User's Manual

5.8GHz PDH User’s Manual
2
2. System Basic Features
2.1 PDH System
PDH system is different from the traditional microwave equipment in smaller size, lighter
weight, easy set up and can be conveniently moved from place to place. The main
characteristics lie in its advantageous use of high frequency band microwave
transmission (above 5.7GHz frequency), digital transformation, concise structure, quick
connection and adapt to complex topographical structure. Extensively use in mobile
phone base station’s interconnection and signal transmission, short distance local
connection, urgent communication, public and specialized network has large application
as well. The present wireless low frequency band is jam-packed and with the demand to
build a quicker communication network, the use of high frequency band PDH equipment
connection is especially meaningful.
2.2 Core Technology
PDH system includes a lot of high technique, which are:
(1) High RF microwave and other related components (amplifier, LNA, MIX, duplexer etc.)
(2) Frequency integrator randomly changes to different frequency band
(3) High amplifier gain control technique（ALC & ATPC）
(4) Advanced QPSK de/modulation
(5) Microwave frame de/multiplexer
(6) Digital band limit
(7) Digital equalizer
(8) Forward Error Correction
(9) Random N*E1 de/multiplexer, where N=1~32
(10) Digital cross-connection
(11) Computer monitoring and signal communication
(12) Network management
(13) Digital service
(14) Digital interface transformation
(15) Highly efficient and improved overall design
※ Audio frequency: Each voice signal needs a 64kbps; made of 8 bits-per-sample code,
A/D and D/A conversions.
※ E1 is an European Standard, 1*E1 is 30 voice channels, plus a channel for transmitting
and signaling, i.e. 32*64kbps = 2.048Mbps