Power control is a hot issue of the physical layer due to the potentially significant performance gains achieved when nodes limit their power level. In wireless communication systems, mobile terminals respond to the time varying nature of the channel by regulating their transmitter powers. Specifically, in a CDMA system, where signals of other terminals can be modeled as interfering noise signals, the major goal of this regulation is to achieve a certain signal to interference (SIR) ratio regardless of the channel conditions while minimizing the interference due to terminal transmit power level. Hence, there are two major reasons for a terminal to perform power control; the first one is the limit on the energy available to the mobile node, and the second reason is the increase in quality of service (QoS) by minimizing the interference (Mehta, & Kwak, 2009).