The RTL-SDR project aims to use cheap USB DVB-T receviers as Software Defined Radio receivers. I've recently made some SubVIs for LabVIEW that grab I/Q samples from these devices, and I've also implemented a demodulator for FM broadcasts.
It's important to note that the corresponding National Instruments USRP hardware have much better performance and also able to transmit as well, so actually USRP is suitable for industrial purposes, while RTL-SDR might only be recommended for students and hobbyists. There's a table below that shows a comparison between some parameters of the two systems. (However, these are also dependent on hardware configuration, e. g. for RTL-SDR dongles the tuner chip on the panel.)
|Frequency range||400 Mhz - 4.4 GHz||50 MHz - 1800 MHz|
|Bandwidth||max. 40 MHz||max. 2 MHz|
|Bit depth||max. 16 bit||8 bit|
|2×2 MIMO available||yes||no|
RTL-SDR devices also suffer from image rejection problems, "birdies" showing up in the spectrum, and intermodulation products. Anyway, they have quite a good sensitivity, and can be used to receive amateur radio operators, PMR walkie-talkies, FM radio and also TV audio. There have even been successful experiments to decode raw GSM packets and GPS signals with these devices.
Nevertheless, our project might help some people to start out with SDR and signal processing, particularly other students, who can't afford costly hardware, but can buy a DVB-T tuner for ~15 USD, and might start to experiment with LabVIEW using real-world signals. Similarly LabVIEW supports cheap devices like Arduino with a free add-on. Considering the limitations of RTL-SDR, the software we release is useful mainly for educational purposes.
There's a list of compatible hardware devices over here. You can also search for RTL-SDR or RTL2832U on eBay.
The project is available for download and use under the BSD licence:
I would like to say thanks to Ferenc Ender for his great course on LabVIEW I've taken at the university last year (and this software also started out as homework for this course). Also thanks to Alipio Fernandez for testing and feedback.
-- András Retzler, HA7ILM