►
From YouTube: Uplink Simulator Part 2
Description
Walks through the creation of a Phase 4 uplink simulator using M17 signals in an FDMA scheme. Details at https://github.com/phase4ground/documents/tree/master/Engineering/Uplink%20Modem/Simulator
A
Okay,
here
we
have
a
preliminary
demo
using
three
different
signals
simultaneously,
starting
with
the
same
file
source
we
had
before.
This
is
a
premodulated
data
and
then
it's
being
converted
to
float
and
modulated
and
scaled
and
then
three
different
frequency
shifts
are
applied,
zero
and
plus
or
minus
12.5
kilohertz,
which
is
the
nominal
frequency
spacing
for
m17.
A
A
Okay,
here's
a
modified
flow
graph.
Now
we
have
three
different
files
being
played
out
and
they're
all
going
through.
This
parallel
construction
here
short
to
float,
frequency,
modulator
scaling
and
then
the
three
different
frequency
shifts
being
added
up,
resampled
and
transmitted.
So
let's
run
it.