The Research On CDMA's Power Control System And The Circuit Of Power Control Of CDMA Mobile Phone

CDMA (Code Division Multiple Access) is a sort of Multiple Access techniquethat many users communicate simultaneously in electric ware of finity bandwidth .itcan solve the distance affect audio quality issue with mobile phone's TX powercontrol, The system capacity of FDMA and TDMA are mostly related with bandwidth,and CDMA system are mostly related with interfere, reducing interfere can addsystem capacity of CDMA. Usually use power control technique to reduce interferebetween each cell, compensate channel break up, make the CDMA mobilecommunication get the most system capacity, minimize mobile radio's transmit power,extend life of mobile phone battery.In the part 1-3 of this paper,study and discuss forward power control that controlcell station's transmit power and reverse power control that control mobile phone'stransmit power. And reverse power control has reverse open loop power controlwhich only mobile station participate in, and reverse closed loop power control whichmobile station and BSS system participate in. power control and parameter related inCDMA IS-95 and CDMA2000. Base on these knowledge, and base on structuralcharacteristics of command frame of CDMA system reverse power control, we bringforword one reverse power control arithmetic of compensate calculated. It canforecast signal comedown and going compensate calculated, so it decrease the changeof receiver signal-to-noise , and it decrease the change of station's power. It canacceptance more customer, this power control arithmetic has good performance thanthe other power control arithmetic.Discuss and study the transmit power adjust way and perform of QualcommMSM5105 IC set in 4th part of paper. HDET parameter is importance compose part inCDMA mobile communications power control, it's one ADC value to indicatetransmit power level, through CDMA phone's power detect circuit to adjust, wediscuss one optimize design for CDMA phone's power detect circuit. This projectimprove performance of the radio circuit of power detect and aGPS receiver, andusing the 6 sigma analysis method in solving and analyzing this design issue, thisoptimize design for CDMA phone's power detect circuit reach 6 sigma quality designstandard, this project has importance guidance to future other design of CDMA radio,and share to other CDMA phone design.