Carrier for CMMB

China Multimedia Mobile Broadcasting (CMMB), a mobile television and multimedia standard developed and specified by the State Administration of Radio, Film, and Television (SARFT) in China. It is based on the satellite and terrestrial interactive multiservice infrastructure (STiMi), also developed by China. Announced in October 2006, it has been described as being similar to Europe's DVB-SH standard for digital video broadcast from satellites to handheld devices.

Multi-path Channel (not shown above) is a new parameter under 2. CMMB Settings.

1. Basic

State

Choice: On |Off

Default: On

Double-click or use the drop-down menu to control the operating state of the carrier.

Format

The format of the carrier.

Frequency Offset

Range: -40.0 to 40.0 MHz

Default: 0.000000 Hz

Set the frequency offset for the carrier relative to the signal generator’s frequency setting. The valid range will be different for every format due to the different over-sampling ratios.

For example, for 2 carriers configuration, set the center frequency of signal generator to 1 GHz, and make the two carriers distributed on the both sides of the center frequency with 5 MHz offset each. Therefore, the actual frequency of each carrier would be 1GHz+5MHz and 1GHz-5MHz respectively.

Initial Phase

Range: 0 to 359 degrees

Set the initial phase of the carrier.

Power

Range: -50 to 0 dB

Set the carrier’s power relative to the signal generator’s amplitude setting.

2. CMMB Settings

Number of Frames

Set the number of CMMB data frames.

Bandwidth

Display the bandwidth of the signal.

Region Index

Range: 0 to 127

Default: 0

There are 256 sequences in TxID sequence, among which 0~127 is region Index- it’s used for identifying the regions of the transmitter and will be transmitted in the even slots of signal frame (the slot 0, the slot 1, …)

Transmitter Index

Range: 128 to 255

Default: 128

128~255 is transmitter Identifier- it’s used for identifying different transmitters in the same region and will be transmitted in the odd slots of signal frame (the 1st slot, the slot 3, …).

Multi-path Channel

Default: OFF

Click in the right side of the cell to open the Multi-path Channel configuration window.

A multi-path channel which contains up to 20 paths can be set according to your test requirements.

3. Data Source Settings

Data Source Type

Choice: Test Pattern | Demo File | Multiplexed File | File by LICH

Default: Test Pattern

Double or use the drop-down menu to select which type to be used as the data source.

1.PLCH Settings

Index

Display the PLCH index.

Number of Slots

Range: 1 to 40

Default: 40

Set the number of timeslots.

Status

Choice: On |Off

Default: On

Reed Solomon Code Rate

Choice: RS(240, 240)|RS(240, 224)|RS(240, 192)|RS(240, 176)

Default: RS(240, 240)

LDPC Code Rate

Choice: 1/2|3/4

Default: 1/2

Interleaving

Choice: Interleaving Mode 1|Interleaving Mode 2| Interleaving Mode 3

Default: Interleaving Mode 1

Modulation Type

Choice:BPSK|QPSK|16QAM

Default: BPSK

Scramble Initial Code

Choice: 0000 0000 0001| 0000 1001 0011| 0000 0100 1100| 0010 1011 0011| 0111 0100 0100|1000 0101 1100| 0001 0110 1101| 1010 1001 0011

Default: 0000 0000 0001

Scramble code is a binary system sequence used for data randomizing. For scramble initial code, it has 8 different available options.

2. Data Source Settings

Pattern Bits

The data bits used as test pattern.

Click the button on the right side to open the "Data Pattern Selection" dialog and select test pattern to use.