Comtech EF Data CDM-625A, Installation And Operation Manual

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D–1
Appendix D. CARRIER ID
(DVB-CID M
ETA
C
ARRIER
®
)
D.1 Overview
CDM-625A Advanced Satellite Modems incorporate a patent-pending carrier identification (CID)
technique that uses MetaCarrier® spread spectrum technology to embed a unique carrier
identification sequence for the transmitted carrier.
The CDM-625A with MetaCarrier® is used in tandem with the Comtech EF Data MCDD-100
MetaCarrier® Detection Device to provide a complete MetaCarrier embedding and decoding
solution.
Since the initial release of this technology in the CDM-625A, the European Telecommunications
Standards Institute (ETSI) has adopted a modified version of Comtech’s original scheme, which
is defined in ETSI TS 103 129 – Digital Video Broadcasting (DVB) Framing Structure, Channel
Coding and Modulation of a Carrier Identification System (DVB-CID) for Satellite Transmission.
CDM-625As running Firmware Version 1.2.1 or later fully comply with this new ETSI
specification.
D.2 About MetaCarrier
The DVB-CID (MetaCarrier) concept employs a low-speed data sequence containing identifying
information about a host carrier that is spread using Direct Sequence Spread Spectrum (DSSS),
and then combined, at a low power level, directly underneath that host carrier. The composite
signal therefore carries its own embedded identification. The power level and bandwidth of the
MetaCarrier is sufficiently low that it is completely hidden below the host carrier, and has
minimal effect on system Eb/No (approximately 0.1 dB).
DVB-CID operates independent of the modulation and Forward Error Correction (FEC) rate of
the host carrier. In configurations where the carrier is encrypted or uses cryptographic
technologies, the information carried in the DVB-CID is not affected.
Traditionally, the method for identifying an interfering carrier involves using a geo-location
system that, in turn, uses the phase offset from an adjacent satellite to triangulate the
approximate location on the surface of the earth where the interference is being generated.
While such “tried-and-true” geo-locating methods have proven beneficial to satellite operators