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
Next, how many baseband samples are generated by DPSK or Frequency mod block for a single symbol input 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 > >
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