Hi Sebastian, well, it would sound like you've discovered the multipath channel!
I don't really understand what you mean with "Modulate vector is called"; what /is/ "Modulate vector"? You can actually simply attach small files to emails to the list. Such a simple GRC file would certainly not upset us :) Best regards, Marcus On 26.08.2017 18:10, Sebastian wrote: > > > > > > Hi all, > > > > i run into trouble using the correlate estimation block. > > > > As far as i understand this blocks is used to search for a praeamble > which is modulated and filtered with match filter. > > To achieve this i used modulate vector. I used this block like it`s > done in the corr_est exapmles provided in /gnuradio/gr-digital/examples/. > > > > Using no UHD but a channel modell everything works fine having clear > correlation peak. > > Using it with hardware device it doesn`t work anymore, having more > peaks avaiable. > > > > My flowgraph is very simple: > > > > Vector_source (using prae+data as vector tagged with tx_sob and > tx_eob) -> constellation Modulator(default-QPSK-object) -> stream mux > with null_source for break -> uhd sink(sync = PC_clock) > > > > Uhd source (sync = PC_clock) -> low_pass -> corr_est(modulated_vector, > 0.9) -> Pll-clock-sync -> Costas Loop -> constellation-demodulator -> > float_to_char -> qt time sink > > > > > > Modulate vector is called with default-qpsk-object as constellation > object and [1] as filter taps which i think is right. > > The praeamble i am using is the one provided in the examples, so it > should be ok too. > > > > I dont have that much experience in this topic so I hope somebody is > able to help me. > > I am looking forward to hearing from you and thank you in advance. > > > > > > Sebastian > > > > PS : I am not sure where and how to provide the flowgraph itself but > i´ll try to do it asap. > > > > > > > > > > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
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