Comtech EF Data CDM-625 Installation And Operation Manual page 15

CDM-625 Advanced Satellite Modem
Table of Contents
7.4 Reed-Solomon Outer Codec ................................................................................................ 7-3
7.4.1 Closed Network Modes ............................................................................................................................ 7-3
7.4.2 Open Network Modes .............................................................................................................................. 7-4
7.5 Trellis Coding (FAST Option) ................................................................................................ 7-4
7.6 Turbo Product Codec (Hardware Option) ............................................................................. 7-5
7.7 TPC and Low Density Parity Check (LDPC) coding ................................................................. 7-6
7.7.1 Introduction ............................................................................................................................................... 7-6
7.7.2 LDPC versus TPC ........................................................................................................................................ 7-7
7.7.3 End-to-End Processing Delay ................................................................................................................. 7-10
7.8 VersaFEC (Short-block LDPC) .............................................................................................. 7-11
7.8.1 VersaFEC Extensions ............................................................................................................................... 7-13
7.8.1.1 Extended CCM Codes......................................................................................................................... 7-13
7.8.1.2 Ultra-Low-Latency (ULL) Codes ......................................................................................................... 7-13
7.9 Uncoded Operation (No FEC) ............................................................................................. 7-14
CHAPTER 8. AUTOMATIC UPLINK POWER CONTROL (AUPC) .................................... 8-1
8.1 Introduction ....................................................................................................................... 8-1
8.2 Setting AUPC Parameters .................................................................................................... 8-2
8.2.1 Target Eb/No ............................................................................................................................................. 8-2
8.2.2 Max Range ................................................................................................................................................. 8-2
8.2.3 Alarm .......................................................................................................................................................... 8-3
8.2.4 Demod Unlock ........................................................................................................................................... 8-3
8.3 Compensation Rate ............................................................................................................. 8-3
8.4 Monitoring ......................................................................................................................... 8-4
CLOCK MODES AND DROP AND INSERT (D&I) ........................................ 9-1
CHAPTER 9.
9.1 Introduction ....................................................................................................................... 9-1
9.2 Transmit Clocking ............................................................................................................... 9-1
9.2.1 Internal Clock ............................................................................................................................................. 9-1
9.2.2 TX Terrestrial.............................................................................................................................................. 9-2
9.2.3 RX Loop-Timed, RX=TX ............................................................................................................................. 9-2
9.2.4 RX Loop-Timed, RX<>TX (Asymmetric Loop Timing) ............................................................................ 9-2
9.2.5 External TT with ST = RX Satellite ............................................................................................................ 9-2
9.3 Receive Clocking ................................................................................................................. 9-4
9.3.1 Buffer Disabled (RX Satellite) ................................................................................................................... 9-4
9.3.2 Buffer Enabled, TX=RX (TX Terrestrial or Int (SCT) Clock) ..................................................................... 9-4
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Revision 13
MN-CDM625