Well, I was studying correlator, and it's pretty straight forward approach. If you specify threshold of k bits, then it will output 0x3 every time it finds pattern that differs from given preamble at max. k bits. Maybe you can provide some more information. In my designs I usually use threshold 0.
Best Nemanja On Wed, Jun 19, 2013 at 10:21 PM, yeran <yeran0...@hotmail.com> wrote: > Hi everyone, > > I'm trying to learning the algorithm of the correlator in > generic_mod_demod.py. Then use the similar algorithm in my own block. > > In the file digital_correlate_access_code_bb.cc, according to my > understanding, the original algorithm is compare each bit of the 8-Byte > access code with the default 8-Byte access code. If the wrong bits is less > than 12 bits (the threshold), then it is decided as "access code found". > > I wrote a file to detect access code, too. I compared each of the 8-Byte > with the default access code. If the correct bits is more than (64bits - 12 > bits), then it is decided to be found. > > But when I us my program, when decoding the same data, I can always found > more than the original method. For instance, when I use benchmark's > original method, I can get n_rcvd=570 pkt, which means in the > generic_mod_demod correlator, 570 access code are found. But my program > found 577. > > Has anybody been study the correlator block before? and see if there is a > misunderstanding in my work? > > Thanks in advance! > > Ada > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > -- Nemanja Savić
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