一种基于OFDM的多用户认知无线电系统联合资源分配算法  

A joint resource allocation algorithm for multiuser OFDM based cognitive radio systems

作　　者：马月槐[1] 徐友云[1] 蔡跃明 

机构地区：[1]解放军理工大学通信工程学院,江苏南京210007

出　　处：《电路与系统学报》2010年第6期82-89,共8页Journal of Circuits and Systems

基　　金：国家863计划资助项目(2007AA01Z267);国家973计划资助项目(2009CB3020402)

摘　　要：针对频谱共享环境,研究了采用OFDM调制方式的多用户认知无线电系统中,综合考虑自身发射功率约束与主用户干扰功率约束的资源分配问题。基于最大化认知用户和速率的优化目标,给出了连续比特条件下最优的多水位注水功率分配表达式;针对更实际的整数比特要求情况,通过基于相对增益因子RG的子信道选择机制与每个认知用户内多约束的贪婪比特与功率分配策略,来最大限度地提高频谱利用率。仿真结果表明:联合的子信道、功率与比特分配算法在不同的参数设置下均达到了良好的性能,在不影响主用户通信的前提下有效地提高了认知系统的频谱利用率。In spectrum sharing environments, the resource optimization problem which consider both transmit power constraints of cognitive users and interference power constraints of primary users, is studied for multiuser OFDM based cognitive radio systems. With the objective of maximizing the sum rate of cognitive users, the multi-level waterfilling power allocation is analyzed under the constraint of continuous bit rate constraint. For the more practical condition when integral bit rate requirement is present, the joint method of subchannel selection based on RG factors as well as bit and power allocation based on multi-constraint greedy mechanism is proposed to enhance the spectrum efficiency. Simulation results show that the proposed joint subchannel, power and bit allocation algorithm could make efficient use of spectrum with various system parameter values.

关 键 词：OFDM 认知无线电系统 资源分配 凸优化 

分 类 号：TN929.5[电子电信—通信与信息系统]