Hi #HamRadio folks, do any of you have a decent book/article reference that contains a practical explanation of using the Fourier transform to obtain a frequency spectra from a sampled audio waveform - with code if possible - that doesn’t go overboard with masses of EE-graduate-level maths? Some maths is fine. Thanks!
#GNURadio has its annual conference coming up just around the corner on September 5-9, 2023. Follow their account on Mastodon at @gnuradio and check out their website at https://www.gnuradio.org/
This whitepaper https://www.aldec.com/en/company/blog/190--development-of-real-time-sdr-systems-with-aldec-hes describes a method by which the designer can leverage the rapid signal prototyping capability in GNU Radio and use it in co-simulation with Aldec Riviera-PRO....
One set of my hobbies is based around wanting to see the world in different ways. Such as with radio waves...
This time around, I wanted to explore what the local RF spectrum looks like, from 80 Mhz to 6 Ghz, averaged over a period of days.
I realized some of the signal wasn't coming from the antenna, so I did some experiments. #mystery
The bottom graph shows the spectrum with inputs terminated. Ideally I should see flat noise. But when I zoom in, I can see local radio stations. Not ideal.
Front end gain is 72db, so these signals are closer to -100db, which is fairly small. I haven't calibrated to dbm yet.
The top graph is the same, but with the radio wrapped in metal foil. The radio stations go away. This is much better, but some peaks remain.
Data collected and processed with python, #gnuradio, and #numpy / matplotlib. 56Mhz of bandwidth is recorded (RT priority) for a day or two per run. Outliers are removed > 3* stddev. Each data set is then rendered at 1khz resolution. #SDR#RF
Blending GNU Radio and Aldec Riviera-PRO for verification of Software Defined Radio
This whitepaper https://www.aldec.com/en/company/blog/190--development-of-real-time-sdr-systems-with-aldec-hes describes a method by which the designer can leverage the rapid signal prototyping capability in GNU Radio and use it in co-simulation with Aldec Riviera-PRO....