Description:

    RMD 940 is a high performance remodulator, designed to recover the key features of digital QPSK-modulated radio signal, distributed for long distances by aid of multiple retransmissions.     There are 4 independent remodulator-channels composed of L-band (950-2150 MHz) module tuner at the input and L-band QPSK modulator module at the output. Signal, coming out of the modulator output can be transferred to a desired frequency band area by aid of frequency converter (for instance, to Ku-band for satellite broadcasting systems and MITRIS).     Efficient control and monitoring of RMD940 is done through the operator’s PC and “Crypton DTV Master” software. Communications environment between remodulator and control computer is a common TCP/IP network (100BaseTX, UTP5 cable, RJ45 jack). There are no limits to the quantity of equipment in the network.     The main application of RMD940 is found in MITRIS networks.
    The Crypton base station is designed on the basis of RMD940 remodultaor.

Scope:

• Four channels of remodulation. One remodulator is able to recover 4 channels from 4 different sources.
  
• L-band QPSK-tuner. Allowed level for QPSK tuner input signal is -25… -65 dBm.
  
• L-band QPSK-modulator. -3 dBm is at 50 Ohm. Frequency tolerance is ±5 kHz.
  
• Channels’ disabling (if required). Any channel can be disabled if there is no need in using all 4 channels. At the same time if signal is missed then at the modulator output the channel goes to a low power consumption mode. When channel is disabled it is still possible to change the channel settings but the changes will only be effective when channel is switched on.
  
• TCP/IP network. RMD940 is connected to the control computer by means of TCP/IP network equipment.
  
• Reliable software. “Crypton DTV Master” software package provides devices’ control and monitoring in real-time.

Design:<     Multipac design with built-in power supply. To be easily assembled into 19" rack. Dimensions: height – 2U (89mm), depth – 295 mm, width – 483 mm. The RMD940 technical characteristics:

Input
Tuner	Quantity: 4 Demodulation: QPSK (EN 300421 compliance) Input frequencies range: 950…2150 MHz Allowed level of input signal: -25…-65 dBm Input impedance: 75 Ом Input stream rate: 25-30 Msym/s FEC modes- 1/2, 2/3, 3/4, 5/6, 7/8 F-type connector (IEC 169-24)
Output
Modulator	Quantity: 4 QPSK modulation: EN 300421 compliance Output signal level: -7…-3 dBm Symbol rate: 25-30 Мsymb/s (0,125 Msymb/s spacing) Bandwidth: 950 – 1800 MHz (2 subbands, according to performance) 950-1450 MHz 1450-1800 MHz Frequency tolerance: ±5 kHz FEC modes- 1/2, 2/3, 3/4, 5/6, 7/8 Output impedance: 50 Ом SMA connector
Control and monitoring
Remote	Ethernet (TCP/IP) Software: «Cryptоn DTV Master»
Physical characteristics
Size	2U(19") 93mm х 482,6mm х 300mm 3.65" х 19" x 13.25"
Weight	4,3 kg
Power	90-260V AC 50/60 Hz Power consumption: 35W maximum
Environment
Operation	Temperature: 0 °С - +45 °С Humidity: 5% - 85% (non-condensing)
Storage and transportation	Temperature: -40 °С - +70 °С Humidity: 0% - 85% (non-condensing)

The RMD940 block diagram:


Concise description of RMD940 core modules:

• QPSK tuner. The tuner module provides signal reception, its demodulation and error correction. A regenerated signal is given to the tuner module output by way of a digital stream that corresponds to DVB specification.
  
• QPSK modulator. The modulator module provides a QPSK modulation and input DVB-stream processing by a noise protection code. Thereafter an input DVB-stream is transformed into L-band output signal.
  
• Control module. Commands, received from control computer are processed by the control module. The tuners and modulators’ operations of control are realized by the control module. The modulators and tuners’ status query is occasionally done by the control module and in case of improper operation of these modules the control module tries to recover their proper functioning.