有限字符输入下AF中继系统安全互信息量分析及功率控制策略  

Secrecy Mutual Information Analysis and Power Control in Amplify-and-forward Relay Networks with Finite-Alphabet Input

作　　者：曹阔[1] 管新荣[1] 蔡跃明 

机构地区：[1]解放军理工大学通信工程学院,南京210007

出　　处：《信号处理》2014年第11期1394-1400,共7页Journal of Signal Processing

基　　金：国家自然科学基金(61371122;61301162);中国博士后科学基金(2013T60912)资助项目

摘　　要：本文针对有限字符输入下多中继通信系统,推导了源和中继节点总功率受限条件下的安全互信息量。在已知理想信道状态信息的条件下,给出了一种基于对窃听节点迫零的波束赋形方案,并设计了一种提高安全互信息量的功率控制策略。针对所提功率控制策略,研究了该策略下目的节点和窃听节点的平均误符号率性能,分析表明该策略在高信噪比下存在误码平层。针对误码平层缺陷,本文提出了一种高信噪比下适当增大源节点发射功率的改进方案。改进方案虽然损失了部分安全互信息量,但换来误符号率的明显改善,消除了功率控制方案的误码平层问题。In this paper,we compute the secrecy mutual information of Amplify-and-forward（AF） relay networks with finite alphabet input under the total power constraint. Under the assumption that the full CSI is obtained,we propose a beamforming scheme that completely null in the direction of the eavesdropper,on the other hand,we use the strategy of power control to maximize the secrecy mutual information. Besides,we study the average symbol error rate of the proposed strategy. The analysis indicates that the error floor appears in the proposed strategy at high total power. Consequently,we propose a modified scheme that appropriately enhancing the source power to cope with this problem. The modified scheme sacrifices little secrecy mutual information to achieve noteworthy improvement of the symbol error rate,and it eliminates the error floor of the proposed strategy at high total power.

关 键 词：有限字符输入 安全互信息量 功率控制 误符号率 

分 类 号：TN911.23[电子电信—通信与信息系统]