A.V. Rabin – Ph.D. (Eng.), Associate Professor, 

Department of Aerospace Computer and Program Systems; Director of the Centre for Scientific Research Coordination, 

St. Petersburg State University of Aerospace instrumentation  E-mail: alexey.rabin@guap.ru

Most works on coding theory are devoted to the analysis of systems in that part of the bandwidth curve, which corresponds to low spectral efficiency or low signal-to-noise ratio. The reason for this factor was the fact that most of the applications using coding theory used in satellite systems are limited in terms of the used power, but with a wide bandwidth. Thus, to date, none of the coding schemes used can provide noise immunity and significant energy gain with high spectral efficiency.

Noise immunity is one of the most important characteristics of modern information transmission systems. There is a contradiction between the requirements for the noise immunity of radio engineering systems, due to the capabilities of countermeasures, and the lack of methods for increasing the noise immunity at high spectral efficiency and coding rate.

The research of ways to increase noise immunity at a fixed transmission rate through the development of special mathematical methods is an urgent task.

The goal of the research is to develop and investigate orthogonal coding as a method of increasing noise immunity with high spectral efficiency using the example of information transmission systems with discrete amplitude modulation (AM).

The orthogonal coding proposed by the author as a method of increasing noise immunity using the example of information transmission systems with discrete AM allows ensuring the required transmission quality at lower energy costs. 

The energy gain in the signal-to-noise ratio (up to 4.2 dB for channels with additive white Gaussian noise), obtained due to more efficient use of the transmitted signal energy, is achieved without increasing the complexity and, consequently, the cost of transmitting and receiving devices.

The novelty of the orthogonal coding method lies in the fact that it can be considered as a kind of reception as a whole of M-fold discrete amplitude modulation signals with an optimal choice of the manipulation code that matches the binary combinations of the AM signal magnitude source.

The technical implementation of orthogonal coding is characterized by low complexity: decoding is reduced to calculating a number of dot products and performing a comparison with a zero threshold. For this reason, the proposed method for coding and construction of transmitting and receiving devices can be used in various communication systems.

Rabin A.V. Application of orthogonal coding in conjunction with discrete amplitude modulation. Radiotekhnika. 2020. V. 84. № 8(16). P. 28−36. DOI: 10.18127/j00338486-202008(16)-04 (In Russian).

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8. Rabin A.V., Michurin S.V., Lipatnikov V.A. Razrabotka klassa sistemnyh i obratnyh sistemnyh matric, obespechivajushhih povyshenie pomehoustojchivosti spektral'no-jeffektivnyh moduljacionnyh shem na osnove ortogonal'nogo kodirovanija. Voprosy radiojelektroniki. 2018. № 10/2018. Serija «Obshhetehnicheskaja» (OT). Vyp. 6. S. 75-79 (In Russian).
9. Svidetel'stvo o gos. registracii ot 28.08.2018 №2018660770 (RF). Zajavka ot 02.08.2018 №2018618185. Programma dlja JeVM  «Programmnaja realizacija algoritma sinteza klassa sistemnyh i obratnyh sistemnyh matric, obespechivajushhih vypolnenie ortogonal'nogo kodirovanija. Rabin A.V. (In Russian).
10. Rabin A.V. Realizacija kodirujushhih i dekodirujushhih ustrojstv v telekommunikacionnyh sistemah s ortogonal'nym kodirovaniem. Uspehi sovremennoj radiojelektroniki. 2018. № 12. S. 116-120. DOI: 10.18127/j20700784-201812-24 (In Russian). 
11. Rabin A.V. Design of encoding and decoding devices in infocommunication systems with orthogonal coding. «International Conference on Metrological Support of Innovative Technologies» (ICMSIT-2020). Krasnoyarsk: Journal of Physics. Conference Series (In Russian). 
12. Rabin A.V. Encoding and Decoding Schemes in Communication Systems using Orthogonal Coding for Noise Immunity's Increase. 2019 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF 2019). Saint-Petersburg: IEEE Xplore. Nomer stat'i 8840610. 
13. Rabin A.V., Dobrosel'skij M.A., Lipatnikov V.A. Issledovanie harakteristik pomehoustojchivosti pri ispol'zovanii ortogonal'nogo kodirovanija. Voprosy radiojelektroniki. 2018. № 10/2018. Serija «Obshhetehnicheskaja» (OT). Vyp. 6. S. 80-85 (In Russian).
14. Rabin A.V. Orthogonal coding for noise immunity's increase with the fixed code rate. International Conference on Information Technologies in Business and Industries (ITBI 2019). Novosibirsk: Journal of Physics: Conference Series. V. 1333. Is. 2. Nomer stat'i 022013. 
15. Svidetel'stvo o gos. registracii ot 11.01.2018 №2018610819 (RF). Zajavka ot 22.11.2017 №2017662032. Programma dlja JeVM «Imitacionnaja model' sistemy peredachi dannyh po kanalu s additivnym belym gaussovskim shumom s ispol'zovaniem ortogonal'nogo kodirovanija». Rabin A.V. (In Russian)
16. Svidetel'stvo o gos. registracii ot 11.09.2019 №2019661928 (RF). Zajavka ot 29.08.2019 №2019660626. Programma dlja JeVM «Programmnaja realizacija procedury soglasovanija simvolov ortogonal'nogo koda s diskretnoj amplitudnoj moduljaciej. Rabin A.V. (In Russian)
17. Svidetel'stvo o gos.registracii ot 11.09.2019 №2019661885 (RF). Zajavka ot 29.08.2019 №2019660606. Programma dlja JeVM «Programma ocenki jenergeticheskogo vyigrysha ot primenenija ortogonal'nogo kodirovanija sovmestno s diskretnoj amplitudnoj moduljaciej». Rabin A.V. (In Russian)
18. Rabin A.V. Matching orthogonal code symbols and modulation methods. 2nd International Scientific Conference on Advanced Technologies in Aerospace, Mechanical and Automation Engineering, MIST: Aerospace 2019. Krasnoyarsk: IOP Conference Series: Materials Science and Engineering. V. 734. Is. 1. Nomer stat'i 012216.