WEB-BASED SIMULATORS FOR THE LEARNING OF COMMUNICATION SYSTEMS

Communication Theory is a mandatory junior-level course on communication systems offered by the University of Jaén as part of the Telecommunication Engineering Degree program. This course is focused on studying the main mathematical models used to describe analogue and digital communication systems. The two main objectives of the course are to determinate: (1) how these systems work and (2) their performance in a noisy channel. In order to improve the understanding of the mathematical models studied, over the past years we have included exercises based on programming in MATLAB. These exercises were designed to extend, during the laboratory sessions, the material covered in the theoretical lessons. During these sessions, the students must program the algorithms required to model different kinds of modulation techniques and simulate them. The main drawback in this approach (as per other teaching fields) is that during these sessions the students spend most of the time developing programs and therefore, the time spent in the main course objectives (simulation results analysis and conclusions extraction) is reduced. That is to say, there is an important risk of making a communication system laboratory session a programming course lecture, which is far away from the topics of the course. Another important matter is the students’ availability of MATLAB licenses and their access to the laboratory out of the established hours.
Different approaches followed to avoid these two problems have in common the use of certain multimedia applications in order to make easier the students access to complex simulations. The approach presented here is based on introducing as a course activity the simulation of Simulink models via remote access. The tool presented here allows the development of web applications to simulate remotely digital system models based on Simulink. This tool provides the facility of creating automatically different simulators, merely by changing the configuration loaded on a Simulink generated file (MDL). This automatic generation also requires the development of a software collection suppoted by Matlab script files and Java classes and packages. The final version of the simulators developed with this tool also allows editing and changing the parameters of the different blocks via a web user interface, and the simulation results visualization through different display controls in time/frequency domain.
Although Simulink is a complex tool that allows simulating dynamic systems, the models provided to the students are restricted in order to allow them change only those parameters chosen by the lecturer. Therefore, using this tool we solved the two problems reported. First, the use of Simulink technology does not require programming skills; and second, the students can access the simulators by way of navigating through a web page, hence avoiding the necessity of a license. Students can change certain parameters of both, the system block diagram and the simulation process. After configuring the required parameters, the students can run the simulator and formulate conclusions from the results obtained. Therefore, they can only focus on learning basics aspects of communication systems without getting lost in unnecessary programming details.