NON-ORTHOGONAL MULTIPLE ACCESS BASED ON PARTIAL CODING

Рассмотрены вопросы повышения эффективности использования спектра частот при построении систем сотовой связи 5G и 6G, а также проблемы снижения вычислительных затрат при реализации алгоритма последовательного подавления взаимного влияния сигналов. Подробно проанализирована суть нового принципа неортогонального множественного доступа на основе парциального кодирования, а также проведено его сравнение с методом разделения сигналов по мощности Power Division Non-Orthogonal Multiple Access (Рй-NOMA). Результаты получены с помощью программы «Моделирование Telecomm», предназначенной для численного математического моделирования систем связи на физическом уровне. The article considers the increasing the efficiency of using the frequency spectrum when building 5G and 6G cellular communication systems and the problems of reducing computational costs when implementing an algorithm for sequential suppression of the mutual influence of signals. The essence of the new principle of non-orthogonal multiple access based on partial coding is analyzed in detail, and it is compared with the Power Division Non-Orthogonal Multiple Access (PD-NOMA) method. The results are obtained using the software Modeling Telecomm intended for numerical mathematical modeling of communication systems at the physical level.

Interactive Learning Media for Cellular Communication Systems using the Multimedia Development Life Cycle Model

Based on the observations conducted to the students of Diploma of Telecommunications Engineering Telkom University. It revealed that the students have difficulty learning and understanding the chapters of call processing and network optimization in the course of cellular communication systems. It has resulted from the current learning media, which are only in the form of textbooks and Powerpoint slides considered less attractive. Hence, the learning process becomes ineffective and has an impact on low learning outcomes. In this study, an interactive learning media was designed with the Multimedia Development Life Cycle (MDLC) method, Adobe Flash professional CS6 software, using the action script 2.0 programming language. Learning media were designed according to users’ needs and learning outcomes of cellular communication system courses. Based on the testing results, the functionality showed 100% of features function as design specifications. Meanwhile, the user satisfaction testing results obtained an average MOS of 4.73, which means that the learning media is classified great. Furthermore, based on the quantitative testing, the average value of Quiz after using this interactive learning media was 81, which means that the learning media can increase students’ interest so that it affects the increase in learning outcomes by 66% from previous years.

CHARACTERISTICS OF UHF WAVES DISTRIBUTION IN LAND AND WATER SURFACE TROPOSPHERIC WAVEGUIDE

The article considers examples of ultra-long propagation of UHF radio waves in mobile cellular communication systems. The phenomena are mainly observed in the Astrakhan region in the spring-summer period (May-June) and are presumably associated with sharp seasonal changes of air temperature followed by rains. The effect of temperature inversion results in changing the refraction index in the surface layer and, as a result, in changing the wave direction as the effect of superrefraction in the surface atmospheric layer. The properties of radio waves in their propagation in the land and sea-water surface waveguide are investigated. The values of the heights of land and sea-water surface tropospheric waveguides for cellular communication systems of different ranges are obtained. The features of existing of tropospheric land and sea-water surface tropospheric waveguides are described. The need to use their properties in the mobile communication systems design is stated.