Take your first steps in using labAlive with Oscilloscope demo, Spectrum analyzer demo or the app shown in the video Signal-to-noise ratio demonstrator.
This digital education initiative makes 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.
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 to digital learning in higher education.
06/23/2020 Lessons learned from practical courses. Video and project description in German: Wie kann das Studium digital fortgesetzt werden? Praxiswissen digital vermitteln mit dem Virtual Communications Lab.
Not only lectures can be delivered online but also practical experiments which are an integral part of engineering education. In combination with video conferencing it even offers the opportunity to work with students individually or in small groups.
The tutor - video conferencing host - can give individualized feedback, diagnose and remedy specific learning gaps.
myLabAlive is an online tool that on the fly generates simulation apps from text. Give it a try and create your own experiment application. Get a first glimpse of labAlive text, that looks like a simple programming language.
New or updated experiments
New features
Comprehend how a QPSK signal is generated. Two bits are mapped to a symbol. Its phase shifts the carrier phase during the symbol duration.
The invention of amplitude modulation made radio broadcasting possible. The message signal varies the carrier amplitude. Analyze an AM-signal in time and frequency domain and...
An easy way to recover the messsage signal of an AM-modulated signal is the envelope demodulator. In its simplest form the envelope...
In AM transmissions without carrier a simple envelope detection is not possible. A more complex synchronous or coherent detection is required...
In this scenario, a pulse is sent and shall be detected at the receiver. It might represent a symbol for digital transmission or a radar pulse. The received pulse might be ...
A direct path and a reflected path set up a simple multipath propagation environment. Determine the channel impulse response and transfer function!
A baseband equivalent representation of the channel is useful to process the transfer function around the carrier frequency. It's equivalent to the bandpass channel transfer function.
In channels where the receiver moves the signal frequency is shifted depending on the velocity. In practice the Doppler effect occurs in wireless communications.
Select a topic of communications technology and explore online experiments that help you to understand communication technology! It's free for use.
| Term | Description | Experiment |
|---|---|---|
| AM Amplitude modulation |
Amplitude modulation is a form of analog modulation. The amplitude of a high frequency carrier is changed depending on a baseband signal. | Amplitude modulation |
| AWGN Additive white gaussian noise |
A white noise signal whose amplitude distribution is equal to a gaussian function. |
Matched filter in digital communications
OFDM BER vs Eb/N0 in AWGN channel QAM BER for AWGN channel QPSK BER for AWGN channel |
| BER Bit error rate |
Bit error rate means the number of bit errors in relation to the bits sent. |
OFDM BER vs Eb/N0 in AWGN channel
QAM BER for AWGN channel QPSK BER - equivalent baseband QPSK BER for AWGN channel |
| FM Frequency modulation |
Frequency modulation is a form of analog modulation. The frequency of a high frequency carrier is changed depending on a baseband signal. |
Spectra of FM signals
Frequency modulation Frequency modulation audio demo FM demodulator using PLL FM transmitter |