DTMB Modulator DMM 5000

Features

• 30 MHz to 1 GHz RF Output
• SFN and MFN support
• Near seamless switching between inputs
• Superior MER performance
• Linear and Non-Linear Digital Precorrection
• Web Browser Remote Control
• SNMP Remote Control

Overview

Designed to meet the most demanding requirements of Chinese Digital Television Broadcast Market, the DMM 5000 from UBS is ranked number one in its class. A key factor in the product success is the quality of the coding and modulation process. The modular design makes the unit highly flexible and the modulator is easily adaptable to provide the exact features required in a specific application.

Application

The performance and flexibility of the DMM 5000 allows it to excel in any application related to DMB-T modulation. The core function of the DMM 5000 is to modulate a MPEG-2 transport stream (input) onto a DMB-T/H compliant TDS-OFDM spectrum (output) in accordance with the rules for channel coding and modulation specified in the DMB-T/H standards.

RF Output

The RF Output is generated by a high performance RF converter, which covers the entire frequency range from 30 MHz to 1 GHz, in steps of just 1 Hz. The output level is adjustable between –10 to 0dBm, step 0.1dB. The user can set the polarity of the spectrum to Inverted or Non-inverted as required. With this converter the DMM 5000 will cover any spectrum application and frequency requirement that you will come across in the field of DMB-T/H.

Inputs

The DMM 5000 Modulator has two MPEG-2 inputs (ASI format). Switching between the two inputs can be done manually and automatically.

Optional Features

IF Output

The basic version of the DMM 5000 delivers the TDS-OFDM spectrum on a user defined frequency between 35 and 37 MHz. Inverted/non-inverted spectrum is selected on the front panel. The spectrum bandwidth may be user configured to 8, 7 or 6 MHz as required. The IF Output can be directly interfaced to a wide range of transmitters and frequency converters.

SFN Option

This option provides the DMM 5000 with market leading SFN performance, with respect to basic timing accuracy and extent of the local delay offset range. Also, even when the SFN option is installed, you can still select MFN mode via the front panel controls. A convenient feature when conducting pre-testing and alignment of RF parameters on transmitter installations before the timing references and transport stream with MIP are in place (as a general rule SFN modulators must mute the output if either of these signals is absent).

Digital Linear and Non-linear Pre-corrector option

This option is recommended in order to maximize the performance of the transmitter in which the modulator is installed.

• The Non-linear pre-corrector balances out gain and phase non-linearity in the transmitter RF power amplifier, thereby reducing significantly the in-band as well as out of band intermodulation generated by the amplifier. This optimization of the performance will extend the transmitters coverage area and ease the performance requirement from the transmitter output filter, used for suppressing the radiation in adjacent channels below the maximum allowed level.
• The Linear pre-corrector balances out level and group delay variations over the channel bandwidth caused by the transmitter antenna filter and/or channel combiner filters. The linear optimization of the signal radiated from the transmitter means that the channel equalizer of the DMB-T/H receiver may focus all its correction capacity on level and group delay errors originating from the actual transmission path.

The characteristics of the linear and non-linear pre-correction curves are set by means of an easy to use and highly intuitive graphical user interface, the UBS Corrector GUI software package (Windows compatible).

Web Interface option

This option allows remote control of the DMM 5000 via Ethernet (TCP/IP). The system is based on a Web server mounted inside the DMM 5000. The Web pages stored on the Web server are designed as a complete graphical user interface (GUI) for testing the status and setting the parameters of the modulator. The Web Interface concept is popular because remote control with this system only requires a standard PC with a network interface card (NIC) and a Web browser (Microsoft Explorer 6.0).

SNMP client option

This option allows remote control of the DMM 5000 in accordance with the SNMP protocol (Get, Set and SNMP traps). This remote control option is intended for systems solutions where it is desired to integrate the control of a range of SNMP compliant equipment in a common management system.