Cellular Mobile Communication Systems, Power Control Algorithms

For cellular mobile communication systems,power control is one of the most essential elements.For FDMA/TDMA systems,it is used to reduce co-channel interference and higher system capacity.For CDMA systems, power control is one of the most important approaches to effectively solve the near/far effect and the corner problems,to suppress system interferences and to improve the communication quality.The aim of power control is to adjust the transmit power fast according to mobile environment,so it can make the communication quality keep on a certain level and not make too much disturb on other users.In this thesis,distributed power control of the cellular mobile systems is analyzed in details.The main work of this dissertation is recapitulated as follows.Firstly,we discuss the method of power control,based on which the key factors are concluded and point out the performance indicators for measuring algorithm.Secondly,on the base of analysis of the centralized and distributed algorithms,we analyze some classical iterative method of distributed power control,including DAPC and FDPC algorithms,from their convergence and iterative speed.By improved the launch,we analyze and improve the iterative method of distributed power control.Emulations indicate that it has fast convergence and iterative speed.Finally,a noncooperative game is introduced, an appropriate and effective net utility function is chosen and a novel power control algorithm in cellular CDMA system based on game theory is proposed.The existence and uniqueness of Nash equilibrium are proved for the proposed algorithm.The results show that the proposed algorithm reduce the transmit power and speed up the convergence.