User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
4 System Function
4-13
(CRC check bit and end bit) to get the information bits, then sends them to the
higher layer for processing.
4.5 RF Functions
cBTS3612 RF functions meet the requirements of TIA/EIA IS -97-D protocol. It
features high transmission power, high sensitivity, flexible configuration, easy
operation & maintenance, cell breath and diversity receiving.
4.5.1 Power Control
CDMA system is a self-jamming system, in which every subscriber is an interference
source to other subscribers. If it is possible to ensure that every MS transmits the
minimum power it needs, the whole system capacity can be the largest. Therefore,
power control directly affects the system capacity and the service quality.
I. Purpose
The purpose of the power control is to
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Ensure conversation quality, meanwhile restrict the transmitting power on the
forward and reverse links, thus minimizing the system interference.
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Overcome the far-near effect caused by the freely distributed mobile stations,
so the signals of mobile stations whose distances to the BTS are different can
reach the BTS with the same power.
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Realize the system soft capacity control.
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Prolong MS battery life.
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Minimize MS radiation to the human body.
II. Types
Power control can be divided into forward power control and reverse power control.
The forward power control is used to control BTS’s transmit power, while the reverse
power control aims to control MS’s transmit power.
1) Forward power control
Forward power control has various methods, whose applications are subject to the
MS protocol version and the system parameters.
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PMRM (Power Measurement Report Message )
When the MS adopts PMRM power control method, it will determine the method and
frequency of reporting PMRM in accordance with the received control message of
the system parameter message.