Comtech EF Data DD2401 - Manual (Page 11)

DD2401 Satellite Demodulator Introduction
MN-DD2401 - Rev. G 1- 1
Introduction 1
1.0 Description
The Radyne DD2401 Satellite Demodulators (see Figure 1-1) are microprocessor-controlled
Binary Phase Shift Keyed (BPSK), Quadrature Phase Shift Keyed (QPSK), or optional Offset
Quadrature Phase Shift Keyed (OQPSK) Demodulators. They are intended for use as part of the
receiving ground equipment in a satellite communications system. The DD2401 can be ordered
with a 24 Volt power source for operation of the outdoor Low Noise Block (LNB).
Figure 1-1. DD2401 Satellite Demodulator
The DD2401 is designed to perform at one end of a satellite Single Channel Per Carrier (SCPC)
Link or as the VSAT Remote Site Demod in a TDMA Hub System. The DD2401 can be used in a
Mesh or Star Topology Network. The Demodulator operates independently using BPSK, QPSK
or OQPSK (Optional) Modulation in either SCPC or VSAT Modes.
All functions can be accessed with a terminal or personal computer via a serial link for complete
remote monitor and control (M&C) capability.
The DD2401 is also the ideal VSAT Demodulator for use in a Point-to-Point Frame Relay Hybrid
Network. Other applications include FDMA, telephony, video conferencing, long distance
learning, paging and newsgathering.
Selection of any data rate is provided over the following ranges:
BPSK: 9.6 Kbps to 1200 Kbps
QPSK: 9.6 Kbps to 4.375 Mbps
OQPSK: 9.6 Kbps to 4.375 Mbps
8PSK (Optional*): 64.0 Kbps to 5.0 Mbps
* 8PSK Option is available on L-band units only.
Note: Data rates of 4.375 Mbps must operate at 7/8 Rate QPSK or 8PSK.
The DD2401 can track and acquire a carrier over a programmable range of ± 1 kHz to ± 42 kHz.
Acquisition times of less than three seconds are typical at data rates greater than 64 Kbps over a
range of ± 25 kHz.
To facilitate link testing, the DD2401 incorporates a built-in ‘2047’ test pattern with BER
measurement capability.
1.1 DD2401 Available Options