Re: [Discuss-gnuradio] GnuRadio: Clock Recovery MM: imu out of bounds
Hi Tom,
Thanks for your help. I've adapted the sample rate of the result coming out of
the low-pass filter now. However, if I decimate much further, my signal becomes
a bit too weak I think.
New chart:
http://imgur.com/mbt288s,etHbYLT#0
New result:
http://imgur.com/mbt288s,etHbYLT#1
Is this a better approach?
The initial error still persists though.
Regards
From: mibo...@hotmail.com
To: t...@trondeau.com
Date: Thu, 20 Aug 2015 09:09:42 +0200
CC: discuss-gnuradio@gnu.org
Subject: Re: [Discuss-gnuradio] GnuRadio: Clock Recovery MM: imu out of bounds
Hi Tom,
Thanks for your answer. That's indeed something that I need to think about
more. However, as I understand it, the samples per symbol rate is equal to
(samp_rate / data_rate). My sample rate is 500k, and my data rate (i think) is
only around 100 or 200. See this figure of my (cleaned) signal:
http://imgur.com/8pNqCop
You see that it takes approximately 10 ms to transmit one symbol. This means
100 symbols per second. As I have 500k samples per second, this means 5k
samples per symbol, right?
However, I have tried setting the samples per symbol to 4, just to try, and the
'out of bounds' error still persists.
Regards,
Michael
From: t...@trondeau.com
Date: Wed, 19 Aug 2015 09:41:19 -0400
Subject: Re: [Discuss-gnuradio] GnuRadio: Clock Recovery MM: imu out of bounds
To: mibo...@hotmail.com
CC: discuss-gnuradio@gnu.org
On Wed, Aug 19, 2015 at 2:51 AM, Michael B wrote:
I have created a flowgraph, based on an example of Michael Ossmann, which takes
in a signal, and should output bits.I need to use the clock recovery MM block,
which I do not fully understand yet. However, after reading some blogposts, I
am quite sure that I can leave most of the settings default, except for the
Omega one. Here's my flowgraph:
http://imgur.com/pHRXnZu
When running this flowgraph, it gives me the following error:
thread[thread-per-block[5]:]:
mmse_fir_interpolator_ff: imu out of bounds.
While searching, I stumbled upon this piece of code in the source of GnuRadio:
int imu = (int)rint(mu * NSTEPS);
if((imu < 0) || (imu > NSTEPS)) {
throw std::runtime_error("mmse_fir_interpolator_ff: imu out of bounds.\n");
}
So, I suspect it is not due to my Omega setting (which might be wrong, I have
to play with that setting), but that it is due to my Mu setting, which is just
the default (0.5). However, I understand that Mu needs to be between 0 and 1,
so I do not really understand what the problem is. Anyone who does?Environment
details:GNU Radio Companion 3.7.7.1Running a GNU Radio live DVD in a virtual
machine (VirtualBox 4.2.12) on Windows 7.Using Volk machine: ssse3_64
Michael,
I don't have an answer, but I can say where you're doing something wrong.
You're samples/symbol (samp_per_sym) is definitely /not/ 2.5k. That's a
massively oversampled signal and can't be right. You need to think what's the
sampling rate of the system? What's the symbol rate of my signal? That will
tell you the samples/symbol you need. It should small, like 2 or 4.
Tom
___
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
Re: [Discuss-gnuradio] GnuRadio: Clock Recovery MM: imu out of bounds
Hi Tom,
Thanks for your answer. That's indeed something that I need to think about
more. However, as I understand it, the samples per symbol rate is equal to
(samp_rate / data_rate). My sample rate is 500k, and my data rate (i think) is
only around 100 or 200. See this figure of my (cleaned) signal:
http://imgur.com/8pNqCop
You see that it takes approximately 10 ms to transmit one symbol. This means
100 symbols per second. As I have 500k samples per second, this means 5k
samples per symbol, right?
However, I have tried setting the samples per symbol to 4, just to try, and the
'out of bounds' error still persists.
Regards,
Michael
From: t...@trondeau.com
Date: Wed, 19 Aug 2015 09:41:19 -0400
Subject: Re: [Discuss-gnuradio] GnuRadio: Clock Recovery MM: imu out of bounds
To: mibo...@hotmail.com
CC: discuss-gnuradio@gnu.org
On Wed, Aug 19, 2015 at 2:51 AM, Michael B wrote:
I have created a flowgraph, based on an example of Michael Ossmann, which takes
in a signal, and should output bits.I need to use the clock recovery MM block,
which I do not fully understand yet. However, after reading some blogposts, I
am quite sure that I can leave most of the settings default, except for the
Omega one. Here's my flowgraph:
http://imgur.com/pHRXnZu
When running this flowgraph, it gives me the following error:
thread[thread-per-block[5]:]:
mmse_fir_interpolator_ff: imu out of bounds.
While searching, I stumbled upon this piece of code in the source of GnuRadio:
int imu = (int)rint(mu * NSTEPS);
if((imu < 0) || (imu > NSTEPS)) {
throw std::runtime_error("mmse_fir_interpolator_ff: imu out of bounds.\n");
}
So, I suspect it is not due to my Omega setting (which might be wrong, I have
to play with that setting), but that it is due to my Mu setting, which is just
the default (0.5). However, I understand that Mu needs to be between 0 and 1,
so I do not really understand what the problem is. Anyone who does?Environment
details:GNU Radio Companion 3.7.7.1Running a GNU Radio live DVD in a virtual
machine (VirtualBox 4.2.12) on Windows 7.Using Volk machine: ssse3_64
Michael,
I don't have an answer, but I can say where you're doing something wrong.
You're samples/symbol (samp_per_sym) is definitely /not/ 2.5k. That's a
massively oversampled signal and can't be right. You need to think what's the
sampling rate of the system? What's the symbol rate of my signal? That will
tell you the samples/symbol you need. It should small, like 2 or 4.
Tom
___
Discuss-gnuradio mailing list
Discuss-gnuradio@gnu.org
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] GnuRadio: Clock Recovery MM: imu out of bounds
I have created a flowgraph, based on an example of Michael Ossmann, which takes
in a signal, and should output bits.I need to use the clock recovery MM block,
which I do not fully understand yet. However, after reading some blogposts, I
am quite sure that I can leave most of the settings default, except for the
Omega one. Here's my flowgraph:
http://imgur.com/pHRXnZu
When running this flowgraph, it gives me the following error:
thread[thread-per-block[5]:]:
mmse_fir_interpolator_ff: imu out of bounds.
While searching, I stumbled upon this piece of code in the source of GnuRadio:
int imu = (int)rint(mu * NSTEPS);
if((imu < 0) || (imu > NSTEPS)) {
throw std::runtime_error("mmse_fir_interpolator_ff: imu out of bounds.\n");
}
So, I suspect it is not due to my Omega setting (which might be wrong, I have
to play with that setting), but that it is due to my Mu setting, which is just
the default (0.5). However, I understand that Mu needs to be between 0 and 1,
so I do not really understand what the problem is. Anyone who does?Environment
details:GNU Radio Companion 3.7.7.1Running a GNU Radio live DVD in a virtual
machine (VirtualBox 4.2.12) on Windows 7.Using Volk machine: ssse3_64
___
Discuss-gnuradio mailing list
Discuss-gnuradio@gnu.org
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
