Comtech EF Data SDM-300L3 User Manual
M
-
3
p
SD
300L
Satellite Modem
Installation and O
IMPORTANT NOTE: The information contained in this document supersedes all previously
published information regarding this product. Product specifications are subject to change
without prior notice.
Part Number MN/SDM300L3.IOM Revision 1
eration Manual
SDM-300L3
Comtech EF Data is an ISO 9001
Registered Company.
Satellite Modem
Installation and Operation Manual
Part Number MN/SDM300L3.IOM
Revision 1
July 25, 2004
Copyright © Comtech EF Data, 2000. All rights reserved. Printed in the USA.
Comtech EF Data, 2114 West 7th Street, Tempe, Arizona 85281 USA, 480.333.2200, FAX: 480.333.2161.
Customer Support
Contact the Comtech EF Data Customer Support Department for:
• Product support or training
• Information on upgrading or returning a product
• Reporting comments or suggestions concerning manuals
A Customer Support representative may be reached at:
Comtech EF Data
Attention: Customer Support Department
2114 West 7th Street
Tempe, Arizona 85281 USA
480.333.2200 (Main Comtech EF Data Number)
480.333.4357 (Customer Support Desk)
480.333.2161 FAX
or, E-Mail can be sent to the Customer Support Department at:
service@comtechefdata.com
Contact us via the web at www.comtechefdata.com
1. To return a Comtech EF Data product (in-warranty and out-of-warranty) for
repair or replacement:
2. Request a Return Material Authorization (RMA) number from the Comtech EF
Data Customer Support Department.
3. Be prepared to supply the Customer Support representative with the model
number, serial number, and a description of the problem.
4. To ensure that the product is not damaged during shipping, pack the product in
its original shipping carton/packaging.
5. Ship the product back to Comtech EF Data. (Shipping charges should be
prepaid.)
For more information regarding the warranty policies, see, p. xviii.
.
ii
Table of Contents
CHAPTER 1. INTRODUCTION............................................................................................. 1–1
1.1 Overview....................................................................................................................... 1–3
1.2 Options Summary........................................................................................................ 1–3
1.3 Comtech EF Data Part Numbers ................................................................................ 1–4
1.4 FAST Accessible Options........................................................................................... 1–5
1.5 Compatibility................................................................................................................ 1–6
1.6 Description of the Modulator...................................................................................... 1–6
1.6.1 Overview................................................................................................................................1–6
1.6.2 Description.............................................................................................................................1–6
1.6.3 Description of Modulation Types ...........................................................................................1–7
1.6.4 BPSK Encoding .....................................................................................................................1–8
1.6.5 QPSK Encoding.....................................................................................................................1–8
1.6.6 OQPSK Encoding..................................................................................................................1–9
1.6.7 8-PSK Encoding ....................................................................................................................1–9
1.7 Description of the Demodulator............................................................................... 1–10
1.7.1 Overview..............................................................................................................................1–10
1.7.2 Functional Description .........................................................................................................1–11
1.8 Description of Monitor & Control............................................................................. 1–12
1.8.1 Overview..............................................................................................................................1–12
1.8.2 Functional Description .........................................................................................................1–13
1.9 Dimensional Envelope .............................................................................................. 1–15
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CHAPTER 2. INSTALLATION/ UPGRADES ....................................................................... 2–1
2.1 Unpacking .................................................................................................................... 2–1
2.2 Installation.................................................................................................................... 2–2
2.3 Software and Hardware Installation/Upgrades ......................................................... 2–4
2.3.1 Overhead Interface PCB Installation .....................................................................................2–4
2.3.2 Reed-Solomon PCB ..............................................................................................................2–6
2.3.3 Turbo Codec Installation........................................................................................................2–8
2.4 Data I/O Interface Connector (J8) Removal/Installation......................................... 2–11
2.5 Hardware Upgrades................................................................................................... 2–14
2.5.1 Main PCB Firmware Chips .................................................................................................2–14
2.5.2 Overhead Interface PCB Firmware Chips ..........................................................................2–14
2.6 Flash Upgrading ........................................................................................................ 2–16
CHAPTER 3. CONNECTOR PINOUTS ................................................................................ 3–1
3.1 Connector Overview.................................................................................................... 3–1
3.2 Connector Description................................................................................................ 3–3
3.2.1 Remote Connector and Pinouts (J6) .....................................................................................3–3
3.2.2 Fault Connector and Pinouts (J7)..........................................................................................3–4
3.2.3 Data I/O Interface Connector (J8) .........................................................................................3–5
3.2.4 G.703 T1, E1/ASYNC Interface Adapter .............................................................................3–11
3.2.5 Auxiliary 1 Connector and Pinouts (J9) ...............................................................................3–12
3.2.6 Alarms Connector and Pinouts (J10) ..................................................................................3–13
3.2.7 RF Output Connector (CP1)................................................................................................3–13
3.2.8 External Reference (CP2) ...................................................................................................3–13
3.2.9 RF Input Connector (CP3)...................................................................................................3–13
3.2.10 AC Power Connector...........................................................................................................3–14
3.2.11 Ground Connector (GND)....................................................................................................3–14
CHAPTER 4. FRONT PANEL OPERATION ....................................................................... 4–1
4.1 Front Panel................................................................................................................... 4–1
4.2 LED Indicators ............................................................................................................. 4–2
4.3 Front Panel Keypad..................................................................................................... 4–3
4.4 Menu System ............................................................................................................... 4–4
4.5 Menu Tree..................................................................................................................... 4–6
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4.6 Opening Screen ........................................................................................................... 4–7
4.6.1 FUNCTION SELECT: CONFIGURATION.............................................................................4–7
4.6.2 FUNCTION SELECT: MONITOR........................................................................................4–61
4.6.3 FUNCTION SELECT: FAULTS/ALARMS ...........................................................................4–68
4.6.4 FUNCTION SELECT: STORED FLTS/ALMS .....................................................................4–74
4.6.5 FUNCTION SELECT: REMOTE AUPC (Conditional).........................................................4–79
4.6.6 FUNCTION SELECT: UTILITY............................................................................................4–83
4.7 SDM-300L Custom Modem Defaults ...................................................................... 4–129
CHAPTER 5. MODEM TYPE ............................................................................................... 5–1
5.1 Modem Type................................................................................................................. 5–1
5.2 IDR Operation ............................................................................................................. 5–2
5.3 IBS Operation............................................................................................................... 5–3
5.3.1 309 IBS Operation .................................................................................................................5–3
5.3.2 VSAT IBS Operation..............................................................................................................5–3
5.4 D&I Operation .............................................................................................................. 5–4
5.5 ASYNC/AUPC Operation............................................................................................. 5–5
5.6 Closed Network Operation (Comtech EF Data) ........................................................ 5–6
5.7 Custom Operation ....................................................................................................... 5–8
5.8 Reed-Solomon Modes................................................................................................. 5–9
CHAPTER 6. CLOCKING AND RX BUFFERING SETTINGS ............................................ 6–1
6.1 Clocking Options......................................................................................................... 6–1
6.1.1 EIA-232, EIA-422, or V.35 Master/Master.............................................................................6–1
6.1.2 EIA-232, EIA-422, or V.35 Master/Slave...............................................................................6–1
6.2 IDR/IBS G.703 Master/Master ..................................................................................... 6–2
6.2.1 IDR/IBS G.703 Master/Slave.................................................................................................6–2
6.2.2 D&I G.703 Master/Master......................................................................................................6–3
6.3 Buffering....................................................................................................................... 6–9
6.4 Doppler ....................................................................................................................... 6–12
6.5 Plesiochronous.......................................................................................................... 6–13
6.6 ASymmetrical Loop Timing ...................................................................................... 6–14
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6.7 Frame/Multiframe Length.......................................................................................... 6–17
6.7.1 Multiples of the Frame Length.............................................................................................6–17
6.7.2 Total Buffer Length ..............................................................................................................6–17
6.7.3 Converting Between Bits and Seconds ...............................................................................6–17
CHAPTER 7. FEC AND TURBO .......................................................................................... 7–1
7.1 Introduction.................................................................................................................. 7–1
7.2 Coding .......................................................................................................................... 7–2
7.3 Turbo Product Codec (Hardware Option) ................................................................. 7–2
7.3.1 Introduction ............................................................................................................................7–2
7.3.2 Mod/Demod Processing Delay..............................................................................................7–3
7.3.3 Comparison of all TPC Modes...............................................................................................7–4
7.4 Uncoded Operation (No FEC)..................................................................................... 7–5
CHAPTER 8. SYSTEM CHECKOUT .................................................................................... 8–1
8.1 System Checkout ........................................................................................................ 8–1
8.1.1 Interface Checkout ................................................................................................................8–2
8.1.2 Modulator Checkout ..............................................................................................................8–3
8.1.3 Demodulator Checkout..........................................................................................................8–5
CHAPTER 9. FAULT ISOLATION........................................................................................ 9–1
9.1 Fault Isolation .............................................................................................................. 9–1
9.1.1 System Faults/Alarms............................................................................................................9–2
9.1.2 Faults/Alarms Display............................................................................................................9–2
9.1.3 Faults/Alarms Analysis ..........................................................................................................9–2
CHAPTER 10. OPEN NETWORK OPERATIONS............................................................. 10–1
10.1 Introduction................................................................................................................ 10–1
10.2 IBS............................................................................................................................... 10–1
10.3 IDR .............................................................................................................................. 10–5
10.4 Drop & Insert (D&I) .................................................................................................... 10–9
10.4.1 Description of D&I Operation.............................................................................................10–11
10.4.2 D&I Framing Formats ........................................................................................................10–14
10.4.3 D&I Modem Defaults .........................................................................................................10–17
10.5 2xADPCM Voice in 64 kbps IBS ............................................................................. 10–18
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CHAPTER 11. ASYNCHRONOUS INTERFACE/AUPC ...................................................... 11–1
11.1 Asynchronous Interface/AUPC ................................................................................ 11–1
11.2 AUPC .......................................................................................................................... 11–4
11.2.1 AUPC – Between Two Modems..........................................................................................11–5
11.2.2 Self-Monitoring Local Modem AUPC Control ......................................................................11–6
11.3 ASYNC........................................................................................................................ 11–7
11.3.1 Terrestrial Data Interfaces ...................................................................................................11–7
11.3.2 ASYNC Data Interfaces.......................................................................................................11–7
11.3.3 MUX Operation....................................................................................................................11–8
11.3.4 DEMUX Operation...............................................................................................................11–8
11.3.5 Buffer Operation ..................................................................................................................11–8
11.3.6 Loop Timing Operation ........................................................................................................11–9
11.3.7 Baseband Loopback Operation...........................................................................................11–9
11.3.8 Non-ASYNC Operation......................................................................................................11–10
11.4 ASYNC Channel EIA-485 2- and 4-Wire Operation ............................................... 11–10
11.4.1 Valid ASYNC Baud Rates .................................................................................................11–11
11.4.2 Front Panel Operation .......................................................................................................11–11
11.4.3 ASYNC Remote Operation................................................................................................11–12
11.4.4 ASYNC/AUPC Modem Defaults........................................................................................11–24
CHAPTER 12. G.703 ............................................................................................................ 12–1
CHAPTER 13. FULLY ACCESSIBLE SYSTEM TOPOLOGY (FAST)................................ 13–1
CHAPTER 14. SPECIFICATIONS..................................................................................... 14–1
14.1 Specifications ............................................................................................................ 14–1
14.2 Specification Summary............................................................................................. 14–3
14.3 L-Band Modulator Specification Summary ............................................................. 14–4
14.4 Demodulator Specification Summary...................................................................... 14–5
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14.5 L-Band Modulator Specifications ............................................................................ 14–6
14.5.1 Digital Data Rate .................................................................................................................14–6
14.5.2 Modulation and Encoding Types .........................................................................................14–8
14.5.3 Scrambling Types................................................................................................................14–9
14.5.4 Modulator Frequency Reference.........................................................................................14–9
14.5.5 Modulator Spurious Emissions..........................................................................................14–10
14.5.6 Modulator Phase Noise .....................................................................................................14–10
14.5.7 Modulator IF Output Spectrum Shape...............................................................................14–10
14.5.8 L-Band INMARSAT Spurious Emissions...........................................................................14–10
14.5.9 Differential Encoder ...........................................................................................................14–11
14.5.10 BPSK Bit Ordering.........................................................................................................14–11
14.5.11 Interleaver (Reed-Solomon Codec)...............................................................................14–11
14.5.12 Modulator Transmit Frequency (IF) ...............................................................................14–11
14.5.13 Transmit Frequency Change Time ................................................................................14–11
14.5.14 Modulator Transmit IF Output Switch............................................................................14–11
14.5.15 Modulator Transmit IF Power ........................................................................................14–11
14.5.16 Modulator Power Offset.................................................................................................14–12
14.5.17 Modulator I / Q Imbalance .............................................................................................14–12
14.5.18 Modulator Output Noise Floor .......................................................................................14–12
14.5.19 Modulator Spectrum Rotation........................................................................................14–12
14.5.20 Modulator Output Return Loss ......................................................................................14–12
14.5.21 L-Band ODU Reference Signal .....................................................................................14–12
14.5.22 L-Band ODU Control and Monitor .................................................................................14–12
14.5.23 Modulator Transmit IF Test Modes................................................................................14–12
14.5.24 L-Band ODU Supply Voltage.........................................................................................14–13
14.5.25 ODU DC Current Sense ................................................................................................14–13
14.6 Encoding .................................................................................................................. 14–13
14.6.1 BPSK Encoding .................................................................................................................14–13
14.6.2 OQPSK Encoding..............................................................................................................14–14
14.6.3 8PSK Encoding .................................................................................................................14–14
14.7 L-Band Demodulator Specifications...................................................................... 14–15
14.7.1 Digital Data Rate ...............................................................................................................14–15
14.7.2 Demodulation and FEC Decoding Types ..........................................................................14–17
14.7.3 Descrambling Types..........................................................................................................14–18
14.7.4 Differential Decoder...........................................................................................................14–18
14.7.5 BPSK Bit Ordering.............................................................................................................14–18
14.7.6 Deinterleaver (Reed-Solomon Codec) ..............................................................................14–18
14.7.7 Demodulator Spectrum Rotation .......................................................................................14–19
14.7.8 Receive Frequency............................................................................................................14–19
14.7.9 Input Overload ...................................................................................................................14–19
14.7.10 Demodulator Input Return Loss.....................................................................................14–19
14.7.11 LNB Prime Power ..........................................................................................................14–19
14.7.12 LNB Band Control..........................................................................................................14–19
14.7.13 LNB Reference Signal ...................................................................................................14–19
14.7.14 Receive Input Power (Composite).................................................................................14–20
14.7.15 Demodulator Input Shape..............................................................................................14–20
14.7.16 Receive Input Power (Desired Carrier) .........................................................................14–21
14.7.17 Demodulator Channel Spacing/Adjacent Carrier Performance.....................................14–21
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14.8 Bit Error Rate Performance .................................................................................... 14–22
14.8.1 Performance With Noise, Viterbi Decoder, and Closed Network ......................................14–22
14.8.2 Performance With Noise, Viterbi Decoder, and Reed-Solomon (Optional) ......................14–22
14.8.3 Performance With BPSK and {O}QPSK BER Performance..............................................14–22
14.8.4 Performance with Noise Turbo Product Codec (Optional) ................................................14–23
14.8.5 Performance With Noise, 1544 kbps Sequential Decoder and Reed .......................................
Solomon(Optional)..............................................................................................................14–23
14.8.6 Performance With Noise, 56 kbps Sequential Decoder (Optional) ...................................14–23
14.8.7 Performance With Noise, 1544 kbps Sequential Decoder (Optional) ...............................14–24
14.8.8 BER Threshold ..................................................................................................................14–24
14.9 Acquisition Time...................................................................................................... 14–25
14.9.1 Receive Carrier Acquisition Range....................................................................................14–26
14.9.2 Receive Carrier Reacquisition ...........................................................................................14–26
14.9.3 AGC Output .......................................................................................................................14–26
14.9.4 Doppler Tracking Performance..........................................................................................14–26
14.10 Interface Specifications .......................................................................................... 14–27
14.10.1 TX Clock Switching Due to Failure of Selected Clock...................................................14–27
14.10.2 TX Clock Phase Adjustment..........................................................................................14–27
14.10.3 TX Data Phase Adjustment ...........................................................................................14–27
14.10.4 Transmit Clock Source ..................................................................................................14–27
14.10.5 Send Clock Timing Source ............................................................................................14–27
14.10.6 Doppler/Plesiochronous Buffer Clock Source ...............................................................14–28
14.10.7 RX Clock Switching Due to Failure of Selected Clock ..................................................14–28
14.10.8 RX Clock Phase Adjustment .........................................................................................14–28
14.10.9 RX Clock Jitter ...............................................................................................................14–28
14.10.10 RX Data Phase Adjustment...........................................................................................14–28
14.10.11 Buffer Centering.............................................................................................................14–28
14.10.12 Receive Doppler/Plesiochronous Buffer Size................................................................14–29
14.10.13 Switch Faults .................................................................................................................14–29
14.11 Decoding .................................................................................................................. 14–29
14.11.1 BPSK Decoding .............................................................................................................14–29
14.11.2 QPSK Decoding.............................................................................................................14–29
14.11.3 OQPSK Decoding (Optional).........................................................................................14–30
14.11.4 8PSK Decoding .............................................................................................................14–30
14.12 Terrestrial Interface Types...................................................................................... 14–31
14.12.1 EIA-232 Specification ....................................................................................................14–31
14.12.2 V.35 Specification V.10, V.11 Specification, Circuit Supported ....................................14–32
14.12.3 EIA-449/EIA-422 Mil-188-114A Specification................................................................14–33
14.12.4 Optional G.703 with ASYNC (Requires optional Overhead Card) ................................14–33
14.13 Asynchronous Overhead Specification (Optional) .............................................. 14–34
14.13.1 Asynchronous Baud Rates ............................................................................................14–35
14.13.2 Asynchronous Overhead Data Format..........................................................................14–35
14.13.3 Asynchronous Overhead Parameters ...........................................................................14–35
14.13.4 AUPC with Reed-Solomon Option.................................................................................14–35
14.13.5 Turbo AUPC ..................................................................................................................14–36
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14.14 IBS (Optional with Overhead Card)........................................................................ 14–36
14.14.1 IBS Primary Data Interfaces ..........................................................................................14–36
14.14.2 IBS Clock and Dejitter ...................................................................................................14–36
14.14.3 IBS Framing...................................................................................................................14–36
14.14.4 IBS Engineering Service Channel .................................................................................14–37
14.14.5 IBS Scrambling ..............................................................................................................14–37
14.15 Drop and Insert (Optional with Overhead Card)................................................... 14–37
14.14.1 D&I Primary Data Interfaces..........................................................................................14–38
14.14.2 D&I Framing...................................................................................................................14–38
14.16 IDR (Optional with Overhead Card) ....................................................................... 14–38
14.16.1 IDR Primary Data Interfaces..........................................................................................14–39
14.16.2 IDR Framing ..................................................................................................................14–39
14.16.3 IDR Engineering Service Channel.................................................................................14–39
14.16.4 Optional: Dual 32 Kpps ADPCM (2XASPCM Audio).....................................................14–39
14.17 System Specifications ............................................................................................ 14–40
14.17.1 Loopback Modes ...........................................................................................................14–40
14.17.2 Test Modes ....................................................................................................................14–40
14.17.3 Remote Control..............................................................................................................14–41
14.17.4 Modem Remote Address...............................................................................................14–41
14.17.5 Monitored Signals..........................................................................................................14–41
14.18 Stored Faults............................................................................................................ 14–42
14.19 Stored Configurations............................................................................................. 14–42
14.20 Interoperability Modes ............................................................................................ 14–42
CHAPTER 15. BUC FSK COMMUNICATIONS ................................................................... 15–1
15.1 Introduction................................................................................................................ 15–1
15.2 Message Structure .................................................................................................... 15–2
15.2.1 Command Message Structure (IDU to ODU)......................................................................15–2
15.2.2 Response Message Structure (BUC to IDU).......................................................................15–3
15.3 Power Class ............................................................................................................... 16–3
APPENDIX A. Remote Control Operation ........................................................................... A–1
APPENDIX B. Burst Mode Modulator Operation ..............................................................B-1
GLOSSARY .............................................................................................................................. g-1
INDEX ........................................................................................................................................ i-1
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Figures
Figure 1-1. Block Diagram........................................................................................................................1–2
Figure 1-2. Demodulator Block Diagram................................................................................................1–10
Figure 1-3. M&C Block Diagram.............................................................................................................1–13
Figure 1-4. Dimensional Envelope Drawing...........................................................................................1–15
Figure 2-1. Installation of the Optional Mounting Bracket KT/6228-1 ......................................................2–3
Figure 2-2. Overhead Interface PCB Installation .....................................................................................2–5
Figure 2-3. Reed-Solomon Codec Installation .........................................................................................2–7
Figure 2-4. Turbo Codec Installation ......................................................................................................2–10
Figure 2-5. Data I/O Connector (J8) Removal/Installation .....................................................................2–13
Figure 2-6. Overhead Board with Field-Changeable Chips ...................................................................2–15
Figure 2-7. Main Board Field-Changeable Chips (Shown with Overhead Card Removed)...................2–15
Figure 3-1. SDM-300L3 Rear Panel.........................................................................................................3–2
Figure 4-1. Front Panel View....................................................................................................................4–1
Figure 4-2. Keypad ...................................................................................................................................4–3
Figure 4-3. Menu Tree..............................................................................................................................4–6
Figure 4-4. RF Loopback........................................................................................................................4–21
Figure 4-5. IF Loopback .........................................................................................................................4–22
Figure 4-6. Baseband Loopback ............................................................................................................4–30
Figure 4-7. Interface Loopback ..............................................................................................................4–31
Figure 6-1. EIA-422, EIA-232, or V.35 Master/Master Clocking Diagram................................................6–4
Figure 6-2. EIA-422, EIA-232, or V.35 Master/Slave Clocking Diagram..................................................6–5
Figure 6-3. IDR/IBS G.703 Master/Master Clocking Diagram..................................................................6–6
Figure 6-4. IDR/IBS G.703 Master/Slave Clocking Diagram....................................................................6–7
Figure 6-5. D&I G.703 Master/Master Clocking Diagram.........................................................................6–8
Figure 6-6. Clock Slip .............................................................................................................................6–10
Figure 6-7. Doppler Shift ........................................................................................................................6–11
Figure 6-8. Transmit Section of the Asymmetrical Loop Timing Block Diagram....................................6–15
Figure 6-9. Receive Section of the Asymmetrical Loop Timing Block Diagram.....................................6–16
Figure 7-1. Viterbi Decoder ......................................................................................................................7–7
Figure 7-2. Viterbi Decoder and Reed-Solomon ......................................................................................7–8
Figure 7-3. BPSK and (O)QPSK BER Performance ................................................................................7–9
Figure 7-4. Turbo Product Codec...........................................................................................................7–10
Figure 7-5. Sequential Decoder, Reed-Solomon, and 1544 kbps .........................................................7–11
Figure 7-6. Sequential Decoder and 56 kbps.........................................................................................7–12
Figure 7-7. Sequential Decoder and 1544 kbps.....................................................................................7–13
Figure 8-1. Fault Isolation Test Setup ......................................................................................................8–2
Figure 8-2. Typical Output Spectrum .......................................................................................................8–5
Figure 8-3. Typical Eye Constellations.....................................................................................................8–6
Figure 9-1. SDM-300L Fault Tree ............................................................................................................9–3
Figure 10-1. IBS Interface Block Diagram..............................................................................................10–3
Figure 10-2. IDR Interface Block Diagram .............................................................................................10–7
Figure 10-3. D&I with Asynchronous Overhead Data Flow..................................................................10–10
Figure 10-4. E1 Framing Formats ........................................................................................................10–15
Figure 10-5. T1 Framing Formats ........................................................................................................10–16
Figure 11-1. ASYNC/AUPC Block Diagram ...........................................................................................11–3
Figure 11-2. Remote ASYNC Connection Diagram for Y-Cable..........................................................11–13
Figure 11-3. Remote ASYNC Connection Diagram for Breakout Panel ..............................................11–13
Figure 14-1. Block Diagram....................................................................................................................14–2
Figure 14-2. Carrier Level vs Symbol Rate ..........................................................................................14–21
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Tables
Table 1-1. FAST Options and Required Configurations...........................................................................1–5
Table 2-1. Connector (J8) Matrix............................................................................................................2–11
Table 3-1. Modem Rear Panel Connectors..............................................................................................3–2
Table 3-2. Remote Connector and Pinouts (J6).......................................................................................3–3
Table 3-3. Fault Connector and Pinouts (J7) ...........................................................................................3–4
Table 3-4. 25-Pin D Connector Pinouts....................................................................................................3–6
Table 3-5. 34-Pin Winchester Connector Pinouts (V.35) .........................................................................3–7
Table 3-6. 37-Pin Connector Pinouts (Optional) ......................................................................................3–8
Table 3-7. 50-Pin Connector Pinouts .......................................................................................................3–9
Table 3-8. AUX 1 Connector and Pinouts (J9).......................................................................................3–12
Table 3-9. Alarms Connector and Pinouts (J10) ....................................................................................3–13
Table 4-1. LED Indicators.........................................................................................................................4–2
Table 4-2. SDM-300L Custom Modem Defaults ..................................................................................4–129
Table 4-2. SDM-300L Custom Modem Defaults (Continued) ..............................................................4–130
Table 5-1. Modem Type Selection ...........................................................................................................5–1
Table 5-2. IDR Parameter Settings ..........................................................................................................5–2
Table 5-3. IBS Parameter Settings...........................................................................................................5–3
Table 5-4. D&I Parameter Settings ..........................................................................................................5–4
Table 5-5. N x 64 Chart ............................................................................................................................5–4
Table 5-6. Asynchronous Parameter Settings .........................................................................................5–5
Table 5-7. EFD Closed Network Parameter Settings...............................................................................5–7
Table 5-8. Reed-Solomon Modes ............................................................................................................5–9
Table 7-1. Available TPC Modes..............................................................................................................7–2
Table 7-2. Turbo Product Coding processing delay comparison ..............................................................7–3
Table 8-1. Conversion to S/N and Eb/N0 Chart .......................................................................................8–4
Table 10-1. IBS Modem Defaults ...........................................................................................................10–4
Table 10-2. IDR Modem Defaults...........................................................................................................10–8
Table 10-3. D&I Modem Faults ............................................................................................................10–17
Table 11-1. Setting AUPC Parameters ..................................................................................................11–4
Table 11-2. ASYNC Remote Operation ...............................................................................................11–12
Table 11-3. Local EIA-232 to Remote EIA-232....................................................................................11–14
Table 11-4. Local EIA-232 to Remote EIA-485 (4-Wire)......................................................................11–15
Table 11-5. Local EIA-232 to Remote EIA-485 (2-Wire)......................................................................11–16
Table 11-6. Local EIA-485 (4-Wire) to Remote EIA-232......................................................................11–17
Table 11-7. Local EIA-485 (4-Wire) to Remote EIA-485 (4-Wire)........................................................11–18
Table 11-8. Local EIA-485 (4-Wire) to Remote EIA-485 (2-Wire)........................................................11–19
Table 11-9. Local EIA-485 (2-Wire) to Remote EIA-232......................................................................11–20
Table 11-10. Local EIA-485 (2-Wire) to Remote EIA-485 (4-Wire)......................................................11–22
Table 11-11. ASYNC/AUPC Modem Defaults......................................................................................11–24
Table 12-1. G.703 Specifications ...........................................................................................................12–1
Table 13-1. System Specification Summary ..........................................................................................13–3
Table 13-2. L-Band Modulator................................................................................................................13–4
Table 13-3. Demodulator Specification ..................................................................................................13–5
Table 13-4. Modulator Digital Data Rates ..............................................................................................13–6
Table 13-5. Modulation and Encoding Types.........................................................................................13–8
Table 13-6. Scrambling Types ...............................................................................................................13–9
Table 13-7. Demodulator Digital Data Rate .........................................................................................13–15
Table 13-8. L-Band Demodulation and FEC Decoding Types.............................................................13–17
Table 13-9. Descrambling Types .........................................................................................................13–18
Table 13-10. ASYNC Overhead Parameters .......................................................................................13–35
xii
SDM-300L3 Satellite Modem Revision 1
Preface MN/SDM300L3.IOM
About this Manual
This manual provides installation and operation information for the Comtech EF Data
SDM-300L3 satellite modem. This is a technical document intended for earth station
engineers, technicians, and operators responsible for the operation and maintenance of
the SDM-300L3.
Related Documents
The following documents are referenced in this manual:
• Comtech EF Data UB-530 Universal Breakout Panel Installation and Operation
Manual
Conventions and References
Cautions and Warnings
CAUTION indicates a hazardous situation that, if not avoided, may result in
minor or moderate injury. CAUTION may also be used to indicate other
CAUTION
WARN ING
IMPORTANT
unsafe practices or risks of property damage.
WARNING indicates a potentially hazardous situation that, if not avoided,
could result in death or serious injury.
IMPORTANT indicates a statement that is associated with the task
being performed. .
xiii
SDM-300L3 Satellite Modem Revision 1
Preface MN/SDM300L3.IOM
Metric Conversion
Metric conversion information is located on the inside back cover of this manual. This
information is provided to assist the operator in cross-referencing non-metric to metric
conversions.
Recommended Standard Designations
Recommended Standard (RS) Designations are equivalent toElectronic Industries
Association (EIA) designations. Reference to either designation is permissible, however,
Comtech EF Data has determined to use only one designator thru-out the manual.
Trademarks
Windows is a trademark of the Microsoft Corporation.
Other product names mentioned in this manual may be trademarks or registered
trademarks of their respective companies and are hereby acknowledged.
Reporting Comments or Suggestions Concerning this Manual
Comments and suggestions regarding the content and design of this manual will be
appreciated. To submit comments, please contact the Comtech EF Data Technical
Publications department: techpub@comtechefdata.com
Overview of Changes to Revision 0
Incorporated Erratas A through N
Incorporated Addendum A
Incorporated engineering updates.
Updated Front Panel Operation menus to SW Version 2.2.1
Updated Remote Control Commands to FW/8460-1AD
xiv
SDM-300L3 Satellite Modem Revision 1
Preface MN/SDM300L3.IOM
Electrical Safety
The SDM-300L3 Satellite Modem has been shown to comply with the following safety standard:
• EN 60950: Safety of Information Technology Equipment, including electrical business
machines.
The equipment is rated for operation over the range 85 to 264 volts AC. It has a maximum
power consumption of 55 watts without BUC power supply. Input power increases to 175W
with 100W, 24V BUC power supply at maximum load. Input power increases to 230W with
150W, 48V BUC power supply at maximum load.
FUSES
The SDM-300L3 Satellite Modem is fitted with two fuses, one each for line and neutral
connections. These are contained within the body of the IEC power connector, behind a small
plastic flap.
• Use T3.15A, 20mm fuses.
IMPORTANT
Environmental
The SDM-300L3 must not be operated in an environment where the unit is exposed to
extremes of temperature outside the ambient range 0 to 50°C (32 to 122°F), precipitation,
condensation, or humid atmospheres above 95% RH, altitudes (un-pressurised) greater
than 2000 metres, excessive dust or vibration, flammable gases, corrosive or explosive
atmospheres.
Operation in vehicles or other transportable installations that are equipped to provide a
stable environment is permitted. If such vehicles do not provide a stable environment,
safety of the equipment to EN60950 may not be guaranteed.
For continued operator safety, always replace the fuses with the
correct type and rating.
xv
SDM-300L3 Satellite Modem Revision 1
Preface MN/SDM300L3.IOM
Installation
The installation and connection to the line supply must be made in compliance to local or
national wiring codes and regulations.
The SDM-300L3 is designed for connection to a power system that has separate ground,
line and neutral conductors. The equipment is not designed for connection to power
system that has no direct connection to ground.
The SDM-300L3 is shipped with a line inlet cable suitable for use in the country of
operation. If it is necessary to replace this cable, ensure the replacement has an equivalent
specification. Examples of acceptable ratings for the cable include HAR, BASEC and
HOXXX-X. Examples of acceptable connector ratings include VDE, NF-USE, UL, CSA,
OVE, CEBEC, NEMKO, DEMKO, BS1636A, BSI, SETI, IMQ, KEMA-KEUR and
SEV.
International Symbols:
Symbol Definition Symbol Definition
~
Alternating Current
Fuse
Telecommunications Terminal Equipment Directive
In accordance with the Telecommunications Terminal Equipment Directive 91/263/EEC,
this equipment should not be directly connected to the Public Telecommunications
Network.
Protective Earth
Chassis Ground
xvi
SDM-300L3 Satellite Modem Revision 1
Preface MN/SDM300L3.IOM
EMC (Electromagnetic Compatibility)
In accordance with European Directive 89/336/EEC, the SDM-300L3 Satellite Modem
has been shown, by independent testing, to comply with the following standards:
Emissions: EN 55022 Class B - Limits and methods of measurement of radio
interference characteristics of Information Technology Equipment.
(Also tested to FCC Part 15 Class B)
Immunity: EN 50082 Part 1 - Generic immunity standard, Part 1: Domestic,
commercial and light industrial environment.
Additionally, the SDM-300L3 has been shown to comply with the following standards:
EN 61000-3-2 Harmonic Currents Emission
EN 61000-3-3 Voltage Fluctuations and Flicker
EN 61000-4-2 ESD Immunity
EN 61000-4-4 EFT Burst Immunity
EN 61000-4-5 Surge Immunity
EN 61000-4-6 RF Conducted Immunity
EN 61000-4-8 Power frequency Magnetic Field Immunity
EN 61000-4-9 Pulse Magnetic Field Immunity
EN 61000-4-11 Voltage Dips, Interruptions, and Variations Immunity
EN 61000-4-13 Immunity to Harmonics
In order that the Modem continues to comply with these standards,
observe the following instructions:
IMPORTANT
• Connections to the transmit and receive IF ports (Type N and Type F, female,
connectors) should be made using a good quality coaxial cable - for example
RG58/U (50Ω or RG59/U (75Ω).
• All 'D' type connectors attached to the rear panel must have back-shells that
provide continuous metallic shielding. Cable with a continuous outer shield
(either foil or braid, or both) must be used, and the shield must be bonded to the
back-shell.
• The equipment must be operated with its cover on at all times. If it becomes
necessary to remove the cover, the user should ensure that the cover is correctly
re-fitted before normal operation commences.
xvii
SDM-300L3 Satellite Modem Revision 1
Preface MN/SDM300L3.IOM
Warranty Policy
This Comtech EF Data product is warranted against defects in material and workmanship
for a period of two years from the date of shipment. During the warranty period, Comtech
EF Data will, at its option, repair or replace products that prove to be defective.
For equipment under warranty, the customer is responsible for freight to Comtech EF
Data and all related custom, taxes, tariffs, insurance, etc. Comtech EF Data is responsible
for the freight charges only for return of the equipment from the factory to the customer.
Comtech EF Data will return the equipment by the same method (i.e., Air, Express,
Surface) as the equipment was sent to Comtech EF Data.
Limitations of Warranty
The foregoing warranty shall not apply to defects resulting from improper installation or
maintenance, abuse, unauthorized modification, or operation outside of environmental
specifications for the product, or, for damages that occur due to improper repackaging of
equipment for return to Comtech EF Data.
No other warranty is expressed or implied. Comtech EF Data specifically disclaims the
implied warranties of merchantability and fitness for particular purpose.
Exclusive Remedies
The remedies provided herein are the buyer's sole and exclusive remedies. Comtech EF
Data shall not be liable for any direct, indirect, special, incidental, or consequential
damages, whether based on contract, tort, or any other legal theory.
Disclaimer
Comtech EF Data has reviewed this manual thoroughly in order that it will be an easy-touse guide to your equipment. All statements, technical information, and
recommendations in this manual and in any guides or related documents are believed
reliable, but the accuracy and completeness thereof are not guaranteed or warranted, and
they are not intended to be, nor should they be understood to be, representations or
warranties concerning the products described. Further, Comtech EF Data reserves the
right to make changes in the specifications of the products described in this manual at any
time without notice and without obligation to notify any person of such changes.
If you have any questions regarding your equipment or the information in this manual,
please contact the Comtech EF Data Customer Support Department.
xviii
Chapter 1. INTRODUCTION
The SDM-300L3 Satellite Modem is designed to meet the requirements of the Satellite
Digital Communications industry. The modem is a high performance, full duplex modem
compliant with IESS-308/309/310/315, FDC, and V.35 specifications, but also adds
significant other features in Closed Network modes. It offers variable data rates from 2.4
kbps to 5.0 Mbps, in BPSK, QPSK, Offset QPSK, and 8-PSK. Viterbi, Sequential,
concatenated Reed-Solomon (R-S), Trellis Coded Modulation (TCM), and Turbo Product
Coding (TPC) are provided as Forward Error Correction (FEC) options. EIA-232, EIA422, G.703, and V.35 (25-pin) interface types are available. The range of IF frequency
simultaneously covers 950 to 1750 MHz.
Burst Modulator Operation: 19.2 kbps and/or 57.6 kbps 1/2 rate QPSK
SDM-300L3
Satellite Modem
1–1
SDM-300L3 Satellite Modem Revision 1
Introduction MN/SDM300L3.IOM
Refer to Figure 1-1 for a system block diagram.
(Optional)
Breakout Panel
UB-530
User
Data
AUX 1
OC-TTL
Faults
Form C
Contacts
Remote
Port
Notes:
1. The UB-530 universal breakout panel (BOP) is an option for V.35, G703, EIA-232, and
2. When the modem is equipped with a 50-pin data I/O connector, the use of the BOP is
3. Contact Comtech EF Data for information concerning universal breakout panels.
AC Or
Optional
DC
Prime
Power
J8
J9
J7
J10
J6
Power
Power
Supply
Supply
AUX 1
Fault Relays
Alarm Relays
Remote Port
Data
Data
Interface
Interface
AUX 1
AUX 1
M&C
M&C
AC Only
Tx Data
Tx Clock
ST Clock
Rx Data
Rx Clock
I/Q
Sat Clock
AGC
Control / Status
Opt ODU
Opt ODU
Supply
Supply
Encoder /
Encoder /
Modulator
Modulator
Demodulator
Demodulator
/ Decoder
/ Decoder
Ref Osc
Ref Osc
Ext Ref
Tx IF
Note 1
Rx IF
Note 2
CP2
CP1
CP3
RF Equipment
Notes:
1) Tx IF (L-Band only) Outputs a 10 MHz
Reference and Optional ODU Voltage.
2) Rx IF Outputs LNB Voltage and 10 MHz
Reference.
SDM-300L Satellite Modem
Figure 1-1. Block Diagram
EIA-422.
required to interface the customer data connector to the modem.
Transmit
Transmit
RF Equipment
LNB
LNB
1–2
SDM-300L3 Satellite Modem Revision 1
Introduction MN/SDM300L3.IOM
1.1 Overview
The SDM-300L3 utilizes advanced technology and digital signal processing techniques.
This design eliminates circuitry to perform modem signal processing, resulting in higher
reliability. The following lists the unit's features:
• 2.4 kbps to 5.0 Mbps
• Fully Accessible System Topology (FAST)
• Closed Network Capability
• Automatic Uplink Power Control (AUPC)
• Asynchronous (ASYNC) Channel Unit Overhead
• Reed-Solomon
• Turbo Product Coding
• FAST Acquisition
• Built-In Test
• BPSK, QPSK, OQPSK, and 8-PSK
• BUC FSK Communications
1.2 Options Summary
A summary of the available options for the unit is provided. Contact Comtech EF Data
Customer Support for upgrade information.
Option
Single Data/Code Rate Yes FAST
Low Rate Variable
Full Rate Variable
OQPSK Yes FAST
8-PSK Requires Viterbi, Reed-Solomon
TX/RX L-Band ± 0.02 ppm
TX only, L-Band ± 0.02 ppm
RX only, L-Band ± 1.0 ppm
TX/RX L-Band ± 1.0 ppm
Sequential or Viterbi Codec Modem can be supplied with either:
TX Reed-Solomon Codec Concatenates with Viterbi Yes User
RX Reed-Solomon Codec Concatenates with Viterbi Yes User
Turbo Codec Yes User
Asymmetrical Loop Timing (SCT) Yes FAST
Asynchronous (Async/AUPC) Interface
with 50 pin D Connector
AUPC (No ASYNC) Requires Reed-Solomon cards Yes User or FAST
2xADPCM Voice (included with IBS or
IDR)
Description & Comments
≤ 512 kbps
≤ 5.0 Mbps
Codec. Overhead card required for
Open Network.
L-Band Modem with high stability
reference.
Hardware limited with high stability
reference.
Hardware limited with 1 ppm reference Yes Factory
L-Band modem with 1 ppm reference Yes Factory
Viterbi, Sequential
Requires Overhead Card. Includes
automatic uplink power control (AUPC)
Two voice channels in a 64 kbps IBS
channel. Requiring Overhead card
Availability
Yes FAST
Yes FAST
Yes User
Standard Factory
Yes Factory
Yes FAST
Yes User
Yes
Install
Option
User
1–3
SDM-300L3 Satellite Modem Revision 1
Introduction MN/SDM300L3.IOM
Option
G.703 Interface. Note, For BNC or 15 pin
D interface see UB-530 breakout panels.
G.703/ASYNC, Closed Network only BNC-F connectors and ASYNC.
37-Pin Female D Connector EIA-422/EIA-449 Interface and
25-Pin Female D Connector EIA-530 (RS-422), EIA-232 and V.35 Yes User
34-Pin Female V.35 “Winchester” Connector with V.35 Yes User
50-Pin Female D Connector for use
Overhead card.
Without
IBS Interface Requires Overhead Card Yes User
IDR Interface Requires Overhead Card Yes User
Drop & Insert Interface Requires Overhead Card Yes User
Primary Power: Auto-ranging AC 85 to 264
VAC
Primary Power: 48 VDC (Modem only, No
BUC)
ODU DC Power: 24V or 48V. Primary
input = AC Only
Description & Comments
Requires Overhead Card with 50 pin D
Connector
Requires Overhead card
Mil-188-114
Includes EIA-422, EIA-232, and V.35
Use with redundancy switches
Yes Factory
Yes Factory
100W @ 24V
150W @ 48V
Availability
Yes User
Yes User
Yes User
Yes User
Yes Factory
1.3 Comtech EF Data Part Numbers
Part No. Description Remarks
PL/9066-3 RX only IF 1.0 ppm Use with internal reference LNBs.
PL/9066-2 TX only IF 0.02 ppm Hardware limited version
PL/9066-1 TX/RX IF 0.02 ppm Full Duplex
PL/9066-5 TX/RX IF 1.0 ppm Full Duplex (No BUCs)
PL/5727-1 25-pin EIA-530 Interface
PL/6031-1 37-pin EIA-449 Interface
PL/5305-2
PL/5509-2
PL/6167-1 50-pin Interface No Overhead
PL/6032-1 34-pin Interface V.35
PL/5305-2
PL/7838-1
PL/6284 TX Reed-Solomon
PL/6285 RX Reed-Solomon
PL/9394-1 TX/RX Turbo
PL/9658-1 Duplex Reed-Solomon
PS/AC65W01P01 90-264 VAC Modem PS Modem only
PS/DC-DC5V65W -48 VDC Modem PS Modem only
KT/9567-2 90 – 264 VAC, 100W
KT/9567-3 90 – 264 VAC, 150 W
50-pin Interface With Overhead
G.703/ASYNC Interface with Overhead
BUC P/S, 24V, CE Mark
BUC P/S, 48 VDC
Hardware limited version.
Closed Network
24 VDC, 100W
AC BUC Power Supply
48 VDC 150 W
AC BUC Power Supply
Install
Option
1–4
SDM-300L3 Satellite Modem Revision 1
Hi
h
V
i
bl
D
t
M/bits)
XXXXXXX
X
Introduction MN/SDM300L3.IOM
1.4 FAST Accessible Options
Comtech EF Data FAST system allows immediate implementation of different options
through the user interface keypad. Some FAST options are available through the basic
platform unit, while others require that the unit be equipped with optional hardware or
that the hardware be installed in the field. Refer to Table 1-1 for a listing of possible
configurations.
The options available through the FAST architecture include:
ASYNC/AUPC*
•
Viterbi Decoder
•
Sequential Decoder
•
8-PSK
•
IDR *
•
Reed-Solomon*
•
2xADPCM Voice*
•
* Optional hardware required.
Asymmetrical loop timing
•
G.703 operation*
•
Variable data rates
•
IBS*
•
D&I
•
OQPSK
•
HARDWARE
Basic Platform SDM-300L3
FAST Option
FAST Option with Reed-
Solomon hardware
FAST Option with Overhead
hardware
Option withTurbo hardware
Notes:
1. The basic modem is shipped with either Sequential or Viterbi decoder.
2. Requires G.703 Interface module and Overhead card.
3. Either IBS Option or IDR option includes 2xADPCM voice in 64 kbps IBS.
4. Duplex Reed-Solomon and Turbo can be installed together, however, only one at a time can
be selected.
Table 1-1. FAST Options and Required Configurations
a
a
e
a
ar
g
Single Data Rate
X
rate (up to 4.375
Low Variable Data
rate(up to 512 k/bits)
X
(Note 1)
Sequential Decoder
X
Viterbi Decoder
(Note
1)
Asymetrical Loop
Timing
X
BUC FSK; DISEQ
OQPSK
8 PSK
Reed-Solomon
CODEC (Note 4)
ASYNC/AUPC
Overhead
X
X X X
Open Network
(IDR/IBS)
Drop and Insert
Turbo CODEC
(Note 4)
G.703 Interface
X
(Note
2)
2 x ADPCM Voice in
X (Note
3)
64 kbps
1–5
SDM-300L3 Satellite Modem Revision 1
Introduction MN/SDM300L3.IOM
1.5 Compatibility
The SDM-300L3 is functionally compatible with many Comtech EF Data modems.
When properly configured, the unit will interoperate with the following Comtech EF
Data modems:
• CDM-550/550T • SDM-650B
• CDM-600/600L
(Open Network and Turbo only)
• SDM-100/100A • SDM-8000
• SDM-300/300A
• SDM-6000
1.6 Description of the Modulator
1.6.1 Overview
The modulator provides PSK modulated carriers within the 950 to 1750 MHz range. The
types of modulation that encode the transmitted baseband data from the interface PCB
are:
• BPSK
• QPSK
• OQPSK
• 8-PSK
1.6.2 Description
The modulator is composed of eight basic subsections. These subsections are divided into
the baseband processing section and the RF section of the modulator. The modulator
controls all programmable functions on this module. Fault information from the
modulator is sent to the M&C. Refer to Chapter 9 for a list of reported faults.
The major modulator subsections are:
• Scrambler/Differential Encoder
• Convolutional Encoder
• Programmable Vector Rotation
• I/Q Nyquist Filters
• Modulator
• RF Synthesizer
• Output Amplifier
• Output Level Control
1–6
SDM-300L3 Satellite Modem Revision 1
Introduction MN/SDM300L3.IOM
If the modem is so equipped, the optional overhead or Reed-Solomon PCB first processes
the data. The data is then sent to the scrambler for energy dispersal, and then to the
differential encoder. The differential encoder is a 2-bit encoder, which allows for
resolution of two of the four ambiguity states of the QPSK or OQPSK demodulator.
The data is sent to the convolutional encoder for encoding the baseband data. The code
rates 1/2, 3/4, 7/8, and 2/3 are based on the symbol rate range of 2.4 kbps to 2.5 Mbps.
For Viterbi codes, the convolutional encoder encodes the data at 1/2 rate. If the selected
code rate is 3/4, then 2 of every 6 symbols are punctured. For 3 bits in, there are 4
symbols out.
• For Sequential codes, the convolutional encoder generates the parity bits from the
input data stream, which allows for error correction at the far end of the link. The
rate of the encoder may be 1/2, 3/4, and 7/8.
For example, the 7/8 rate puts out 8 symbols for every 7 bits in. In {O}QPSK
mode, the data is split into two separate data streams to drive the I and Q channels
of the modulator.
The baseband processing for the SDM-300L3 is the same as for the SDM-300L1 and
SDM-300A modulator except that the digital modulation is not used. Instead, the
baseband Nyquist filtered I and Q signals pass through D/A converters to drive an analog
vector modulator.
The local oscillator input to the vector modulator is a single loop synthesizer
incorporating a Direct Digital Synthesis (DDS) chip to accommodate 100 Hz steps over
the range of 950 to 1750 MHz. The modulator output then passes through amplifiers and
AGC incorporating programmable output level control and switched low pass filters for
harmonic attenuation.
1.6.3 Description of Modulation Types
The modulation types for the modem include BPSK, QPSK, OQPSK, or 8-PSK.
The PSK data transmission encoding method uses the phase modulation technique. This
method varies the phase angle of the carrier wave to represent a different bit value for the
receiver. The higher levels of modulation are required for an operating range that has a
limited bandwidth.
The order of modulation is represented by mPSK, where “m” relates to the number of
discrete phase angles. Refer to the following list for a brief description of the modulation
types.
• BPSK: 2 discrete phase angles represent the 2 possible states of a symbol.
1–7
SDM-300L3 Satellite Modem Revision 1
Introduction MN/SDM300L3.IOM
• QPSK (OQPSK): 4 discrete phase angles represent the 4 possible states of a
symbol.
• 8-PSK: 8 discrete phase angles represent the 8 possible states of a symbol.
Note: The code rate determines the number of symbols per bit.
1.6.4 BPSK Encoding
The modulator converts transmitted baseband data into a modulated BPSK carrier at
2.4 kbps to 1.25 Mbps (1/2 rate). Using vector analysis of the constellation pattern, BPSK
represents one symbol with the carrier phase either at 0° or 180°. The 1/2 rate encoding at
the convolutional encoder provides two symbols output for every bit input.
Uncoded (1/1 rate) BPSK operation also is allowed from 4.8 kbps to 2.5 Mbps.
Code Rate Symbols/Bit Bits/Hz
1/2 2 0.5
1/1 1 1
1.6.5 QPSK Encoding
The modulator converts transmitted baseband data into a modulated QPSK carrier at the
following parameters:
• 4.6 kbps to 5.0 Mbps (1/1 rate, uncoded)
• 4.8 kbps to 2.5 Mbps (1/2 rate)
• 7.2 kbps to 3.75 Mbps (3/4 rate)
• 8.4 kbps to 4.375 Mbps (7/8 rate)
Using vector analysis of the constellation pattern, QPSK represents a symbol with the
carrier phase angle at 45°, 135°, 225°, or 315°. The 1/1, 1/2, 3/4, and 7/8 rates encoded at
the convolutional encoder provide the desired input/output bit rates.
Code Rate Symbols/Bit Bits/Hz
1/1 1 2
1/2 2 1
3/4 1.33 1.5
7/8 1.143 1.75
1–8
SDM-300L3 Satellite Modem Revision 1
Introduction MN/SDM300L3.IOM
1.6.6 OQPSK Encoding
The modulator PCB converts the transmitted baseband data into a modulated OQPSK
carrier within the same parameters as QPSK.
The OQPSK modulation is mainly different from QPSK by offsetting the I and Q channel
modulation signals. This offset prevents the RF envelope from going through zero. Under
certain conditions, this may allow less back-off in the High Power Amplifier (HPA)
system. The 1/1, 1/2, 3/4, and 7/8 rates encoded at the convolutional encoder provide the
desired input/output bit rates.
Code Rate Symbols/Bit Bits/Hz
1/1 1 2
1/2 2 1
3/4 1.333 1.5
7/8 1.143 1.75
1.6.7 8-PSK Encoding
The modulator converts transmitted baseband data into modulated 8-PSK carrier at the
following parameters:
• 64 kbps to 5.000 Mbps (2/3 rate)
Using vector analysis of the constellation pattern, 8-PSK represents a symbol with carrier
phase angles at 22.5°, 67.5°, 112.5°, 157.5°, 202.5°, 247.5°, 292.5°, and 337.5°. The 2/3
rate encoding provides the desired input/output bit rates.
Code Rate Symbol/Bit Bit/s Hz
2/3 1.5 2
1–9
SDM-300L3 Satellite Modem Revision 1
Introduction MN/SDM300L3.IOM
1.7 Description of the Demodulator
A block diagram of the demodulator is shown in Figure 1-2.
1.7.1 Overview
The demodulator converts PSK modulated carriers within the 950 to 1750 MHz range to
a demodulated baseband data stream. The converted modulation types are BPSK, QPSK,
OQPSK, and 8-PSK. The demodulator then performs FEC decoding on the data stream to
produce the error corrected data output to the data interface.
LOOPBACK
L-BAND INPUT
SWITCH
L-BAND INPUT
REF
VCXO
OC XO
OPT
HIGH
STABILITY
EXT REFERENCE
AGC
REF
PLL
LPF BPF
LO #1
REFERENCE
SEQUENTIAL
DECODER
OPTIONAL
REED-SOLOMON
CODEC
OPTIONAL
OVERHEAD DEFRAMING
IBS/IDR, ASYNC/AUPC
DROP & INSERT
LO #2
VITERBI
DECODER
MUX
OPTIONAL
TURBO
CODEC
PLESIOC HRONOUS
BPF
A TO D
CONVERTER
DIGITAL
SIGNAL
PROCESSING
DIGITAL
CLOCK
RECOVERY-
LOOP
DOPPLER/
BUFFER
INTERFACE
Figure 1-2
. Demodulator Block Diagram
1–10
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