Hey Tom Thanks for the tip to use benchmark files for the same.On going through them made me realize they are just as identical to tx_voice.py, rx_voice.py !
And just as you had said, it would be necessary to keep track of the packets but I havent yet been able to figure out a way to overcome the lost packet situation. The bottleneck is that if I could attach header (external preamble)from my side to the data then the sequence could be tracked. On trying to attach external data I dug through the code of pkt.py and packet_utils.py in usr/local/lib/python2.4/site-packages/gnuradio/blksmpl and attached a string to 'payload' from my side. Many-a-times receiver rejects the incoming packet saying: terminate called after throwing an instance of 'std::runtime_error' what(): msg length is not a multiple of d_itemsize Aborted (core dumped) Could you the suggest a possible way to overcome this error? Thanks again! Rashi Tom Rondeau <[EMAIL PROTECTED]> wrote: rashi dixit wrote: > Hello Everyone > > I am currently working on binary file transmission from one system to > another, but couldnt figure a way out yet. > > Using tx_voice.py when I send a binary file with just an arbitrary > stream of ones and zeroes, data is read and transmitted as packets > well. But unfortunately, on receival side on the retrieval of data, it > isnt written back into the file in the binary format as originally but > a combinations of bits are clubbed and expressed by incomprehensible > hashes and stars. So the data cant be deciphered. > > I tried using the GMSK modulation scheme. But the binary data chunks > are filtered out during transmission only....probably due to the > gaussian filter. Please check me out if I am wrong. > > Could anyone suggest a way for a ones and zeroes file to be > transmitted? My final aim is to find the 'Bit error rate' of > transmission form one node to another. > > Also is there any way of comparing two binary files? I mean how should > one approach the bit error analysis keeping correlation in mind etc? > > Thanking you all > Rashi Dixit Rashi, I'm not sue why you are using tx_voice.py for this. It seems to make more sense to use benchmark_tx.py and benchmark_rx.py in the /digital examples directory. This will modulate the bits with GMSK by default. Keep in mind, though, that you _want_ to modulate the data before transmitting it over the air. The GNU Radio file sink/source write and read files as binary data, so the files will look like hashes and stars when viewed with a text editor. You can use gnuradio-core/src/utils/read_*_binary.m in Matlab/Octave to read these files. However, I'm not sure you want to just compare the output file to the input file unless you also keep track of a packet number. If the header is missed or corrupted in the current implementation, the packet is completely dropped, which would completely screw up your calculations unless you can tell that a full packet has been lossed. Then, you have to decide how you want to handle the BER calculation due to one lost packet. Tom _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio --------------------------------- Heres a new way to find what you're looking for - Yahoo! Answers
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