Catv Headend QAM Modulator
Outline
QAM Modulator, is the main equipment CATV digital head-end, receiving DVB transport streams which come from coder, multiplexer, DVB gateway, scrambler, video server etc. It does signal processing like RS coding, convolution interleaving and QAM modulating, providing IF/RF output.
Features
ü Complying DVB standard signal channel coding.
ü Support full range variable data rate, bandwidth and QAM mode Data stuffing
ü super buffer (optional), anti-burst code stream
ü PID filter, re-reflection, PSI, SI information synchronal updating possible.
ü Automatically code stream stuffing and empty pocket deleting.
ü Code stream real-time monitoring, empty pocket filtering
ü Support NIT table modifying
ü real-time code stream monitoring
ü PCR adjusting, output symbol rate variable:1-7Ms/s;
ü Fixed or agile channel output;
ü Providing ASI and Ds3 input port and output port (optional)
ü Providing RF output monitoring port(-20dB);
ü Local or Remote administration possible.
ü LCD display, flexible in operating
ü High reliability design, stable in running
Specifications
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Data interface
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ASI interface (Asynchronous Serial interface)
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Input
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Connector
Impedance
Packet format
Access data rate
Max valid bit rate
DVB standard
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BNC
75Ω
188/204 bits
270Mbps
51.6Mbps
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Loop output
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Connector
Impedance
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BNC
75Ω
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SPI input interface(Synchronous Parallel interface)
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Connector
Packet format
DVB Standard
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DB-25 female
188 or 204 bits
LVDS
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IF interface
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IF input
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Connector
Impedance
IF frequency
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BNC
50Ω
35.25/36/36.15/44 MHz (optional)
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IF Bandwidth≤8MHz
Reflect loss ≥18dB
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Input level
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100dBuV (rms)
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IF loop output
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Connector
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BNC
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Impedance
IF frequency
IF Bandwidth≤8MHz
Reflect loss ≥18dB
Output level
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50Ω
35.25/36/36.15/44 MHz (optional)
100±2dBuV(rms)
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RF interface
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RF output
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Connector
Impedance
Output Frequency
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BNC
75Ω
48~800MHz
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Reflect loss ≥15dB
Output level
105~115dBuV (adjustable)
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Carrier rejection
SNR(out of band)
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> 55dB
≥50dB
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RF output for test
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Connector
Impedance
Output level
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BNC
75Ω
85dBuV~105dBuV (adjustable)
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Channel signal encoding
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Constellation
Channel encoding
MER
SNR(out of band)
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16QAM, 32QAM, 64QAM, 128QAM, 256QAM.
RS encode, DVB standard
≥42dB
≥50dB
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Network management interface
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IEEE802.3 ETHERNET, RJ45 interface
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Software protocol
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SNMP protocol
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Power supply
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Voltage
Frequency
Power consumption
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165V～265VAC or 85V～265VAC
50Hz±2%
50W
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Operation environment
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Operation temperature+5~45°C;
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Storage temperature
Relative humidity
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-25~+55°C.
10~75%
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Radiation and safety
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Up to GB13837-92 and GB8898-88
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E3 /DS3 Interface (optional)
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Input (G.703 standard)
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Connector
Impedance
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BNC
75Ω
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Packet format 188/204 bits
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Bit rate
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E3/DS3 No-frame format (34.368Mbps/44.736Mbps)
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Output (loop)
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Connector
Impedance
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BNC
75Ω
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