Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Greetings, finnaly got it working :D Problem was with descrambler. Now it gives results as follows: Service: 'ok' Duration: '' Source_MAC_Adress: '232323232323' Destination_MAC_Adress: '' Protocol_version: 'Supported' Type: 'Data' Subtype: 'Data' To_DS: 'False' From_DS: 'False' More_fragments: 'No' Power_menagement: 'Active' More_data: 'No' Protected: 'No' Order: 'Random' But I still dunno how to estimate initial descrambler state (checked all and found correct one this time). Descrambler graph sould be the same as the scrambler from you paper right? Best, Ernest -- View this message in context: http://gnuradio.4.n7.nabble.com/GRC-3-6-802-11-a-g-test-signal-tp50585p50709.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
On 10/09/2014 10:40 AM, Ernest Szczepaniak wrote: Greetings, finnaly got it working :D Problem was with descrambler. Now it gives results as follows: Service: 'ok' Duration: '' Source_MAC_Adress: '232323232323' Destination_MAC_Adress: '' Protocol_version: 'Supported' Type: 'Data' Subtype: 'Data' To_DS: 'False' From_DS: 'False' More_fragments: 'No' Power_menagement: 'Active' More_data: 'No' Protected: 'No' Order: 'Random' Great But I still dunno how to estimate initial descrambler state (checked all and found correct one this time). Descrambler graph sould be the same as the scrambler from you paper right? On the receiving side, take the first 7 bits, put them in the scrambler register, and use the very same algorithm on as on TX side. (Since the output of the scrambler is fed back the first seven bits are also the internal state of the scrambler). Bastian ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Ok. All working fine :D -- View this message in context: http://gnuradio.4.n7.nabble.com/GRC-3-6-802-11-a-g-test-signal-tp50585p50731.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
On 10/07/2014 04:57 PM, Ernest Szczepaniak wrote: Nope, Any way to get it? Is it downloadable? Should be helpfull indeed. As far as I know it is not downloadable. You would have to extract (copy - paste) the data from the pdf. Bastian ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Ok. After couple of days trying to decode your frame i decided to check my receiver with real samples. Could it be possible that after demodulation (de-interleaving, de-convolutional, de-scrambling) im getting over 40x0's in correct positions (9 reserved bits, 16x0s in duration, correct pads) and still cant work out your frames? Such amount of correct data couldnt be a coincidence :( That test frame from Annex L is fully coded (scrambled, interleaved and conv coded)? Best, Ernest -- View this message in context: http://gnuradio.4.n7.nabble.com/GRC-3-6-802-11-a-g-test-signal-tp50585p50672.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
On 10/08/2014 11:54 AM, Ernest Szczepaniak wrote: Ok. After couple of days trying to decode your frame i decided to check my receiver with real samples. Could it be possible that after demodulation (de-interleaving, de-convolutional, de-scrambling) im getting over 40x0's in correct positions (9 reserved bits, 16x0s in duration, correct pads) and still cant work out your frames? Such amount of correct data couldnt be a coincidence :( As I already mentioned, it is very hard to help you without the code... That test frame from Annex L is fully coded (scrambled, interleaved and conv coded)? Yes, it is. And it's clearly stated. But for your convenience I can copy paste from the standard. The encoding illustration goes through the following stages: a) Generating the short training sequence section of the preamble; b) Generating the long preamble sequence section of the preamble; c) Generating the SIGNAL field bits; d) Coding and interleaving the SIGNAL field bits; e) Mapping the SIGNAL field into frequency domain; f) Pilot insertion; g) Transforming into time domain; h) Delineating the data octet stream into a bit stream; i) Prepending the SERVICE field and adding the pad bits, thus forming the DATA; j) Scrambling and zeroing the tail bits; k) Encoding the DATA with a convolutional encoder and puncturing; l) Mapping into complex 16-QAM symbols; m) Pilot insertion; n) Transforming from frequency to time and adding a circular prefix; o) Concatenating the OFDM symbols into a single, time-domain signal. Bastian ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
On 10/08/2014 11:54 AM, Ernest Szczepaniak wrote: Ok. After couple of days trying to decode your frame i decided to check my receiver with real samples. Could it be possible that after demodulation (de-interleaving, de-convolutional, de-scrambling) im getting over 40x0's in correct positions (9 reserved bits, 16x0s in duration, correct pads) and still cant work out your frames? Such amount of correct data couldnt be a coincidence :( One last idea: If groups of bits are correct, then most likely you forgot to invert the pilot patter according to the sequence given in Equation 18-25 of the standard. Bastian ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Got the pilot sequence but ill check it once more. I also got Annex L so not neccesary to post it but thanks. Ill check everything once more, according to L. -- View this message in context: http://gnuradio.4.n7.nabble.com/GRC-3-6-802-11-a-g-test-signal-tp50585p50678.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
So... After going deep into Annex L i found that my scrambler fails. Also MATLAB built-in scrambler gives wrong results. Could you pls check this code fragment? Asumme that we have 20 data bits to scramble. Initial scrambler state is [1 0 1 1 1 0 1] (bit nr 7 left side). scrambler_register=[1 0 1 1 1 0 1]; % scrambler seed data_bits=randi([0 1],1,20); % data to be scrambled for i=1:20 temp=xor(scrambler_register(1),scrambler_register(4)); % x7 and x4 xor operation data_scrambled(i)=xor(data_bits(i),temp); % output bit register=circshift(scrambler_register',-1,1)';% shift left register register(7)=data_scrambled(i); % insert data to register end To clarify, left side of register has index (1), right side has index (7). Best, Ernest -- View this message in context: http://gnuradio.4.n7.nabble.com/GRC-3-6-802-11-a-g-test-signal-tp50585p50685.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
On 08 Oct 2014, at 14:23, Ernest Szczepaniak ernest_szczepan...@wp.pl wrote: So... After going deep into Annex L i found that my scrambler fails. Also MATLAB built-in scrambler gives wrong results. Could you pls check this code fragment? Asumme that we have 20 data bits to scramble. Initial scrambler state is [1 0 1 1 1 0 1] (bit nr 7 left side). scrambler_register=[1 0 1 1 1 0 1]; % scrambler seed data_bits=randi([0 1],1,20); % data to be scrambled for i=1:20 temp=xor(scrambler_register(1),scrambler_register(4)); % x7 and x4 xor operation data_scrambled(i)=xor(data_bits(i),temp); % output bit register=circshift(scrambler_register',-1,1)';% shift left register register(7)=data_scrambled(i); the scrambler is independent from the data. you want to feedback temp and not data_scrambled. Maybe you want to have a look at Figure 1 in http://www.ccs-labs.org/bib/bloessl2015scrambler/ Bastian end To clarify, left side of register has index (1), right side has index (7). Best, Ernest -- View this message in context: http://gnuradio.4.n7.nabble.com/GRC-3-6-802-11-a-g-test-signal-tp50585p50685.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- Dipl.-Inform. Bastian Bloessl Distributed Embedded Systems Group University of Paderborn, Germany http://www.ccs-labs.org/~bloessl/ ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Ok fixed. Now giving correct results :) Ill try with your frame once more and hit you up later. Thanks for your amazing feedback Bastian. Best, Ernest -- View this message in context: http://gnuradio.4.n7.nabble.com/GRC-3-6-802-11-a-g-test-signal-tp50585p50690.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Hi, I can’t help you much without the code, but did you see the example frame in Annex L of the standard? Maybe it helps you to debug your scripts. Bastian On 06 Oct 2014, at 22:19, Ernest Szczepaniak ernest_szczepan...@wp.pl wrote: Ok, so i decoded all of the payload (123 data symbols, de-interleaving every one in receiver's loop). After Viterbi and descrambling it gives some strange results: 7 of SERVICE bits are random - OK (i read in standard that those 7 bits are 0's at the transmitter, and will set receivers descrambler to correct initial state). 9x0's in RESERVED field - OK. and now: FRAME CONTROL - !incorrect! TAIL bit's looks fine (11x0's - 6 zeros from TAIL field and probably 5 PAD bits). I also checked autocorelation function of received data bits. It indicates that there is some cyclicness in payload (every 96 bits function shows a simple peak). Assuming that your frame consist of text:Hello world! - its 12 characters, 8 bits each - together 96 bits repeating sequence, but cant find Hello world text. Its rather imposible, that those results are correct. You have mentioned that i should try with some test sequence (dont have any one). If i will try to generate it on my own, i wouldnt be sure that its following the standard :( PS. I was also searching for 48x1 bit broadcast adress. Found only 43x1 in row. Close but not the same :D Best, Ernest -- View this message in context: http://gnuradio.4.n7.nabble.com/GRC-3-6-802-11-a-g-test-signal-tp50585p50639.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Nope, Any way to get it? Is it downloadable? Should be helpfull indeed. -- View this message in context: http://gnuradio.4.n7.nabble.com/GRC-3-6-802-11-a-g-test-signal-tp50585p50661.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
On 10/05/2014 01:37 PM, Ernest Szczepaniak wrote: Greetings, Ok, got this. After some test's i think that the problem is with my descrambler (de-interleaver and Viterbi seems to be ok). Currently, im using Matlab's one provided by comm. toolbox. Is it correct to use 127-bit length pre-defined scrambling/descrambling seq? No, this is an example output if you initialize the scrambler with 0b111. (i found it in 802.11 standard). Or it sould be only implemented as a shift register with poly 1+x4+x7? yes. And last one question: In any of frames generated by your grc script, there sould be 16x0 in SERVICE field (as it a part of PLCP Header) yes. - becouse a typical wlan card is able to decode it, it is following the 802.11 standard - am I right? No. It's following the standard and, thus, a normal card can decode it :-) Best, Bastian ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Hi, much appreciate for your reply Bastian. I have succefully found your frame.bin signal, forwarded by my USRP (generated in MATLAB, received with Windows Network Monitor and wlan card). You were right. It is Data frame, 232323:232323 Source MAC and FF:FF Destination MAC. Still dunno what's wrong. Could you please check my methodology?? 1st OFDM symbol is carrying a SIGNAL field - it is decoded correctly (i checked all rates with your grc wlan script) - no problem here. 2nd OFDM symbol is carrying Data. Assuming BPSK 1/2, it should carry 16 bit SERVICE field, and 8 bits from FRAME CONTROL field (together - 24 uncoded bits). And my algorythm goes as follows (for 2nd OFDM symbol): - OFDM demodulation (to get 48 complex data points) - BPSK demodulation (to get 48 coded bits) - de-interleaving (1st and 2nd permutation) - Viterbi decoding ([133 171 poly] to get 24 uncoded bits) - descrambling and if its correct way, i should get 24 bits of data (16x0 and 8 bits depending on FRAME CONTROL paylaod) right? Best, Ernest -- View this message in context: http://gnuradio.4.n7.nabble.com/GRC-3-6-802-11-a-g-test-signal-tp50585p50621.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Hi, On 06 Oct 2014, at 10:33, Ernest Szczepaniak ernest_szczepan...@wp.pl wrote: Hi, much appreciate for your reply Bastian. I have succefully found your frame.bin signal, forwarded by my USRP (generated in MATLAB, received with Windows Network Monitor and wlan card). You were right. It is Data frame, 232323:232323 Source MAC and FF:FF Destination MAC. Still dunno what's wrong. Could you please check my methodology?? 1st OFDM symbol is carrying a SIGNAL field - it is decoded correctly (i checked all rates with your grc wlan script) - no problem here. 2nd OFDM symbol is carrying Data. Assuming BPSK 1/2, it should carry 16 bit SERVICE field, and 8 bits from FRAME CONTROL field (together - 24 uncoded bits). And my algorythm goes as follows (for 2nd OFDM symbol): - OFDM demodulation (to get 48 complex data points) - BPSK demodulation (to get 48 coded bits) - de-interleaving (1st and 2nd permutation) - Viterbi decoding ([133 171 poly] to get 24 uncoded bits) - descrambling and if its correct way, i should get 24 bits of data (16x0 and 8 bits depending on FRAME CONTROL paylaod) right? The payload is scrambled (as opposed to the signal field). So maybe your scrambler has a bug. Did you try to generate the example sequence from the standard? Do not try to decode the next OFDM symbol on its own, but the rest of the frame. The decoder is not reset with a zero sequence as with the “signal tail” bits. So it might not work with the same decoding function that you used for the first symbol. Best, Bastian ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Ok, so i decoded all of the payload (123 data symbols, de-interleaving every one in receiver's loop). After Viterbi and descrambling it gives some strange results: 7 of SERVICE bits are random - OK (i read in standard that those 7 bits are 0's at the transmitter, and will set receivers descrambler to correct initial state). 9x0's in RESERVED field - OK. and now: FRAME CONTROL - !incorrect! TAIL bit's looks fine (11x0's - 6 zeros from TAIL field and probably 5 PAD bits). I also checked autocorelation function of received data bits. It indicates that there is some cyclicness in payload (every 96 bits function shows a simple peak). Assuming that your frame consist of text:Hello world! - its 12 characters, 8 bits each - together 96 bits repeating sequence, but cant find Hello world text. Its rather imposible, that those results are correct. You have mentioned that i should try with some test sequence (dont have any one). If i will try to generate it on my own, i wouldnt be sure that its following the standard :( PS. I was also searching for 48x1 bit broadcast adress. Found only 43x1 in row. Close but not the same :D Best, Ernest -- View this message in context: http://gnuradio.4.n7.nabble.com/GRC-3-6-802-11-a-g-test-signal-tp50585p50639.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Please, stay on the list. On 04 Oct 2014, at 18:20, Ernest Szczepaniak ernest_szczepan...@wp.pl wrote: Hi, we are talking about 'frame.bin' signal right? yes Becouse my decoder says: Service: 'ok' Protocol_version: 'Supported' Type: 'Menagement' Subtype: 'Probe Request' To_DS: 'True' From_DS: 'False' More_fragments: 'No' Power_menagement: 'Power-Saving Mode' More_data: 'No' Protected: 'No' Order: 'Random' and the initial state was 0b0101011. Furthermore, i cant see those 1, which will indicate the broadcast adress thou:( So i think it is not working correctly yet. If you are still not convinced, you can very easily send the frame with a USRP and receive it with a WiFi card to inspect the MAC header with Wireshark. You can either use a simple GNU Radio flow graph (file source - USRP sink) or use the tx_samples_from_file example that ships with UHD. At least my card agreed with my interpretation of the payload :-) Best, Bastian W dniu 2014-10-04 19:56, Bastian Bloessl pisze: Hi, On 04 Oct 2014, at 15:50, Ernest Szczepaniak ernest_szczepan...@wp.pl wrote: Hello, First of all, much love for your reply (it made my day). So i started with sent frame [2]. And my receiver gives some nice results: - found OFDM symbol - aquired time synchronization - Shmidl/Cox says that there is no frequency offset (so it is good for no noise frame) - SIGNAL field is modulated with BPSK 6 Mbps (correct) and it says that: - rest of the data is modulated with BPSK 6Mbps - coderate is 1/2 - 1 bit per carrier - 364 octets of data (is that correct?) - reserved field, parity bit and tail bits seems to be fine. Further MAC decoding says that: - descrambler initial state is [0 1 0 1 0 1 1] (correct?) - 16 zeros in SERVICE field (7 for desrcambler synchro and 9 reserved - seems to be correct) - according to standard this is a PNC Selection (PNCS) frame type with retry ([0 0 0 1] in frame type field) is that correct? my decoder says: new mac frame (length 360) = duration: 00 00 frame control: 00 08 (DATA) Subtype: Data seq nr: 0 mac 1: ff:ff:ff:ff:ff:ff mac 2: 23:23:23:23:23:23 mac 3: ff:ff:ff:ff:ff:ff Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World! It does not contain a LLC, just a MAC header. It is BPSK 1/2 encoded. I guess the initial scrambler state was 0b0101010 (=42) and it is a data frame. Best, Bastian Best, Ernest W dniu 2014-10-04 11:16, Bastian Bloessl pisze: Hi, you can use gr-ieee802-11 [1] to generate WiFi frames. Just start the TX flow graph and pipe the output to a file. I uploaded a frame (IQ data, no noise) [2] for you that you can use to get started. I don’t use Matlab, so i don’t know how to import the data, but you can display the IQ samples with od -fw8 frame.bin There is also a GNU Radio script [3] that might be helpful. Hope it helps, Bastian [1] https://github.com/bastibl/gr-ieee802-11 [2] https://www.ccs-labs.org/~bloessl/frame.bin [3] https://github.com/gnuradio/gnuradio/blob/master/gr-utils/octave/read_complex_binary.m On 02 Oct 2014, at 17:25, Ernest Szczepaniak ernest_szczepan...@wp.pl wrote: Greetings engi's! I'm currently working on my masters (802.11 wlan receiver with MATLAB/USRPN210). After creating all the important stuff ie: -symbol finder -time synchronization -coarse and fine frequency compensation -symbol demodulator -deinterleaver -Viterbi decoder -descrambler etc. -MAC layer decoding i'm looking for any tested 802.11 a/g IQ signal for further research becouse live samples captured by USRP seem to have incorrect result's (wrong frame type MAC field, random MAC adress, CRC, parity bits etc). And here comes my 1st question. Is there any place where i can get some real, tested IQ wlan signal i a/g standard and full description (rate, coded data, adresses, included MAC fields)? Tried with Agilent Signal Studio but files are saved in .wfm encrypted format :( I also found GRC beacon frames transmitter, written in GRC http://rrsg.ee.uct.ac.za/members/jwamicha/gr-wlan.tar.gz but due to having GRC 3.7 (where 'gnuradio-core' was repleaced with 'gnurdaio-runtime') i can't simply compile this file becouse of an error: --- checking for GNURADIO_CORE... configure: error: Package requirements (gnuradio-core = 3) were not met: No package 'gnuradio-core' found Consider adjusting the PKG_CONFIG_PATH environment variable if you installed software in a non-standard prefix. Alternatively,
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Greetings, Ok, got this. After some test's i think that the problem is with my descrambler (de-interleaver and Viterbi seems to be ok). Currently, im using Matlab's one provided by comm. toolbox. Is it correct to use 127-bit length pre-defined scrambling/descrambling seq? (i found it in 802.11 standard). Or it sould be only implemented as a shift register with poly 1+x4+x7? And last one question: In any of frames generated by your grc script, there sould be 16x0 in SERVICE field (as it a part of PLCP Header) - becouse a typical wlan card is able to decode it, it is following the 802.11 standard - am I right? Best, Ernest -- View this message in context: http://gnuradio.4.n7.nabble.com/GRC-3-6-802-11-a-g-test-signal-tp50585p50614.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Hi, you can use gr-ieee802-11 [1] to generate WiFi frames. Just start the TX flow graph and pipe the output to a file. I uploaded a frame (IQ data, no noise) [2] for you that you can use to get started. I don’t use Matlab, so i don’t know how to import the data, but you can display the IQ samples with od -fw8 frame.bin There is also a GNU Radio script [3] that might be helpful. Hope it helps, Bastian [1] https://github.com/bastibl/gr-ieee802-11 [2] https://www.ccs-labs.org/~bloessl/frame.bin [3] https://github.com/gnuradio/gnuradio/blob/master/gr-utils/octave/read_complex_binary.m On 02 Oct 2014, at 17:25, Ernest Szczepaniak ernest_szczepan...@wp.pl wrote: Greetings engi's! I'm currently working on my masters (802.11 wlan receiver with MATLAB/USRPN210). After creating all the important stuff ie: -symbol finder -time synchronization -coarse and fine frequency compensation -symbol demodulator -deinterleaver -Viterbi decoder -descrambler etc. -MAC layer decoding i'm looking for any tested 802.11 a/g IQ signal for further research becouse live samples captured by USRP seem to have incorrect result's (wrong frame type MAC field, random MAC adress, CRC, parity bits etc). And here comes my 1st question. Is there any place where i can get some real, tested IQ wlan signal i a/g standard and full description (rate, coded data, adresses, included MAC fields)? Tried with Agilent Signal Studio but files are saved in .wfm encrypted format :( I also found GRC beacon frames transmitter, written in GRC http://rrsg.ee.uct.ac.za/members/jwamicha/gr-wlan.tar.gz but due to having GRC 3.7 (where 'gnuradio-core' was repleaced with 'gnurdaio-runtime') i can't simply compile this file becouse of an error: --- checking for GNURADIO_CORE... configure: error: Package requirements (gnuradio-core = 3) were not met: No package 'gnuradio-core' found Consider adjusting the PKG_CONFIG_PATH environment variable if you installed software in a non-standard prefix. Alternatively, you may set the environment variables GNURADIO_CORE_CFLAGS and GNURADIO_CORE_LIBS to avoid the need to call pkg-config. --- It seems that those binaries arent compatible with my GRC version :( Any helpful guy to install this library and send me IQ signal of this beacon frame? (in any MATLAB readable format - simple file sink in GRC). Looking forward for any reply. Thanks ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- Dipl.-Inform. Bastian Bloessl Distributed Embedded Systems Group University of Paderborn, Germany http://www.ccs-labs.org/~bloessl/ ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Hi, On 04 Oct 2014, at 15:50, Ernest Szczepaniak ernest_szczepan...@wp.pl wrote: Hello, First of all, much love for your reply (it made my day). So i started with sent frame [2]. And my receiver gives some nice results: - found OFDM symbol - aquired time synchronization - Shmidl/Cox says that there is no frequency offset (so it is good for no noise frame) - SIGNAL field is modulated with BPSK 6 Mbps (correct) and it says that: - rest of the data is modulated with BPSK 6Mbps - coderate is 1/2 - 1 bit per carrier - 364 octets of data (is that correct?) - reserved field, parity bit and tail bits seems to be fine. Further MAC decoding says that: - descrambler initial state is [0 1 0 1 0 1 1] (correct?) - 16 zeros in SERVICE field (7 for desrcambler synchro and 9 reserved - seems to be correct) - according to standard this is a PNC Selection (PNCS) frame type with retry ([0 0 0 1] in frame type field) is that correct? my decoder says: new mac frame (length 360) = duration: 00 00 frame control: 00 08 (DATA) Subtype: Data seq nr: 0 mac 1: ff:ff:ff:ff:ff:ff mac 2: 23:23:23:23:23:23 mac 3: ff:ff:ff:ff:ff:ff Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World! It does not contain a LLC, just a MAC header. It is BPSK 1/2 encoded. I guess the initial scrambler state was 0b0101010 (=42) and it is a data frame. Best, Bastian Best, Ernest W dniu 2014-10-04 11:16, Bastian Bloessl pisze: Hi, you can use gr-ieee802-11 [1] to generate WiFi frames. Just start the TX flow graph and pipe the output to a file. I uploaded a frame (IQ data, no noise) [2] for you that you can use to get started. I don’t use Matlab, so i don’t know how to import the data, but you can display the IQ samples with od -fw8 frame.bin There is also a GNU Radio script [3] that might be helpful. Hope it helps, Bastian [1] https://github.com/bastibl/gr-ieee802-11 [2] https://www.ccs-labs.org/~bloessl/frame.bin [3] https://github.com/gnuradio/gnuradio/blob/master/gr-utils/octave/read_complex_binary.m On 02 Oct 2014, at 17:25, Ernest Szczepaniak ernest_szczepan...@wp.pl wrote: Greetings engi's! I'm currently working on my masters (802.11 wlan receiver with MATLAB/USRPN210). After creating all the important stuff ie: -symbol finder -time synchronization -coarse and fine frequency compensation -symbol demodulator -deinterleaver -Viterbi decoder -descrambler etc. -MAC layer decoding i'm looking for any tested 802.11 a/g IQ signal for further research becouse live samples captured by USRP seem to have incorrect result's (wrong frame type MAC field, random MAC adress, CRC, parity bits etc). And here comes my 1st question. Is there any place where i can get some real, tested IQ wlan signal i a/g standard and full description (rate, coded data, adresses, included MAC fields)? Tried with Agilent Signal Studio but files are saved in .wfm encrypted format :( I also found GRC beacon frames transmitter, written in GRC http://rrsg.ee.uct.ac.za/members/jwamicha/gr-wlan.tar.gz but due to having GRC 3.7 (where 'gnuradio-core' was repleaced with 'gnurdaio-runtime') i can't simply compile this file becouse of an error: --- checking for GNURADIO_CORE... configure: error: Package requirements (gnuradio-core = 3) were not met: No package 'gnuradio-core' found Consider adjusting the PKG_CONFIG_PATH environment variable if you installed software in a non-standard prefix. Alternatively, you may set the environment variables GNURADIO_CORE_CFLAGS and GNURADIO_CORE_LIBS to avoid the need to call pkg-config. --- It seems that those binaries arent compatible with my GRC version :( Any helpful guy to install this library and send me IQ signal of this beacon frame? (in any MATLAB readable format - simple file sink in GRC). Looking forward for any reply. Thanks ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- Dipl.-Inform. Bastian Bloessl Distributed Embedded Systems Group University of Paderborn, Germany http://www.ccs-labs.org/~bloessl/ ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal
Greetings engi's! I'm currently working on my masters (802.11 wlan receiver with MATLAB/USRPN210). After creating all the important stuff ie: -symbol finder -time synchronization -coarse and fine frequency compensation -symbol demodulator -deinterleaver -Viterbi decoder -descrambler etc. -MAC layer decoding i'm looking for any tested 802.11 a/g IQ signal for further research becouse live samples captured by USRP seem to have incorrect result's (wrong frame type MAC field, random MAC adress, CRC, parity bits etc). And here comes my 1st question. Is there any place where i can get some real, tested IQ wlan signal i a/g standard and full description (rate, coded data, adresses, included MAC fields)? Tried with Agilent Signal Studio but files are saved in .wfm encrypted format :( I also found GRC beacon frames transmitter, written in GRC http://rrsg.ee.uct.ac.za/members/jwamicha/gr-wlan.tar.gz but due to having GRC 3.7 (where 'gnuradio-core' was repleaced with 'gnurdaio-runtime') i can't simply compile this file becouse of an error: --- checking for GNURADIO_CORE... configure: error: Package requirements (gnuradio-core = 3) were not met: No package 'gnuradio-core' found Consider adjusting the PKG_CONFIG_PATH environment variable if you installed software in a non-standard prefix. Alternatively, you may set the environment variables GNURADIO_CORE_CFLAGS and GNURADIO_CORE_LIBS to avoid the need to call pkg-config. --- It seems that those binaries arent compatible with my GRC version :( Any helpful guy to install this library and send me IQ signal of this beacon frame? (in any MATLAB readable format - simple file sink in GRC). Looking forward for any reply. Thanks ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
