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REFURBISHED - COMTECH SDM-2020M - Digital Video Satellite Modulator
The SDM-2020 Satellite Modulator is a programmable, variable-rate satellite modulator used for digital video and high-speed data applications.
The SDM-2020 supports open network modes compliant with the EN 300 421/EN 301 210 specification for Digital Video Broadcasting (DVB) by satellite.
The SDM-2020 has a plug-in data interface module installed in the rear of the chassis.
This module provides flexible adaptation to the various physical and electrical interfaces found in the communications industry.
FEATURES
- DVB or Transparent Data Transmission
- Programmable 1.5 to 100 Mbps
- QPSK
- 8PSK and 16QAM (Optional)
APPLICATIONS
The SDM-2020 Satellite Modulator is ideal for:
- Digital Video Broadcast (DVB)
- Digital Satellite News Gathering (DSNG)
- Primary and backhaul transmission for:
- Contribution
- Distribution
- ATSC (HDTV)
- Direct To Home (DTH)
The SDM-2020 Satellite Modulator also excels in:
- High-speed data distribution
- Fiber and cable restoration
- Internet
INTERFACES
Field-changeable interfaces for the SDM-2020 Satellite Modulator include:
- EIA-422 Serial/Parallel Data Interface
- LVDS Low Voltage Differential Signal Interface
- ASI / 422 ASYNC/Serial Data Interface
- ECL-HSSI Serial Data Interface
- G.703 Data Interface
- SMPTE 310M (SSI-DVB) Serial Data Interface
- DVB ASI / LVDS
DIGITAL VIDEO BROADCAST (DVB)
The SDM-2020 Satellite Modulator supports satellite channel adaptation for DVB applications.
It translates the data stream from an MPEG-2 multiplexer to an RF satellite channel as defined by EN 300 421(QPSK) and EN 301 210 (8PSK and 16QAM):
- Randomization for energy dispersal (scrambling)
- Outer coding, Reed-Solomon EIA (204, 188, T=8)
- Convolutional interleaving (depth I=12)
- Inner coding QPSK, 1/2, 2/3, 3/4, 5/6, and 7/8 rates
- Inner coding 8PSK, 2/3, 5/6, 8/9
- Inner coding 16QAM, 3/4 and 7/8
- Spectral masks for DVB and 99% within 1.2 x symbol rate
DATA RATE FLEXIBILITY
The SDM-2020 Satellite Modulator is a data rate programmable unit.
Desired data or symbol rates are easily programmed.
MAXIMUM DATA THROUGHPUT 8PSK and 16QAM increase the data rate through a satellite transponder compared to QPSK.
The examples below are for a 36 MHz transponder:
- 8PSK 5/6: 1 carrier at 68 Mbit/s (1 modem)
- 16QAM 7/8: 2 carriers at 34.36 Mbit/s (2 modems) Similar results are available using transponders with different bandwidths.
The advanced higher order modulation of the SDM-2020 optimizes video or data applications.
POWERFUL CONCATENATED CODING
The powerful industry standard concatenated coding used by the SDM-2020 product family reduces the Eb/No needed to produce low bit error rates (BER).
This combination of inner coding (Viterbi/trellis) combined with outer Reed- Solomon coding yields unparalleled performance.
CONFIGURATION RETENTION
The SDM-2020 modulator maintains its configuration in non-volatile memory. Once power is restored, the unit returns to the configuration in use before the power loss.
Datasheet :
pdf/SDM 2020 Comtech qpsk satellite modulator.pdf
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