Re: [Discuss-gnuradio] GNU radio: where to start?

[michael taylor]

On 12/6/06, Mario Rossi <address@hidden> wrote:
> GNUradio looks very interesting, but I haven't found too much
> documentation for very beginners (I'm not en engineer, and I've
> problems understanding many things behind radio and frequencies).

I think of it very much as a project still (at this point in time
anyhow) mainly aimed at people who have some engineering, DSP
programming, or radio experience. I guess I'm saying it's pre-beta on
the whole. It isn't a turn-key like say Myth-TV (Linux based personal
video recorder), but more tinker / hacker level.

> It looks to me a great idea! Having one single receiver useful for all
> sort of signals! Instead of chasing all new standards of digital and
> analogue broadcast!

That's the appeal of software defined radio, using a fairly generic
and flexible RF (radio frequency) hardware front-end, and doing all
the information theory processing (encoding / decoding, modulating /
demodulating) in software which is far cheaper / low-barrier to
change.

> But it looks too good to be true, since I haven't understood whether
> such a receiver exists. It looks one has to assemble it personally,
> but then again I have no idea of how to do it. And would it be good
> for all frequencies? What is a reasonable range for a single device?

As I suggested, it is not (in my opinion) a consumer application at
this point in time. Hardware does exist, and you can purchase it (i.e.
a USRP from Ettus Research), and a variety of daughterboards covering
common frequencies are available.

The basic USRP is good for the GNU/Radio project, the daughterboard(s)
determine what frequency range(s) you can use.

"Range"? Distance (transmitter/receiver distance)? or frequency
range?, dynamic range?

If you are looking for a software based radio receiver, I'd say
something like WinRadio (/LiNradio) or the like might be more what you
are looking for. <http://www.winradio.com/>.

> Another question: the project http://drm.sourceforge.net looks to be a
> subset of GNUradio, decoding only DRM.
> There as well a receiver is needed. Unfortunaltely I cannot understand
> whether the same sort of device is required for DRM and GNUradio. Has
> anybody seen it?

the DReaM project is only software to decode an audio signal from a
shortwave broadcast(*) signal that is DRM encoded, and outputs
(typically from the speaker) the human intelligent audio content.

The DRM / DReaM software would typically use an average quality
shortwave receiver, such as the made by Grundig / Eton, Sangean, and
Kaito. US online store:
<http://www.universal-radio.com/catalog/portable.html>.

*) I'm only aware of DRM - Digital Radio Mondiale being used for
international shortwave broadcast transmissions. It could be used for
AM/MW I believe, but I don't know if that is being used anywhere.

I hope that clarify things a bit.