Playing around with RTLSDR
1 Introduction & Motivation
Long time has passed by with lots of things and new developments. I have seen now that modern digital radar cards sample the radar signal with ~~ 100 MSPS and can produce a good radar resolution of 7m per pixel. Since I'm working in the radar technology field now (expecially configuring and tweaking Terma Scanter 2001 radars, I have been wondering what I can do with SDR and radar. First of all I thought maybe I can get some precision out of an RTL SDR stick. For my first attempts, sampling a signal at those 3 MSPS should bee good enough before shifting over to my USRP2.
Let me note that my USRP2 was a fantastic device in 2010 and it still is. But it is noteworthy that the RedPitaya costs 230 Euro today and samples at 125 MSPS.
2 First attempts on the RTLSDR stick
I have purchased this device: (lsusb output)
Realtek Semiconductor Corp. RTL2832U DVB-T
I have blacklisted the native driver in /etc/modprobe.d/blacklist.conf
and I have played around with Alex Csete's GQRX tool. Really great, I can receive BC FM stations, notably the classical music station at 103.2 MHz.
After this attempt, I started to go a little urther and play around with GNURadio again. I noticed that so many things have changed since I last tried out gnuradio-companion. Many more blocks, much more functionality, everything has changed. Anyway, here is my first sketch. I copied from here: http://www.instructables.com/id/RTL-SDR-FM-radio-receiver-with-GNU-Radio-Companion/
3 Multichannel Reception
A lot of responses have come on a thread I triggered on the gnuradio discussion list on how to receive multiple channels in parallel.
Discuss-gnuradio] isolate channels from wideband http://lists.gnu.org/archive/html/discuss-gnuradio/2015-07/msg00380.html
Here is another thread:
[Discuss-gnuradio] GRC Polyphase Channelizer examples? http://lists.gnu.org/archive/html/discuss-gnuradio/2011-10/msg00120.html
Here is a program that can do it: ham2mon
Another tool that can do it:
4 Multichannel Transmission
Here are some notes. This solution does not work with the RTLSDR stick, but it works with the USRP2...: