Recently some talks from the OpenFest 2014 conference have been uploaded to YouTube. One of the talks uploaded is titled “Software Defined Radio and RTL-SDR” and is by Harald Welte. Although a couple of years old, the talk is still valid and quite clearly explains some concepts about how software defined radio works, and then goes on to talk about the RTL-SDR dongle and some of it’s applications. The introduction reads:
This talk is about getting started with the basics of software defined radio (SDR). It introduces the fundamental concept of SDR constrasting classic radio systems, and continue to cover the rtl-sdr project, a software/driver architecture for the ultra-cheap RTL2832U based hardware. There will be practical demonstration using some of the readily-available Open Source projects implementing receivers for various radio systems.
If you are interested in his talk, then his slides appear to have been uploaded here.