Hi, original presenter here :) The beginning is FTs 101. The end gets more application-centric around OFDM and is why it feels 'unreasonably effective' to me. If it feels obvious, there's a couple of slides at the end that are food for thought jumping off points. And if that's obvious to you too, let's collab on building an open source LTE modem!
Lance -- I really like this comment because it is a compelling argument for something other than the viewpoint I hold. Obviously I am not fully convinced by it (yet?). But this is the kind of discussion that we had hoped for in response to this post. Thanks for posting it.
I was Chris's housemate at the time, the victim of the hours of 'sssshhhh sssshhhh shhhhh'. Interestingly, he rendered this mostly by drawing boxes in pov-ray -- I'm not sure what he used to make dimensioned drawings, but it was definitely not any of the modern CAD tools, and they were mostly for his reference.
But these days, I do highly recommend Onshape -- it breaks down a lot of the 'rules' that I thought I knew about CAD software. I started using it about two months ago; one of my clients uses it for real industrial design of some IoT hardware, so it is powerful enough to do real things. Before I started using Onshape, I thought that 1) all CAD software was a million billion gigabytes, and required stupidly powerful hardware for no readily apparent reason, and 2) had an annoying licensing model that requires you to jump through hoops to get access to the free tier. Well, neither of these are true with Onshape: I went from 'hmm, maybe I should try this for my personal projects' to 'constraining a sketch' in about 90 seconds ... on Linux ... in Firefox ... on my Shenzhen ThinkPad ... with an Intel GPU. I was blown away at how much it failed to suck.
Anyway, my suggestion on choosing software is: it probably doesn't all that much matter. What you want to learn is the CAD mindset, not the software. An experienced MechE once told me that if you are not careful, you can end up writing 'spaghetti CAD'. These tools these days give you a lot of features that are, in theory, more expressive, but in practice, can result in unmanufacturable parts or unmaintainable designs: be careful!