Re: [Discuss-gnuradio] Large FFTs

[Carles Fernandez]

On Tue, Aug 24, 2010 at 1:02 AM, Thomas Hobiger <address@hidden> wrote:
> Hi Carles,
>
> Thanks for the reply. That's a very helpful comment.
>
>> we have found some problems when using USRP2+DBSRX for GPS due to
>> phase noise. See details in http://www.ruby-forum.com/topic/213845
>>
>
> Once we have the components in the lab, I am going to play with them, having
> your comment on my check-list.
>>
>> If someone have succeded on this, we would appreciate some hints to
>> make it work. Our software GPS receiver was not able to track signals,
>> while it run smoothly when using USRP1 + DBSRX without modification.
>>
>
> By tracking signals, do you mean that one of the receiver loops (DLL, PLL)
> lost lock or does it only prevent to extract the navigation bits?
>

I mean that the PLL lost lock after a few seconds, so we were able to
extract only a few (and useless) navigation bits. We played with the
filter loop, without success for the moment. We are quite confident in
the software receiver, it works nice with other hardware
configurations, and that is why we suspect that it could be a hardware
issue. We will be working on this in the next month. I will let you
know our advaces.

Best regards,
Carles


> Best regards,
>  Thomas Hobiger
>
>
>
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> Dr. Thomas Hobiger
> Space-Time Measurement Project
> Space-Time Standards Group
> New Generation Network Research Center
> National Institute of Information and Communications Technology
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