衰落环境下信道增益和时延的联合估计算法  

Joint Estimation Algorithm of Channel Gain and Delay in Fading Environment

作　　者：王鑫[1] 戴丽 WANG Xin;DAI Li(School of Information&Control Engineering,Shenyang Jianzhu University,Shenyang,China,110168)

机构地区：[1]沈阳建筑大学信息与控制工程学院,辽宁沈阳110168

出　　处：《沈阳建筑大学学报（自然科学版）》2020年第5期939-946,共8页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金项目(61903357);辽宁省博士启动基金项目(20170520444);辽宁省自然科学基金项目(20170540752);沈阳建筑大学一般科研项目(2017034)。

摘　　要：目的研究衰落环境中认知用户与授权用户之间存在未知时延情况下的频谱感知问题,提出一种信道增益和时延的联合估计算法.方法建立一种新的动态状态空间模型,用以描述授权用户状态、时变衰落信道状态和感知时延之间的关系;通过最大后验概率准则估计出信道状态,用以表述信道状态随时间变化的情况;最后基于粒子滤波方法得到授权用户状态估计以及感知时延估计;通过仿真实验,分别从信道增益和感知时延两个角度与现有方法的正确检测概率进行对比与分析.结果笔者所提出的信道增益和时延的联合估计算法(SFH)在信道增益角度正确检测概率相比信道增益估计算法(SFC)和能量检测算法(ED)分别提升2%、2.6%,在感知时延角度上提升3.4%、8.7%.结论笔者所提算法提高了接收信号统计特性,在保证实时检测的同时,显著提升了存在未知时延的衰落信道环境下的频谱感知性能.Aiming at the problem of spectrum sensing under unknown delay between secondary users and primary users in fading environment,a joint estimation algorithm of channel gain and perceptual delay is proposed.First,a new dynamic state space model is established to describe the relationship between primary users′ state,time-varying fading channel state and perceived delay;then,the channel state is estimated by the maximum posterior probability criterion to express the channel state changes with time.Finally,we can get the estimation results of primary user state and perceived delay based on particle filtering method.The simulation experiment compares and analyzes the correct detection probability of the existing method from two perspectives of channel gain and perceived delay.Compared with the channel gain estimation algorithm(SFC)and energy detection algorithm(ED),the proposed joint estimation algorithm(SFH)has a 2% and 2.6% increase in the probability of correct detection in terms of channel gain perspective,and has a 3.4% and 8.7% improvement in the perceptual delay perspective.The algorithm improves the statistical characteristics of the received signal.On the premise of ensuring real-time detection,the spectrum sensing performance under fading channel environment with unknown delay is significantly improved.

关 键 词：频谱感知 认知网络 感知时延 衰落信道 联合估计 

分 类 号：TN92[电子电信—通信与信息系统] TN911[电子电信—信息与通信工程]