Cdma Power Control Algorithm And Analysis

Code Division Multiple Access(CDMA) technology to access high spectrum efficiency,anti-fading,interference,soft capacity,low-power,frequency planning easy and convenient user access and other communication technologies can not be replaced by the superiority of a wide range of recognized and accepted,at the same time there are also many problems,Such as "near-far effect" and the "angle effect" and so on.Power control is based on fast-changing mobile environment,adjust their transmitting power Allows not only must be able to guarantee the quality of the communication does not have much to interfere with.other users,so the use of power control can not only effectively overcome these problems,but also be able to suppress interference,Increase system capacity.In addition,from an economic point of view,power control can also minimize the mobile station transmitting power,thereby extending the battery life of mobile stations.Power control problem is the core of power control algorithms,power control algorithm and implemented in accordance with the location and can be divided into centralized algorithm and distributed algorithm,Although the centralized algorithm can be the optimal solution,but the overall information required and the implementation of a long time,this is unrealistic;and distributed algorithm required only partial information,and the implementation of fast,Ideal distributed algorithm can quickly converge to the optimal solution,so the focus of this paper is based,on signal-to-noise balanced distributed algorithm,the completion of the major ones are as follows:In this paper,distributed power control law on basic principles,through the iteration of the distributed power control methods and control technology in-depth analysis,A new variable step-size distributed power control algorithm and an adaptive variable step-size power control algorithm.In these algorithms,the System of each mobile station is by measuring the corresponding channel signal to noise ratio value to adjust its transmission power,and not know the other mobile station and information between the base station. But also taking into account time-varying channel gain of the situation,and therefore closer to the actual situation,and in theory the convergence of the algorithm give the proof.