BMS-Europe GmbH CT2020, Справочное руководство

Страница: 11 / 43

Chapter 3: Options and Upgrades
Reference Guide: CT2020 Page 11
November 10
1.3 Description
General Information on D-ENG (Digital Electronic News Gathering)
The introduction of the DVB standard established the basis for digital broadcast video
transmission making efficient use of the available bandwidth. Powerful compression
algorithms allow a reduction in the amount of data to be transferred, while
maintaining the high quality standards for video and audio signals used in broad-
casting applications. New modulation techniques and error correction algorithms
ensure a secure signal transmission even when the transmission conditions are poor.
The DVB-T standard was established for terrestrial digital TV broadcasting, in
particular considering the difficult conditions of radio transmission. The highly efficient
OFDM multicarrier modulation procedure enables transmission without interference
even under multipath propagation conditions occurring with non-directional
transmission or reception. Practical experience soon has proved that the DVB-T
standard guarantees ruggedness of transmission to an extent even allowing mobile
reception.
Increasing miniaturization, in particular of MPEG encoders and OFDM modulators,
enables using the DVB-T standard for mobile portable transmission systems.
Previous analog FM systems were adversely affected by signal reflections directly
resulting in video and audio interferences. Such effects do not occur when the digital
ENG system (D-ENG) is deployed. Even mobile transmission from moving vehicles or
the use of omni-directional antennas on the transmitting or receiving side does not
impair the picture or sound quality at all, opening a completely new range of
applications in TV production and news gathering.
Video Inputs
The CT2020 accepts only HDSDI*(HD version) and SDI information at the input:
• SDI BNC(f)
OFDM (Orthogonal Frequency Division Multiplex) Modulator
The digital data signal for wireless transmission is processed by the OFDM Modulator
and following IQ Modulator. The OFDM modulation procedure has a major impact on
the transmission properties and was specifically developed for terrestrial radio
transmission.
User interface
The integrated Multifunctional Display allows easy configuration of the device. The
current Software and firmware version can also be displayed.
Linear Power Amplifier
The linear power amplifier amplifies the output signal of the Modulator to an output of
about 400 mW (+26 dBm at 2GHz, depending on frequency). The output port is
located on top of the device.