Re: [Discuss-gnuradio] OFDM channel estimation
On 10/04/2016 06:25 AM, Andreas Weinand wrote: > Hello, > > i'm currently dealing with OFDM channel estimation and try to read out > the estimated values for this purpose. It works when i take the ones > that are given by the tag debug block (Key: ofdm_sync_chan_taps). But > somehow the values look a bit strange to me. Can anybody explain why > there are some carriers in the upper frequency range that are not > allocated, although they should be (see the plotted values). I did not > change the number of active subcarrier which is 48. So carriers should > be allocated up to carrier 59. > I have used N210 USRPs und SBX daughterboards to get these values, but > the same thing happens when i run the ofdm receiver in a simulation. The > magnitude of these upper carriers is still approx. 1 Decade below the > magnitude of the other active carriers in that case like in the OTA > setup. Can anybody help with this problem? Andreas, as you can see, the length of the channel estimate vectors is equal to the FFT length. However, channel estimates are only calculated for those bins that are actually occupied. Here's the code: https://github.com/gnuradio/gnuradio/blob/807bba681d56589d2f02cd6227181d9abc796e17/gr-digital/lib/ofdm_chanest_vcvc_impl.cc#L198-L210 There's several reasons why the length of channel taps is FFT length instead of the number of carriers, but one major one is that we shift the channel taps around according to the coarse frequency offset. Cheers, Martin ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] OFDM channel estimation
Hello, i'm currently dealing with OFDM channel estimation and try to read out the estimated values for this purpose. It works when i take the ones that are given by the tag debug block (Key: ofdm_sync_chan_taps). But somehow the values look a bit strange to me. Can anybody explain why there are some carriers in the upper frequency range that are not allocated, although they should be (see the plotted values). I did not change the number of active subcarrier which is 48. So carriers should be allocated up to carrier 59. I have used N210 USRPs und SBX daughterboards to get these values, but the same thing happens when i run the ofdm receiver in a simulation. The magnitude of these upper carriers is still approx. 1 Decade below the magnitude of the other active carriers in that case like in the OTA setup. Can anybody help with this problem? Best regards Andreas Weinand ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] OFDM channel Estimation Block
Hiii
I did following :
build% make
build% make test
gr-digital% gr-modtool makexml ofdm_chanestMMSE_vcvc
build% make install
everything seemed successful but WHEN opening GRC one block pop ups with :
Cannot import gnuradio.
Is the python path environment variable set correctly?
All OS: PYTHONPATH
Is the library path environment variable set correctly?
Linux: LD_LIBRARY_PATH
Windows: PATH
MacOSX: DYLD_LIBRARY_PATH
What happened ? Previously it was running... please help..
On Mon, Jul 20, 2015 at 6:56 PM, Marcus Müller marcus.muel...@ettus.com
wrote:
Probably you're in gnuradio/gr-digital instead of gnuradio/build.
Best regards,
Marcus
Am 20. Juli 2015 12:12:20 MESZ, schrieb monika bansal
monika19...@gmail.com:
Hiii
The previous problem is solved. Now after
gr-digital % make -j4
It is saying :
make: *** No targets specified and no makefile found. Stop.
But Configuring and Generating is done.
What should i do ?
On Mon, Jul 20, 2015 at 3:21 PM, Marcus Müller marcus.muel...@ettus.com
wrote:
Monika,
obviously, there's a mistake in gr-digital/lib/CMakeLists.txt, line 189.
A little more trying to solve this yourself might probably help you find
the typo; we can't tell you what you've changed, so we can't help you :)
Best regards,
Marcus
On 20.07.2015 11:29, monika bansal wrote:
Hii
After the command :
gnuradio % cmake ..
Configuring for all other blocks except gr-digital is completed. I am
posting the output for gr-digital only :
-- Configuring gr-digital support...
-- Dependency Boost_FOUND = 1
-- Dependency ENABLE_VOLK = ON
-- Dependency ENABLE_GNURADIO_RUNTIME = ON
-- Dependency ENABLE_GR_FFT = ON
-- Dependency ENABLE_GR_FILTER = ON
-- Dependency ENABLE_GR_BLOCKS = ON
-- Dependency ENABLE_GR_ANALOG = ON
-- Dependency ENABLE_GR_BLOCKS = ON
-- Dependency ENABLE_GR_FILTER = ON
-- Enabling gr-digital support.
-- Override with -DENABLE_GR_DIGITAL=ON/OFF
CMake Error: Error in cmake code at
/home/spclab/Desktop/Monika/GNURADIO/gnuradio-3.7.5.1/gr-digital/lib/CMakeLists.txt:189:
Parse error. Expected a command name, got unquoted argument with text
${CMAKE_CURRENT_SOURCE_DIR}/qa_ofdm_chanestMMSE_vcvc.cc.
Configuring incomplete, errors occurred!
What should i do ?
On Mon, Jul 20, 2015 at 2:39 PM, Marcus Müller marcus.muel...@ettus.com
wrote:
Hi Monika,
In-Tree components (like gr-digital) are meant to be built within the
whole GNU Radio tree, so you don't make a build/ directory under
gr-digital, but under gnuradio:
gr-digital % cd ..
gnuradio % mkdir build
gnuradio % cd build
gnuradio % cmake ..
gr-digital % make -j4
this will build all GNU Radio. You could selectively only build
gr-digital, but you will probably want to install a complete GNU Radio, so
that doesn't really help you much.
Best regards,
Marcus
On 20.07.2015 10:58, monika bansal wrote:
Hii
After the following command :
gr-digital % gr_modtool add -t general ofdm_chanestMMSE_vcvc
and editing the files: include/.h , lib/.h , lib/.cc and
python/digital/qa_ofdm_chanest_vcvc.py
I run the command
gr-digital % mkdir build
gr-digital % cmake ../
It giving the following output :
-- The C compiler identification is GNU 4.8.2
-- The CXX compiler identification is GNU 4.8.2
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
CMake Error at CMakeLists.txt:23 (include):
include could not find load file:
GrBoost
CMake Error at CMakeLists.txt:28 (include):
include could not find load file:
GrComponent
CMake Error at CMakeLists.txt:29 (GR_REGISTER_COMPONENT):
Unknown CMake command GR_REGISTER_COMPONENT.
CMake Warning (dev) in CMakeLists.txt:
No cmake_minimum_required command is present. A line of code such as
cmake_minimum_required(VERSION 2.8)
should be added at the top of the file. The version specified may be
lower
if you wish to support older CMake versions for this project. For more
information run cmake --help-policy CMP.
This warning is for project developers. Use -Wno-dev to suppress it.
-- Configuring incomplete, errors occurred!
See also
/home/spclab/Desktop/Monika/GNURADIO/gnuradio-3.7.5.1/gr-digital/build/CMakeFiles/CMakeOutput.log.
What should i do ? have i done something wrong ?
On Sat, Jul 18, 2015 at 11:37 AM, monika bansal
monika19...@gmail.commonika19...@gmail.com wrote:
yes... i will.
On Fri, Jul 17, 2015 at 9:48 PM, Martin Braun
martin.br...@ettus.commartin.br...@ettus.com wrote:
Monika,
please make sure you've gone through the tutorials at
Re: [Discuss-gnuradio] OFDM channel Estimation Block
yes... i will. On Fri, Jul 17, 2015 at 9:48 PM, Martin Braun martin.br...@ettus.com wrote: Monika, please make sure you've gone through the tutorials at http://gnuradio.org/redmine/projects/gnuradio/wiki/Guided_Tutorials, to make sure we're speaking the same terminology and all the basics are clear. Cheers, M On 17.07.2015 06:20, monika bansal wrote: Ok... Thanks :) On Fri, Jul 17, 2015 at 6:47 PM, Marcus Müller marcus.muel...@ettus.com mailto:marcus.muel...@ettus.com wrote: You can of course add that later on, but don't forget to change both your include/blockname.h, your lib/blockname_impl.h and your lib/blockname_impl.cc. If you want to work with GRC, remember to edit the .xml in grc/, too! Best regards, Marcus PS: gr_modtool doesn't do anything magical; it really just adds files with the content you specify. I'd like to encourage you to try around a bit more! You can't break much. And with version control (git) having your back, you can hardly do any harm even to your own work :) On 17.07.2015 14:38, monika bansal wrote: Hii One more doubt... As the gr-digital / include/ ofdm_chest_vcvc.h file have the argument list given as static sptr make( const std::vectorgr_complex sync_symbol1, const std::vectorgr_complex sync_symbol2, int n_data_symbols, int eq_noise_red_len=0, int max_carr_offset=-1, bool force_one_sync_symbol=false ); Do we need to give Argument list at time of gr_modtool add when it asks... Or we can add it later if we are not sure at the time of adding new block. On Fri, Jul 17, 2015 at 5:42 PM, monika bansal monika19...@gmail.com mailto:monika19...@gmail.com wrote: Thanks... On Fri, Jul 17, 2015 at 5:16 PM, Marcus Müller marcus.muel...@ettus.com mailto:marcus.muel...@ettus.com wrote: Hi Monika, absolutely the same method: cd gr-exisitingmodule gr_modtool add Note that this can only work with modules that follow gr_modtool's conventions (i.e. practically only with modules generated with gr_modtool in the first place) Best regards, Marcus On 17.07.2015 13:01, monika bansal wrote: Hii I understood how to create new module and block within this new module using gr-modtool from http://gnuradio.org/redmine/projects/gnuradio/wiki/OutOfTreeModules. I want to add new block in the existing module. How can i do that ? ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org mailto:Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org mailto: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 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] OFDM channel Estimation Block
Hi Monika, absolutely the same method: cd gr-exisitingmodule gr_modtool add Note that this can only work with modules that follow gr_modtool's conventions (i.e. practically only with modules generated with gr_modtool in the first place) Best regards, Marcus On 17.07.2015 13:01, monika bansal wrote: Hii I understood how to create new module and block within this new module using gr-modtool from http://gnuradio.org/redmine/projects/gnuradio/wiki/OutOfTreeModules. I want to add new block in the existing module. How can i do that ? ___ 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] OFDM channel Estimation Block
Hii One more doubt... As the gr-digital / include/ ofdm_chest_vcvc.h file have the argument list given as static sptr make( const std::vectorgr_complex sync_symbol1, const std::vectorgr_complex sync_symbol2, int n_data_symbols, int eq_noise_red_len=0, int max_carr_offset=-1, bool force_one_sync_symbol=false ); Do we need to give Argument list at time of gr_modtool add when it asks... Or we can add it later if we are not sure at the time of adding new block. On Fri, Jul 17, 2015 at 5:42 PM, monika bansal monika19...@gmail.com wrote: Thanks... On Fri, Jul 17, 2015 at 5:16 PM, Marcus Müller marcus.muel...@ettus.com wrote: Hi Monika, absolutely the same method: cd gr-exisitingmodule gr_modtool add Note that this can only work with modules that follow gr_modtool's conventions (i.e. practically only with modules generated with gr_modtool in the first place) Best regards, Marcus On 17.07.2015 13:01, monika bansal wrote: Hii I understood how to create new module and block within this new module using gr-modtool from http://gnuradio.org/redmine/projects/gnuradio/wiki/OutOfTreeModules. I want to add new block in the existing module. How can i do that ? ___ Discuss-gnuradio mailing listDiscuss-gnuradio@gnu.orghttps://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 mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] OFDM channel Estimation Block
You can of course add that later on, but don't forget to change both your include/blockname.h, your lib/blockname_impl.h and your lib/blockname_impl.cc. If you want to work with GRC, remember to edit the .xml in grc/, too! Best regards, Marcus PS: gr_modtool doesn't do anything magical; it really just adds files with the content you specify. I'd like to encourage you to try around a bit more! You can't break much. And with version control (git) having your back, you can hardly do any harm even to your own work :) On 17.07.2015 14:38, monika bansal wrote: Hii One more doubt... As the gr-digital / include/ ofdm_chest_vcvc.h file have the argument list given as static sptr make( const std::vectorgr_complex sync_symbol1, const std::vectorgr_complex sync_symbol2, int n_data_symbols, int eq_noise_red_len=0, int max_carr_offset=-1, bool force_one_sync_symbol=false ); Do we need to give Argument list at time of gr_modtool add when it asks... Or we can add it later if we are not sure at the time of adding new block. On Fri, Jul 17, 2015 at 5:42 PM, monika bansal monika19...@gmail.com mailto:monika19...@gmail.com wrote: Thanks... On Fri, Jul 17, 2015 at 5:16 PM, Marcus Müller marcus.muel...@ettus.com mailto:marcus.muel...@ettus.com wrote: Hi Monika, absolutely the same method: cd gr-exisitingmodule gr_modtool add Note that this can only work with modules that follow gr_modtool's conventions (i.e. practically only with modules generated with gr_modtool in the first place) Best regards, Marcus On 17.07.2015 13:01, monika bansal wrote: Hii I understood how to create new module and block within this new module using gr-modtool from http://gnuradio.org/redmine/projects/gnuradio/wiki/OutOfTreeModules. I want to add new block in the existing module. How can i do that ? ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org mailto:Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org mailto: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] OFDM channel Estimation Block
Ok... Thanks :) On Fri, Jul 17, 2015 at 6:47 PM, Marcus Müller marcus.muel...@ettus.com wrote: You can of course add that later on, but don't forget to change both your include/blockname.h, your lib/blockname_impl.h and your lib/blockname_impl.cc. If you want to work with GRC, remember to edit the .xml in grc/, too! Best regards, Marcus PS: gr_modtool doesn't do anything magical; it really just adds files with the content you specify. I'd like to encourage you to try around a bit more! You can't break much. And with version control (git) having your back, you can hardly do any harm even to your own work :) On 17.07.2015 14:38, monika bansal wrote: Hii One more doubt... As the gr-digital / include/ ofdm_chest_vcvc.h file have the argument list given as static sptr make( const std::vectorgr_complex sync_symbol1, const std::vectorgr_complex sync_symbol2, int n_data_symbols, int eq_noise_red_len=0, int max_carr_offset=-1, bool force_one_sync_symbol=false ); Do we need to give Argument list at time of gr_modtool add when it asks... Or we can add it later if we are not sure at the time of adding new block. On Fri, Jul 17, 2015 at 5:42 PM, monika bansal monika19...@gmail.com wrote: Thanks... On Fri, Jul 17, 2015 at 5:16 PM, Marcus Müller marcus.muel...@ettus.com wrote: Hi Monika, absolutely the same method: cd gr-exisitingmodule gr_modtool add Note that this can only work with modules that follow gr_modtool's conventions (i.e. practically only with modules generated with gr_modtool in the first place) Best regards, Marcus On 17.07.2015 13:01, monika bansal wrote: Hii I understood how to create new module and block within this new module using gr-modtool from http://gnuradio.org/redmine/projects/gnuradio/wiki/OutOfTreeModules. I want to add new block in the existing module. How can i do that ? ___ Discuss-gnuradio mailing listDiscuss-gnuradio@gnu.orghttps://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 mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] OFDM channel Estimation Block
Hii I understood how to create new module and block within this new module using gr-modtool from http://gnuradio.org/redmine/projects/gnuradio/wiki/OutOfTreeModules. I want to add new block in the existing module. How can i do that ? ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] OFDM channel Estimation Block
Monika, please make sure you've gone through the tutorials at http://gnuradio.org/redmine/projects/gnuradio/wiki/Guided_Tutorials, to make sure we're speaking the same terminology and all the basics are clear. Cheers, M On 17.07.2015 06:20, monika bansal wrote: Ok... Thanks :) On Fri, Jul 17, 2015 at 6:47 PM, Marcus Müller marcus.muel...@ettus.com mailto:marcus.muel...@ettus.com wrote: You can of course add that later on, but don't forget to change both your include/blockname.h, your lib/blockname_impl.h and your lib/blockname_impl.cc. If you want to work with GRC, remember to edit the .xml in grc/, too! Best regards, Marcus PS: gr_modtool doesn't do anything magical; it really just adds files with the content you specify. I'd like to encourage you to try around a bit more! You can't break much. And with version control (git) having your back, you can hardly do any harm even to your own work :) On 17.07.2015 14:38, monika bansal wrote: Hii One more doubt... As the gr-digital / include/ ofdm_chest_vcvc.h file have the argument list given as static sptr make( const std::vectorgr_complex sync_symbol1, const std::vectorgr_complex sync_symbol2, int n_data_symbols, int eq_noise_red_len=0, int max_carr_offset=-1, bool force_one_sync_symbol=false ); Do we need to give Argument list at time of gr_modtool add when it asks... Or we can add it later if we are not sure at the time of adding new block. On Fri, Jul 17, 2015 at 5:42 PM, monika bansal monika19...@gmail.com mailto:monika19...@gmail.com wrote: Thanks... On Fri, Jul 17, 2015 at 5:16 PM, Marcus Müller marcus.muel...@ettus.com mailto:marcus.muel...@ettus.com wrote: Hi Monika, absolutely the same method: cd gr-exisitingmodule gr_modtool add Note that this can only work with modules that follow gr_modtool's conventions (i.e. practically only with modules generated with gr_modtool in the first place) Best regards, Marcus On 17.07.2015 13:01, monika bansal wrote: Hii I understood how to create new module and block within this new module using gr-modtool from http://gnuradio.org/redmine/projects/gnuradio/wiki/OutOfTreeModules. I want to add new block in the existing module. How can i do that ? ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org mailto:Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org mailto: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 mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] ofdm channel estimation
Hi Martin: Greeting from xd.Thank you so much for your example tx_ofdm.grc and rx_ofdm.grc.I want to ask a question about channel estimation.And I know that the channel estimate is on a tag.But I want to make some changes on your example.So I just want to ask whether my understanding is right or not. I know the rx_ofdm include header stream and payload stream.In the payload stream,if i denote the data come from FFT block rx_data. channel=rx_data/tx_data Is it right?Is my understanding right?Thank you. Best regards, xd ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] ofdm channel estimation
On 07/30/2014 10:57 AM, xianda wrote: Hi Martin: Greeting from xd.Thank you so much for your example tx_ofdm.grc and rx_ofdm.grc.I want to ask a question about channel estimation.And I know that the channel estimate is on a tag.But I want to make some changes on your example.So I just want to ask whether my understanding is right or not. I know the rx_ofdm include header stream and payload stream.In the payload stream,if i denote the data come from FFT block rx_data. channel=rx_data/tx_data Is it right?Is my understanding right?Thank you. Yep. M ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] ofdm channel estimation
Hi Martin: Thank you for your kindly reply. Another question I want to ask. When I use the rx_ofdm,I add a UHD:USRP Source.(Environment: USRP N210)I know when the block Schmidl Cox OFDM synch. detect the signal,the port detect will output 1.And I test it.I use the rx_ofdm when I don't use the tx_ofdm.It means that no signal exist.But I find 1 in the port detect.Why?When no signal exist,it should output 0.Why I see 1 from it? Thank you so much. Best regards, xd At 2014-07-14 04:37:37, Martin Braun martin.br...@ettus.com wrote: On 07/13/2014 01:06 PM, xianda wrote: Hi all: Have you ever using the gnuradio/gr-digital/examples/ofdm/rx_ofdm.grc?And I change the rx_ofdm.py as follows: self.connect((self.digital_ofdm_chanest_vcvc_0, 1), blocks.file_sink(gr.sizeof_gr_complex * fft_len, 'channel-estimate.dat')) And i use the matlab: Please read the fine manual: http://gnuradio.org/doc/doxygen/classgr_1_1digital_1_1ofdm__chanest__vcvc.html#details. The channel estimate is on a tag. M ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradi___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] ofdm channel estimation
On 07/15/2014 09:39 AM, xianda wrote: Hi Martin: Thank you for your kindly reply. Another question I want to ask. When I use the rx_ofdm,I add a UHD:USRP Source.(Environment: USRP N210)I know when the block Schmidl Cox OFDM synch. detect the signal,the port detect will output 1.And I test it.I use the rx_ofdm when I don't use the tx_ofdm.It means that no signal exist.But I find 1 in the port detect.Why?When no signal exist,it should output 0.Why I see 1 from it? ...bad luck? It's not impossible to generate false alarms. What did you feed the block? Martin Thank you so much. Best regards, xd At 2014-07-14 04:37:37, Martin Braun martin.br...@ettus.com wrote: On 07/13/2014 01:06 PM, xianda wrote: Hi all: Have you ever using the gnuradio/gr-digital/examples/ofdm/rx_ofdm.grc?And I change the rx_ofdm.py as follows: self.connect((self.digital_ofdm_chanest_vcvc_0, 1), blocks.file_sink(gr.sizeof_gr_complex * fft_len, 'channel-estimate.dat')) And i use the matlab: Please read the fine manual: http://gnuradio.org/doc/doxygen/classgr_1_1digital_1_1ofdm__chanest__vcvc.html#details. The channel estimate is on a tag. M ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradi ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] ofdm channel estimation
Hi Martin: Thank you very much.But I test again and again,the rx_detect don't exist 1.And some little value approach 0 exists.But in the header stream chain some values exist.I think when 1 don't exist there shouldn't have value in the header stream chain.Why? Best regards, xd At 2014-07-15 05:17:35, Martin Braun martin.br...@ettus.com wrote: On 07/15/2014 09:39 AM, xianda wrote: Hi Martin: Thank you for your kindly reply. Another question I want to ask. When I use the rx_ofdm,I add a UHD:USRP Source.(Environment: USRP N210)I know when the block Schmidl Cox OFDM synch. detect the signal,the port detect will output 1.And I test it.I use the rx_ofdm when I don't use the tx_ofdm.It means that no signal exist.But I find 1 in the port detect.Why?When no signal exist,it should output 0.Why I see 1 from it? ...bad luck? It's not impossible to generate false alarms. What did you feed the block? Martin Thank you so much. Best regards, xd At 2014-07-14 04:37:37, Martin Braun martin.br...@ettus.com wrote: On 07/13/2014 01:06 PM, xianda wrote: Hi all: Have you ever using the gnuradio/gr-digital/examples/ofdm/rx_ofdm.grc?And I change the rx_ofdm.py as follows: self.connect((self.digital_ofdm_chanest_vcvc_0, 1), blocks.file_sink(gr.sizeof_gr_complex * fft_len, 'channel-estimate.dat')) And i use the matlab: Please read the fine manual: http://gnuradio.org/doc/doxygen/classgr_1_1digital_1_1ofdm__chanest__vcvc.html#details. The channel estimate is on a tag. M ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradi ___ 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] ofdm channel estimation
Oh,I guess that because i receive signal which at the frequency of 2.45e9.It is like the wifi.May be I receive the wifi signal?Am i right? Thank you. At 2014-07-15 05:17:35, Martin Braun martin.br...@ettus.com wrote: On 07/15/2014 09:39 AM, xianda wrote: Hi Martin: Thank you for your kindly reply. Another question I want to ask. When I use the rx_ofdm,I add a UHD:USRP Source.(Environment: USRP N210)I know when the block Schmidl Cox OFDM synch. detect the signal,the port detect will output 1.And I test it.I use the rx_ofdm when I don't use the tx_ofdm.It means that no signal exist.But I find 1 in the port detect.Why?When no signal exist,it should output 0.Why I see 1 from it? ...bad luck? It's not impossible to generate false alarms. What did you feed the block? Martin Thank you so much. Best regards, xd At 2014-07-14 04:37:37, Martin Braun martin.br...@ettus.com wrote: On 07/13/2014 01:06 PM, xianda wrote: Hi all: Have you ever using the gnuradio/gr-digital/examples/ofdm/rx_ofdm.grc?And I change the rx_ofdm.py as follows: self.connect((self.digital_ofdm_chanest_vcvc_0, 1), blocks.file_sink(gr.sizeof_gr_complex * fft_len, 'channel-estimate.dat')) And i use the matlab: Please read the fine manual: http://gnuradio.org/doc/doxygen/classgr_1_1digital_1_1ofdm__chanest__vcvc.html#details. The channel estimate is on a tag. M ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradi ___ 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] ofdm channel estimation
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hi Xianda, how should we possibly tell? You expect us to be able to guess what is going wrong with your measurement, in an environment that is unknown to us, using a receiving antenna, modified flowgraph and tx signal that you did not really define. As Martin said, if a detector outputs a 1, it might be a false alarm, also known as bad luck. With stochastic problems, you always have to make a trade off between false alarm rate and type II errors. This is called receiver operating characteristic. With most detectors, you can adjust their parameters to accommodate your false alarm rate/detection rate needs. Greetings, Marcus On 15.07.2014 12:56, xianda wrote: Oh,I guess that because i receive signal which at the frequency of 2.45e9.It is like the wifi.May be I receive the wifi signal?Am i right? Thank you. At 2014-07-15 05:17:35, Martin Braun martin.br...@ettus.com wrote: On 07/15/2014 09:39 AM, xianda wrote: Hi Martin: Thank you for your kindly reply. Another question I want to ask. When I use the rx_ofdm,I add a UHD:USRP Source.(Environment: USRP N210)I know when the block Schmidl Cox OFDM synch. detect the signal,the port detect will output 1.And I test it.I use the rx_ofdm when I don't use the tx_ofdm.It means that no signal exist.But I find 1 in the port detect.Why?When no signal exist,it should output 0.Why I see 1 from it? ...bad luck? It's not impossible to generate false alarms. What did you feed the block? Martin Thank you so much. Best regards, xd At 2014-07-14 04:37:37, Martin Braun martin.br...@ettus.com wrote: On 07/13/2014 01:06 PM, xianda wrote: Hi all: Have you ever using the gnuradio/gr-digital/examples/ofdm/rx_ofdm.grc?And I change the rx_ofdm.py as follows: self.connect((self.digital_ofdm_chanest_vcvc_0, 1), blocks.file_sink(gr.sizeof_gr_complex * fft_len, 'channel-estimate.dat')) And i use the matlab: Please read the fine manual: http://gnuradio.org/doc/doxygen/classgr_1_1digital_1_1ofdm__chanest__vcvc.html#details. The channel estimate is on a tag. M ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradi ___ 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 -BEGIN PGP SIGNATURE- Version: GnuPG v1 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJTxSMPAAoJEBQ6EdjyzlHtRwEH+gPol6VhuE5BBqyq5GUD7H9P GhTufylcZhwuK5XLbZg1l5ZrcqrcJu8+CZRFmWuK2vIml4JhzVPre5gPSbYeRdFs e+aZ+mT3TN62oXXurvq+YM6mnBdewR2bi8h/DtkC77OkB5SvL6j6rREWSg73flCB /sh2hgHuQkJ8d2sh8ut0L1NF6rlbB3l+unwEgjGeLnDyH3fdFjfUDPlh7OiX318w GmfPasCiSMMmcSqXCIaXcHaaVF/cdip7Yd8LQACMKJvZBT9AvGh5i725z3Drytdl 20B69ymrWD93bEdBjN7WAyAAvDJVbE6nWv1gXuUYfkbnGHwIaGomXfU8PQrPY14= =qRmz -END PGP SIGNATURE- ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] ofdm channel estimation
XD, I'm having real trouble understanding what you're doing. Try this: generate white noise and put it into the detector. Do you see any 1s? I would guess no. M On 07/15/2014 03:11 PM, xianda wrote: Hi Marcus: Thank you.Sorry for that. I wrongly use the read_complex_binary to analyse the detect at the second time.As I said(But I test again and again,the rx_detect don't exist 1.And some little value approach 0 exists.).If I use the read_char_binary to analyse the detect.There is 1 under every test.I said the truth.It isn't stochastic problems maybe.And I attached my modified rx_ofdm.grc.You can run it when no tx signal exist.And you will see r_detect.dat will exist 1.(In matlab,use the read_char_binary.m).And a1.dat and a.dat isn't null.(In matlab,use the read_complex_binary.m).You can test it.Thank you. Maybe I am wrong,please correct me.Thank you. Best regards, xd At 2014-07-15 08:48:15, Marcus Müller mar...@hostalia.de wrote: Hi Xianda, how should we possibly tell? You expect us to be able to guess what is going wrong with your measurement, in an environment that is unknown to us, using a receiving antenna, modified flowgraph and tx signal that you did not really define. As Martin said, if a detector outputs a 1, it might be a false alarm, also known as bad luck. With stochastic problems, you always have to make a trade off between false alarm rate and type II errors. This is called receiver operating characteristic. With most detectors, you can adjust their parameters to accommodate your false alarm rate/detection rate needs. Greetings, Marcus On 15.07.2014 12:56, xianda wrote: Oh,I guess that because i receive signal which at the frequency of 2.45e9.It is like the wifi.May be I receive the wifi signal?Am i right? Thank you. At 2014-07-15 05:17:35, Martin Braun martin.br...@ettus.com wrote: On 07/15/2014 09:39 AM, xianda wrote: Hi Martin: Thank you for your kindly reply. Another question I want to ask. When I use the rx_ofdm,I add a UHD:USRP Source.(Environment: USRP N210)I know when the block Schmidl Cox OFDM synch. detect the signal,the port detect will output 1.And I test it.I use the rx_ofdm when I don't use the tx_ofdm.It means that no signal exist.But I find 1 in the port detect.Why?When no signal exist,it should output 0.Why I see 1 from it? ...bad luck? It's not impossible to generate false alarms. What did you feed the block? Martin Thank you so much. Best regards, xd At 2014-07-14 04:37:37, Martin Braun martin.br...@ettus.com wrote: On 07/13/2014 01:06 PM, xianda wrote: Hi all: Have you ever using the gnuradio/gr-digital/examples/ofdm/rx_ofdm.grc?And I change the rx_ofdm.py as follows: self.connect((self.digital_ofdm_chanest_vcvc_0, 1), blocks.file_sink(gr.sizeof_gr_complex * fft_len, 'channel-estimate.dat')) And i use the matlab: Please read the fine manual: http://gnuradio.org/doc/doxygen/classgr_1_1digital_1_1ofdm__chanest__vcvc.html#details. The channel estimate is on a tag. M ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradi ___ 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 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 signature.asc Description: OpenPGP digital signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] ofdm channel estimation
On 07/13/2014 01:06 PM, xianda wrote: Hi all: Have you ever using the gnuradio/gr-digital/examples/ofdm/rx_ofdm.grc?And I change the rx_ofdm.py as follows: self.connect((self.digital_ofdm_chanest_vcvc_0, 1), blocks.file_sink(gr.sizeof_gr_complex * fft_len, 'channel-estimate.dat')) And i use the matlab: Please read the fine manual: http://gnuradio.org/doc/doxygen/classgr_1_1digital_1_1ofdm__chanest__vcvc.html#details. The channel estimate is on a tag. M ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] ofdm channel estimation
Hi all:
Have you ever using the
gnuradio/gr-digital/examples/ofdm/rx_ofdm.grc?And I change the rx_ofdm.py as
follows:
self.connect((self.digital_ofdm_chanest_vcvc_0, 1),
blocks.file_sink(gr.sizeof_gr_complex * fft_len, 'channel-estimate.dat'))
And i use the matlab:
csi=read_complex_binary('channel-estimate.dat');plot(1:64,real(csi(1:64,1)),'rs-')
The result is attached.But I think the result is wrong.Have someone do
the similar thing like me?Can we discuss this?
Environement: 2 USRP N210 and SBX
Thank you.
Best regards,
xd___
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