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4 BTS3900 Components
Functions
The LRFU processes uplink and downlink services and controls and monitors internal boards
or modules.
Figure 4-41 Logical structure of the LRFU
The uplink RX channels implement the following functions:
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The downlink TX channels implement the following functions:
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The control module implements the following functions:
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4-58
Figure 4-41
shows the logical structure of the LRFU.
Filters and amplifies two uplink signals and performs digital down-conversion, analog-to-
digital (A/D) conversion, digital Inphase Quadrature (IQ) signal demodulation, and
matched filtering.
Performs uplink Automatic Gain Control (AGC) and stabilizes the level in the IQ digital
domain of the BBU-RFU interface.
Frames the IQ signals of the BBU-RFU interface.
Reports the Received Signal Strength Indicator (RSSI).
Deframes the IQ signals of the BBU-RFU interface.
Shapes and filters downlink IQ signals, performs digital up-conversion, digital-to-analog
(D/A) conversion, and amplifies the power.
Reports the transmit power.
Provides overload protection of the power amplifier.
Enables or disables TX channels.
Provides closed-loop power control.
Simulates the downlink load.
Provides the interface for reporting backup power alarms.
Provides the functions of the Remote Electrical antenna Tilt (RET) antenna.
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Copyright © Huawei Technologies Co., Ltd.
BTS3900
Hardware Description
Issue 04 (2011-02-15)
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