The MO-280 is a professional SFN/MFN DTMB modulator fully compliant with the GB20600-2006 and the GY/T 229. 1-2008 standards contained in a 19” 1U chassis. The unit has two serial ASI MPEG-2 TS inputs, one 10 MHz GPS reference input and one 1pps GPS reference input. The GPS inputs are used in combination with the Second Frame Initialization Packet (SIP) embedded in the transport streams for SFN synchronisation purposes.
In MFN mode, the MO-280 is able to work with any incoming bit rate as long as the net bit rate resulting from dropping all NULL packets present in the stream is strictly lower than the value given in the DTMB specification for the modulation parameters in use.
Two test modes are available in the MO-280 DTMB modulator, single tone output and test TS generation.
|MPEG-2 TS INPUTS|
|2xSerial ASI-TS MPEG-2 inputs|
|TS packets of length 188 or 204 bytes (automatic detection)|
|Inputs 10 MHz input and 1 pps input|
|Outputs 10 MHz output|
|IF Output 31 to 26 MHz (1 Hz steps). MER > 43 dB|
|RF Output 45 to 875 MHz (1 Hz steps). MER > 38 dB|
|Carrier mode Single, Multicarrier|
|Frame header length 420, 595, 945 symbols|
|Frame header phase Fixed, Rotating|
|FEC rates 0.4, 0.6, 0.8|
|Constellations 4QAM-NR, 4QAM, 16QAM, 32QAM, 64QAM|
|Time interleaving 240, 720|
|MFN operation Available|
|Generate to single carrier at the channel central frequency whose level equals the average DTMB output power.|
|Internal generation of test TS using PRBS sequences (length 15 / 23 embedded within NULL packets)|