Thread: New Twist for This Hobby -- GnuRadio

Attention folks, ( and suppliers as well I suppose );

Check out this site;




GNU Radio

This is a software radio ( open source ) that interfaces to various GNURadio specific transceivers including ones that operate in the band pass of your typical FTA LNB

S/W and H/W schematics are all there open source.

The implication here, is that you could pole mount one of these "radios" on your dish mount and operate the whole shebang over your home LAN using power over Ethernet and any internet appliance in the house...

There are multiple transceivers that can be supported, which implies a single point OTA TV, AM/FM Radio, CB, FRS and other capabilities ( it is S/W controlled after all ) as well as WiFi ( a/b/g/n ) and more importantly "WhiteFI" .

Now if our suppliers could get a source for this stuff and get the price under say $100, I'd say things could take a very interesting turn here. Don't you agree?

Something to look forward to in the New Year eh?

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I read the "Getting Started", and the "FAQ", and nowhere did I find a definitive discussion on what it was for.
It sounds like a solution looking for a problem.

If it's somehow relevant to FTA Satellite, please share. -
Not that it has to be, of course, but I'm a little lost.

Please describe what and how this might be used in my home.

I also have read the FAQ and not understanding the potential uses or applications.

It looks like it can replace band tuner and (de)modulation specific hardware like cellphone or sat card, making a PC universal radio device by using a universal or broader purpose card and specific for each application software add-ons. "The Universal Software Radio Peripheral, or
USRP

(pronounced usurp) is designed to allow general purpose computers to function as high bandwidth software radios. In essence, it serves as a digital baseband and IF section of a radio communication system."

Ok, I am lost here. Say what?

Zamar - That's as I read it, I seem to remember this being used as an RF hacking device.

I think someone has too much time on their hands and, re inventing and over engineering the wheel

This is the other end of the spectrum from where most of us reside. We buy receivers implemented in hardware. Whenever some new standard comes along, be it DVB-S2, H.264 or 4:2:2, we dig into our pockets and buy the next generation unit. For those of us who dabble in more than just C-band and Ku-band, we repeat this story for each band we target. And then there are Hams who want to also transmit.

The premise of a software defined radio is to drastically simplify the hardware and generalize it to cover multiple bands with receive/transmit functions. The smarts all reside in PC-based software. The hardware does no demodulation. It simply captures the portion of the spectrum you want to receive (or the converse for transmitting) with A/D converters. The software does the demodulation (or modulation for transmitting) and any other specialized processing that is required.

Thus when a new type of signal is introduced, there is no reason to buy new hardware. The software is updated to handle whatever new processing is required. In addition this allows a lot of control of the signal processing. We're pretty much used to letting our receiver make the choices for optimizing reception. In fact, when these choices are built into hardware, there's usually not much that can be done. However with a software-based signal processing, there are many tricks and techniques to improve reception conditions and mitigate interference.

The basic hardware receiver/transmitter is pretty much just an interface between the computer and the A/D and D/A converters. There are daughtercards that plug into the base system that will downconvert/upconvert to the actual IF or RF required. For example, one would need the DBSRX daughtercard for FTA purposes, as it downconverts our friendly L-band (we use 950-2150 MHz, the card actually does 800-2400 MHz, which covers other applications beyond just FTA). I don't know the state of the software, but its pretty easy to develop the various components or piece them together from existing code. Thus one could build a single receiver system that could handle analog, DVB-S, DVB-S2, DSS, DCII, etc. and when something else comes along, it would be straightforward to add that, too.

This is probably not that useful for most people, but if you wanted to push the limits of your FTA system, this would be one way to do it. One could likely get very close to the theoretical limits of reception in terms of CNR. For example if you wanted to perform aperture combining (using more than one dish to cancel interference from adjacent orbital positions, cross-polarization cancellation, or improve CNR) this would be an effective path to take. And if you are interested in receiving other signals beyond FTA, and possibly transmitting (as a Ham) this one system could act as a centerpiece.

Those of us who dabble in Linux, there is a distribution made for Ubuntu going back to 6.06 and up to 9.10 Karmic. All you have to do some cutting and pasting into the terminal to get it set up in Ubuntu. Pretty much..., the days of typing obscure commands into the terminal has long been over. Linux desktop is pretty much now point and click like Windows is.


UbuntuInstall ? GNU Radio

When I got more time I'll look into this further, I have several Linux machines (been dabbling in it for a couple of years). Looks more like another computer project for me down the road.


Linux.....

Without getting too off topic, Linux can be installed on your Windows machine either as a dual boot where the hard drive has Windows and Linux partitions. Or another method is to use a built in installer called WUBI , (like a program that can easily be installed or deleted with no permanent partitions). The best method I found is just to swap out hard drives and install Linux on the swapped out hard drive.

Hardware might be a single RF DSP VLSI chip.