Comtech EF Data CDM-625A - Page 59

CDM-625A Advanced Satellite Modem MN-CDM625A
Introduction Revision 4
1–17
LNB 10 MHz Reference
On center conductor of L-Band input connector, selectable ON/OFF. Level: -3dBm
±
3 dB.
Source: either Internal modem reference or External reference
Performance: For phase noise, refer to L-Band modulator 10 MHz. Frequency stability same as the modulator 10
MHz reference.
LNB Voltage
On center conductor of L-Band input connector, selectable ON/OFF, 13, 18 volts per DiSEq 4.2 and 24VDC at 500
mA maximum.
LNB Current Alarm
Programmable Min/Max current alarms.
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: 950-2250 MHz band accuracy: ±3 dB
50-180 MHz band accuracy: ±2 dB
Receive signal level – ‘ER’ VERSION: 950-2250 MHz band accuracy: ±4 dB
50-180 MHz band accuracy: ±3 dB
BER Performance on CDMER-625A Version units may degrade 0.1 to 0.2 dB from the specifications that follow, when
operated under extreme conditions.
VITERBI BER performance
(met in the presence of two
adjacent carriers, each 7 dB
higher than the desired
carrier)
For BER=10
-X
Rate – Guaranteed Eb/No (typical value in parentheses)
BER=10
-5
BER=10
-6
BER=10
-7
Rate 1/2 (B, Q, OQ)
5.4 dB (4.9 dB)
6.0 dB (5.5 dB)
6.7 dB (6.2 dB)
Rate 3/4 (Q, OQ)
6.8 dB (6.3 dB)
7.4 dB (6.9 dB)
8.2 dB (7.7 dB)
Rate 7/8 (Q, OQ)
7.7 dB (7.2 dB)
8.4 dB (7.9 dB)
9.0 dB (8.6 dB)
VITERBI and RS 220,200 or
200,180 Outer Code BER
(With two adjacent carriers,
each 7 dB higher than the
desired carrier)
BER=10
-5
BER=10
-6
BER=10
-7
Rate 1/2 (B, Q, OQ)
4.3 dB (4.0 dB)
4.4 dB (4.1 dB)
4.5 dB (4.2 dB)
Rate 3/4 (Q, OQ)
5.6 dB (4.7 dB)
5.8 dB (4.8 dB)
6.0 dB (5.2 dB)
Rate 7/8 (Q, OQ)
6.5 dB (6.0 dB)
6.7 dB (6.2 dB)
6.9 dB (6.5 dB)
8PSK/TCM CODEC BER
(With two adjacent carriers,
each 7 dB higher than the
desired carrier)
BER=10
-5
BER=10
-7
BER=10
-8
Rate 2/3 8PSK/TCM
7.9 dB (7.2 dB)
9.5 dB (8.7 dB)
10.4 dB (9.5 dB)
Rate 2/3 8PSK/TCM
w/concatenated RS
6.3 dB (5.4 dB)
6.7 dB (5.8 dB)
6.9 dB (6.0 dB)
16-QAM VITERBI/
220,200 RS BER
(With two adjacent carriers,
each 7 dB higher than the
desired carrier)
BER=10
-6
BER=10
-8
16-QAM Rate 3/4 Viterbi/RS
8.1 dB (7.5 dB)
8.6 dB (8.0 dB)
16-QAM Rate 7/8 Viterbi/RS
9.5 dB (9.0 dB)
10.1 dB (9.5 dB)
Attention:
For 126,112 Reed-Solomon
add 0.2 dB to these figures
SEQUENTIAL at 64 kbps
BER performance (met in the
presence of two adjacent
carriers, each 7 dB higher
than the desired carrier)
BER=10
-4
BER=10
-6
BER=10
-8
Rate 1/2 (B, Q, OQ)
4.4 dB (4.0 dB)
5.1 dB (4.6 dB)
5.7 dB (5.2 dB)
Rate 3/4 (Q, OQ)
5.2 dB (4.7 dB)
5.8 dB (5.4 dB)
6.4 dB (6.0 dB)
Rate 7/8 (Q, OQ)
6.2 dB (5.7 dB)
7.0 dB (6.6 dB)
7.9 dB (7.4 dB)
SEQUENTIAL at 2048 kbps
BER performance (met in the
presence of two adjacent
carriers, each 7 dB higher
than the desired carrier)
BER=10
-4
BER=10
-6
BER=10
-8
Rate 1/2 (Q, OQ)
5.0 dB (4.6 dB)
5.8 dB (5.4 dB)
6.7 dB (6.3 dB)
Rate 3/4 (Q, OQ)
5.6 dB (5.2 dB)
6.4 dB (6.0 dB)
7.3 dB (6.8 dB)
Rate 7/8 (Q, OQ)
6.5 dB (6.0 dB)
7.6 dB (7.2 dB)
8.7 dB (8.2 dB)
SEQUENTIAL and RS
220,200 Outer Code at 512
kbps BER performance
(With two adjacent carriers,
each 7 dB higher than the
desired carrier)
BER=10
-4
BER=10
-6
BER=10
-8
Rate 1/2 (B, Q, OQ)
4.5 dB (4.1 dB)
4.7 dB (4.3 dB)
4.9 dB (4.6 dB)
Rate 3/4 (Q, OQ)
5.0 dB (4.6 dB)
5.2 dB (4.8 dB)
5.4 dB (5.0 dB)
Rate 7/8 (Q, OQ)
5.9 dB (5.5 dB)
6.1 dB (5.7 dB)
6.3 dB (5.9 dB)