ОЦЕНКА СКРЫТНОСТИ OFDM!СИГНАЛОВ, ОСНОВАННЫХ НА BPSK МОДУЛЯЦИИ, С ПОМОЩЬЮ МЕТОДОВ НЕЛИНЕЙНОЙ ДИНАМИКИ

Abstract

This article evaluates the stealth of signals based on the technology of orthogonal frequency discrete multiplexing (OFDM-signals) and BPSK modulation, using statistical methods for assessing stealth, represented by methods of nonlinear dynamics (Hurst exponent and BDS-statistics). As a result of the conducted studies, it was found that OFDM-signals based on BPSK modulation, in general, have insufficient stealth, since they can be detected using the Hurst exponent and BDS-statistics. The features of research using the Hurst exponent and BDS-statistics of OFDM-signals based on BPSK modulation are shown. Among such features, it should be noted that with an increase in the number of subcarriers, the values of the Hurst exponent and BDS-statistics also increase, in particular, the value of the Hurst exponent approaches values corresponding to the concept of white noise, and the value of BDS-statistics approaches values indicating that OFDM-signals with a large number of subcarriers can potentially be attributed to chaotic signals. From the above results, it can be seen that with an increase in the number of subcarriers OFDM-signals, some complication of the structure of the transmitted signals occurs, which, however, does not lead to an increase of stealth. The results obtained coincide with well-known studies from this field, which show that OFDM technology based on harmonic carrier modulation methods does not provide data transmission stealth. Further directions of research on the evaluation of the stealth of OFDM-signals using nonlinear dynamics methods are briefly described, in particular, the study of OFDM-signals with other types of modulation and a different number of subcarriers, as well as the study of OFDM-signals, which use additional methods to increase stealth.