CDM-750 Advanced High-Speed Trunking Modem
Revision 2
Front Panel Operation
MN-CDM750
5–30
5.2.2.5 CONFIG: ACM (Adaptive Coding and Modulation)
Appendix
C.
ADAPTIVE
CODING
AND
MODULATION
(ACM)
OPTION
.
ACM Config: Min/Max-ModCod Unlock-Action
Target-EbNo-Margin Degradation (
v
)
Use
the
W
X
arrow
keys
to
select
Min/Max
‐
ModCod
,
Unlock
‐
Action
,
Target
‐
EbNo
‐
Margin
,
or
Degradation
,
and
then
press
ENTER
.
5.2.2.5.1 (CONFIG) ACM Config: Min/Max-ModCod
If
the
user
wishes
to
constrain
the
system
to
run
at
a
fixed
ModCod,
set
the
Min
and
Max
ModCod
values
to
be
equal.
The
value
of
Max
ModCod
may
be
limited
by
other
FAST
Access
Codes
installed
for
Modulation
and
Symbol
Rate.
Min Modcod: QPSK 1/2
Max Modcod: 32APSK 9/10
To
define
the
range
of
ModCods
over
which
the
system
will
operate
(i.e.,
the
range
for
the
modem’s
Tx
capability):
First,
use
the
W
X
arrow
keys
to
select
the
Min
or
Max
ModCod
.
Then,
use
the
ST
arrow
keys
to
select
the
available
ModCod
(see
for
the
available
ModCod,
modulation,
and
code
rate
combinations).
Press
ENTER
when
done.
5.2.2.5.2 (CONFIG) ACM Config: Unlock-Action
When distant-end demod loses lock:
Go to min Tx ModCod (Maintain,Min) (
v
)
Use
this
submenu
to
establish
the
desired
action
when
the
remote
demod
loses
lock.
This
is
important,
as
the
ACM
system
depends
on
the
feedback
of
the
SNR
metric
from
the
remote
demod
to
determine
the
optimum
ModCod.
On
the
bottom
line:
Use
the
ST
arrow
keys
to
select
Go
to
min
Tx
ModCod
(
recommended)
or
Maintain
Tx
ModCod
,
and
then
press
ENTER
.
The
ACM
Æ
Unlock
selection
will
trigger
when
three
consecutive
ACM
messages
are
missed
(ACM
messages
are
sent
and
received
roughly
every
250
ms).
Summary of Contents for CDM-750
Page 76: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Updating Firmware MN CDM750 4 12 Notes...
Page 224: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Appendix A MN CDM750 A 4 Notes...
Page 234: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Appendix B MN CDM750 B 10 Notes...
Page 256: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Appendix C MN CDM750 C 22 Notes...
Page 280: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Appendix D MN CDM750 D 24 Notes...
Page 300: ...2114 WEST 7TH STREET TEMPE ARIZONA 85281 USA 480 333 2200 PHONE 480 333 2161 FAX...
