Re: [Openbts-discuss] Device doesn't see network at all (openbts-uhd + usrp2 + wbx)

[Thomas T. <tt...@vt...>]

2011/6/10 Љубомир Самарџић <lj...@gm...>:
> Also, one note:
> when I tried to start kal, to perform gsm scan over 900 band, it promts
> these messages:
>
> UHD Warning:
>     The hardware does not support the requested RX sample rate:
>     Target sample rate: 0.270833 MSps
>     Actual sample rate: 0.271739 MSps

The USRP2 is clocked at 100MHz and doesn't output fractional sample
rates, so the actual rate is the closest that the device can get to
the GSM symbol rate - 1625/6 ksps. It's a relatively simple change to
fix the warning by making the usrp2 output the same rate that kal uses
for the usrp1, 400 ksps if I remember correctly. I just haven't gotten
around to doing so.

I'm not familiar with all parts of kalibrate, but with the warning I'm
still able to detect GSM signals and make offset comparisons between
external and internal clocked usrp2's.

What type of antenna are you using, and have you tried increasing the
gain setting?

  Thomas