CDMA系统反向功率控制技术的研究

Research on Uplink Power Control Technology of CDMA System

介绍了基于ＩＳ－９５标准的ＣＤＭＡ反向功率控制的概念和原理，提出了一种用测量Ｍ进制正交符号能量的方法来估计信噪比的反向闭环功率控制算法和一种反向外环功率控制的算法，并对其算法实现进行了仿真。仿真结果对功控调整步长参数作了优化，验证了ＩＳ－９５所建议的功控步长取１．０ｄＢ左右的正确性。另外，还仿真了多普勒效应对仿真结果的影响，指出移动台运动速度加快，其多普勒频移增大，导致了接收信号质量的恶化，降低了系统的爱尔兰容量。

Briefly introduces the concepts and principles of CDMA uplink power control Based on IS-95 and presents an uplink outer loop power control algorithm and an uplink closed loop power control algorithm using estimating the signal to noise ratio from the measurement of the received M ary orthogonal symbol energy.This paper also simulates the above algorithm realization.The simulation result optimizes power control adjustment step to be 1.0dB or so suggested by the IS-95 standard. In addition, it simulates the influence on the result caused by Doppler′s effect,denoting that the faster the moving velocity of the mobile station, the bigger the Doppler freqency shift, which leads to the degradation of the quality of received signal,hence the system Erlang capacity is decreased.