Vislink Strata RX, Техническое справочное руководство

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B
Glossary B-1
Strata RX
Operator’s Guide/Tech Ref Manual
Glossary
This section describes acronyms and abbreviations used in
communications, broadcasting, and in Vislink Products and
documentation.
Table B-1: Useful Terms
Term Explanation
16QAM 16-state Quadrature Amplitude Modulation
The signal (video+audio) is imposed onto the 70 MHz
carrier by varying both the phase and the amplitude
of the signal while keeping the frequency constant.
There are 16 possible combinations of phase and
amplitude that can be used to carry information.
3RU 3 Rack Unit height.
4FSK 4-state Frequency Shift Keying
64QAM 64-state Quadrature Amplitude Modulation
The signal (video+audio) is imposed onto the 70 MHz
carrier by varying both the phase and the amplitude
of the signal while keeping the frequency constant.
There are 64 possible combinations of phase and
amplitude that can be used to carry information.
A & C Alarm and Control.
ADPCM Adaptive Differential Pulse Code Modulation.
AES Audio Engineering Society.
AES/EBU Unofficial name for a digital audio standard
developed as a joint enterprise of the AES and the
EBU.
AFC Automatic Frequency Control.
AGC Automatic Gain Control.
AIS Alarm Indication Signal (all one’s).
AMI Alternate Mark Inversion, line code format for traffic
data.
AVG Average.
ASI Asynchronous Serial Interface
A serial communications interface operating at
270 Mbit/sec., generally used in field news-gathering
operations.
B8ZS Bipolar 8 Zero Substitution, line code format for traffic
data.
Baseband A composite signal in which video and audio signals
are combined together, with video occupying
approximately 0-4.5 MHz and audio modulated onto
subcarriers in the 5-6MHz range. Also called
Composite.
BB Baseband.
BER Bit Error Ratio. The ratio of bits containing errors to
the total number of bits in the signal, over a time
period.
BiasT A type of interconnection between the IDU and the
ODU. In Bias T wiring, IF and DC are combined and
carried on the coax cable up the ODU; blocking
circuitry prevents the DC from entering the IDU.
BISS Basic Interoperable Scrambling System
A means of encrypting and decrypting a digital signal
to prevent unauthorized reception. The encryption
and decryption are controlled by a digital key, which
is shared at both the transmitting and receiving
location.
Table B-1: Useful Terms (Continued)