The most popular CMMB modulator in the world

[Bill Song@UBS]

The most popular CMMB modulator in the world

 

UBS DVU5000 CMMB modulator is the world most popular CMMB modulator

 

CMMB network is the world biggest multimedia broadcasting network. Now the network has covered more than 330 cities, there are 125 SFN networks. More than 600 transmitters are installed. More detail read the link: http://cbc.cn/English/Index.html

 

UBS company provided the more than 50% of the modulators in the networks. UBS cooperated with the most renowned transmitter manufacturer companies from China, German, Japan, USA to supply the transmitter for the project.

 

 

The most popular CMMB modulator is as below:

 

 

Modulator Features

· Direct RF output from 47 MHz to 946 MHz in 1 Hz steps
· Superior Shoulders and MER 
· SFN and MFN Support
· Adaptive Non-linear Pre-corrector
· Manual Linear and Non-linear Digital Pre-correctors
· GbE Transport Stream Input based on Pro-MPEG Forum CoP #3
· Interfaces for Web GUI, SNMP and Telnet remote control, 
   machine to machine interface and software upgrades
·CE Compliance


Modulator Supported Waveforms 

·   CMMB compliant with GY/T 220.1-2006 and 220.2-2006

 

Optional Modulator Features

· Internal GPS/GLONASS Receiver
· Integrated DVB-S/S2, DVB-T/H or ISDB-T/TB Receiver
· Adaptive Linear and Non-linear Digital Pre-correctors
· 0 dBm to 10 dBm output

Modulator Overview

The UBS Universal Modulator Series utilizes the innovative UBS Universal Waveform engine, supporting all world standards for mobile and terrestrial digital broadcasts. Using the latest technology, UBS has developed a direct conversion process that allows the Universal Modulator to provide an RF output from 47 MHz to 946 MHz with superior shoulders and MER. The Universal Modulator can be configured to support one, two or all the waveforms listed above. The user can easily switch from one waveform to another through software selection. UBS’ modulators can also be upgraded in the field as standards evolve.

This open architecture design enables carriers to take advantage of a proven, robust platform, while designing networks to meet current and future broadcast standards. This series incorporates all of UBS high performance signal processing stages including integrated linear and non-linear pre-correctors.

Full remote management and control as well as remote firmware and waveform upgrades are provided.

Modulator Application
The core function of the Universal Modulator is to modulate an input stream in accordance with the rules for channel coding and modulation defined in the specific standards for each waveform.

Modulator Signal Inputs 
The DVU 5000 is provided with two serial DVB-ASI inputs and two serial G.703/G.704 inputs. The DVB-ASI inputs accept a MPEG-2 TS, a CMMB multiplex stream or an ISDB-T/TB multiplexed TS. The G.703/G.704 inputs are used in DAB mode and accept either NA or NI signals. Optionally, two serial SMPTE-310M inputs can be installed.
The DVU 5000 can also be equipped with a GbE Transport Stream input (based on Pro-MEG CoP #3) only when a DVB-T/H or DVB-SH waveform is selected.

The DVB-ASI, G.703/G.704 and SMPTE-310M inputs can be automatically
selected, or assigned by the user. The automatic switching provides near seamless switching to a secondary transport stream in case the primary transport stream source fails (a truly valuable feature for broadcast applications.)
RF Output


Modulator RF Output Signal
The RF output covers a frequency range of 47 MHz to 946 MHz (L-Band optional) in 1 Hz steps. The output level is adjustable from -10 dBm to 0 dBm (0 dBm to 10 dBm optional), in 0.1 dB steps and the user can set the polarity of the spectrum to Inverted or Non-inverted as required.  The direct conversion process offers superior performance with Shoulder Levels = -57 dBc and MER = 50 dB.

In DAB mode, the RF output covers Band-III (channels 5A-13F). 

Modulator IF Output
Based on the selected waveform, the DVU 5000 provides an output channel on a user defined frequency between 35 MHz and 46 MHz (Optional fixed IF frequency from 5 MHz to 80 MHz).  Inverted/non-inverted spectrum is selected through the control interface.  The IF Output can be directly interfaced to a wide range of transmitters and frequency converters.

Modulator SFN Mode
This mode provides the DVU 5000 with market leading SFN performance, with respect to basic timing accuracy and extent of the  local delay offset range.  The user can select either the SFN or MFN mode via the control interfaces.  The primary reference clock is the external 10 MHz signal, which is applied to the 10 MHz input from a GPS.  If the external 10 MHz signal is missing, the system will operate synchronized to its internal 10 MHz oscillator.

Modulator Web Interface
This feature allows remote control of the DVU 5000 via Ethernet (TCP/IP).  The system is based on a Web server mounted inside the DVU 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+). 

Modulator SNMP Client 
This feature allows remote control of the DVU 5000 in accordance with the SNMP protocol (Get, Set and SNMP traps).  This remote control feature 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.

Adaptive Non-linear Pre-corrector (optional)
The Adaptive Non-linear Pre-corrector is a superior pre-distortion solution that compensates for RF Power Amplifier non-linearities including AM/AM and AM/PM distortion and protects against IMD and spectral regrowth while maximizing EVM performance.
The complex signal processing is done in the RF domain and supports a fully adaptive operation: the feedback signal (HPA output) is compared to the modulator’s RF output signal (HPA input) in order to optimize the correction which will improve the shoulders of the RF output.

Note: The Adaptive Non-linear Pre-corrector is a standard feature on the DVU 5000. The customer has the option to have this feature removed if desired.


Manual Digital Linear and Non-linear Pre-corrector
This 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 significantly reducing the in-band and out of band intermodulation products. Optimizing the 
       transmitter’s performance will extend the coverage area. The performance requirement of the transmitter 
       output filter, which is used to suppress radiation in adjacent channels below a maximum allowed level, will 
       also be eased. 

  •   The Linear Pre-corrector balances out level and group delay varia­tions that are seen across the channel   
       bandwidth and are caused by the transmitter mask filter and/or channel combiner filters. The linear 
       optimization of the transmitter’s radiated signal allows the ISDBT receiver’s channel equalizer to focus all of 
       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).

GPS Receiver (optional)
Optionally, the DVU 5000 can be equipped with an internal GPS unit. In this case, the frequency references for the modulator and upconverter are derived from the internal GPS.  The 10MHz and 1PPS connectors on the rear panel become monitoring outputs (high impedance).

Power Amplifier (optional)
Optionally, the DVU 5000 can be equipped with a 10dB amplifier installed at the output of the Upconverter.  With the amplifier installed, the RF output level can be set from 0 dBm to +10 dBm.