Transmission power amplifier unit

Abstract

A transmission power amplifier unit of a base-station apparatus for compensating for non-linear distortion of a transmission power amplifier by feed-forward control is provided with a gain varying unit for varying gain of the transmission power amplifier unit. At start-up of the transmission power amplifier unit, a controller determines whether the base-station apparatus is in a blossoming mode or breathing mode, maximizes gain of the transmission power amplifier unit by controlling the gain varying unit if the mode is the blossoming mode and increases the gain gradually in proportion to the passage of time if the mode is the breathing mode.

1 . A base station provided with a transmission power amplifier unit, which has a main amplifier and a sub-amplifier, for compensating distortion of the main amplifier by feed-forward control using a signal output from the sub-amplifier, comprising: 
 a controller for controlling a gain of the transmission power amplifier unit to be constant at a predetermined value in a blossoming mode, wherein in the blossoming mode cell radius is enlarged at a fixed rate by increasing gradually a level of a signal input to the transmission power amplifier unit, from a value below a set level.    
   
   
       2 . A base station according to  claim 1 , further comprising: 
 a gain varying unit for varying gain of the transmission power amplifier unit, wherein the controller determines whether the base-station apparatus is in the blossoming mode or breathing mode and increases the gain of the transmission power amplifier unit gradually if the mode is breathing mode.    
   
   
       3 . A base station according to  claim 1 , wherein said controller includes: 
 a detection circuit provided in an input section of the transmission power amplifier unit for detecting input power; and    means for discriminating mode based upon whether said input is equal to or greater than a threshold level.    
   
   
       4 . A base station according to  claim 1 , wherein said controller includes: 
 a detection circuit provided in an output section of the transmission power amplifier unit for detecting output power; and    means for discriminating mode based upon said output power value.    
   
   
       5 . A base station according to  claim 1 , wherein the controller controls the gain of the transmission power amplifier unit to be constant at the predetermined value in the blossoming mode by fixing an amount of attenuation of a variable attenuator provided in said transmission power amplifier unit.