User Manual Part 2

8
Theory of Operation 8-1MTX5000 User and Technical Manual
Theory of Operation
8.1 Chapter Overview
This chapter provides additional details about the design and
function of the MTX5000 Transmitter System (MTX5000). This
chapter is intended to complement information contained in the
“Product Description” Chapter on page 2-1.
The descriptions in this chapter assume you are already familiar
with the information contained in Chapter 2. We recommend you
review that chapter before beginning to read this one.
Here are the topics covered:
8.2 System Architecture
8.2.1 General
The MTX5000 is a van-mounted, High Definition (HD) ready,
Topic Page
System Architecture 8-1
General 8-1
Architecture 8-1
MPEG Encoding and COFDM Transmission 8-2
Analog Video Encoding and FM Modulation 8-2
MTX5000 User Interface 8-2
ODU RF Output 8-3
MTX5000 Internal Software 8-3
Outdoor Unit Details 8-5
video transmission system capable of both analog and digital
operation in different formats. The MTX5000 system provides a
sophisticated user interface with an intuitive keypad scheme,
touch screen, and an adjustable color LCD display. The
MTX5000 system consists of the MTX5000 Indoor Unit (IDU)
and the mast-mounted Outdoor Unit(s) (ODU).
A fully equipped MTX5000 package is HD ready and provides a
robust HD link from field to studio. Several digital video input
formats are accepted, as well as analog composite for Digital
Video Broadcasting - Terrestrial (DVB-T) and analog FM
transmission. In addition, the MTX5000 can accept several
digital audio input formats and up to four analog audio inputs for
analog or digital transmission.
The MTX5000 has several mast-mounted ODU configurations
available. These ODUs contain integrated RF up conversion
circuitry and high power RF amplifiers for maximum power and
signal quality. With the demands of digital modulation, the ODUs
have been optimized for improved Modulation Error Ratio/Error
Vector Magnitude (MER/EVM) performance with digital
transmissions.
8.2.2 Architecture
The MTX5000 system consists of the IDU and the ODU(s). The
IDU is responsible for video encoding, modulation, system
control, and power distribution. The ODU contains RF up
conversion circuitry and a power amplifier.
The ODU is mounted at the top of the van mast and is
responsible for all aspects of the RF transmission. Modulated
signals are passed from the IDU to the ODU using a 70MHz IF
signal. In addition, the IDU and ODU communicate through a
bidirectional Frequency-Shift Keying (FSK) modem. This FSK
link allows the IDU to control, calibrate, and monitor the state of
the mast-mounted ODU.