On Fri, 2011-06-24 at 04:00 +0900, Songsong Gee wrote: > Ok. First of all, I'd like to run a code like below (pseudo): > for i = 1 to 200 // preamble duration > amp = 32767 > end for > amp = 100
Like I said earlier, this is unlikely to be a good approach to synchronizing with a preamble. > > Next, how many baseband samples are generated by DPSK or Frequency mod > block for a single symbol input Did you read the email you just replied to? > > Composed with Android (Galaxys) > > 2011. 6. 24. 오전 3:31에 "Nick Foster" <n...@ettus.com>님이 작성: > > On Fri, 2011-06-24 at 01:17 +0900, Songsong Gee wrote: > >> Continueing with http://www.ruby-forum.com/topic/1983866, > >> > >> > >> I have planned to append a preamble before an actual signal and > turn > >> RX on earlier than TX. > >> > >> > >> Then RX will receive a signal like below: > >> |---RX turn on------|---TX turn > >> on----------------------------- > >> (---trash signal---)(---preamble---)(---actual signal---) > >> > >> > >> And this signal is demodulated and stored into a sink file. > >> After that, I run a program that extracts an actual data only and > >> compare it to the original. > >> > >> > >> My concern is that this preamble should be assumed to be perfect > i.e. > >> no errors > >> Of course, there isn't no error. However if I set an amplitude to > >> maximum value, it can be said to be no error. > > > > I don't understand what you mean here. You can find an "imperfect" > > preamble sequence using a correlator. > > > >> I have a pre-defined preamble sequence with length n (n = around > >> 100-200, can be changed) > >> > >> > >> Thus, I am trying to change amplitude of modulated signal for > preamble > >> and actual signal > >> But I have problem with some quadrature modulation. Flow graphs are > in > >> below: > >> > http://dl.dropbox.com/u/11382666/for_gnuradio_mailinglist/M-DPSK.png > >> http://dl.dropbox.com/u/11382666/for_gnuradio_mailinglist/M-FSK.png > >> > >> > >> My question is that, how many samples after DPSK mod or frequency > mod > >> block corresponds to each sample from file source? > > > > It's right there in the block, where it says "samples/symbol". > > > >> I have to solve this problem in order to figure out how many > samples > >> are generated from preamble with length n. > >> If I know that information, I can set a duration for Multiply const > >> block having large value for preamble and normal value for actual > >> signal > > > > Why would you set the amplitude of the preamble differently than the > > actual data? > > > > --n > > > >> > >> > >> And second question is that, although I know that information, I > don't > >> know how I can control value. > >> For example, preamble with length 200, then I want to set large > value > >> for duration 200 * x (number of samples generated after DPSK, > >> Frequency mod), and after that I want to set normal value for > >> remaining duration. > >> > >> > >> Is it too complex for gnuradio-companion flow graph to make? And is > >> python hard coding possible? > >> > >> > >> -- > >> Seokseong Jeon (aka Songsong Gee) > >> > >> > >> _______________________________________________ > >> 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