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Revision as of 19:56, 17 April 2019 by Cmpxchg (talk | contribs) (3. Quick 'theory' of signal processing)
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Event Foundations Friday: Software Defined Radio workshop
Name Foundations Friday: Software Defined Radio workshop

Duration 2019-06-28 20:00 - 2019-06-28 23:00

* Location: Overgoo 1, Leidschendam
* Open from: 20:00

1 Prerequisites:

Please bring your own RTL-SDR hardware (very cheap, $20-$40 or less) or other SDR hardware (USRP or other GNURadio supported SDR). There might be a few available @ revspace coin-op machine by the time the workshop starts.

2. Quick introduction

Quick introduction into GNURadio companion user interface and concepts and keyboard shortcuts (have it preinstalled and git client to download the samplecode)

3. Quick 'theory' of signal processing

This could take about an hour or 1.5 hrs of interactive session

3.1 Real signals - real-sinewaves in the timedomain / displayed using time sink / oscillioscope - Multiplying real-sinewaves and frequency domain/spectrogram (mixing in radioterms)

3.2 Complex signals - Quadrature or complex (IQ) sinewave signal sources and displaying in timedomain ('constellation' diagram) and frequency domain (FFT) - Multiplying quadrature (IQ) sinewaves and spectrogram

3.3 Filtering complex signals - Filtering IQ signals using FIR filters with complex taps

3.4 Calculating FIR filter coefficients or parameters - Filtering coefficients/taps, impulse response of filter - (very quick) calculating FIR filter coefficients/taps using gr-filter - Performance limitations, tradeoffs between

 - computational complexity of filter (number of multiplies per processed sample)
 - steepness of cut-off frequency
 - flatness of passband of filter (integrity of signal that still should pass through the filter)
 - depth and ripple of stopband of filter (flatness of suppression of unwanted signal)

- Using inverse FFT/inverse DFT and windowing functions to determine filter coefficients/taps

4. Radio receivers and/or detectors

- Build a simple mono FM receiver using blocks with built-in feedback networks - Build a RDS FM receiver and connect it with your RTL-SDR or other gnuradio-support SDR/radiodata input device

5. Bonus

Build with welle.io a SDR-based DAB+ receiver from source. For this a QTQuick 5.x installation might be required.


(Nick)Name Has (some) SDR Reciever
cmpxchg Yes
minicom Yes