协同通信中的基于信道统计信息的联合中继选择的功率分配  

Statistically Optimal Power Allocation and Relay Selection in Cooperative Networks

作　　者：王丽洁[1] 习勇[1] 唐艺[1] 魏急波[1] 

机构地区：[1]国防科技大学电子科学与工程学院,湖南长沙410073

出　　处：《国防科技大学学报》2011年第5期110-115,共6页Journal of National University of Defense Technology

基　　金：国家自然科学基金资助项目(61002032;60903206);教育部高等学校博士点专项科研基金资助项目(20094307110004)

摘　　要：分析Rayleigh信道下分集/无分集的AF(Amplify and Forward)和DF(Decode and Forward)模式单中继传输的平均中断概率,给出解析表达式。在总功率约束下推导了4种模式下的统计最优功率分配的解析表达式来最小化系统的平均中断概率,并提出通过最佳中继选择进一步降低系统的平均中断概率。仿真结果表明,虽然AF模式和分集DF模式下的功率分配是在高发送SNR条件下推导的,但其在低发送SNR下依然有效;相对于固定功率分配,依据节点统计信息的最优功率分配可以有效降低系统的平均中断概率,多中继网络中的最佳节点选择进一步降低了系统的平均中断概率。The average outage probabilities of the amplify-and-forward（AF） relaying and the decode-and-forward（DF） relaying with/without diversity in Rayleigh fading were analyzed respectively,and the analytical expressions were presented.To minimize the average outage probability,with total transmit power constraint,the statistically optimal power allocation problem of the AF relaying and DF relaying were considered,and also the analytical expressions are provided.Then the statistical optimal relay selection was suggested to further minimize the average outage probability.Though the analytical expressions of power allocation for AF and DF with diversity were obtained under the condition of high transmit SNR,the simulation results show that they are also valid in the low transmit SNR region.Compared with fixed power allocation,the statistical optimal power allocation effectively reduces the average outage probability.Meanwhile,the optimal relay selection further reduces the average outage probability.

关 键 词：中断概率 放大前传 解码前传 功率分配 中继选择 

分 类 号：TN929.5[电子电信—通信与信息系统]