Can anyone recommend a decent overview of SDR these days coming from a software (non hardcore maths/physics background) perspective? A few years ago it seemed like a fascinating area but the hardware was still quite expensive. I guess it has gotten cheaper? I am mostly interested to see what kind of signals are in the local environment, and maybe increase my understanding of some common wireless protocols.
The thing that happened is RTL-SDR, which is _not_ the name of a product but refers to the _use_ of a mass-market TV receiver USB device that happened to have a raw IQ signal mode in the hardware (RTL2832U chip). This being so cheap ($15-20) lots and lots of people jumped on it and this created a lot of interest in SDR in general.
I don't have a good overview to recommend you, but for ‘what kind of signals…’ I do recommend grabbing a RTL-SDR device, and just reading about how to use it should give you lots of pointers into the rest of the SDR world.
