基于协作干扰器的OFDM-CR保密通信系统功率控制  

Power Control for Cooperative Jammer-based OFDM-CR Secure Communication System

作　　者：李林[1,2] 蒋卫恒[1] 冯文江[1] 

机构地区：[1]重庆大学通信工程学院,重庆400044 [2]重庆电子工程职业学院,重庆401331

出　　处：《重庆师范大学学报（自然科学版）》2016年第1期154-162,共9页Journal of Chongqing Normal University:Natural Science

基　　金：国家自然科学基金(No.60872038);重庆市教委科学技术研究项目(No.KJ102201)

摘　　要：针对OFDM-CR系统中认知收发信机在独立并行高斯窃听信道上的安全通信与功率控制展开研究。以无协作干扰器的OFDM-CR系统为对象,导出了最大化安全速率的认知发射机功率分配表达式;为了提高信道资源利用率,在OFDM-CR系统中引入协作干扰器,并讨论最大化安全速率的联合认知发射机与协作干扰器功率控制策略。首先不考虑主用户干扰约束,分析引入协作干扰器能获得安全速率增益的信道条件,并计算各子信道固定发射功率下的干扰功率,然后将安全速率最大化模型用混合整数非线性规划近似,基于启发式贪婪算法求解其次优解,最后就提出的功率控制策略与其他几种典型的功率控制策略进行了性能对比仿真,结果表明,提出的功率控制策略在不同条件下均有性能提升。This paper investigates the OFDM CR system secure communication and power allocation problem whether a cognitivebased transmitter and a cognitive-based receiver communicate over a bank of idle independent parallel Gaussian wiretap channels. We initially focus on the scenario without the assistance of a cooperative jammer （CJ） and characterize the secrecy rate maximization power allocation strategy. In order to improve the utilization of spectrum, we then extend our scenario by introducing a CJ and discuss the joint transmitter and CJ power control. For this extension problem, without considering the primary network interference constraints, we first analyze the channel conditions under which we can obtain positive secrecy rate gain by introducing CJ and calculate the optimal jamming power strategy under fixed transmit power, then a mixed integer non-linear programming is used to approximate the original secrecy rate maximization problem. Based on the greedy scheme, we proposed a heuristic algorithm to obtain a suboptimal solution. By comparing the proposed algorithm with some classical benchmark schemes, the simulation results indicates that our proposed algorithm outperforms them under different conditions.

关 键 词：认知无线电 并行高斯窃听信道 协作干扰器 功率分配 

分 类 号：TN92[电子电信—通信与信息系统]