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.