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