I would suggest these two as a crashcourse to the math that is used in SDR: https://www.dsprelated.com/showarticle/192.php https://www.dsprelated.com/showartic

I would suggest these two as a crashcourse to the math that is used in SDR: https://www.dsprelated.com/showarticle/192.php https://www.dsprelated.com/showarticle/192.php https://www.katjaas.nl/home/home.html https://www.katjaas.nl/home/home.html We are maintaining a long list with theory/math: https://brmlab.cz/event/dsp#zdroje https://brmlab.cz/event/dsp#zdroje , and engineering stuff: https://brmlab.cz/project/sdr/start#links https://brmlab.cz/project/sdr/start#links . However, I agree it is rather difficult to get into the topic. I'm playing with SDRs for almost 10 years (increasingly "fulltime" lately), and we still need to employ a professional mathematician to help me with some advanced problems.