[hpsdr] pc control

[alex]

Chris Albertson wrote:
> On Mon, Sep 29, 2008 at 10:21 AM, alex <ajbr at btconnect.com> wrote:
>
>   
>> could anyone decribe the details of what happens in between the atlas and
>> audio becuase all i know is that it goes via ozy over usb to pc where some
>> sort of software takes care of the rest
>>     
>
> The direct answer to you question is this:  Think of a modern HF radio.  Not
> an SDR.  There are several stages some filters and so on inside.  There is
> a point inside the radio what you have an IF signal but prior to a narrow band
> filter being applied.  With the SDR the HPSDR hardware provides a signal
> that is about like the un-filtered IF.  This is sent to the computer in digital
> form.  What happens inside the computer is just about like what a conventional
> radio does with that same signal.   Actually most of the functionality is in
> the software.
>
> How is this done?  Could you describe what happens inside a conventional
> HF receiver in an email?
>
> Years ago I worked on a radar project.  My area is software.  I was working with
> one of the RF engineers to develop a high level block diagram of the system.
> Of course a modern radar is like our SDR systems in that there is an RF section
> and then all the tracking and display is done with a computer.  The funny thing
> was that his initial diagram had about 20 blocks that described things like a
> phased array antenna, local oscillators and filters and so on and then
> had one block
> called "computer".  Mine diagram had about 20 blocks with stuff like
> "track file",
> "Kalman filter", "autocorrelation:, "operator workstation" and so on
> and then one called "RF
> Front End".
>
> With SDR most of the functionality is in the software.  Yes there is a lot of
> hardware but half of it is because a desktop PC is used and you have to deal
> with a USB interface.
>   
i understand dsp its just i dont know: a- how the sdr comunicates with 
the pc and b- what sort of software is used to control it

alex
m0gjr

 1222791482.0