QAM256 Digital Video Modulator and Cable Upconverter
The Comtech Radyne DVB-compliant QAM256 Modulator meets all DVB
requirements for transmission of digital video on broadband
coaxial cable and microwave radio. The QAM256 features
4-QAM to 256-QAM modulation, 1 to 52 Mbps data rate, 1 to
8 MHz channel spacing and Reed-Solomon forward error
correction. The modulator also supports field-changeable
RS-422 Parallel, ASI and other standard DVB interfaces.
Remote Monitor and Control (M&C) Interface is provided
through either a RS-485 or Ethernet Remote Port using
The QAM256 provides efficient bandwidth utilization for
digital video distribution systems.
MMDS, LMDS, AML, Cable Television and Multiple Dwelling
Unit systems all benefit from this innovative modulator.
QAM modulation solves the problem of providing multiple
video and data channels within bandwidth limitations. The
QAM256 has the versatility to adapt to the terrestrial
broadband medium and give system operators full
management and control of the available bandwidth.
The space and money-saving internal cable upconverter
option conveniently removes the need for an external
The modulator meets the specifications of the ITU-T
Recommendation; J.83 Annex A & B (Telecommunication
Standardization of the ITU for Television and Sound
The Interface Module is a field-changeable module that
contains either RS-422 Parallel, ASI or other standard
interface. The interface accepts data in an MPEG-2
transport format. The data is then passed to the channel
encoder for processing.
The Channel Encoder synchronizes to the MPEG-2
transport frame and performs scrambling (energy dispersal),
and Reed-Solomon encoding (240, 188) and interleaving.
Specifications Without Cable Upconverter
1 to 52 Mbps
4, 16, 32, 64, 128, 256-QAM
(7 Msps Maximum)
12, 15, and 18% Selectable
With I = 1 - 204 Programmable
Forney Convolutional Interleaver
Meets J.83 Annex A, Annex B