Method and apparatus for controlling a TX power amplifier

Abstract

A method and an apparatus for controlling a TX power amplifier are provided in the present invention. The invention is applied for generating a power control curve in a power variation area to control the power variation for signal transmission when the TX power amplifier transmits the data during two continuous time slots, which are a first time slot and a second time slot, respectively have a first transmission power value K 1 and a second transmission power value K 2. The invention is aimed at producing a concave down inter-ramp control curve in a inter-ramp division of the power variation area for controlling the power variation of the TX power amplifier, where the power for signal transmission is transformed from the first transmission power value K 1 to the second transmission power value K 2.

1 . A power controlling method, applied in a power amplifier for controlling power of a signal to-be-transmitted, the method producing a power control curve in a power variation area for controlling the power variation of the signal, the power variation area having at least one transmission power value K, the method comprising: 
 generating an original curve according to the transmission power value K, the original curve being horizontally and equally divided into an original left section FL and an original right section FR;    determining a lowest power value H in the power variation area according to the transmission power value K;    determining a left section ratio SL and a right section ratio SR according to the transmission power value K and the lowest power value H;    calculating a left section FL′ of the power control curve according to the lowest power value H, the original left section FL and the left section ratio SL;    calculating a right section FR′ of the power control curve according to the lowest power value H, the original right section FR and the right section ratio SR; and    producing the power control curve in the power variation area according to the left section FL′ and the right section FR′ to control the power variation of the signal.    
     
     
         2 . The method according to  claim 1 , wherein the left section FL′ of the power control curve satisfies FL′=H+SL*FL while the right section FR′ of the power control curve satisfies FR′=H+SR*FR.  
     
     
         3 . The method according to  claim 1 , wherein the power amplifier is installed in a wireless communication apparatus having a memory, which comprises: 
 an original left section table, for storing a plurality of original left sections, each of which corresponds to one transmission power value;    an original right section table, for storing a plurality of original right sections, each of which corresponds to one transmission power value; and    a lowest power value table, for storing a plurality of lowest power values, each of which corresponds to one transmission power value;    wherein according to the transmission power value of the power variation area, the power controlling method searches the original left section table and the original right section table to obtain a corresponding original left section and a corresponding original right section for generating the original curve, and according to the transmission power value of the power variation area, the power controlling method searches the lowest power value table to obtain a corresponding lowest power value.    
     
     
         4 . The method according to  claim 3 , wherein the memory further comprises: 
 a left section ratio table, for storing a plurality of left section ratios, each of which corresponds to one transmission power value and one lowest power value; and    a right section ratio table, for storing a plurality of right section ratios, each of which corresponds to one transmission power value and one lowest power value;    wherein according to the transmit power value of the power variation area and the lowest power value H, the power controlling method searches the left section ratio table and the right section ratio table to obtain a corresponding left section ratio and a corresponding right section ratio.    
     
     
         5 . The method according to  claim 1 , wherein the power variation area is an inter-ramp division having a first transmission power value K 1  and a second transmission power value K 2 , and the power control curve is an inter-ramp control curve.  
     
     
         6 . The method according to  claim 5 , wherein the inter-ramp control curve comprises a concave curve.  
     
     
         7 . The method according to  claim 6 , wherein a left end and a right end of the original left section FL respectively are a highest point and a lowest point of the original left section FL, and a left end and a right end of the original right section FR respectively are a lowest point and a highest point of the original right section FR.  
     
     
         8 . The method according to  claim 7 , wherein the left section ratio SL satisfies SL=K 1 −H while the right section ratio SR satisfies SR=K 2 −H.  
     
     
         9 . The method according to  claim 1 , wherein the power variation area is a ramp-up division having a first transmission power value K 1 , and the power control curve is a ramp-up control curve.  
     
     
         10 . The method according to  claim 9 , wherein a left end of the original left section FL is a lowest point of the original left section FL, and a right end of the original right section FR is a highest point of the original right section FR, and the original left section FL is continuously connected with the original right section FR.  
     
     
         11 . The method according to  claim 10 , wherein the left section ratio SL satisfies SL=K 1 −H while the right section ratio SR satisfies SR=K 1 −H.  
     
     
         12 . The method according to  claim 1 , wherein the power variation area is a ramp-down division having a second transmission power value K 2 , and the power control curve is a ramp-down control curve.  
     
     
         13 . The method according to  claim 12 , wherein a left end of the original left section FL is a highest point of the original left section FL, and a right end of the original right section FR is a lowest point of the original right section FR, and the original left section FL is continuously connected with the original right section FR.  
     
     
         14 . The method according to  claim 13 , wherein the left section ratio SL satisfies SL=K 2 −H while the right section ratio SR satisfies SR=K 2 −H.  
     
     
         15 . The method according to  claim 1 , wherein the original left section FL and the original right section FR are represented by values with float points, and wherein the power amplifier is installed in a wireless apparatus having a memory which comprises: 
 an original left section table, for storing a plurality of original left sections FL_TABLE, each of which satisfies FL_TABLE=FL*2 N ;    an original right section table, for storing a plurality of original right sections FR_TABLE, each of which satisfies FR_TABLE=FL*2 N ; and    a lowest power value table, for storing a plurality of lowest power values, each of which corresponds to one transmission power value;    wherein according to the transmission power value of the power variation area, the power controlling method searches the original left section table and the original right section table to obtain the original left section FL_TABLE and the original right section FR_TABLE for generating the original curve, and according to the transmission power value of the power variation area, the power controlling method searches the lowest power value table to obtain a corresponding lowest power value.    
     
     
         16 . The method according to  claim 15 , wherein the memory further comprises: 
 a left section ratio table, for storing a plurality of left section ratios, each of which corresponds to one transmission power value and one lowest power value; and    a right section ratio table, for storing a plurality of right section ratios, each of which corresponds to one transmission power value and one lowest power value;    wherein according to the transmission power value of the power variation area and the lowest power value H, the power controlling method searches the left section ratio table and the right section ratio table to obtain a corresponding left section ratio and a corresponding right section ratio.    
     
     
         17 . The method according to  claim 15 , wherein the left section FL′ and the right section FR′ of the power control curve are calculated by shift operations, the calculation formulas comprising: 
 FL′=H+(FL_TABLE*SL) with shifting N bits to the right, namely, FL′=H+(FL*2 N )*SL/2 N ; and    FR′=H+(FR_TABLE*SR) with shifting N bits to the right, namely, FR′=H+(FR*2 N )*SR/2 N .