Access code and preamble


#1

Hi all,
I was going through the pkt.py and packet_utils.py just to try and
understand how packets are generated. Is it right to say that preamble
has
not being added to the payload?
“(packed_preamble, ignore) =
conv_1_0_string_to_packed_binary_string(preamble)”

If it is being added how is it helpful on the receiver side because i
don’t
see where it has been used or extracted. I know that it can be used to
contain the training sequence for channel estimation but i doubt it has
been
used for the same here. I can only see the access code correlator to
mark
the beginning of payload and no correlator for the preamble. Is it right
to
assume that the access code correlator alone can be suffice? What is
the
significance of ‘\x55’ at the end of the packet before introducing
usrp
pad? I am asking because according to my understanding it should make
the
end of payload(post amble) but I don’t see a correlator for it.

Kind regards,
Nelson