GNU Radio for Exploring Signals
Talk Hard: A technical, historical, political, and cultural look at FM
https://fosdem.org/2016/schedule/event/gnu_radio/
The presentation has a lot of examples in it. The uploaded set of slides is actually expanded over what I actually presented, but I cut it down to make sure I stayed (just about) within time. I've provided all of the GRC files here that go along with the slide material. The slide numbers for referencing the GRC files is based on the extended slide deck.
Also, many of these examples assume a specific WAV file for the audio source. The path names when you download them will be wrong as you don't have these files. All you need to do is create your own WAV files, preferably in stereo (2 channels) at 32 kHz. You can even use the GNU Radio WAV sink block to create your own.
- The extended slide deck
- The presented slide deck
- Slide 4: AM DSB/SC
- Slide 6: AM DSB
- Slides 8/9: AM SSB and VSB
- Slide 10: Adding noise
- Slide 13: FM basics
- Slide 21: Calculating signal power
- Slide 28: Broadcast FM modulator
- Slide 29: Broadcast FM demodulator
- Slide 29: Broadcast FM demodulator (with PLL)
- Slide 30: Channelizing FM
- Slide 36: FM receiver (UHD)
Some other GRC files I built up while creating this talk:
- FM Loopback example: a TX/RX simulation
- FM Capture Effect: what I was hoping to show at the end of the talk with the two radios actually broadcasting but couldn't get the power correct. Here, adjust the amplitudes of the two different sources (a WAV file and a sine wave) to see how they interact.