CDMA System Power Control And Distributional Algorithm Research

Power control is a crucial module in the radio resource management,and also is one of key technologies.The purpose of power control is to combat the "far-near"effect and "the edge effect",suppress system interference and increase the system capacity.This dissertation mainly study the power control algorithm based on the CDMA communication system,the main work of this dissertation is discussed as follows:(1) This paper has analyzed the goal and the significance of the power control.Based on the power control criterion, the principle and the method of power control was discussed.The primary factor effect on power control is summarized and then we analysised the influence of power control to the capacity of CDMA communication system.Power control algorithm and the typical distributional model are studied which provided the basis theory for the later power control algorithm's design and realization.(2) Power control will be described as a non-cooperative game of multi-user , with utility function being described as the quality of service (QoS) levels of all users ,with prices function being expressed as rating cost, and then power control process will be equivalent to the process to achieve the net effect of the largest users. A new kind of power control algorithm based on SIR balance is proposed, which is made clear to have one only Nash point of equilibrium.The simulation result show that algorithm can meet the different user QoS rank ,simultaneously, effectively reduce user's telephone conversation interrupt probability, increase the user capacity and has the good performance and the very strong usability.(3) The thesis have studied many kinds of service speed and power joint distribution in the CDMA honeycomb communications system ,due to 3G most major characteristic of the multimedia services. According to the different service user to grade of service's demand, we divide many kinds of services into the bit speed invariable service and the bit speed invariable service.In view of the different service's characteristic assigning different utility function, we introduce one power price function affected by communicition link quality to control power resources assignment, and then obtain a new speed and power distribution union algorithm. The simulation result show that the new algorithm may save system power, namely the CDMA system may hold more numbers of users.