Mocomtech CDM-QX User Manual
Page 41

CDM-Qx/QxL Multi-Channel Satellite Modem with DoubleTalk™ Carrier-in-Carrier® Revision
7
Introduction
MN/CDMQx.IOM
1–17
TURBO PRODUCT 
CODEC 
Rate 7/8 QPSK
Rate 7/8 8-PSK
Rate 7/8 16-QAM
BER
(with two adjacent 
carriers, each 7 dB 
higher than the 
desired carrier) 
 
 
 
For: 
 
BER=10
-6
 
BER=10
-7
 
BER=10
-8
Rate 7/8 (Q) 
Guaranteed Eb/No: 
(typical value in 
parentheses) 
 
4.3 dB (4.0 dB) 
 
4.4 dB (4.1 dB) 
 
4.5 dB (4.2 dB) 
Rate 7/8 (8-PSK) 
Guaranteed Eb/No: 
(typical value in 
parentheses) 
 
7.3 dB (6.6 dB) 
 
7.4 dB (6.7 dB) 
 
7.5 dB (6.8 dB) 
Rate 7/8 (16-QAM) 
Guaranteed Eb/No: 
(typical value in 
parentheses) 
 
8.1 dB (7.7 dB) 
 
8.2 dB (7.8 dB) 
 
8.3 dB (7.9 dB) 
TURBO PRODUCT 
CODEC 
Rate 17/18 QPSK
Rate 17/18 8-PSK
BER
(with two adjacent 
carriers, each 7 dB 
higher than the 
desired carrier) 
 
 
 
For: 
 
BER=10
-6
 
BER=10
-7
 
BER=10
-8
Rate 17/18 (Q) 
Guaranteed Eb/No: 
(typical value in 
parentheses) 
 
6.4 dB (6.0 dB) 
 
6.7 dB (6.3 dB) 
 
6.9 dB (6.5 dB) 
Rate 17/18 (8-PSK) 
Guaranteed Eb/No: 
(typical value in 
parentheses) 
 
9.3 dB (8.9 dB) 
 
9.8 dB (9.4 dB) 
 
10.3 dB (9.9 dB) 
HIGHER-ORDER 
MODULATION AND 
CODING 
(with two adjacent 
carriers, each 7 dB 
higher than the 
desired carrier) 
 
 
 
 
For: 
 
BER=10
-6
 
BER=10
-8
16-QAM Rate 3/4 
Viterbi/RS 
Guaranteed Eb/No: 
(typical value in 
parentheses) 
 
8.1 dB (7.5 dB) 
 
8.6 dB (8.0 dB) 
16-QAM Rate 7/8 
Viterbi/RS 
Guaranteed Eb/No: 
(typical value in 
parentheses) 
 
9.5 dB (9.0 dB) 
 
10.1 dB (9.5 dB) 
Plesiochronous / 
Doppler Buffer 
Selectable size of 512, 1024, 2048, 4096, 8192, 16384 and a32768 bits 
Size selection is displayed in bytes 
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 16 dB (
± 0.10 dB accuracy)
Corrected Bit Error Rate, 1E-3 to 1E-10 
Frequency offset, 
± 32 kHz range, 100 Hz resolution (70/140 MHz IF)
Frequency offset,
± 200 kHz range, 100 Hz resolution (L-Band)
Buffer fill state, in percent 
Receive signal level accuracy = 
± 3.0 dB)
 
 
