S.A. Yakushenko – Ph.D. (Eng.), Associate Professor, Professor of the Department, Military Communication Academy (St. Petersburg)
I.U. Kuznetsov – Ph.D. (Mil.), Associate Professor, Military Communication Academy (St. Petersburg)
А.N. Frolov – Deputy Technical Director, JSC «SPE «Radiosvyaz» (Krasnoyarsk)
S.S. Kuznetsov – Adjunct, Military Communication Academy (St. Petersburg)
To ensure continuous high-speed reliable communication in general-purpose networks for special purposes, multichannel radio com-munication facilities, including tropospheric (over-horizon), are used. They provide a large length of communication intervals, which allows increasing the structural connectivity of the network and significantly reducing its cost. At present, the widespread use of radio links in tropospheric radio communications is limited by insufficient quality and low reliability of communication, which reduces the capacity of radio links. Therefore, an increase in noise immunity, reliability of radio communication and the throughput of radio links of tropospheric communication is now of great importance.
Insufficient quality of communication and restriction of information transfer speed in the radio links of troposphere communication are caused by fast and slow fading characteristic for the mechanism of distant tropospheric propagation of ultrashort waves.
Currently, the fight against fading in the tropospheric radio links is reduced to eliminating the consequences of their influence on the quality of radio communications. Therefore, the main method of combating fast fading is the use of diversity reception, and with slower – increasing the transmitter power, i.e., increasing the power of the radio link. These methods of control do not allow meeting the reliability and reliability requirements for high-speed tropospheric communication lines due to the inconsistency between the increase in diversity branches and the linearity of noise immunity enhancement, as well as to reduce the intelligence and mobility of stations. The proof of this statement is a comparative analysis of the effect of fast fading and multiplicity of diversity reception on the reliability of tropospheric communication conducted in the work.
The work determines the causes that affect the noise immunity and reliability of communication when using diversity technologies. A quantitative estimation of noise immunity using correlation dependencies between diversity branches is carried out. Requirements are formulated for the multiplicity and types of diversity in digital radio links of tropospheric communication for given noise immunity and reliability of communication.
It is possible to provide quality indicators of high-speed tropospheric communication lines with the required reliability and reliability of communication by increasing the diversity multiplicity by more than four. To reduce the correlation dependence of fast fading in diversity branches, it is proposed to use several types of diversity of different physical nature, with in each of them not more than four diversity branches and the introduction of technologies to reduce the correlation intervals in each of them, as well as the introduction of modern information technologies equipment and transmission of information.
- Yakushenko S.A., Sazonov M.A. Sovershenstvovanie troposfernyh sistem peredachi dlya primeneniya v usloviyah Arktiki // Uspehi sovremennoj radio]lektroniki. M.: 2015. № 10. S. 34–37.
- Voennye sistemy radiorelejnoj i troposfernoj svyazi / Pod red. E.A. Volkova. L.: VAS. 1982.
- Ignatov V.V., Chistyakov A.P. Obosnovanie osnovnyh tehnicheskih parametrov perspektivnoj tehniki mnogokanal'noj radiosvyazi. L.: VAS. 1988.
- Volkov E.A. i dr. Metodiki raschetov voennyh radiorelejnyh i troposfernyh linij svyazi s analogovymi i cifrovymi signalami pri planirovanii ih razvertyvaniya. L.: VAS. 1983.
- Andronov I.S., Fink L.M. Peredacha diskretnyh soobschenij po parallel'nym kanalam. M.: Sov. radio. 1971.