Re the spectrum estimation toolbox

Hello GR,

I have multiple questions re the gr-specest toolbox:

1/ Is there any MTM estimator block for GRC

2/ Can anyone explain to me the figures in
https://www.cgran.org/wiki/SpecEst related to Cyclostationarity-Based
Modulation Classification. I am actually confused aren’t they inverted
(QPSK
and BPSK) because it is in the QPSK that you find components on the Im.
axis
not in the BPSK. Any explanations is well appreciated.

3/ The README file talks about how to tune the update rate (sample_rate
/
block_len) however I tried to decrease it to almost 15, sample rate =
32k
and block_len = 2048 and even I tried to have an FFT size 256, I always
get
the plot stuck and is hardly updating. No zoom is possible after I run
the
estimator.
And after I run that, I cannot Pause nor close. I just have to kill the
process.
Am I missing something or some tuning.

Best Regards,
Ruecan


View this message in context:
http://gnuradio.4.n7.nabble.com/Re-the-spectrum-estimation-toolbox-tp47483.html
Sent from the GnuRadio mailing list archive at Nabble.com.

On 04/10/2014 12:12 AM, Ruecan wrote:

Hello GR,

I have multiple questions re the gr-specest toolbox:

1/ Is there any MTM estimator block for GRC

Yes!

2/ Can anyone explain to me the figures in
https://www.cgran.org/wiki/SpecEst related to Cyclostationarity-Based
Modulation Classification. I am actually confused aren’t they inverted (QPSK
and BPSK) because it is in the QPSK that you find components on the Im. axis
not in the BPSK. Any explanations is well appreciated.

This is not IQ, it’s frequency and symbol rate on the axes.

3/ The README file talks about how to tune the update rate (sample_rate /
block_len) however I tried to decrease it to almost 15, sample rate = 32k
and block_len = 2048 and even I tried to have an FFT size 256, I always get
the plot stuck and is hardly updating. No zoom is possible after I run the
estimator.
And after I run that, I cannot Pause nor close. I just have to kill the
process.
Am I missing something or some tuning.

Not sure here, but I know guys at CEL have been working to update the
toolbox to 3.7, maybe that’ll fix it.

Martin

On 04/10/2014 05:54 PM, Martin B. wrote:

Not sure here, but I know guys at CEL have been working to update the
toolbox to 3.7, maybe that’ll fix it.

When this gets updated to 3.7, it’s a good candidate for including on
the GNU Radio DVD.

Johnathan