This program is an effort to make high-quality academic experiments in the field of communications technology available on the Internet. Similar to hardware experiments the goal is to learn, deepen and apply theoretical knowledge through practical experience.
The virtual experiments of this lab are computer simulations that implement the techniques to be analyzed. These applications are built with a simulation framework developed by the author - labAlive. Put very simply, the experiments are online applications that are perhaps comparable to Matlab/Simulink. Furthermore, the virtual experiment environment emulates a real-world laboratory:
Almost unlimited combinations of options and possibilities enable active experimentation and individual learning. The accurate simulation implementation assures mathematically valid results in any case.
First of all, the common online learning advantages such as availability, reproducibility and scalability become effective. Even for on-site courses, this approach facilitates a didactically meaningful synchronization of lectures and practical experiments. Within lectures an experiment application can easily be started - e.g. a click in PowerPoint - and demonstrate a theoretical topic.
Furthermore, the virtual lab leverages a potential beyond hardware experiments:
Configuration of suitable initial experiment settings avoids unnecessary and time-consuming manual instrument adjustments and helps students to achieve the interesting results and insights of the experiment. Students can easily recover a previous state if they become lost.
The experiment environment can be customized following didactic aspects. Irrelevant details may be omitted to reduce distraction and the set of available options be tailored to concentrate on the relevant aspects.
Altogether, the lab conditions shall be designed to enhance a creative atmosphere and encourage students to experiment actively and learn experientially.
Experiments built with the labAlive simulation framework might constitute a valuable contribution within online learning initiatives, e.g. massive open online courses (MOOC).
myLabAlive: Give it a try and create your own simulation app. Get a first glimpse of labAlive text, that looks like a simple programming language.
App implementation: The dynamic calculation of the app main window size has been optimized.
Take a look at the latest experiments:
Start with your first steps to use the labAlive environment. Adjust some scope settings and see how the scope displays the signal.
Start with your first steps to use the labAlive environment. Adjust some spectrum analyzer settings and see how the spectrum is displayed.
In channels where the receiver moves the signal frequency is shifted depending on the velocity. In practice the Doppler effect occurs in wireless communications.
See how even small movements strongly impact frequency-selective channel characteristics. Fast fading describes mobile radio channels.
Analyse the bit error rate of M-QAM over an AWGN channel. Adjust Eb/N0 and the constellation size. Compare the measured BER to the analytical bit error probability.
Understand OFDM and process each step using example values. A pilot sequence initializes the equalizer. Transmit an OFDM symbol and detect ISI-free.
Why do OFDM systems show a high peak-to-average power ratio? How does the PAPR depend on the number of subcarriers? Has the underlying M-QAM constellation size any impact?
Explore the relationship of signals in the time and frequency domain. Adjust time parameters and see how the spectrum changes! Take a look at selected Fourier transform pairs of waveforms and pulses.
Select a topic of communications technology and explore online experiments that help you to understand communication technology! It's free for use.