基于CDMA-TDD系统的联合功率控制算法

Joint power control algorithm for CDMA-TDD system

针对常规的码分多址CDMA (CodeDivisionMultipleAccess)时分双工TDD (TimeDivisionDuplex)系统功率控制算法存在的缺陷,提出了一种基于通信链路当前状态信息的联合功率控制算法.从理论上推导了联合功率控制方程.在新算法中,所有移动终端调整后的新发射功率值是基于共同的通信资源得出的.分配在同一时隙的各个移动终端的功率调整是基于通信链路的当前状态信息,其中包括各移动终端下一步使用的调整后的新发射功率值.使得各移动终端能够平等的共享链路资源,加快功率控制的收敛.通过建立功能模型,验证和评估了这一新的算法.仿真结果表明这一新的功率控制算法优于当前的常规算法,能减小接收端信噪比动态范围,降低干扰信号强度,提高能量效率和系统容量.

A joint power control algorithm based on current link information was proposed to address the shortcoming of the conventional power control algorithms for CDMA （code division multiple access） TDD （time division duplex） system. The joint power control equation was deduced in theory. In the new algorithm, the power adjustment of all UEs （user equipments） was derived jointly from the common network resource. The adjust of transmission power all UEs assigned in the same time slot was based on current information, which took into account the power adjustment of other UEs in next step. The goal is to allow UEs to share network resources equally so as to speed up the convergence of power control. A function model was developed to verify the new algorithm and evaluate its performance. The simulation results indicate that the new algorithm outperforms the conventional algorithms in terms of smaller standard deviation of receiver SIR （signal-to-interference-ratio）, lower system interference, higher energy efficiency, and thus better system capacity.