User's Manual

Meadowlands Fiber Fed BDA Equipment
User Handbook
Handbook Nō.-60-165801HBKM Issue No:-1
Date:-03/01/06
Page:-
12 of 25
2. OVERVIEW/ SYSTEM DESCRIPTION
The system consists of a fibre optic transmitter and receiver that are co located with the
existing BTS in order to convert the RF signals to optical, which can then be fed to the
optical BDA remotes.
The optical fibre remote BDA’s comprise of a high selectivity filter and duplexing system
built into an environmentally protected enclosure to enable the high power downlink and
low power uplink signals to co-exist on a common antenna port. The D/L signals from the
fibre are fed via an adjustable attenuator and a pair of High Power 20Watt amplifiers
coupled to provide 40Watts downlink power output. In the U/L direction, the low level
signals are passed via the receive duplexer and low noise LNA, before gain adjustment to set
the uplink sensitivity. The signals then pass through a further bank of filters to reduce any
residual Tx carrier power before further amplification to drive the uplink fibre transmitter.
The final uplink amplifier has an ALC loop to ensure that the fibre module cannot be
damaged by large local signals coupled into the antenna system.
All active components in the remote BDA’s have alarm monitoring with local indicators, an
external panel indicator is fitted to the enclosure. The alarm loop is fed to a 21.4MHz pilot
signal generator which is fed over the fibre back to the FO Mastersite.