4 summary of specifications, 4 summary of specifications 1.4.1 modulator – Comtech EF Data CDM-570 User Manual

Page 51

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CDM-570/570L Satellite Modem with Optional IP Module

Revision 12

Introduction

MN/CDM570L.IOM

1–11

1.4

Summary of Specifications

1.4.1 Modulator

Modulation

BPSK, QPSK, OQPSK, 8-PSK, 8-QAM and 16-QAM

Symbol Rate Range

4.8 ksps to 3.0 Msps

Data Rate Range

See Section 1.7.5

Operating Modes

Transparent, Closed Network, IESS-315 (VSAT Turbo)
Proprietary EDMAC framed mode:

• 5% overhead – EDMAC

(All modes except BPSK Turbo, Rate 21/44 OQPSK Turbo, and data rates < 2.048 Mbps)

• 1.6% overhead - EDMAC-2

(Rate 21/44, 5/16 Turbo, Rate 21/44 OQPSK Turbo, and all other rates >2.048 Mbps)

Automatic Uplink Power Control (AUPC) mode
R-S Outer Codec (optional)

• 220,200 outer code (transparent mode)

• 200,180 outer code (EDMAC modes)

Turbo Product Codec (optional):

• Rate 21/44 BPSK

• Rate 5/16 BPSK

• Rate 21/44 QPSK/OQPSK

• Rate 3/4 QPSK/OQPSK/8-PSK/8-QAM/16-QAM

• Rate 7/8 QPSK/OQPSK/8-PSK/8-QAM/16-QAM

• Rate 0.95 QPSK/OQPSK/8-PSK/8-QAM (exact Code Rate is actually 0.944)

Transmit Filtering

Per INTELSAT IESS-308 (FIR digital filter implementation)

Scrambling

Transparent Closed Network mode, no R-S or Turbo coding - per ITU V.35 (Intelsat variant)
EDMAC mode, no R-S coding - externally frame synchronized - proprietary
Turbo Product Code mode - externally frame synchronized - proprietary
All R-S modes - externally frame synchronized per IESS-308/309/310

FEC None: Uncoded BPSK/QPSK/OQPSK

Viterbi: k=7, per IESS-308/309
BPSK: Rate 1/2
QPSK/OQPSK: Rate 1/2, Rate 3/4 and Rate 7/8
16-QAM: Rate 3/4 and Rate 7/8 (requires Reed-Solomon)
Reed-Solomon (Closed Network):
220,200 outer code (transparent mode)
200,180 outer code (EDMAC modes)
Interleaver depth = 4
8-PSK/TCM Rate 2/3 (Trellis) with concatenated Reed-Solomon
CLOSED NETWORK - NOT IESS-310 COMPATIBLE
Turbo Product Codec (optional plug-in card):
Rate 5/16 BPSK - 2 dimensional
Rate 21/44 BPSK - 3 dimensional
Rate 21/44 QPSK/OQPSK - 3 dimensional
Rate 3/4 QPSK/OQPSK/8-PSK/8-QAM/16-QAM - 2 dimensional
Rate 7/8 QPSK/OQPSK/8-PSK/8-QAM/16-QAM - 2 dimensional
Rate 0.95 QPSK/OQPSK/8-QAM/8-PSK - 2 dimensional eTPC
(exact Code Rate is actually 17/18, or 0.944)

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