Abstract:

The authors of the article share their experience in the online teaching of disciplines included in the curriculum of the Telecommunications major at the University of Plovdiv.

When studying disciplines related to the processes taking place in communication systems - radio frequency distortions, nonlinearity, phase noise, thermal noise, etc., which are processes that require analysis of the effects of noise overlap and interference inherent in physical devices, the use of specialized simulation software platforms greatly facilitates the teaching and learning process during the COVID19 pandemic.

The MATLAB/Simulink software platform is suitable for teaching telecommunications disciplines because Simulink is a dynamic interdisciplinary environment for modeling complex technical systems, such as communication systems.

The authors of the article share their experience of using MATLAB/Simulink's Communications System Toolbox (CST), as it offers learners algorithms and tools for developing, modeling and analyzing communication systems. These capabilities are realized in the form of system objects, functions and blocks, including algorithms for channel coding and source coding, layering, modulation and demodulation, stabilization, synchronization and models of communication channels. Communications System Toolbox allows modeling of dynamic communication systems that use techniques such as Orthogonal Space Time Block Coding (OSTBC) and MIMO (Multiple-Input-Multiple-Output). CST supports fixed point arithmetic and C and HDL code generation.
The report presents a methodology that includes step-by-step description of the process of developing the Adaptive MIMO System with OSTBC, which facilitates the simulation research conducted by the students in order to thoroughly master the subject matter.

Simulation studies of the behavior of the Adaptive MIMO System with OSTBC are presented. The MIMO System allows the use of a variable number of antennas for transmission and reception. The simulation studies, conducted by the students, of the operation of the system with one, two, three or four antennas for transmission or reception are presented and analyzed. The number of transmitting and receiving antennas is adaptive and varies, either manually or according to an adaptation algorithm, based on the difference between the target and the actual error rate within the whole system. Graphical visualization of the different modes of operation of the system is a prerequisite for in-depth analysis of the results and their comparison. The results obtained, their processing and their analysis in an educational environment is a good opportunity for students to build skills necessary for engineering work - design, experimentation and analysis of results.

Conducting this type of online learning during the COVID19 pandemic has led to an increase in the students' motivation to learn, as they easily accept modern interactive teaching methods and techniques, namely hands-on learning, shared experience and feedback.

Keywords:

Adaptive MIMO System, OSTBC, online learning, COVID19.