User's Manual

E1 Spread Spectrum Radios
2-2
2.3 Composition and Principle
2.3.1 System Composition
E1 Spread Spectrum Radios is composed of the Outdoor Unit (ODU) and the Indoor Unit (IDU). Other
accessories include the antenna systems and terminals.
ODU is the Rx/Tx unit of microwave signal. It is composed of microwave components (amplifier, LNA,
up/downconverter, frequency synthesizer etc.), duplexer, IF unit (include dual converter, local oscillator, IF
processing segment etc.), monitor unit, remote unit, and power processing board.
IDU mainly comprised of QPSK modulator, multiplexer, monitor unit, NMS, digital service, power system, other
interfaces etc.
Antenna systems include antenna, connectors and other installation accessories for fixing to the pole or stand.
ODU and IDU are connected by an IF cable.
Figure 2-1 E1 IDU Block Diagram
2.3.2 System Principle
N number of E1 signals, digital service, 9600bps system net control and 9600bps data relays multiplexed in a
multiplexer to a specific microwave frame code. After QPSK modulation, the system sends the transmission to
the ODU through an IF cable. It enter the ODU IF upstream balance circuit, upconverter, power amplifier, filter,