Study of the probabilistic characteristics of PSP synchronization methods: a majority method for processing synchronizing information in MAS protocols for multiple access and Ward's sequential estimation method

The relevance of the study is due to the need to develop a methodology for choosing the optimal sync sequence length during majority processing of a pseudo-random sequence segment (PRS), which will reduce the synchronization time in the face of increasing errors. In this regard, this article is aimed at studying the probabilistic characteristics of the compared PRS synchronization methods and developing a methodology for choosing the optimal sync sequence length. The leading method to study this problem is the Ward sequential estimation method, which allows for a small signal / noise ratio in the band of the received signal (H 2 < 1) to enter synchronism within one period. The article presents the results of simulation for the method based on majority checks and the Ward method. The dependences of the decoding bit error Pм on the length of the processed segment N, the dependencies of the symbolic decoding error Pсимв on the length of the processed segment N, and the dependence of the average search time on the PRS on the length of the processed segment N are constructed. A comparative analysis of the simulation results for the Ward method and the method based on majority decoding is performed. Based on the studies, a methodology was developed for choosing the optimal length of the synchronization sequence during majority processing of the PRS segment. The materials of the article are of practical value for scientists, doctoral students, graduate students, teachers, practitioners working and studying in the field of information security.

1. Novikov I.A., Nomokonov V.N., Shebanov A.A., Yakovlev D.O. K voprosu o mazhoritarnom dekodirovanii M-posledovatel`nostej [On the question of majority decoding of M-sequences]. Voprosy radioelektroniki. 1976;5:50-55 (in Russian).

2. Kilgus С. Pseudonoise code acquisition majority logic decoding. IEEE Transactions on Communications. 1973;21(6):772-774.

3. Uord R. Razlichenie psevdosluchajny`x signalov metodom posledovatel`noj ocenki [Distinguishing pseudo-random signals by sequential estimation]. Zarubezhnaya radioelektronika. 1966;8:20-37 (in Russian).

4. Podoltsev V.V. Ocenka veroyatnostny`x xarakteristik mazhoritarnogo metoda obrabotki korotkix segmentov psevdosluchajnoj posledovatel`nosti [Estimation of the probabilistic characteristics of the majority method for processing short segments of a pseudo-random sequence]. Radiopromy`shlennost`. 2020;30(1):8-15 (in Russian).

5. Messi D. Porogovoe dekodirovanie [Threshold decoding]. M.: Mir. 1966:208 (in Russian).

6. Podoltsev V.V. Ocenka vremenny`x xarakteristik mazhoritarnoj obrabotki sinxroniziruyushhej informacii v PSP-orientirovanny`x MAC-protokolax mnozhestvennogo dostupa [Evaluation of the temporal characteristics of majority processing of synchronization information in the PRS-oriented MAC protocols of multiple access]. Radiopromy`shlennost`. 2019;29(3):26-34 (in Russian).