F.G. Khisamov - Dr.Sc. (Eng.), Professor, Krasnodar higher military school named after General of the army S.M. Shtemenko E-mail: kiiz@rambler.ru A.V. Krupenin - Dr.Sc. (Eng.), Professor, Deputy Head Of School For Academic And Scientific Work, Krasnodar higher military school named after General of the army S.M. Shtemenko E-mail: kiiz@rambler.ru Y.V. Chernukha - Ph.D. (Eng.), Associate Professor, Krasnodar higher military school named after General of the army S.M. Shtemenko E-mail: kiiz@rambler.ru A.D. Zolotuev - Engineer, Krasnodar higher military school named after General of the army S.M. Shtemenko E-mail: andrew.gold@mail.ru A.S. Zelenkov - Senior Research Scientist, Krasnodar higher military school named after General of the army S.M. Shtemenko E-mail: zelenkov.pg@yandex.ru

Some medium access control (MAC) protocols are based on the pseudo-noise sequence (PNS). So there is a protocol based on the maximal length sequence (m-sequence), which is a feature of high throughput. This sequence used in the protocol to control access to the transmission medium in a distributed network architecture. Obviously, for the efficient operation of these protocols is require robust pseudo-noise sequence acquisition mechanism. To improve reliability of special communication systems authors of this paper has been developed PNS acquisition method for communication systems with multi-carrier code division multiple access (MC-CDMA) signals that can be used in MAC protocols. Therefore, in this paper a computer model of the PNS acquisition module for PNS-oriented multiple access control protocols and carried out a study of its time characteristics. The method is based on the majority decoding of pseudo-noise sequence via parity equation generated by the linear shift-back register (LSBR) and is running in the opposite direction. So if we consider the m-sequence like a cyclic code (2k-1, k), for each received symbol of m-sequence we can form a system of equations and the corresponding parity matrix. After a majority decoding PNS initial phase is records in LSBR, which shift PNS on the processed segment length «N». «N» determine number of PNS symbols, which will be received by majority decoder. After shifting the new phase compare with the phase of the channel. If the phases coincides, acquisition process is finish, differently proceeds. An important advantage of this method is a higher probability of receiving the PNS over conventional acquisition techniques. From this, it can be assumed that the system will also has time acquisition gain. To verify this, in the paper, the experimental study of this method and the sequential search method is implement. Study of time characteristics is carried out using a modified formula of the average return time series of successes. Analysis of the PNS acquisition time characteristics shows that the variation in length of the processed segment «N» leads to change in the average acquisition time. Thus, using the obtained analytical assessment can minimize the average PNS acquisition time. The analytical results can be checked by computer simulation. To do this in Simulink two models have been designed: for suboptimal (majority) method and the sequential search method. The model allows to experimentally estimate the probability and time characte-ristics. The main blocks of the model are: the block «Base Station» containing PNS generator, binomial channel unit «communication channel» and block «subscriber station», which contains the majority decoder and LSBR. The experimental study was carried out for a system with a length of LSBR 10 and the probability of error 0,05-0,15. The achieved results prove the adequacy of the analytical evaluation of the time characteristics of the method and confirm the efficiency of this PNS acquisition method in comparison with sequential search method.

 

1. Lojjko V.I., KHisamov F.G., Milovanov M.V., Zolotuev A.D. Issledovanie algoritma sinkhronizacii PSP dlja sistem svjazi s mnogochastotnymi signalami s pomoshhju kompjuternogo modelirovanija // Nauchnyjj zhurnal KubGAU [EHl. resurs]. Krasnodar: KubGAU, 2015. № 111 (07). http://ej.kubagro.ru/2015/07/pdf/110.pdf
2. Skljar B. Cifrovaja svjaz. Teoreticheskie osnovy i prakticheskoe primenenie. Izd. 2-e, ispr. / Per. s angl. M.: Izdatelskijj dom «Viljams». 2003.
3. Markhasin A. QoS-oriented multifunctional wireless MAC for remote, rural, and difficult for access areas. // IEEE region 8 Sibircon 2008. Russia.
4. Khisamov F., Zolotuev A., Sobachkin D., Milovanov M. MC-DS-CDMA Pseudo-Noise Acquisition Algorithm Research Using Computer Model, 23-rd Telecommunications Forum Telfor. Serbia. 2015. S. 329-332.
5. Novikov I.A., Nomokonov V.N., SHebanov A.A., JAkovlev D.O. K voprosu o mazhoritarnom dekodirovanii M-posledovatelnostejj // Voprosy radioehlektroniki. Ser. OT. 1976. № 5. S. 50-55.
6. Lojjko V.I., KHisamov F.G., Zolotuev A.D. Issledovanie vremennykh kharakteristik metoda sinkhronizacii PSP dlja sistem svjazi voennogo i grazhdanskogo naznachenija na osnove MC-DS-CDMA // Politematicheskijj setevojj ehlektronnyjj nauchnyjj zhurnal Kubanskogo gosudarstvennogo agrarnogo universiteta (Nauchnyjj zhurnal KubGAU) [EHl. resurs]. Krasnodar: KubGAU. 2015. № 09 (113). http://ej.kubagro.ru/2015/09/pdf/15.pdf
7. Zolotuev A.D. Mazhoritarnyjj algoritm sinkhronizacii psevdosluchajjnykh posledovatelnostejj v sistemakh svjazi s mnogochastotnymi signalami MC-DSSS. Mezhdunarodnyjj sojuz uchenykh «Nauka. Tekhnologii. Proizvodstvo». 2015. № 9. S. 36-39.