Description
This mini DVB QAM Modulator is a modular, digital headend Component designed for use in minimized rack space. The modulator will accept a MPEG2 transport stream input in the SPI format and provide a QAM output at the IF frequency of 44mhz.The output format will be 16,32,64,128, 256, 512 or 1024 QAM mode. The FEC encoding is DVB compliant as this model will be for DVB market only.The DVB QAM modulator willoperate in either of the two clock modes:
a.) Fixed Mode :
In this mode, the clock rate will be set up by using front panel keys to output a symbol rate required.
If input rate is less then the setup value, null packets will be added by the modulator.
b.) Auto Mode
In this mode, the modulator will lock, automatically, to the incoming bit rates and provide an output rate
set by the input stream.The QAM IF signal will, then, be looped and converted to the channel required with a Mini Agile Channel Processor. Specifications
| INPUT |
| • |
Format |
DVB SPI |
| • |
Connector |
DB25, Female |
| • |
Levels |
LVDS |
| |
| OUTPUT |
| • |
Output IF Frequency |
44Mhz |
| • |
Output level |
30dBmV |
| • |
Output Impedance |
75ohms |
| • |
Spurious |
-55dBC |
| |
| MODULATION |
| • |
Mode |
16,32,64,128,256,512,1024 QAM |
| • |
Excess Bandwidth |
15%(ITU-A)，18%(ITU-B) |
| • |
Symbol rate |
7.0 Ms/s Max |
| |
| FEC ENCODING |
| • |
FEC modes |
DVB/DAVIC(ITU-T J.83 Annex A) |
| |
|
Digicipher II(ITU-T J.83 Annex B) |
| |
| GENERAL |
| • |
Power x |
5VDC @400mA |
| • |
Size |
2.0 (W) x.9.5 (D) x 3.5 (H) in. |
| • |
Weight |
tbd |
|
