 0.7 dB. However, as for the two-color transmission scheme, in its modern form it is capable of increasing throughput, but not range. On the other hand, for muddy water, a twofold increase in the capacity of an underwater wireless optical data transmission channel is possible. 2. Vershinin, A. S. Sravnitel'nyj analiz gidroakusticheskih modemov / A. S. Vershinin. – Tekst : neposredstvennyj // Molodoj uchenyj. — 2015. — ¹ 12 (92). — S. 156-161. – URL: https://moluch.ru/archive/92/19982/ (data obrashcheniya: 27.04.2021) 3. Kirillov S.N. Propusknaya sposobnost' podvodnogo opticheskogo kanala peredachi infor-macii s kodoimpul'snoj modulyaciej po intensivnosti [Tekst] / S. N. Kirillov, L. V. Aronov // Vestnik RGRTU. 2020. ¹ 4 (74). S. 3-13. DOI: 10.21667/1995-4565-2020-74-3-13k. 4. Aronov L. V. Kody Rida – Solomona v podvodnom opticheskom kanale peredachi informa-cii s kodoimpul'snoj modulyaciej po intensivnosti [Tekst] / L. V. Aronov // Vestnik RGRTU – 2021. – ¹ 4 (78). – s. 12-20. DOI: 10.21667/1995-4565-2021-78-12-20 5. Aronov L.V. Geometricheskie poteri v podvodnom kanale peredachi informacii na osnove istochnika kogerentnogo opticheskogo izlucheniya[Tekst] / L. V. Aronov // Sovremennye tekhnologii v nauke i obrazovanii – STNO-2019: sb. tr. mezhdunar. nauch.-tekhn. i nauch.-metod. konf.: v 10 t. T.1./ pod obshch. red. O.V. Milovzorova. – Ryazan': Ryazan. gos. radiotekhn. un-t, 2019; Ryazan'. – 206s. , s. 118-121. 6. Kirillov S.N. Opredelenie harakteristik podvodnogo otkrytogo opticheskogo kanala pe-redachi informacii na bol'shih glubinah [Tekst] / S. N. Kirillov, L. V. Aronov // Vestnik RGRTU – 2018. – ¹ 1 (63). – s. 40-48. 7. Baskakov S.I. Radiotekhnicheskie cepi i signaly. 3-e izd. [Tekst] // S.I. Baskakov. /M.: Vysshaya shkola, 2000. 462s. 8. Kirillov S.N. Algoritm ob"ektivnoj ocenki kachestva dekodirovannogo rechevogo signa-la na osnove izmeneniya spektral'noj dinamiki kriticheskih polos spektra / S.N. Kirillov, V.T. Dmitriev, YA.O. Kartavenko // Vestnik RGRTU, 2011. ¹3(37). S.3-7.
An extended model of the microwave path of a pulsed reflectometric level meter was obtained for measuring the coolant level in the primary circuit of a nuclear power plant, which allows taking into account additional inhomogeneities. The calibration method based on reference marks makes it possible to correct the error in measuring the coolant level in the primary circuit of a nuclear power plant, which arises due to changes in the relative dielectric constant as a result of temperature fluctuations from 277 to 523 K and pressure from 0.1 to 25 MPa . The computer model in the dynamic modeling environment SimInTech allows you to solve problems related to optimization of parameters. The disadvantages include the fact that the impulse response of sections of the microwave path and reflections on inhomogeneities are not taken into account, however, for analysis and decision-making in a first approximation, the existing capabilities of the model are sufficient, and the flexibility and adaptability of the SimInTech environment allows you to expand and adapt model for additional tasks, taking into account new parameters. 2. Atayants B.A. Measuring the filling level of a waveguide guide system with a frequency range finder with a minimum number of signal samples / B.A. Atayants, V.M. Davydochkin, V.V. Yezersky // Radio engineering. 2016. No. 11. P. 97-102 3. Baranov I.V. The influence of noise on the accuracy of distance determination by a rangefinder with adaptive frequency modulation / I.V. Baranov, V.V. Ezersky // Bulletin of the Ryazan State Radio Engineering University. 2007. No. 21. P. 31-36. 4. Baranov I.V. The influence of interference on the error of distance measurement in a frequency range meter for industrial use / I.V. Baranov, V.V. Ezersky // Bulletin of the RGRTU. Ryazan. RGRTU. 2011. Issue. 3 (37). pp. 34-40. 5. Trenkal E.I. Measuring liquid levels using pulse reflectometry (review) / E.I. Trencal, A.G. Loschilov // TUSUR reports. – 2016. – T. 19, No. 4. – P. 67–73. 6. Mulev Yu.V. Experimental study of the dielectric constant of dry saturated water vapor / Yu. V. Mulev, S. N. Smirnov, M. Yu. Mulev // Thermal energy: Monthly theoretical and scientific-practical journal / Russian Academy of Sciences. Russian Scientific and Technical Society of Power Engineers and Electrical Engineers. -Moscow . – 2011. – No. 4. – pp. 57-60 7. Bokov L.A. Electrodynamics and propagation of radio waves: textbook. allowance / L.A. Bokov, V.A. Zamotrinsky, A.E. Mandel. – Tomsk: Tomsk. state University of Control Systems and radio electronics, 2013. – 410 p. 8. Vasiliev E.P. Modeling of microwave dividers-adders of power amplifier submodules / E.P. Vasiliev // Bulletin of RGRTU. Ryazan. RGRTU. 2020. Issue. 1 (71). pp. 23-33. 9. Vasiliev E.P. Analysis of methods for modeling microwave devices using the example of a band-pass filter with an extended stop band / E.P. Vasiliev // Bulletin of RGRTU. Ryazan. RGRTU. 2020. Issue. 2 (72). pp. 62-70. 10. Bogoslovsky A.V. Scattering of electromagnetic waves by dielectric and metallized objects with axial symmetry / A.V. Bogoslovsky // Bulletin of RGRTU. Ryazan. RGRTU. 2022. Issue. 4 (82). pp. 19-26. 11. Kartashov B.A. Environment for dynamic modeling of technical systems SinInTech: Workshop on modeling automatic control systems [Text] / B.A. Kartashov, E.A. Shabaev, O.S. Kozlov, A.M. Shchekaturov - M.: DMK Press, 2017. – 424 p.
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