认知OFDM系统的功率分配  

Power Allocation for OFDM Cognitive System

作　　者：于世军[1] 郑文秀[1] 

机构地区：[1]西安邮电大学通信与信息工程学院,陕西西安710121

出　　处：《无线电通信技术》2013年第5期26-28,88,共4页Radio Communications Technology

基　　金：国家自然科学基金项目(61271276);陕西省自然科学基础研究计划项目(2011JQ8027)

摘　　要：针对OFDM认知系统资源分配问题,提出了一种基于最优功率算法和次优功率算法的联合自适应分配方案。利用香农定理求出信道最大容量,在满足干扰门限的条件下,通过拉格朗日定理和改进了的线性注水算法,求出子载波信道状态、认知用户对主用户干扰与子载波功率之间的线性关系,利用这个线性关系进行功率分配,最后根据功率门限验证分配结果。仿真结果显示,提出的方案更能实现公平性的功率分配,极大地提高了频谱的利用率,满足认知网络通信的需求。An adaptive allocation scheme based on power optimal algorithm and power sub-optimal algorithm is proposed to solve the resource allocation problem in OFDM cognitive system. Under the condition of meeting the requirement of interference threshold, Shannon theorem is used to find the maximum channel capacity,the state of sub-carrier channel and the linear relationship between the cognitive user＇ interference to the primary user and sub-carrier power are obtained by Lagrange＇s theorem and improved linear water-fill- ing algorithm, power allocation is realized by using the linear relationship and the allocation result is verified according to the power threshold. Simulation results show that this scheme can achieve a more fair power allocation,which greatly improves the spectrum utiliza- tion and satisfies the communication needs of cognitive networks.

关 键 词：认知OFDM系统 功率分配 线性注水法 

分 类 号：TN971.4[电子电信—信号与信息处理]