Appendix A - Datum Systems

Appendix A - Datum Systems
DATUM
SYSTEMS
Preliminary Appendix A
Datum Systems PSM-500 Satellite Modem
Technical Specification
PSM-500, 500H and 500L VSAT / SCPC - Modem Specification
Revision History
Rev 0.8
7-10-2007 Preliminary Release.
Rev 0.85
1-10-2008 Preliminary Release added new performance statistics.
Rev 0.86
4-6-2008 Added new 8QAM performance statistics.
Introduction
This document defines the technical performance parameters and requirements for a low-cost
flexible, state-of-the-art VSAT/SCPC Satellite Modem. The PSM-500 Modem series is designed to
meet the needs of general purpose applications including those as a remote station VSAT modem
and as a Single Channel Per Carrier (SCPC) modem where both outgoing and incoming RF data is
continuous. Many of the capabilities of this modem series are largly determined by firmware in
FPGAs, and are expected to evolve in the future with added functions.
The PSM-500 series includes three basic types defined by their IF frequencies: The standard 70
MHz IF, a special order variation of the standard that uses a 140 MHz IF, and a full L-Band
version. A fourth “Hybrid” IF version with 70 MHz transmit IF and L-Band Receive IF may be
produced if demand is sufficient. The IF minimum and maximum settings are shown in Table 1
below. All versions are settable in 1 Hz increments via the front panel or remote control interfaces.
Table 1 - PSM-500 Series IF Interface Versions.
Interface
Versions
IF Transmit
IF Receive
PSM-500S
50 ~ 90 MHz
50 ~ 90 MHz
PSM-500N
100 ~ 180 MHz
100 ~ 180 MHz
PSM-500L
950 ~ 1750 MHz
950 ~ 1900 MHz
PSM-500H**
50 ~ 90 MHz
950 ~ 1900 MHz
** Note: The Hybrid version production is dependent on demand.
The IF interface is fixed in a particular modem by the design and manufacturing. It is not possible
to change the IF interface in a modem either by hardware or software changes.
Any of the PSM-500 IF versions is also available in one of 3 “Feature Sets” versions consisting of
Modulation modes and maximum data rates designed to meet the needs of specific applications.
The modulation modes and minimum and maximum data rates in each mode are shown below,
followed by specific limitations of specific FEC options.
Feature Sets are field software upgradable. Options are field hardware upgradable.
A-1
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
Table 2 - PSM-500 Series Feature and Option Matrix.
Feature
Modulation
BPSK
QPSK
OQPSK
8PSK/8QAM*
16QAM/APSK*
M505
PSM-500S/N/L Series
M511
M523
a"
a"
a"
Upgrade !
Upgrade !
a"
a"
a"
a"
Upgrade !
a"
a"
a"
a"
a"
Max Data Rate
BPSK
QPSK/OQPSK
8PSK/8QAM*
16QAM/APSK*
2.5 Mbps
5 Mbps
N/A
N/A
5 Mbps
10 Mbps
10 Mbps
N/A
7.38 Mbps
28.04 Mbps
29.52 Mbps
29.52 Mbps
The tables below show the data rate limits depending on specific hardware and user selected
operating modes. Rate ½ includes rate 0.453 and 21/44. Rate 0.9x includes 0.922 and 0.95.
The modem maximul symbol rate is 14.76 Mega Samples Per Second.
Table 3 – Maximum Data Rates vs. Modulation and Code Rates-Mbps
Modulation
BPSK
QPSK/OQPSK
8PSK/8QAM*
16QAM/APSK*
5/16
4.61
1/2+
7.38
14.76
3/5
8.86
17.71
29.52
29.52
2/3
29.52
29.52
3/4
11.07
22.14
29.52
29.52
4/5
11.81
23.62
29.52
29.52
5/6
12.3
24.6
29.52
29.52
7/8
12.92
25.83
29.52
29.52
0.9x
14.02
28.04
29.52
29.52
Table 4 – Maximum Data Rates vs. FEC Type and Code Rates-Mbps
FEC Type
Viterbi
TCM
TPC-4K
TPC-16k
S-Tec - Std
S-Tec – HS
5/16
1/2+
29.52
4.61
4.61
5
29.52
10
20
3/5
2/3
3/4
29.52
4/5
5/6
29.52
7/8
29.52
0.9x
5
29.52
10
20
5
29.52
10
20
5
29.52
10
20
5
29.52
10
20
5
29.52
10
20
29.52
10
20
Table 5 – Minimum Data Rates vs. Modulation and Code Rates-kbps.
5/16 1/2+
3/5
2/3
3/4
4/5
5/6
7/8
Modulation
1.2
1.2
1.2
N/A
2.4
2.4
BPSK
2.4
2.4
7.20
8.0
8.0
8.4
QPSK/OQPSK
4.8
9.6
4.8
9.6
9.6
9.6
8PSK/8QAM*
4.8
19.2
19.2
19.2
19.2
16QAM/APSK*
* 8QAM only operates in TPC FEC Modes. 16APSK operating mode not yet available.
0.9x
2.4
8.4
9.6
19.2
*** Interface Maximum Data Rates ***
The built-in synchronous serial interface selectable for RS-449, V.35, IEA530 and variants is
limited to 10 Mbps by cables and available DTE devices. The RS-232 is limited to 128 kbps.
The optional SnIP and HSSI interfaces will operate up to 29.52 Mbps if other selections permit.
A-2
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
Table 6 shows the currently available standard and optional FEC types and code rates. Note that
this table changes frequently. The latest version can be seen on the web site.
Table 6 – FEC, Modulation and Code Rates.
PSM-500 Series FEC Option Table Rev. 1.6 Firmware 0.72+
Sel Code Sel
FEC Type
#
Rates
#
R-S
Modulation Modes (see notes)
Option
(O) Available (C) Option
Sel
FEC #
Type (T)
BPSK QPSK OQPSK 8PSK 8QAM 16APSK 16QAM
0
1
2
3
4
5
6
None
0 N/A
Viterbi 1
TCM
2
TPC
4
0
N/A
0
Normal
0
Swap C0/C1
1
CT
2
1/2
3/4
5/6
7/8
1/2
3/4
5/6
7/8
3/4
7/8
0
1
2
3
0
1
2
3
1
3
"
"
"
"
"
"
"
"
"$
"$
2/3
0
"
0
Advanced
M5 Full
*TPC4k Only
M5 Short
*TPC4k Only
M5 Legacy
CT
*TPC16k only
0 0.453-16k
1/2-16k
1/2-4k
3/4-16k
3/4-4k
7/8-16k
7/8-4k
0.922-16k
0.950-4k
1
1/2
3/4
7/8
2
3/4
7/8
3
3/4
7/8
4
5/16
21/44
3/4
7/8
0.95
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A-3
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
Sel
FEC #
Type (T)
VSAT/SCPC Modem Specification
PSM-500 Series FEC Option Table Rev. 1.6 Firmware 0.72+
Sel Code Sel
FEC Type
#
Rates
#
R-S
Modulation Modes (see notes)
Option
(O) Available (C) Option
BPSK QPSK OQPSK 8PSK 8QAM 16APSK 16QAM
0
1
2
3
4
5
6
S-Tec 6
Any
Interleaver
Block Size
Option 0~4
0
1/2
3/5
3/4
4/5
5/6
7/8
0
1
2
3
4
"
"
"
"
"
"
"
"
"
"
"
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"
"
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"
"
"
"
"
"
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"
"
Notes: 8QAM requires modem firmware version 0.72 and later. 8QAM with the S-Tec FEC is not
implemented yet.
16APSK modes not implemented yet, and will have added options available.
* TPC4k and TPC16 restrictions apply to that line and Code Rate only.
TPC4k M5 Mode Limits: Rate 1/2 = 2.46 Mbps, Rate 3/4 or 7/8 = 4.92 Mbps.
TPC4k CT Mode Limits: Rate 5/16 = 2.048 Mbps, Rate 21/44 = 3.2 Mbps, Rate 3/4 = 5 Mbps,
Rate 0.95 = 6.6 Mbps.
The Modulation Modes, FEC Types, Option and Code Rates plus Reed-Solomon selection form a
number completely defining that FEC Mode. The acronym for these 5 numbers is “MTOCR”.
Table 7 below shows the Spectral Efficiency of the above FEC modes in bits per Hz of occupied
bandwidth at the 3 dB occupied bandwidth point.
Table 7 – Spectral Efficiency vs. Modulation and FEC Code Rates.
Modulation
BPSK
QPSK OQPSK
8PSK 8QAM
16QAM/16APSK
Bits/Sym !
1
2
3
4
Efficiency in Bits/Hz at 3 dB Bandwidth
FEC Code Rate
0.3125
0.625**
0.9375**
1.25**
5/16
0.453
0.906
1.359
1.812
0.453
0.477
0.95
1.43 **
1.91**
21/44
0.50
1.00
1.50
2.00
1/2
0.60
1.20
1.80
2.40
3/5
0.66
1.33
2.00
2.66
2/3
0.75
1.50
2.25
3.00
3/4
0.80
1.60
2.40
3.20
4/5
0.833
1.667
2.50
3.333
5/6
0.875
1.75
2.625
3.50
7/8
0.922
1.844
2.766
3.688
0.922
0.95
1.90
2.85
3.80
0.95
** These modes not available in any setting
Each of these FEC Types can operate up to the maximum 20 Mbps, except TPC-4K is limited to 5
Mbps and S-Tec Standard is limited to approximately 10 Mbps at all rates. The S-Tec High speed
version is capable of 20 Mbps or more in all modes.
The possible FEC operating modes has exploded in recent years because of the variety of
available and common FECs in use. The PSM-500 Series has many current modes and additional
ones in development. Below is a table showing the currently available modes depending on
modulation.
A-4
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
The basic modem design includes separate synthesized transmit and receive interfaces, flexible
clocking options and on-board Viterbi Forward Error Correction (FEC). The on-board standard data
interface is programmable for either RS-449, V.35, V.36, EIA-530/A or synchronous RS-232, while
a separate Serial Control Port allows external monitor and control of all variable functions and
parameters from either a terminal device or control computer. Front panel control and display
allows full operation of the unit without external devices.
The modem includes an internal microprocessor for controlling all transmit and receive functions
and user display control. The processor also accepts commands from and responds to the Serial
Control Port. The processor stores its current configuration in non-volatile memory for proper
power-up recovery of the last state. The incorporation of an embedded processor allows intelligent
modem features such as smart reacquisition of a lost carrier, real Eb/No and BER display and full
interactive monitor and control of the modem. This control can be translated to a PC running
terminal emulation software for full screen terminal display.
A second internal Digital Signal Processor, or DSP, gives the modem acquisition capabilities
significantly faster than a standard modem at lower data rates. It does this by mathematically
determining the location of a carrier based upon sampled, digitized data input.
The modem design incorporates a unique combination of reliability, cost and flexibility. The design
uses large scale proprietary ASIC/FPGA devices to reduce the complexity and cost to a minimum
while providing full flexibility. The modulation and demodulation is accomplished directly at the IF
frequency without heterodyning, eliminating all adjustments.
Modulator Specifications
IF Output
Output Frequency Range: Standard & Hybrid. 50.000 to 90.000 MHz. (100 to 180 MHz Optional)
L-Band ................... 950 to 1750 MHz
Tuning Method: ................................................ Via internal synthesizer.
Output Level Control: ....................................... Programmable in 0.1 dB steps over 40 dB from
.......................................................... +5 to -35 dBm, +3 dBm max at 50Ω standard unit
Output Level Accuracy/Stability: ...................... ± 0.5 dB over 0 - 50°C @ any level or frequency
.......................................................... ± 0.25 dB over any 10°C range.
Output Impedance:
Standard..................... Programmable 50 or 75Ω.
L-Band ....................... 50Ω.
Output Return Loss: Standard & Hybrid ........ 20 dB minimum
L-Band .......................... 10 dB minimum, 14 dB typical
Output Burst Control: ....................................... Contact factory for burst definition and capability.
Output Burst Off Isolation................................. >60 dB
Modulation Technique:..................................... BPSK, QPSK, OQPSK, 8PSK, 8QAM or 16QAM Selectable.
Spectral Density:.............................................. The modulated band shall be -3 dB at the
.......................................................... Nyquist frequency of the symbol rate, then
.......................................................... approximating an n=8 Butterworth filter
.......................................................... response.
Spurious Output:
Standard & Hybrid ......... < -50 dBc from 2 to 200 MHz.
L-Band .......................... < -50 dBc from 400 MHz to 5000 MHz
Harmonic Output:
Standard & Hybrid ......... < -50 dBc.
L-Band .......................... < -50 dBc up to –10 dBm out, -40 dBc at +5 dBm.
Phase Balance:................................................ < 1 degree.
Transmit Synthesizer
Tuning Step Size:............................................. 1 Hz steps.
A-5
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
Standard & Hybrid........ ± 2.0 ppm. (176 Hz max) internal reference
L-Band .......................... ± 0.01 ppm (1 E-8). (17.5 Hz max) internal
reference
.......................................................... OR locked to external reference’s stability.
L-Band Note: ................................... The internal 10 MHz OCXO reference can be
.......................................................... used to phase lock an external BUC.
Standard & Hybrid ......... ±1 ppm per year using internal reference.
L-Band .......................... ± 0.2 ppm per year using internal reference
Frequency Stability:
Aging:
Phase Noise:
Standard & Hybrid ......... <-87dBc @1kHz.
.......................................................... <-93dBc @10kHz.
.......................................................... <-108dBc @100kHz.
L-Band .......................... Better than IESS-308/309 by 4 dB min, 6 dB typical
Synthesizer Control:......................................... Via Front Panel and serial control port.
Transition Time: ............................................... < 100 msec. to any frequency including
.......................................................... command latency.
Transmit Baseband Processing
Data Rate: ........................................................ Variable under program control and dependent on
.......................................................... Feature Set, FEC selected and interface type.
.......................................................... See Tables 2 to 5 above.
Note: Maximum rates are limited using Reed-Solomon and IBS Multiplexer Options.
Settability ........................................................ Any rate settable to 1 bps increments. Accurate
.......................................................... to 2 PPT at rate 1/2, or 4 PPT, rate 3/4 or 7/8,
.......................................................... relative to either internal (nominally 2.0 ppm) or
.......................................................... external reference clock as selected.
Data Clock Tracking Range ............................ External or Terminal Timing = +/-400 ppm.
.......................................................... Reverts to internal clock outside this range.
Data Rate Clock Sources ................................ a. Internal.
.......................................................... b. Terminal Timing input on data connector
.......................................................... c. External input on data connector.
.......................................................... d. Receive Clock recovered from demodulator.
Forward Error Correction: ............................ See Table 6 above for current modes and rates.
Viterbi ............................................... Convolutional encoder, k= 7.
.......................................................... Rate 1/2. G0 code = 171 octal,
.......................................................... ............ G1 code = 133 octal.
.......................................................... Rate 3/4, 5/6 or 7/8 using punctured code
Trellis Code Modulation (TCM): ....... Rate 2/3 in 8PSK only, may use R-S.
Standard Reed-Solomon Concatenated Codec:
Available in Viterbi or TCM.
R-S Rates ..................... Disabled, IESS-308, IESS-309, IESS-310,
CT220-200 and custom.
Optional Turbo Product Codes and S-Tec Codecs Available.
Differential Encoding:....................................... Selectable On or Off @ Front Panel and
.......................................................... via serial control port.
Scrambler:........................................................ IESS-308 or 309, Intelsat and V.35 selectable with
.......................................................... enable @ Front Panel and via serial control port.
.......................................................... IBS and Reed-Solomon specific modes are available
.......................................................... when these options are enabled/installed.
A-6
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
Demodulator Specifications
IF Input
Input Frequency Range Standard:................... 50.000 to 90.000 MHz. (100 to 180 MHz Optional)
Hybrid & L-Band): ......... 950.000 to 1900.000 MHz
Tuning Method: ................................................ Via internal synthesizer.
Input Carrier Level: .......................................... -20 to -84 dBm total. 40dB range window shifts
.......................................................... .with the data rate. Lower levels at lower rates.
Acquisition/Tracking Range: ............................ ± 100 Hz and ± 1.25 MHz in 1 Hz increments.
Smart reacquisition: ......................................... In “Search” mode the demodulator will search
.......................................................... for return of a lost carrier within a specified
.......................................................... range for a selected time before reverting to full
.......................................................... acquisition range.
Reacquisition range:......................... ± 100 Hz and ± 1.25 MHz in 1 Hz increments
Reacquisition sweep time: ............... 0.1 to 6000 seconds in 0.1 second increments.
Input Impedance:
Standard........................ Programmable 50 or 75Ω.
Hybrid & L-Band ........... 75Ω.
Input Return Loss: Standard ........................ 20 dB. (17 dB with 140 MHz IF option.)
Hybrid & L-Band ........... 10 dB minimum, 14 dB typical.
Modulation Technique:..................................... BPSK, QPSK, OQPSK, 8PSK, 8QAM or 16QAM Selectable.
Type of demodulation: ..................................... Continuous Coherent.
Receive Synthesizer
Tuning Step Size:............................................. 1 Hz steps.
Frequency Stability: Standard & Hybrid........ ± 2.0 ppm. (176 Hz max) internal reference
L-Band .......................... ± 0.1 ppm. (175 Hz max) internal reference
.......................................................... OR locked to external reference’s stability.
L-Band Note: ................................... The internal 10 MHz OCXO reference can be
.......................................................... used to phase lock an external LNB.
Synthesizer Control:......................................... Front Panel and via the Serial Control port.
Receive Baseband Processing
Data Rate: ........................................................ Variable under program control and dependent on
.......................................................... Feature Set, FEC selected and interface type.
.......................................................... See Tables 2 to 5 above.
Note: Maximum rates are limited using Reed-Solomon and IBS Multiplexer Options.
Settability ........................................................ Any rate settable in 1 bit per second increments.
Data Clock Tracking Range ............................ > +/-400 ppm.
Data Rate Change Settling Time: .................... < 100 mSeconds.
Baseband Filter:............................................... Digital, n=6 Butterworth filter response.
Forward Error Correction: ............................ See Table 6 above for current modes and rates.
Viterbi ............................................... Convolutional encoder, k= 7.
.......................................................... Rate 1/2. G0 code = 171 octal,
.......................................................... ............ G1 code = 133 octal.
.......................................................... Rate 3/4, 5/6 or 7/8 using punctured code
Trellis Code Modulation (TCM): ....... Rate 2/3 in 8PSK only, may use R-S.
Standard Reed-Solomon Concatenated Codec:
Available in Viterbi or TCM.
R-S Rates ..................... Disabled, IESS-308, IESS-309, IESS-310,
CT220-200 and custom.
Optional Turbo Product Codes and S-Tec Codecs Available.
A-7
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
BER vs. Eb/No Performance: .......................... 0.2 dB typical over theoretical.
.......................................................... 0.4 dB maximum. See performance curves below.
Differential Decoding:....................................... Selectable On or Off.
Descrambler:.................................................... IESS 308 or 309, Intelsat and V.35 selectable with
.......................................................... enable @ Front Panel and via serial control port.
.......................................................... IBS, Reed-Solomon and TPC specific modes are
.......................................................... available when these options are enabled/installed.
Receive Data FIFO Buffering........................... 4 bits to 524,280 bits, programmable in 1 bit
Plesiochronous or Doppler .......................... increments or in time increments. The buffer is a
Elastic Store ................................................. 1048,560 bit (maximum) self centering FIFO. Over
.......................................................... or under-flow result in re-centering. When set to even
.......................................................... multiples of the number of frame bits the re-centering
.......................................................... minimizes frame disruption.
Buffer Output Clock Options ............................ a. Receive Clock (disables buffer)
.......................................................... b. Modulator Clock
.......................................................... c. Internal Clock. Same rate as receive data rate clock
.......................................................... setting, but accurate to 2 PPT at rate 1/2, or 4 PPT,
.......................................................... rate 3/4 or 7/8, relative to either internal or external
.......................................................... reference clock as selected.
.......................................................... d. External Clock, input on data interface.
L-Band Internal OCXO Reference Specifications – PSM-500L only
Frequency: ....................................................... 10 MHz
Stability and Aging: .......................................... ±1 x 10-8, ±2 x 10-7 per year
Phase Noise:.................................................... -110 dBc @ 10 Hz
.......................................................... -130 dBc @ 100 Hz
.......................................................... -140 dBc @ 1 kHz
.......................................................... -150 dBc @ 10 kHz
.......................................................... -155 dBc @ 100 kHz
A-8
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
Bit Error Rate Performance
The following tables and their associated “waterfall” curves show typical Bit Error Rate vs. Eb/No
performance for a modem including the effect of using differential encoding and the appropriate
scrambler.
The values shown are typical, but are extremely repeatable since the entire transmit and receive
processes that affect the performance are digitally produced.
The volume of measurements required plus the significant data that must be collected to
characterize the low error rates achievable by Turbo Product Codes and S-Tec FECs are difficult
and time consuming. Therefore all of these measurements are made by carefully calibrated and
temperature controlled test equipment under computer control. Single measurements of a BER in
the 10-9 range may require several days.
Although the tables show Eb/No values at fixed logarithmic BER increments for easy reading, the
graphs are created from the actual measurment points. That data and the graph program (GPL
open source) used are available from Datum Systems.
The tabular data contains a 5 digit number above each column of Eb/No data. This number is
called “MTOCR”. It is a short nemonic acronym for Modulation, FEC Type, Option, Code Rate and
Reed-Solomon selection options. To set the modem for any particular combination of MTOCR you
would first select the modulation type (by the number if desired), then the Type, Option and Code
Rate for the FEC and then the Reed-Solomon option. The M, T, O and C values for all currently
available FEC modes are shown in Table 6.
The Eb/No values shown are those referenced to the customer data rate at the decoder output.
Performance would appear improved if measured relative to the decoder input (i.e. at the satellite
data rate).
Note that the performance is subject to change. We periodically have improved the performance of
multiple options via software revisions.
Viterbi FEC and Concatenated Reed-Solomon Performance
The standard Viterbi FEC plus the Viterbi concatenated with Reed-Solomon performance is shown
in the following table and the accompanying graph.
The typical performance with the optional Reed-Solomon codec (concatenated on the Viterbi
codec) is shown in the table below. All values shown are using the standard IESS-308 ReedSolomon codec values of n = 126, k=112, depth =4, and the synchronous IESS-308
scrambler/descrambler. Significant changes in performance, positive and negative, are achieved
using different n, k and depth values.
A-9
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
Viterbi FEC Performance for BPSK, QPSK and OQPSK with and without Reed-Solomon
Required Eb/No in dB dB - Typical
Rate -->
Rate 1/2
Rate 3/4
Rate 5/6
Rate 7/8
RS Opt--> None 1
2
5 None 1
2
5 None 1
2
5 None 1
2
5
BER
11000 11001 11002 11005 11010 11011 11012 11015 11020 11021 11022 11025 11030 11031 11032 11035
1.00E-03 3.09 2.33 2.36 2.28 3.94 3.36 3.39 3.33 4.49 4.01 4.03 3.97 4.90 4.44 4.52 4.66
1.00E-04 3.84 2.52 2.53 2.46 4.70 3.57 3.58 3.52 5.25 4.23 4.22 4.18 5.62 4.73 4.73 4.68
1.00E-05 4.52 2.67 2.67 2.60 5.40 3.75 3.74 3.68 5.98 4.43 4.41 4.35 6.32 4.94 4.91 4.86
1.00E-06 5.12 2.82 2.80 2.73 6.04 3.91 3.89 3.82 6.66 4.60 4.57 4.50 7.01 5.14 5.10 5.03
1.00E-07 5.66 2.95 2.92 2.84 6.65 4.06 4.03 3.96 7.27 4.78 4.73 4.66 7.66 5.33 5.26 5.20
1.00E-08 6.20 3.08 3.04 2.95 7.19 4.20 4.16 4.08 7.82 4.95 4.89 4.80 8.22 5.52 5.43 5.35
1.00E-09 6.65 3.22 3.14 3.05 7.66 4.35 4.28 4.19 8.35 5.12 5.07 4.94 8.78 5.70 5.61 5.49
Waterfall curves for the common Viterbi FEC at various Code Rates for BPSK, QPSK, OQPSK
modulation modes are shown in the graphs below.
DATUM
BER
Datum Systems M500 Modem Performance
11000 - Vit, Rate 1/2
Viterbi BPSK/QPSK/OQPSK
SYSTEMS
11005 - Vit Rate 1/2, RS - 5
0.1
11010 - Vit Rate 3/4
11015 - Vit Rate 3/4, RS 5
11020 - Vit Rate 5/6
11025 - Vit Rate 5/6, RS 5
0.01
11030 - Vit Rate 7/8
11035 - Vit Rate 7/8, RS 5
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
Eb/No
1E-10
0.5
A-10
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
10.5
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
16QAM Modulation Viterbi FEC Performance
Waterfall curves for the common Viterbi FEC at the available Code Rates for 16QAM modulation
modes are shown in the graphs below. TPC 16QAM performance is shown with the TPC FEC data
later.
Viterbi FEC Performance for 16QAM with and without Reed-Solomon
Required Eb/No in dB dB - Typical
Rate -->
1/2
3/4
5/6
7/8
RS Opt-->
None
4
None
4
CT-5 None
4
None
4
CT-5
BER
61000 61004 61010 61014 61215 61020 61024 61030 61034 61235
1.00E-03 5.65
5.13
7.24
6.68
6.60
7.92
7.49
8.46
7.96
1.00E-04 6.38
5.38
8.08
6.93
6.79
8.74
7.75
9.24
8.18
1.00E-05 7.02
5.57
8.89
7.15
6.95
9.51
8.00 10.01
8.40
1.00E-06 7.65
5.70
9.62
7.35
7.12 10.23 8.23 10.72
8.60
1.00E-07 8.23
5.84 10.28 7.54
7.26 10.92 8.45 11.33
8.79
1.00E-08 8.75
5.97 10.87 7.72
7.39 11.53 12.15 11.98
8.96
1.00E-09 9.24
6.11 11.47 7.91
7.53 12.02 20.67 12.54
9.13
Datum Systems M500 Modem Performance
DATUM
BER
0.1
61000 - Vit 16QAM, Rate 1/2
Viterbi 16QAM
SYSTEMS
61004 - Vit 16QAM, Rate 1/2, RS 4
61010 - Vit 16QAM, Rate 3/4
61015 - Vit 16QAM, Rate 3/4, RS 5
61020 - Vit 16QAM, Rate 5/6
61025 - Vit 16QAM, Rate 5/6, RS 5
0.01
61030 - Vit 16QAM, Rate 7/8
61035 - Vit 16QAM, Rate 7/8, RS 5
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
Eb/No
1E-10
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
10.5
11
11.5
12
12.5
A-11
13
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
8PSK Trellis Code Modulation Performance
The Trellis Code Modulation (TCM) codec is designed for and used only with 8PSK modulation. It
is not possible to operate TCM at any data rate other than 2/3 or in any modulation mode other
than 8PSK. Typical performance of TCM rate 2/3 in 8PSK with and without concatenated ReedSolomon is shown in the table below. All values shown are using the synchronous IESS-308
scrambler/descrambler. Significant changes in performance, positive and negative, are achieved
using different n, k and depth values.
8PSK TCM FEC Performance for 8PSK
Required Eb/No in dB dB - Typical
2/3 with R-S, 2/3 with R-S,
Rate -->
2/3
IESS-310
CT 220,200
BER
32000
32003
32005
5.36
4.72
4.81
1.00E-03
6.26
4.90
5.03
1.00E-04
7.19
5.05
5.23
1.00E-05
8.04
5.18
5.37
1.00E-06
8.75
5.30
5.54
1.00E-07
9.40
5.41
5.68
1.00E-08
5.55
5.83
1.00E-09 10.05
Datum Systems M500 Modem Performance
BER
DATUM
32000 - T CM 8PSK, Rate 2/3
TCM 8PSK
SYSTEMS
0.1
32003 - T CM 8PSK, Rate 2/3, RS 3
32005 - T CM 8PSK, Rate 2/3, RS 5
0.01
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
Eb/No
1E-10
2
A-12
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
10.5
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
Turbo Product Codes Performance
The typical performance with the optional Turbo Product Codes FEC is shown in the tables below.
The Eb/No values shown are those referenced to the customer data rate at the decoder output.
Performance would appear improved if measured relative to the decoder input (i.e. at the satellite
data rate). All values shown are using the synchronous TPC scrambler.
TPC M5 Compatible Modes
Turbo Product Codes FEC M5 Full Mode Typical
Performance Data
Rate ½
Rate ¾
Rate 7/8
MTOCR
14100
14110
14120
BER
Eb/No
Eb/No
Eb/No
10-4
2.20
3.00
4.80
10-5
-6
2.50
3.23
5.12
10
2.80
3.50
5.50
10-7
3.09
3.84
5.88
10-8
3.40
4.15
6.31
10-9
3.70
4.50
6.80
10-10
Turbo Product Codes FEC M5 Short Block Mode
Typical Performance Data
Rate ½
Rate ¾
Rate 7/8
MTOCR
14200
14210
14220
BER
Eb/No
Eb/No
Eb/No
10-4
3.90
5.20
10-5
4.07
5.58
10-6
4.30
6.00
10-7
4.56
6.47
10-8
4.87
6.91
10-9
5.20
7.30
10-10
Turbo Product Codes FEC M5 Legacy Mode
Typical Performance Data
Rate ½
Rate ¾
Rate 7/8
MTOCR
14300
14310
14320
BER
Eb/No
Eb/No
Eb/No
10-4
3.2 dB
4.6 dB
10-5
3.3 dB
4.7 dB
10-6
3.5 dB
4.8 dB
10-7
3.6 dB
5.0 dB
10-8
3.7 dB
5.3 dB
10-9
-10
3.9 dB
5.5 dB
10
A-13
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
TPC M5 Compatible Modes Waterfall Curves
Note: M5 Legacy mode not shown
Datum Systems M500 Modem Performance
BER
DATUM
14100 - T PC M5 Full - QPSK - Rate 1/2
SYSTEMS
0.1
14110 - T PC M5 Full - QPSK - Rate 3/4
M5 Compatible TPC Modes
14120 - T PC M5 Full - QPSK - Rate 7/8
14210 - T PC M5 Short- QPSK - Rate 3/4
14220 - T PC M5 Short- QPSK - Rate 7/8
0.01
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
1E-10
Eb/No
1E-11 1.5
A-14
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
10.5
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
TPC Advanced Performance Mode
The TPC Advanced FEC option is a new TPC implementation proprietary to Datum Systems.
These specific modes were optimized for optimized performance covering a broad range of system
needs. They will typically outperform any TPC modes by any modem manufacturer.
TPC-Advanced BPSK/QPSK Performance
Rate -->
BER
1.00E-03
1.00E-04
1.00E-05
1.00E-06
1.00E-07
1.00E-08
1.00E-09
TPC Advanced FEC Performance for BPSK, QPSK and OQPSK
Required Eb/No in dB - Typical
0.453-16k 1/2-16k 1/2-4k 3/4-16k 3/4-4k 7/8-16k 7/8-4k 0.922-16k 0.95-4k
14000
14010
14020
14030
14040
14050 14060
14070
14080
1.44
1.90
1.82
2.54
2.89
3.62
3.83
4.47
5.02
1.51
2.01
1.97
2.61
3.06
3.72
4.02
4.60
5.30
1.58
2.08
2.09
2.67
3.20
3.80
4.18
4.70
5.52
1.63
2.15
2.20
2.72
3.32
3.87
4.31
4.77
5.75
1.68
2.22
2.38
2.76
3.43
3.93
4.44
4.84
6.10
1.73
2.27
2.72
2.81
3.52
3.98
4.56
4.91
6.59
1.78
2.32
3.12
2.85
3.62
4.04
4.68
4.97
7.10
Datum Systems M500 Modem Performance
DATUM
BER
14000 - T PC Adv Rate 0.453-16k
SYSTEMS
14010 - T PC Adv Rate 1/2-16k
TPC Advanced QPSK
0.1
14020 - T PC Adv Rate 1/2-4k
14030 - T PC Adv Rate 3/4-16k
14040 - T PC Adv Rate 3/4-4k
14050 - T PC Adv Rate 7/8-16k
14060 - T PC Adv Rate 7/8-4k
0.01
14070 - T PC Adv Rate 0.922-16k
14080 - T PC Adv Rate 0.950-4k
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
Eb/No
1E-10
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
A-15
10.5
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
TPC-Advanced 8PSK Performance
TPC Advanced FEC Performance for 8PSK
Required Eb/No in dB dB - Typical
3/4-16k 3/4-4k 7/8-16k 7/8-4k 0.922-16k 0.95-4k
34030
34040
34050
34060
34070
34080
4.85
5.31
6.40
6.59
7.38
8.00
4.94
5.52
6.51
6.82
7.52
8.32
5.01
5.68
6.59
7.00
7.63
8.58
5.08
5.82
6.66
7.14
7.72
8.90
5.13
5.96
6.74
7.28
7.80
9.33
5.19
6.08
6.81
7.46
7.87
9.86
5.25
6.19
6.88
7.73
7.94
10.36
Rate -->
BER
1.00E-03
1.00E-04
1.00E-05
1.00E-06
1.00E-07
1.00E-08
1.00E-09
BER
Datum Systems M500 Modem Performance
DATUM
34030 - T PC Adv 8PSK, Rate 3/4-16k
TPC Advanced 8PSK
SYSTEMS
34040 - T PC Adv 8PSK, Rate 3/4-4k
0.1
34050 - T PC Adv 8PSK, Rate 7/8-16k
34060 - T PC Adv 8PSK, Rate 7/8-4k
34070 - T PC Adv 8PSK, Rate 0.922-16k
34080 - T PC Adv 8PSK, Rate 0.95-4k
0.01
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
Eb/No
1E-10
2
A-16
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
10.5
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
TPC-Advanced 8QAM Performance
TPC Advanced FEC Performance for 8QAM
Required Eb/No in dB dB - Typical
Rate --> 0.453-16k 1/2-16k 1/2-4k 3/4-16k 3/4-4k 7/8-16k 7/8-4k 0.922-16k 0.95-4k
BER
44000
44010
44020
44030
44040
44050 44060
44070
44080
1.00E-03
3.24
3.79
3.53
4.50
4.92
5.66
6.00
6.66
7.17
1.00E-04
3.32
3.91
3.69
4.58
5.11
5.77
6.24
6.81
7.56
1.00E-05
3.39
4.01
3.82
4.65
5.27
5.86
6.43
6.92
7.96
1.00E-06
3.45
4.09
3.97
4.70
5.41
5.93
6.61
7.03
8.46
1.00E-07
3.51
4.15
4.20
4.75
5.53
6.00
6.77
7.13
8.99
1.00E-08
3.56
4.22
4.59
4.80
5.67
6.06
6.99
7.22
9.50
1.00E-09
3.62
4.29
4.98
4.85
5.82
6.11
7.27
7.30
10.00
Datum Systems M500 Modem Performance
BER
44000 - T PC Adv 8QAM Rate 0.453-16k
DATUM
0.1
44010 - T PC Adv 8QAM Rate 1/2-16k
TPC Advanced 8QAM
SYSTEMS
44020 - T PC Adv 8QAM Rate 1/2-4k
44030 - T PC Adv 8QAM Rate 3/4-16k
44040 - T PC Adv 8QAM Rate 3/4-4k
44050 - T PC Adv 8QAM Rate 7/8-16k
44060 - T PC Adv 8QAM Rate 7/8-4k
0.01
44070 - T PC Adv 18QAM, Rate 0.922-16k
44080 - T PC Adv 8QAM, Rate 0.95-4k
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
1E-10
Eb/No
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
A-17
10.5
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
TPC-Advanced 16QAM Performance
TPC Advanced FEC Performance for 16QAM
Required Eb/No in dB dB - Typical
Rate --> 0.453-16k 1/2-16k 1/2-4k 3/4-16k 3/4-4k 7/8-16k 7/8-4k 0.922-16k 0.95-4k
BER
64000
64010
64020
64030
64040
64050 64060
64070
64080
1.00E-03
4.28
4.57
4.63
5.64
6.19
7.10
7.23
8.02
8.63
1.00E-04
4.40
4.69
4.84
5.73
6.40
7.22
7.46
8.17
8.94
1.00E-05
4.49
4.80
5.08
5.81
6.56
7.31
7.63
8.27
9.23
1.00E-06
4.58
4.88
5.46
5.88
6.71
7.39
7.78
8.36
9.53
1.00E-07
4.75
4.96
5.86
5.93
6.84
7.46
7.95
8.44
9.94
1.00E-08
4.98
5.06
6.22
5.98
6.96
7.52
8.09
8.51
10.41
1.00E-09
5.15
5.16
6.59
6.04
7.07
7.58
8.23
8.59
10.86
Datum Systems M500 Modem Performance
BER
DATUM
64000 - T PC Adv 16QAM, Rate 0.453-16k
TPC Advanced 16QAM
64010 - T PC Adv 16QAM, Rate 1/2-16k
SYSTEMS
64020 - T PC Adv 16QAM, Rate 1/2-4k
0.1
64030 - T PC Adv 16QAM, Rate 3/4-16k
64040 - T PC Adv 16QAM, Rate 3/4-4k
64050 - T PC Adv 16QAM, Rate 7/8-16k
64060 - T PC Adv 16QAM, Rate 7/8-4k
0.01
64070 - T PC Adv 16QAM, Rate 0.922-16k
64080 - T PC Adv 16QAM, Rate 0.95-4k
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
Eb/No
1E-10
2
A-18
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
10.5
11
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
TPC-CT BPSK/QPSK Performance
TPC CT FEC Performance for BPSK, QPSK and OQPSK
Required Eb/No in dB dB - Typical
BPSK
Rate -->
5/16
21/44
3/4
7/8
0.95
BER
04400
14410
14420
14430
14440
1.00E-03 1.39
1.69
2.70
3.56
4.97
1.00E-04 1.56
1.89
2.89
3.65
5.25
1.00E-05 1.72
2.13
3.05
3.72
5.50
1.00E-06 1.94
2.45
3.24
3.78
5.78
1.00E-07 2.22
2.79
3.49
3.84
6.16
1.00E-08 2.48
3.07
3.84
3.92
6.63
1.00E-09 2.71
3.34
4.17
4.00
7.12
Datum Systems M500 Modem Performance
DATUM
BER
SYSTEMS
0.1
14410 - T PC-CT , QPSK, Rate 21/44
TPC-CT QPSK
14420 - T PC-CT , QPSK, Rate 3/4
14430 - T PC-CT QPSK, Rate 7/8-16k
14440 - T PC-CT , QPSK, Rate 0.95
0.01
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
Eb/No
1E-10
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
A-19
10.5
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
TPC-CT 8PSK Performance
TPC CT FEC Performance for 8PSK
Required Eb/No in dB dB - Typical
Rate -->
3/4
7/8
0.95
BER
34420
34430
34440
1.00E-03 5.06
6.33
8.01
1.00E-04 5.27
6.44
8.33
1.00E-05 5.45
6.52
8.60
1.00E-06 5.64
6.59
8.88
1.00E-07 6.01
6.67
9.35
1.00E-08 6.43
6.75
9.81
1.00E-09 6.87
6.85
10.27
BER
Datum Systems M500 Modem Performance
DATUM
34420 - T PC-CT , 8PSK, Rate 3/4
TPC-CT 8PSK
SYSTEMS
34430 - T PC-CT 8PSK, Rate 7/8-16k
0.1
34440 - T PC-CT , 8PSK, Rate 0.95
0.01
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
Eb/No
1E-10
2
A-20
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
10.5
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
TPC-CT 8QAM Performance
TPC CT FEC Performance for 8QAM
Required Eb/No in dB dB - Typical
Rate -->
3/4
7/8
0.95
BER
44420
44430
44440
1.00E-03 4.70
5.60
7.18
1.00E-04 4.92
5.71
7.57
1.00E-05 5.10
5.79
7.96
1.00E-06 5.36
5.87
8.46
1.00E-07 5.72
5.96
9.01
1.00E-08 6.19
6.22
9.55
1.00E-09 6.60
6.53
10.07
Datum Systems M500 Modem Performance
BER
44420 - T PC-CT 8QAM, Rate 3/4
DATUM
44430 - T PC-CT 8QAM, Rate 7/8-16k
SYSTEMS
0.1
TPC-CT 8QAM
44440 - T PC-CT 8QAM, Rate 0.95
0.01
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
1E-10
Eb/No
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
A-21
10.5
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
TPC-CT 16QAM Performance
TPC CT FEC Performance for 16QAM
Required Eb/No in dB dB - Typical
Rate -->
3/4
7/8
0.95
BER
64420
64430
64440
1.00E-03 5.98
7.04
8.64
1.00E-04 6.20
7.15
8.96
1.00E-05 6.42
7.24
9.26
1.00E-06 6.69
7.31
9.59
1.00E-07 7.04
7.40
10.01
1.00E-08 7.42
7.52
10.52
1.00E-09 7.80
7.70
11.05
BER
Datum Systems M500 Modem Performance
DATUM
64420 - T PC-CT 16QAM, Rate 3/4
TPC-CT 16QAM
SYSTEMS
64430 - T PC-CT 16QAM, Rate 7/8-16k
0.1
64440 - T PC-CT 16QAM, Rate 0.95
0.01
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
Eb/No
1E-10
2
A-22
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
10.5
11
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
S-Tec Turbo Convolutional Codes Performance
The typical performance with the optional S-Tec FEC is shown in the tables below. The Eb/No
values shown are those referenced to the customer data rate at the decoder output. Performance
would appear improved if measured relative to the decoder input (i.e. at the satellite data rate). All
values shown are using the synchronous TPC scrambler/descrambler and version 0.63 or greater
modem firmware.
Code
Rate
1/2
2/3
3/4
4/5
5/6
7/8
S-Tec TCT FEC Typical Performance Data for 10-10 BER
BPSK
QPSK
8PSK
16QAM
Bits/Hz
Eb/No
Bits/Hz
Eb/No
Bits/Hz
Eb/No
Bits/Hz
Eb/No
0.50
0.67
0.75
0.80
0.83
0.90
1.60 dB
2.30 dB
2.90 dB
3.50 dB
4.00 dB
- dB
1.00
1.33
1.50
1.60
1.67
1.80
1.60 dB
2.30 dB
2.90 dB
3.50 dB
4.00 dB
- dB
1.50
2.00
2.25
2.40
2.50
2.63
3.30 dB
4.20 dB
5.60 dB
6.20 dB
7.00 dB
- dB
2.00
2.67
3.00
3.20
3.33
3.50
4.20 dB
5.30 dB
6.30 dB
7.00 dB
7.60 dB
- dB
A-23
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
S-Tec Large Block QPSK/BPSK Performance
S-Tec FEC Performance for BPSK, QPSK and OQPSK
Required Eb/No in dB dB - Typical
Rate -->
1/2
3/5
3/4
4/5
5/6
BER
16000
16010
16020
16030
16040
2.10
2.60
3.10
3.60
1.00E-02 1.40
1.00E-03
1.00E-04
1.00E-05
1.00E-06 1.44
1.00E-07 1.48
1.00E-08 1.52
1.00E-09 1.56
2.30
2.90
3.50
4.00
1.00E-10 1.60
BER
Datum Systems M500 Modem Performance
DATUM
16000 - S-T ec LB QPSK Rate 1/2
S-Tec TCC FEC - Large Block - QPSK
SYSTEMS
16010 - S-T ec LB QPSK Rate 3/5
0.1
16020 - S-T ec LB QPSK Rate 3/4
16030 - S-T ec LB QPSK Rate 4/5
16040 - S-T ec LB QPSK Rate 5/6
0.01
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
1E-10
Eb/No
1E-11
1
A-24
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
10.5
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
S-Tec Large Block 8PSK Performance
S-Tec FEC Performance for 8PSK
Required Eb/No in dB dB - Typical
Rate -->
1/2
3/5
3/4
4/5
BER
36000
36010
36020
36030
3.90
5.10
5.80
1.00E-02 3.00
1.00E-03
1.00E-04
1.00E-05
1.00E-06
1.00E-07
1.00E-08
1.00E-09
4.20
5.60
6.20
1.00E-10 3.30
BER
5/6
36040
6.50
7.00
Datum Systems M500 Modem Performance
DATUM
36000 - S-T ec LB 8PSK Rate 1/2
SYSTEMS
36010 - S-T ec LB 8PSK Rate 3/5
S-Tec TCC FEC - Large Block - 8PSK
0.1
36020 - S-T ec LB 8PSK Rate 3/4
36030 - S-T ec LB 8PSK Rate 4/5
36040 - S-T ec LB 8PSK Rate 5/6
0.01
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
1E-10
Eb/No
1E-11
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
A-25
10.5
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
S-Tec Large Block 16QAM Performance
S-Tec FEC Performance for 16QAM
Required Eb/No in dB dB - Typical
Rate -->
1/2
3/5
3/4
4/5
BER
66000
66010
66020
66030
5.10
5.90
6.60
1.00E-02 4.00
1.00E-03
1.00E-04
1.00E-05
1.00E-06
1.00E-07
1.00E-08
1.00E-09
5.30
6.30
7.00
1.00E-10 4.20
BER
5/6
66040
7.20
7.60
Datum Systems M500 Modem Performance
DATUM
66000 - S-T ec LB 16QAM Rate 1/2
SYSTEMS
66010 - S-T ec LB 16QAM Rate 3/5
0.1
66020 - S-T ec LB 16QAM Rate 3/4
S-Tec TCC FEC - Large Block - 16QAM
66030 - S-T ec LB 16QAM Rate 4/5
66040 - S-T ec LB 16QAM Rate 5/6
0.01
0.001
0.0001
1E-5
1E-6
1E-7
1E-8
1E-9
1E-10
Eb/No
1E-11
1
A-26
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
10.5
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
Acquisition Performance
The following table shows typical acquisition performance for the Fast Acquisition mode using the
standard Viterbi FEC and the DSP acquisition processor. The times shown are for the average and
95% of acquisition probability at a 6.0 dB Eb/No. These times are measured over 1000
acquisitions.
Bit Rate
in kbps
Modulation
2.4
2.4
9.6
9.6
16
16
32
32
64
64
QPSK
BPSK
QPSK
BPSK
QPSK
BPSK
QPSK
BPSK
QPSK
BPSK
Fast Acquisition Timing
FEC Rate
Typical Average
Fast Acquisition
Time for ±30 KHz
(seconds)
Vit 1/2
1.230
Vit 1/2
0.750
Vit 1/2
0.315
Vit 1/2
0.174
Vit 1/2
0.196
Vit 1/2
0.144
Vit 1/2
0.116
Vit 1/2
0.097
Vit 1/2
0.071
Vit 1/2
0.050
8PSK
TCM 2/3
16QAM
Vit 1/2
Typical 95%
Probability Fast
Acquisition Time for
±30 KHz (seconds)
1.453
0.819
0.371
0.183
0.231
0.163
0.135
0.110
0.082
0.057
Fast acquistion performance is optimized in Viterbi FEC rate ½. When changing to rate ¾ or 7/8
the penalty is approximately 3.5 to 4 times the acquisition time. This is due to the decreased
symbol rate and the FEC and acquisition processors having to deal with twice the number of
ambiguities in determining signal type and lock. Acquisition times with the Turbo Product Codes
FEC are 2 to 4 times that of the Viterbi FEC. Fast acquisition is optimized under normal noise
conditions, where the absence of noise adds time for AGC operation.
A-27
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
Data Interface Specifications
Data Input
Type:
.......................................................... Synchronous, Programmable for RS-449/422,
.......................................................... V.35, V.36, EIA-530, EIA-530A or Synchronous
.......................................................... RS-232 with separate Clock and Data signals.
.......................................................... G.703, Ethernet and others optional via
.......................................................... option interface assembly.
.......................................................... Flexible clock options allow the transmit timing
.......................................................... to be supplied by:
.......................................................... a. An internally generated ± 2 ppm reference
.......................................................... clock or external reference, if supplied.
.......................................................... b. The demodulator RCV clock as recovered
..........................................................
from the receive carrier.
.......................................................... c. A Terminal Timing input as supplied to the
.......................................................... modem TT interface pins.
.......................................................... d. A Separate Send Timing input as supplied to
.......................................................... the modem Ext. Timing interface pins.
Termination: ..................................................... Per applicable interface specification.
.......................................................... Termination can be removed in RS-449 mode.
Data Output
Type:
.......................................................... Synchronous, Programmable for RS-449/422,
.......................................................... V.35, V.36, EIA-530, EIA-530A or Synchronous
.......................................................... RS-232 with separate Clock and Data signals.
.......................................................... G.703, Ethernet and others optional via an
.......................................................... option interface assembly.
.......................................................... Additional clock options allow the demodulator
.......................................................... RCV clock to be supplied by:
.......................................................... a. The actual received bit rate.
.......................................................... b. The modulator transmit clock source.
.......................................................... c. An internally generated timing clock source.
.......................................................... d. A user supplied FIFO output clock source.
.......................................................... Using b, c or d enables the receive FIFO buffer.
Modem Bit Delays
Modulator Transmit Delays
Modulation Processing ..................... 1 user rate bits.
Viterbi FEC Encoder:
Rate ½ .......................................... 12 channel rate bits.
Rate ¾ .......................................... 15 channel rate bits.
Rate 7/8 ........................................ 17 channel rate bits.
Reed-Solomon Encoder ................... (8·k)+10 user/IBS output rate bits
.......................................................... + fixed 500 us delay.
A-28
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
TPC FEC Full Encoder:
Rate ½ .......................................... 1094 user rate bits.
Rate ¾ .......................................... 573 channel rate bits.
Rate 7/8 ........................................ 482 channel rate bits.
TPC FEC Short Encoder:
Rate ¾ .......................................... 208 channel rate bits.
Rate 7/8 ........................................ 164 channel rate bits.
IBS Multiplexer: ................................ 12 user rate bits.
Demodulator Receive Delays
Demodulation Processing ................ 1 user rate bits.
Viterbi FEC Decoder
Rate ½ .......................................... 184 channel rate bits.
Rate ¾ .......................................... 186 to 188 channel rate bits.
Rate 7/8 ........................................ 186 to 190 channel rate bits.
TPC FEC Full Decoder:
Rate ½ .......................................... 2025 user rate bits + fixed 751 uS delay.
Rate ¾ .......................................... 2196 channel rate bits + fixed 446 uS delay.
Rate 7/8 ........................................ 3593 channel rate bits + fixed 447 uS delay.
TPC FEC Short Decoder:
Rate ¾ .......................................... 729 channel rate bits + fixed 218 uS delay.
Rate 7/8 ........................................ 1087 channel rate bits + fixed 290 uS delay.
FIFO Buffer (enabled) ...................... 3 user rate bits plus bit setting.
Reed-Solomon Decoder depth = 4: 32·k+(24·k·(4·D-n))/n+11 User/IBS Demux
.......................................................... Input Rate Bits + Fixed 500us Delay
.......................................................... where D is the smallest integer >=(n-1)/4
depth = 8: .. 64·k+(24·k·(4·D-n))/n+11 User/IBS Demux Input
.......................................................... Rate Bits + Fixed 500us Delay
.......................................................... where D is the smallest integer >=(n-1)/8
IBS Multiplexer ................................. 4 user rate bits.
Bit Rate definition:
"User" bit rate = "Terrestrial" interface rate.
“Channel” bit rate is the Convolotional Encoder Input Data Rate for the Modulator.
“Channel” bit rate is the Viterbi Decoder Output Data Rate for the Demodulator.
"Channel" bit rate = User bit rate X (1/Mux rate) (if mux enabled) X (1/RS rate) (if RS enabled).
Delay Examples:
Reed-Solomon Example 1, if n=126, k=112 and Depth=4 then
Total R-S Encoder Delay=906 User/IBS Mux Output Bits + Fixed 500us Delay
D=32, Total R-S Decoder Delay=3,638 User/IBS Demux Input Bits + Fixed 500us Delay
Reed-Solomon Example 2, if n=201, k=219 and Depth=4 then
Total R-S Encoder Delay=1,618 User/IBS Mux Output Bits + Fixed 500us Delay
D=55, The Total R-S Decoder Delay=6,465 User/IBS Demux Bits + Fixed 500us Delay
Reed-Solomon Example 3, if n=205, k=225 and Depth=4 then
Total R-S Encoder Delay=1,650 User/IBS Mux Output Bits + Fixed 500us Delay
D=56, The Total R-S Decoder Delay=6,549 User/IBS Demux Bits + Fixed 500us Delay
A-29
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
Link Calculation Example:
A modem with R-S and IBS mux is running at a user rate of 128 kbps with rate ½
FEC and no buffer. The Reed-Solomon is set as example 1 above: The IBS multiplexer is set
to 2400 bps ESC Overhead and 300 bps MCC Overhead yielding a Mux ratio of 29/30.
The channel bit rate is then = 128 kbps X 9/8 X 30/29 = 148.9655 kbps. (Note 9/8 is n/k.)
The time/channel bit is 6.7 uS. The time/user bit is 7.8 uS.
The modulator delay is 13 channel rate bits x 6.7 uS plus 906 user rate bits x 7.8 uS
plus 500 uS, for a total delay of 7,653.9 uS or 7.65 mS.
The demodulator delay is 185 channel rate bits x 6.7 uS plus 3638 user rate bits x 7.8 uS
plus 500 uS, for a total delay of 30,115.9 uS or 30.116 mS.
The total end to end delay is then 37.766 mS plus the approximate 250 mS for the path delay.
A-30
Datum Systems PSM-500, 500H & 500L
VSAT/SCPC Modem Specification
Rev. 0.86
Alarm, Monitor and Control Signals
All monitor and control functions are controllable via the front panel and the remote RS-232/RS485 serial control port.
During station setup and normal operation the modem can output either the AGC, receive Eb/No or
transmit power level to the rear panel via a digital to analog converter.
Alarm:
Summary:......................................................... Two summary form-C dry contact alarms, each
.......................................................... represents the OR'd condition of individually
.......................................................... programmed on-board fault sensors.
Indicator .......................................................... Front panel LED indicator.
Timing .......................................................... Alarm activated by any fault condition with 1/2
.......................................................... second hold before removal.
Monitor
AGC Level........................................................ Front Panel and via Remote Control port.
Carrier Lock ..................................................... Green LED on internal PWB.
Demodulator Lock:........................................... Front panel LED indicator.
Transmit Bit Rate Synthesizer Fault: ............... Internal LED indicator.
Transmit RF Synthesizer Fault: ....................... Internal LED indicator.
Receive RF Synthesizer Fault: ........................ Internal LED indicator.
Eb/No:............................................... Front Panel and via Remote Control.
Operating LED indicators................................. 12 Front Panel LED indicators:
Unit
Power ............................................... Green - Lit when power applied
Summary Alarm................................ Red - if summary fault condition
Local ................................................. Green - Unit set to accept local (front panel)
.......................................................... commands.
Remote ............................................. Green - Unit set to accept remote commands.
Modulator
Transmit On...................................... Green - Lit when transmit output is on.
.......................................................... Green Flashing – Indicates carrier off, but
.......................................................... internal carrier on only for loop-back test.
Major Alarm ...................................... Red - Indicates transmit traffic is lost.
Minor Alarm ...................................... Yellow - Warning - Indicates a marginal
.......................................................... condition.
Test Mode ........................................ Yellow Flashing - Modulator currently in test
.......................................................... mode.
Demodulator
Lock .................................................. Green - Indicates RCV lock to incoming CXR.
Major Alarm ...................................... Red - Indicates receive traffic is lost.
Minor Alarm ...................................... Yellow - Warning - Indicates a marginal
.......................................................... condition.
Test Mode ........................................ Yellow Flashing - Demodulator currently in test
.......................................................... mode.
Control
All parameters are controllable from either the front panel or via the remote control interface.
Information and control access to the on-board processor is provided by an asynchronous serial
A-31
Datum Systems PSM-500, 500H & 500L
Rev. 0.86
VSAT/SCPC Modem Specification
interface. The interface is selectable as either RS-232 three line interface (transmit, receive and
ground) or RS-485 interface to a 4 wire bus with 3 state transmit operation. The modem address
and operating mode is settable via the front panel or from terminal mode. The serial command
mode control interface only responds to commands from its associated controller when properly
addressed.
Refer to the associated "Remote Command Interface Specification" for details of the serial link
command structure, protocol and available commands.
General Unit Specifications
Mechanical
IF connection type:........................................... 75Ω BNC female connectors, 1 XMT, 1 RCV
.......................................................... Located on Rear Panel
Reference Input: .............................................. 50Ω BNC female located on Rear Panel.
Data and Digital I/O connector :....................... 37 pin female D type rear panel connector.
Controller Interface: ......................................... 9 pin "D" type female for RS-485 and RS-232
.......................................................... interface located on Rear Panel.
Alarm Interface:................................................ 9 pin “D” type male with 2 form C contacts.
.......................................................... interface located on Rear Panel.
Auxiliary Interface ............................................ 37 pin male D type rear panel connector.
Power Connector: ............................................ IEC 3-pin male with switch located on rear
.......................................................... panel.
Main Board Size:.............................................. Approximately 9.5 x 11 X 1.2 inches.
Option Interface Board Size:............................ Approximately 3.5 x 7 X 1.5 inches.
Packaged Modem Size: .................................. 1 Rack Mounting Spaces by 12 inches deep.
.......................................................... Approximately 19.0 x 12 X 1.75 inches.
Electrical Power Requirements
Prime Power:.................................................... 90 to 260 Vac, 47-63 Hz, 50 Watts maximum
70/140 MHz Unit typical ................... Less than 25 Watts.
L-Band Unit typical ........................... Less than 30 Watts exclusive of BUC power.
Internal Voltages: ............................................. +5 Volts DC ± 5% at 1.5 Amp max.
.......................................................... +12 Volts DC ± 5% at 0.8 Amps max.
.......................................................... -12 Volts DC ± 5% at 0.3 Amp max.
Note: Options may increase internal current draw.
Environmental
Operating: ........................................................ -10 to +50°C, to 95% humidity, non-condensing.
Non-Operating: ................................................ -20 to +70°C, to 99% humidity, non-condensing.
Burst Mode Operation
A standard modulator burst mode has not been implemented in the PSM-500 modem yet. This is
because of the lack of a standard or available burst demodulators. The circuitry is capable of
perfoming this function based on a burst specification. Please contact Datum Systems for specifics
of implementing this function and available burst protocols.
A-32
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