[Discuss-gnuradio] Data transfer through Pre-cog

[GNU radio]

Hi
I am trying from the past week to use the pre-cog library for data
transfer between two USRP N210 devices. I have tried a number of
configurations by replacing many blocks and modifying the Python code.  I
managed to transmit just a single packet and then the transmitter stops
with no error. The spectrum analyzer also shows just a single packet
transfer.

Can some body guide me on how to use the pre-cog simple trx for data
transfer.

Regards
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Re: [Discuss-gnuradio] Data transfer through Pre-cog

[John Malsbury]

E-mail me the flow graph you are using -> john.mals...@ettus.com


On Sat, Jul 20, 2013 at 1:04 AM, GNU radio  wrote:

> Hi
> I am trying from the past week to use the pre-cog library for data
> transfer between two USRP N210 devices. I have tried a number of
> configurations by replacing many blocks and modifying the Python code.  I
> managed to transmit just a single packet and then the transmitter stops
> with no error. The spectrum analyzer also shows just a single packet
> transfer.
>
> Can some body guide me on how to use the pre-cog simple trx for data
> transfer.
>
> Regards
>
>
>
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>
>
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[Discuss-gnuradio] Problem faced with clock_recovery_mm at low data rates

[Waqas Bin Abbas]

Hi all,

We have encountered an interesting problem in the clock_recovery_mm block
used in our BFSK system.
What happening is that, at lower data rates (i.e. at less than 54bps) we are
unable to decode the received data correctly,
however at higher data rates data is decoded fine.


What we are doing ?


We are implementing a BFSK receiver and our flow-graph consist of
Bandpass filter-> Hilbert transform-> quad_demod-> high pass filter ->
clock_recovery_mm-> binary slicer.
We are using 16k and 18k frequencies and our sampling rate is 48k (well
enough according to Nyquist criteria).


How and what we figured out ?


Our system was decoding the data correctly till 54bps and fails below
54bps.For debugging the issue We sent the same sequence from our transmitter
and received
at our receiver end with both 100 bps and 50 bps.we checked the output of
each block in our flow graph, using scope sink in GRC.
We found no difference in the outputs of other blocks except the
clock_recovery_mm block.What we found was that 
for consecutive sequence (either 1 or 0) the block fails to estimate the
symbol correctly (snapshot are provided in the link below ).The boxed area
is where we think the problem exist. 
We checked the block output further for alternating sequence of 1 and 0 and
found that the block is estimating correctly.

http://sysnet.org.pk/w/Snapshots

we also found that for same sequence (either 1 or 0) the problem exists at
each datarate but less than 54bps it become weird.
The link below shows the output of clock_recovery_mm block at 100bps and
50bps for same sequence of bits.
The arguments of the blocks are set as
gr.clock_recovery_mm_ff((samples/symbol),0.000625,0.5,0.01,0.05)
**For 100 bps we are having samples/symbol= 480 and for 50 bps we are
keeping it 960.


Our Questions ?


Now since we are just changing the value of the "Omega"(samples/symbol)  in
clock_recovery_mm block for 100bps and 50bps.
So we want to know the following:
1) Is there a limit to maximum value omega? (due to which we are not getting
the right results at lower data rates)
2) Do we have to change some other parameter in the clock_recovery_mm to
rectify our problem?
3) Is it the limitation of clock_recovery_mm block? 
4) Or there is some other solution to the specified problem?



--
View this message in context: 
http://gnuradio.4.n7.nabble.com/Problem-faced-with-clock-recovery-mm-at-low-data-rates-tp42591.html
Sent from the GnuRadio mailing list archive at Nabble.com.

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Re: [Discuss-gnuradio] 3.7 build failure ICE_ICESTORM-NOTFOUND etc.

[Tom Rondeau]

On Thu, Jul 18, 2013 at 11:23 AM, Barry Jackson  wrote:
> On 18/07/13 15:19, Tom Rondeau wrote:
>>
>>
>> Do you know what version of ICE is installed on your system? GNU Radio
>> explicitly looks for version 3.4, so if you're using 3.5 it won't work
>> by default. I've tested and compiled against 3.5, though, so it's only
>> the cmake FindICE script that's the problem.
>>
>> Also, ticket #564 is about faulty ICE detection, so this could also be
>> a problem with your system. I hope to work on this soon to resolve
>> that issue and make it easier to use either 3.4 or 3.5.
>>
>> Tom
>>
>
> Hi Tom,
> Ice version is 3.4.2.
>
> Yes, #564 does look like the same issue except that it is reported on OSX
> where I am seeing it in Linux.

Barry,

I just pushed branch 'cmake_ice' to my github repo
(github.com/trondeau/gnuradio). It does a better job of handling ICE,
the include dirs, and the required libs. It also adds the ability to
use Ice 3.5, which isn't important for you, though.

Could you check out this branch and give it a try? I'd like to know
how it works on other machines besides those which I've already gotten
things to work.

Thanks,
Tom

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Re: [Discuss-gnuradio] Gnuradio 3.6.x recipe for pybombs ?

[M Dammer]

This does not work. I am getting a "branch not found, building HEAD
instead" like error and then it builds 3.7. It looks as the gitbranch
part of the recipe really only works with branches while the version
numbers are tags. Does pybombs has a similar command than gitbranch to
define a tag in a recipe ?

On 19/07/13 20:00, Tom Rondeau wrote:
> On Fri, Jul 19, 2013 at 12:31 PM, M Dammer  wrote:
>> Has anyone a recipe for installing the 3.6-branch via pybombs ? I need a
>> 3.6 parallel installation on my system, because many old projects are
>> not working "out of the box" in 3.7.x. Even many of the projects
>> referenced by recipes that currently come with pybombs do not compile.
>> tnx, Mark
> Mark,
>
> You can edit the recipe file to change the branch you want to check
> out. In pybombs/recipes/gnuradio.lwr look for the 'gitbranch' line.
> Change this from 'master' to the tag of the version you want, such as
> 'v3.6.5.1' for the latest in the 3.6 version.
>
> Tom




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Re: [Discuss-gnuradio] Problem faced with clock_recovery_mm at low data rates

[Tom Rondeau]

On Sat, Jul 20, 2013 at 9:44 AM, Waqas Bin Abbas  wrote:
> Hi all,
>
> We have encountered an interesting problem in the clock_recovery_mm block
> used in our BFSK system.
> What happening is that, at lower data rates (i.e. at less than 54bps) we are
> unable to decode the received data correctly,
> however at higher data rates data is decoded fine.

The M&M block is known not to work well with a very large number of
samples per symbol.

Tom

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[Discuss-gnuradio] Can I add frequency offset at sender in ofdm example

[Yingjie Chen]

Hi, guys
Thanks in advance.
I plan to do a experiment in usrp that intentionally adding some
frequency offset in data symbol before transmission. Is that feasible
to implement it in gnuradio? Which block should I modify at sender
side?

Sent from my iPhone

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Re: [Discuss-gnuradio] Gnuradio 3.6.x recipe for pybombs ?

[Nathan West]

On Sat, Jul 20, 2013 at 10:26 AM, M Dammer  wrote:
> This does not work. I am getting a "branch not found, building HEAD
> instead" like error and then it builds 3.7. It looks as the gitbranch
> part of the recipe really only works with branches while the version
> numbers are tags. Does pybombs has a similar command than gitbranch to
> define a tag in a recipe ?
>
> On 19/07/13 20:00, Tom Rondeau wrote:
>> On Fri, Jul 19, 2013 at 12:31 PM, M Dammer  wrote:
>>> Has anyone a recipe for installing the 3.6-branch via pybombs ? I need a
>>> 3.6 parallel installation on my system, because many old projects are
>>> not working "out of the box" in 3.7.x. Even many of the projects
>>> referenced by recipes that currently come with pybombs do not compile.
>>> tnx, Mark
>> Mark,
>>
>> You can edit the recipe file to change the branch you want to check
>> out. In pybombs/recipes/gnuradio.lwr look for the 'gitbranch' line.
>> Change this from 'master' to the tag of the version you want, such as
>> 'v3.6.5.1' for the latest in the 3.6 version.
>>
>> Tom
>
>

Leave the branch as whatever you want (master, maint...) but add a
line for gitrev:
gitrev: tags/v3.6.5.1

Of course this could be whatever rev you want.

Nathan

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[Discuss-gnuradio] Video streaming through gr-extras tuntap in pre-cog

[GNU radio]

Hi
   I am trying to stream a VLC video stream to the gr-extras tuntap device.
I have modified the simple_trx demo to include tuntap device and run the
flow graph as a root. I assign the tap device the required ip address but I
am not sure how to assign a port number to it.

Then I configure the vlc media player to stream webcam video to the tap
device address. I disable the ARQ in the pre-cog.

The flow graph runs correctly but on a spectrum analyzer I just see a
single packet and then everything turns off.

Does any body know how to stream video in to the tuntap device.

Regards
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Re: [Discuss-gnuradio] Video streaming through gr-extras tuntap in pre-cog

[John Malsbury]

Dear GNU Radio Guru,

For the sake of this list, I'm going to have to ask you to send all support
requests for pre-cog to john.malsb...@ettus.com.  I'll be getting to the
other three e-mails you sent last night in a little while.

-John


On Sat, Jul 20, 2013 at 9:05 AM, GNU radio  wrote:

> Hi
>I am trying to stream a VLC video stream to the gr-extras tuntap
> device. I have modified the simple_trx demo to include tuntap device and
> run the flow graph as a root. I assign the tap device the required ip
> address but I am not sure how to assign a port number to it.
>
> Then I configure the vlc media player to stream webcam video to the tap
> device address. I disable the ARQ in the pre-cog.
>
> The flow graph runs correctly but on a spectrum analyzer I just see a
> single packet and then everything turns off.
>
> Does any body know how to stream video in to the tuntap device.
>
> Regards
>
>
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>
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Re: [Discuss-gnuradio] Gnuradio 3.6.x recipe for pybombs ?

[M Dammer]

thanks for the suggestion. I already solved the problem here, by putting
this configure section in the recipe:
configure {
git checkout tags/v3.6.5.1
cmake .. -DCMAKE_BUILD_TYPE=$cmakebuildtype
-DCMAKE_INSTALL_PREFIX=$prefix $config_opt
}


On 20/07/13 17:04, Nathan West wrote:
> On Sat, Jul 20, 2013 at 10:26 AM, M Dammer  wrote:
>> This does not work. I am getting a "branch not found, building HEAD
>> instead" like error and then it builds 3.7. It looks as the gitbranch
>> part of the recipe really only works with branches while the version
>> numbers are tags. Does pybombs has a similar command than gitbranch to
>> define a tag in a recipe ?
>>
>> On 19/07/13 20:00, Tom Rondeau wrote:
>>> On Fri, Jul 19, 2013 at 12:31 PM, M Dammer  wrote:
 Has anyone a recipe for installing the 3.6-branch via pybombs ? I need a
 3.6 parallel installation on my system, because many old projects are
 not working "out of the box" in 3.7.x. Even many of the projects
 referenced by recipes that currently come with pybombs do not compile.
 tnx, Mark
>>> Mark,
>>>
>>> You can edit the recipe file to change the branch you want to check
>>> out. In pybombs/recipes/gnuradio.lwr look for the 'gitbranch' line.
>>> Change this from 'master' to the tag of the version you want, such as
>>> 'v3.6.5.1' for the latest in the 3.6 version.
>>>
>>> Tom
>>
> Leave the branch as whatever you want (master, maint...) but add a
> line for gitrev:
> gitrev: tags/v3.6.5.1
>
> Of course this could be whatever rev you want.
>
> Nathan




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Re: [Discuss-gnuradio] Can I add frequency offset at sender in ofdm example

[Tom Rondeau]

On Sat, Jul 20, 2013 at 10:43 AM, Yingjie Chen  wrote:
> Hi, guys
> Thanks in advance.
> I plan to do a experiment in usrp that intentionally adding some
> frequency offset in data symbol before transmission. Is that feasible
> to implement it in gnuradio? Which block should I modify at sender
> side?

Quite easily and in a few different ways. You can use the "Channel
Model" block and just set the frequency offset and nothing else. You
can use a frequency xlating filter, or you can do a complex multiply
of your signal against a complex sinusoid.

Just remember that you need to have a high enough sampling rate to
accommodate the bandwidth of your new signal.

Tom

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Re: [Discuss-gnuradio] Gnuradio 3.6.x recipe for pybombs ?

[Tim Newman]

On 07/20/2013 12:38 PM, M Dammer wrote:
> thanks for the suggestion. I already solved the problem here, by putting
> this configure section in the recipe:
> configure {
> git checkout tags/v3.6.5.1
> cmake .. -DCMAKE_BUILD_TYPE=$cmakebuildtype
> -DCMAKE_INSTALL_PREFIX=$prefix $config_opt
> }
>
>
> On 20/07/13 17:04, Nathan West wrote:
>> On Sat, Jul 20, 2013 at 10:26 AM, M Dammer  wrote:
>>> This does not work. I am getting a "branch not found, building HEAD
>>> instead" like error and then it builds 3.7. It looks as the gitbranch
>>> part of the recipe really only works with branches while the version
>>> numbers are tags. Does pybombs has a similar command than gitbranch to
>>> define a tag in a recipe ?
>>>
>>> On 19/07/13 20:00, Tom Rondeau wrote:
 On Fri, Jul 19, 2013 at 12:31 PM, M Dammer  wrote:
> Has anyone a recipe for installing the 3.6-branch via pybombs ? I need a
> 3.6 parallel installation on my system, because many old projects are
> not working "out of the box" in 3.7.x. Even many of the projects
> referenced by recipes that currently come with pybombs do not compile.
> tnx, Mark
 Mark,

 You can edit the recipe file to change the branch you want to check
 out. In pybombs/recipes/gnuradio.lwr look for the 'gitbranch' line.
 Change this from 'master' to the tag of the version you want, such as
 'v3.6.5.1' for the latest in the 3.6 version.

 Tom
>> Leave the branch as whatever you want (master, maint...) but add a
>> line for gitrev:
>> gitrev: tags/v3.6.5.1
>>
>> Of course this could be whatever rev you want.
>>
>> Nathan
>
>
>
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Nathan's correct, the proper way would be by using the "gitrev:" line,
you should be table to specify either a tag or a specific git revision.

Tim

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Re: [Discuss-gnuradio] Gnuradio 3.6.x recipe for pybombs ?

[Tom Rondeau]

On Sat, Jul 20, 2013 at 3:05 PM, Tim Newman  wrote:
> On 07/20/2013 12:38 PM, M Dammer wrote:
>> thanks for the suggestion. I already solved the problem here, by putting
>> this configure section in the recipe:
>> configure {
>> git checkout tags/v3.6.5.1
>> cmake .. -DCMAKE_BUILD_TYPE=$cmakebuildtype
>> -DCMAKE_INSTALL_PREFIX=$prefix $config_opt
>> }
>>
>>
>> On 20/07/13 17:04, Nathan West wrote:
>>> On Sat, Jul 20, 2013 at 10:26 AM, M Dammer  wrote:
 This does not work. I am getting a "branch not found, building HEAD
 instead" like error and then it builds 3.7. It looks as the gitbranch
 part of the recipe really only works with branches while the version
 numbers are tags. Does pybombs has a similar command than gitbranch to
 define a tag in a recipe ?

 On 19/07/13 20:00, Tom Rondeau wrote:
> On Fri, Jul 19, 2013 at 12:31 PM, M Dammer  wrote:
>> Has anyone a recipe for installing the 3.6-branch via pybombs ? I need a
>> 3.6 parallel installation on my system, because many old projects are
>> not working "out of the box" in 3.7.x. Even many of the projects
>> referenced by recipes that currently come with pybombs do not compile.
>> tnx, Mark
> Mark,
>
> You can edit the recipe file to change the branch you want to check
> out. In pybombs/recipes/gnuradio.lwr look for the 'gitbranch' line.
> Change this from 'master' to the tag of the version you want, such as
> 'v3.6.5.1' for the latest in the 3.6 version.
>
> Tom
>>> Leave the branch as whatever you want (master, maint...) but add a
>>> line for gitrev:
>>> gitrev: tags/v3.6.5.1
>>>
>>> Of course this could be whatever rev you want.
>>>
>>> Nathan
>>
>>
>>
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> Nathan's correct, the proper way would be by using the "gitrev:" line,
> you should be table to specify either a tag or a specific git revision.
>
> Tim


Great, thanks guys! I've added this information to gnuradio.org/pybombs.

Tom

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[Discuss-gnuradio] GRCon12 Videos

[Tom Rondeau]

Hi everyone,

I've finally started editing, cutting, and posting the videos from
last year's GRCon12 to Youtube. Only the presentations from day 1 of
the conference are live right now.

I will post individual links to each video on the conference website
under the Abstracts section:
www.trondeau.com/grcon12

You can find all of the videos on my Youtube channel:
http://www.youtube.com/channel/UCGyGGPdPlTUdOU1cOw210Rg

I hope to get the rest of the videos out over the next week or so and
will send an update when they are all available. Just thought some of
you might be interested in these right now.

Sorry for the delay in getting these out. I had hoped to do it must
sooner, but I could never justify the time away from our 3.7 efforts.

Enjoy!

Tom

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[Discuss-gnuradio] Using GMSK Mod to send digital data (e.g. an ASCII string)

[embyte]

Hello list, I would like to transmit some data using gnu-radio. My data 
is a binary representation of an ASCII string.


I wrote my own block that builds the frame (header, payload, CRC, 
trailer) as an array of 256 bytes (0s or 1s):


gr_make_io_signature(0, 0, 0)
gr_make_io_signature(1, 1, sizeof(char))

char *out = (char *) output_items[0];

[build the frame]

memcpy (out, frame, 256);
noutput_items = 256;

My question are:

1. Still I have to insert a "Packer Encoder"  between my code and the 
GMSK mod? If yes, with which parameters? The GMSK mod is configured with 
Samples/Sym=50 , BT=0.4.


2. Can someone explain me how to use the bitrate parameter? I mean, 
should I "sync" the output of my block with the modulator? If yes, how?


I tried to redirect the transmitted signal to a file, and use a receiver 
(that I know working), but without success. The parameters used in the 
receiver's GMSK demod are the same configured in the modulator.


Thanks!

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Re: [Discuss-gnuradio] Problem faced with clock_recovery_mm at low data rates

[Adeel Anwar]

Waqas,

U can use PFB_clock_sync instead of M&M. PFB_clock_sync implements the
maximum likelihood estimation algorithms, so using this block increasing
sps should not produce incorrect results.

http://gnuradio.org/doc/doxygen/classgr_1_1digital_1_1pfb__clock__sync__ccf.html

-Adeel


On Sat, Jul 20, 2013 at 6:44 PM, Waqas Bin Abbas wrote:

> Hi all,
>
> We have encountered an interesting problem in the clock_recovery_mm block
> used in our BFSK system.
> What happening is that, at lower data rates (i.e. at less than 54bps) we
> are
> unable to decode the received data correctly,
> however at higher data rates data is decoded fine.
>
>
> What we are doing ?
>
>
> We are implementing a BFSK receiver and our flow-graph consist of
> Bandpass filter-> Hilbert transform-> quad_demod-> high pass filter ->
> clock_recovery_mm-> binary slicer.
> We are using 16k and 18k frequencies and our sampling rate is 48k (well
> enough according to Nyquist criteria).
>
>
> How and what we figured out ?
>
>
> Our system was decoding the data correctly till 54bps and fails below
> 54bps.For debugging the issue We sent the same sequence from our
> transmitter
> and received
> at our receiver end with both 100 bps and 50 bps.we checked the output of
> each block in our flow graph, using scope sink in GRC.
> We found no difference in the outputs of other blocks except the
> clock_recovery_mm block.What we found was that
> for consecutive sequence (either 1 or 0) the block fails to estimate the
> symbol correctly (snapshot are provided in the link below ).The boxed area
> is where we think the problem exist.
> We checked the block output further for alternating sequence of 1 and 0 and
> found that the block is estimating correctly.
>
> http://sysnet.org.pk/w/Snapshots
>
> we also found that for same sequence (either 1 or 0) the problem exists at
> each datarate but less than 54bps it become weird.
> The link below shows the output of clock_recovery_mm block at 100bps and
> 50bps for same sequence of bits.
> The arguments of the blocks are set as
> gr.clock_recovery_mm_ff((samples/symbol),0.000625,0.5,0.01,0.05)
> **For 100 bps we are having samples/symbol= 480 and for 50 bps we are
> keeping it 960.
>
>
> Our Questions ?
>
>
> Now since we are just changing the value of the "Omega"(samples/symbol)  in
> clock_recovery_mm block for 100bps and 50bps.
> So we want to know the following:
> 1) Is there a limit to maximum value omega? (due to which we are not
> getting
> the right results at lower data rates)
> 2) Do we have to change some other parameter in the clock_recovery_mm to
> rectify our problem?
> 3) Is it the limitation of clock_recovery_mm block?
> 4) Or there is some other solution to the specified problem?
>
>
>
> --
> View this message in context:
> http://gnuradio.4.n7.nabble.com/Problem-faced-with-clock-recovery-mm-at-low-data-rates-tp42591.html
> Sent from the GnuRadio mailing list archive at Nabble.com.
>
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Re: [Discuss-gnuradio] Using GMSK Mod to send digital data (e.g. an ASCII string)

[Adeel Anwar]

>>1. Still I have to insert a "Packer Encoder"  between my code and the
GMSK mod? If yes, with which parameters? The GMSK mod is configured with
Samples/Sym=50 , BT=0.4.
No. U can make custom packet structure and in that case u need not to use
Packet-Encoder.

>>2. Can someone explain me how to use the bitrate parameter? I mean,
should I "sync" the output of my block with the modulator? If yes, how?
Sync is not required because Signal-Processing blocks in GR don’t
understand bitrate/sampling-rate. If u have connected  Transmitter-FG with
USRP,  then u can determine the "effective bitrate" of transmitter by
calculating it backwards from USRP-sink sampling-rate.

symbol-rate = usrp-sampling-rate / samples-per-symbol
bit-rate = symbol-rate * modulated_bits_per_symbol

-Adeel





On Sun, Jul 21, 2013 at 1:44 AM, embyte  wrote:

> Hello list, I would like to transmit some data using gnu-radio. My data is
> a binary representation of an ASCII string.
>
> I wrote my own block that builds the frame (header, payload, CRC, trailer)
> as an array of 256 bytes (0s or 1s):
>
> gr_make_io_signature(0, 0, 0)
> gr_make_io_signature(1, 1, sizeof(char))
>
> char *out = (char *) output_items[0];
>
> [build the frame]
>
> memcpy (out, frame, 256);
> noutput_items = 256;
>
> My question are:
>
> 1. Still I have to insert a "Packer Encoder"  between my code and the GMSK
> mod? If yes, with which parameters? The GMSK mod is configured with
> Samples/Sym=50 , BT=0.4.
>
> 2. Can someone explain me how to use the bitrate parameter? I mean, should
> I "sync" the output of my block with the modulator? If yes, how?
>
> I tried to redirect the transmitted signal to a file, and use a receiver
> (that I know working), but without success. The parameters used in the
> receiver's GMSK demod are the same configured in the modulator.
>
> Thanks!
>
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