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On 05/21/2018 11:14 PM, Yeo Jin Kuang
Alvin (IA) wrote:
Hi Marcus,
Thank you for
the quick reply!
Is there any
block in GRC that works with the FPGA in the USRP B210? And
I have tried lowering the transition width from 1000 to
~150 but I still see overflow, does this means that the only
solution to it is to get a faster computer?
There are no FPGA-for-B210 blocks in Gnu Radio. That's not how Gnu
Radio works. RFNoC is an exception, but B210 is not an
RFNoC-capable radio.
Narrowing the transition width (as a fraction of sample-rate) is
precisely how you end up with really-long, hard-to-compute,
filters. Try a transition
width of 100e3, and see how that does. That's a roughly 2%
fractional bandwidth. Which, in the analog world, would be a pretty
"tight" filter.
Thank you in
advanced!
From: Discuss-gnuradio
[mailto:address@hidden]
On Behalf Of Marcus D. Leech
Sent: Tuesday, 22 May 2018 11:02 AM
To: address@hidden
Subject: Re: [Discuss-gnuradio] GNURadio
Companion LPF
On 05/21/2018 10:54 PM, Yeo Jin Kuang
Alvin (IA) wrote:
Hi all,
Apparently, I tried connecting the USRP
Source to a Low Pass Filter and to a File Sink, I get
overflows “OOOOOO”. However, when I removed the LPF, there
is no overflow. The question is, why is this happening? Is
the Low Pass Filter in GRC done in the FPGA or in the
computer itself? I am using USRP B210 and my sampling rate
is 6MHz.
Is there a solution to this?
Thank you in advanced!
'O'
are caused by the computer not "keeping up". Gnu Radio is a
software-defined-radio framework, and all the blocks execute
on the PC host.
It is typically the case that new users make low-pass
filters with very "aggressive" transition bandwidths, which
leads to a very expensive-to-compute
filter. Try relaxing the transition bandwidth.
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