Integrated Microwave Technologies LLC. 25VST 사용자 설명서
VST
X
User Manual
Revision
2.
3
20
2.1.2 Power and Control Interface Connector
The VSTx Power and Control Interface includes power and ground connections plus two RS-232 serial
port interfaces. One of the RS-232 interfaces can be connected to a laptop or other PC to program the
transmitter configuration. The second RS-232 interface can be used to transmit user data through the
transmitter along with the audio and video streams.
port interfaces. One of the RS-232 interfaces can be connected to a laptop or other PC to program the
transmitter configuration. The second RS-232 interface can be used to transmit user data through the
transmitter along with the audio and video streams.
2.1.3 Audio and Video Input Connectors
This VST
X
model has two analog audio inputs that can be used for stereo audio and one NTSC or PAL
composite video input. Refer to Chapter 3 for specifications of these signals.
2.1.4 User Data Input
User Data is available on the ribbon version only. In the “ribbon” version aA
data channel may be
transmitted along with the audio and video information. The data channel is accessed through a
separate RS-232 serial interface
separate RS-232 serial interface
on the ribbon connectorin the Power/Control connector
.
2.1.5 MPEG4 Encoder
The VST
X
compresses the input video signal before modulation and transmission to reduce bandwidth.
The VST
X
contains a built-in MPEG4 (H.264) compliant encoder for this purpose. The VSTx features
the latest compression methods utilizing B frames for more accurate encoding of compressed video
signals.
signals.
2.1.6 Encryption
The transmitter supports BCRYPT1 and BCRYPT2. BCRYPT2 is very similar to BCRYPT1 with
improvements made to support re-multiplexing. Both encryption modes support AES 128 and AES256
key lengths.
improvements made to support re-multiplexing. Both encryption modes support AES 128 and AES256
key lengths.
MPEG4
Encoder
COFDM
Modulator
AES Encryption
RF Output
Figure 2-3 - Encryption Circuit
2.1.7 COFDM Modulator
The COFDM modulator receives data from the output of the MPEG4 encoder through a circuit that
enhances the security of transmissions.
The VST
enhances the security of transmissions.
The VST
X
is able to transmit data at high data rates and with low error rates using COFDM
modulation techniques. The data rate used by the transmitter depends upon the CODFM modulator
settings used.
Refer to Chapter 5, “Operation” for more information.
settings used.
Refer to Chapter 5, “Operation” for more information.