Comtech EF Data CDM-625 - Manual (Page 54)

CDM-625 Advanced Satellite Modem Revision 15
Introduction MN-CDM625
1–18
Plesiochronous/
Doppler Buffer
Selectable size of 64 to 262,144 bits, in 16-bit steps (with added limitations for G.704 frame boundaries).
Size selection is displayed in bytes and milliseconds.
Supports asymmetric operation – when buffer is clocked from Tx clock, Rx and Tx rates do not need to be
identical.
Monitor Functions Eb/No estimate:
• 2 to 10 dB with ±0.3 dB accuracy
• 0 to 16 dB with ±0.5 dB accuracy
Corrected Bit Error Rate, 1E-3 to 1E-10
Frequency offset, ±32 kHz range, (or 200 kHz range, depending on band and symbol rate) 100 Hz resolution
Buffer fill state, in percent
Receive signal level:
• 950-2000 MHz band accuracy: ±3 dB
• 50-180 MHz band accuracy: ±2 dB
Figure 1-5. Rx Carrier Level vs. Symbol Rate – L-Band (950-2000 MHz)
Figure 1-6. Rx Carrier Level vs. Symbol Rate – IF Band (50-180 MHz)
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10 100 1000 10000 100000
Symbol Rate in ksps
Ca
rri
er
Le
ve
l i
n dBm
Maximum
Minimum
-80
-70
-60
-50
-40
-30
-20
-10
0
10
10 100 1000 10000 100000
Symbol Rate in ksps
C
ar
rier
L
ev
el
in
d
B
m
Maximum
Minimum