[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] Some Basic USRP questions
From: |
satarkar |
Subject: |
Re: [Discuss-gnuradio] Some Basic USRP questions |
Date: |
Fri, 10 Apr 2009 17:03:58 -0400 (EDT) |
User-agent: |
SquirrelMail/1.4.16 |
>
>>>> 1) When I run my scripts I sometimes get "uOuOuO" message. I read in
>>>> the
>>>> archives that I need to increase the decimation rate but I have
>>>> already
>>>> set it to the maximum limit of 256. What should I do? Also, why do I
>>>> not
>>>> get the message all the time?
>>>>
> Hi,
>
> A problem I had a while ago was that my operating system (Ubuntu 8.10)
> was throttling my CPU down
> to 800MHz. Have a look in /proc/cpuinfo (or similar) to see your current
> working clock- speed.
>
> //Mattias
>
>
>
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>
the cpuinfo denotes the speed as 993 MHz.
I am currently following this formula for calculating the interpolation
and decimation rates.
r_tx = r_dac / interp / sps
r_rx = r_adc / decim / sps
Where r_dac is the DAC rate, r_adc is the ADC rate, interp is the
interpolation rate, decim is the decimation rate, and sps is the
samples per symbol. With the values sps = 8, r_dac = 128e6, r_adc = 64e6
and r_tx = r_rx = 32e3 bps, I get interp = 500, and decim = 250. I use
these interp and decim values when initializing the USRP. I was earlier
using additional software interpolation using a low pass filter, but I
have now removed it.
Can someone please tell me why I still get "uOuOuO" message on both Tx and
Rx ? I am trying to transmit a file and I believe this is the reason it is
not getting received properly.
thanks and regards,
Sumit