Abstract:

The main goal of this article is to present the improvements obtained by using low-cost hardware devices, which allow the realization of laboratory practices in real environments instead of computer simulated ones. That is the case of three courses: Biomedical Digital Signal Processing and Radiocommunication Systems in the Communication Systems Engineering Degree (GISC), and Advanced Signal Processing in the Sound and Image Engineering Degree (GISI). Students perform practices in a blended-learning mode (classroom plus autonomous learning), which improves the versatility, access and efficiency of the student's work, with the consequent improvement in the acquisition of the learning outcomes.

The ETSIST (“Escuela Técnica Superior de Ingeniería de Sistemas de Telecomunicación”) of the UPM (“Universidad Politécnica de Madrid”) stands out for the number and quality of its laboratories, which support the teaching of almost all the courses. Several of them are very specific (for example, the anechoic chamber, the reverberation chamber and the music and TV recording studios), while many others are computer laboratories with a large amount of simulation software, where the “Learning By Doing” methodology acquires its full meaning. In this context, and with the intention of improving the quality of learning, new practices are designed, and at the same time some existing practices are extended through the use of low-cost hardware devices, allowing the generation or acquisition of real signals in real processes instead of the use of simulation programs and/or simulated signals.

In that sense, this paper will contextualize and describe experiences in the use of two different low-cost, portable and easy-to-use hardware devices. These devices allow to obtain real signals in order to process or analyze them later, therefore increasing the motivation and interest for students. Although these two experiences are radically different in their technical contents and in their specific learning competencies, both have several aspects in common. Those aspects are the methodology and the implementation process, as well as the advantages of using both devices: their sustainability and their portability.

In particular, the first experience to be described deals with the use of "Bitalino" boards for the acquisition of real biomedical signals and their subsequent processing in the courses Advanced Signal Processing (GISI) and Biomedical Digital Signal Processing (GISC), while the second deals with the use of SDR (Software Defined Radio) devices for the creation of communications signals and their transmission/reception in the course Radiocommunication Systems. The linked learning activities will be presented, as well as the assessment methodology for the acquisition of the learning outcomes.

In order to analyze the success in the implementation of the proposal and the impact on the learning process, a qualitative analysis of the students' impressions, obtained through a process of short interviews and open multiple-choice questionnaires, will be carried out. On the other hand, a quantitative and comparative analysis with previous years will be carried out, based on the students’ scores and the teachers' satisfaction surveys as well. The obtained results will allow improving the design of practical activities and extending their implementation in next editions by following an action-research process.

Keywords:

Learning by Doing, Action-Research, “Bitalino”, SDR, Learning Outcomes, Signal Processing, Radiocommunications.