Re: [Discuss-gnuradio] uhd_fft and other wx stuff does not work...
The fix worked out :) Thanks a lot! Ralph. -Original Message- From: discuss-gnuradio-bounces+ralph=schmid@gnu.org [mailto:discuss-gnuradio-bounces+ralph=schmid@gnu.org] On Behalf Of Ralph A. Schmid, dk5ras Sent: Tuesday, December 30, 2014 17:01 To: 'Johnathan Corgan'; discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] uhd_fft and other wx stuff does not work... Waaah - and I was so sure that the problem sits in front of the PC :) Well, at least I had a task during a longer and boring trip by train... OK, so I will wait for the next commit. Thank you for all the efforts!! Ralph. -Original Message- From: Johnathan Corgan [mailto:johnat...@corganlabs.com] Sent: Tuesday, December 30, 2014 16:26 To: Ralph A. Schmid, dk5ras; discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] uhd_fft and other wx stuff does not work... Old Signed by an unverified key: 2014-12-30 at 16:25:35 On 12/30/2014 06:37 AM, Ralph A. Schmid, dk5ras wrote: I installed gnuradio master from source on a Kubuntu 14.04 64 bit system, and it appears that all wxgui stuff does not work. What may be the issue here? Gnuradio and uhd build without error, without missing features, but for example uhd_fft gives this output: This is indeed a bug, an unfortunate side effect of a semi-last minute commit before the 3.7.6 release. Fortunately, it's a one line bug fix I'll be committing to the repository shortly. -- Johnathan Corgan, Corgan Labs SDR/DSP Training and Consulting Services http://corganlabs.com * Johnathan Corgan johnat...@corganlabs.com * 0x671DA2F7 - Unverified ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Slow GUI in GRC
Hi, We recently bought a new machine with like 4 GHz processor, 16 GB of RAM. For the graphic card, we use the Radeon R7 250 1000 MHz GDDR5. Latest version of Ubuntu (14.04 LTS) was installed along with GNU Radio built from the source. Everything seems to be installed just fine. However, when trying to use GNU Radio Companion (GRC), the GUI's are so slow. Every time I try to place in or move the blocks in GRC, the whole GUI stuck for a while and it gets so slow. Because of this, I am not able to run GRC. Prior to this, GRC used to work just fine on another machine with a much lower specs for the RAM and the processor but with RS880 [Radeon HD 4200] graphic card. What is the cause for this problem and how to fix it? Could it be the new graphic card (Radeon R7 250 GDDR5)? Thank you. Best regards, Khalid ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Question on threshold mathematics in correlate_and_sync block
Hi.
Can someone give me a brief clue about the threshold testing in the
correlate_and_sync block?
In the constructor:
for(size_t i=0; i d_symbols.size(); i++)
corr += abs(d_symbols[i]*conj(d_symbols[i]));
d_thresh = 0.9*corr*corr;
corr looks like the value (at offset 0) of the discrete autocorrelation
of the matched filter.
d_thresh looks like 90% of the value of the autocorrelation of the
matched filter squared.
So far this makes sense to me.
Then in the work function (corr is a totally different array variable
here):
// Calculate the correlation with the known symbol
d_filter-filter(noutput_items, in, corr);
// Find the magnitude squared of the correlation
std::vectorfloat corr_mag(noutput_items);
volk_32fc_magnitude_squared_32f(corr_mag[0], corr, noutput_items);
int i = d_sps;
while(i noutput_items) {
if((corr_mag[i] - corr_mag[i-d_sps]) d_thresh) {
This if test confuses me slightly. We check to see if the value of
the output of the matched filtering has crossed the threshold relative
to one symbol previous? Why not just check relative to 0?
Regards,
Andy
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Re: [Discuss-gnuradio] Question on threshold mathematics in correlate_and_sync block
On Wed, 2014-12-31 at 14:00 -0500, Andy Walls wrote:
Hi.
Can someone give me a brief clue about the threshold testing in the
correlate_and_sync block?
In the constructor:
for(size_t i=0; i d_symbols.size(); i++)
corr += abs(d_symbols[i]*conj(d_symbols[i]));
d_thresh = 0.9*corr*corr;
corr looks like the value (at offset 0) of the discrete autocorrelation
of the matched filter.
d_thresh looks like 90% of the value of the autocorrelation of the
matched filter squared.
So far this makes sense to me.
Then in the work function (corr is a totally different array variable
here):
// Calculate the correlation with the known symbol
d_filter-filter(noutput_items, in, corr);
// Find the magnitude squared of the correlation
std::vectorfloat corr_mag(noutput_items);
volk_32fc_magnitude_squared_32f(corr_mag[0], corr, noutput_items);
int i = d_sps;
while(i noutput_items) {
if((corr_mag[i] - corr_mag[i-d_sps]) d_thresh) {
This if test confuses me slightly. We check to see if the value of
the output of the matched filtering has crossed the threshold relative
to one symbol previous? Why not just check relative to 0?
An additional note: The if test doesn't work too well, if the preamble
sequence is 101010101010..., since then the correlation will have
peaks at the symbol spacing, d_sps. Maybe
if((corr_mag[i] - corr_mag[i-d_sps/2]) d_thresh) {
would be better, since the correlation should sag at the half symbol?
Regards,
Andy
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