To improve the deteriorated capacity gain and source recovery performance due to channel mismatch problem,this paper reports a research about blind separation method against channel mismatch in multiple-input multiple...To improve the deteriorated capacity gain and source recovery performance due to channel mismatch problem,this paper reports a research about blind separation method against channel mismatch in multiple-input multiple-output(MIMO) systems.The channel mismatch problem can be described as a channel with bounded fluctuant errors due to channel distortion or channel estimation errors.The problem of blind signal separation/extraction with channel mismatch is formulated as a cost function of blind source separation(BSS) subject to the second-order cone constraint,which can be called as second-order cone programing optimization problem.Then the resulting cost function is solved by approximate negentropy maximization using quasi-Newton iterative methods for blind separation/extraction source signals.Theoretical analysis demonstrates that the proposed algorithm has low computational complexity and improved performance advantages.Simulation results verify that the capacity gain and bit error rate(BER) performance of the proposed blind separation method is superior to those of the existing methods in MIMO systems with channel mismatch problem.展开更多
This paper is concerned with distributed fault detection of second-order discrete-time multi-agent systems with adversary,where the adversary is regarded as a slowly time-varying signal.Firstly,a novel intrusion detec...This paper is concerned with distributed fault detection of second-order discrete-time multi-agent systems with adversary,where the adversary is regarded as a slowly time-varying signal.Firstly,a novel intrusion detection scheme based on the theory of unknown input observability( UIO) is proposed. By constructing a bank of UIO,the states of the malicious agents can be directly estimated. Secondly,the faulty-node-removal algorithm is provided.Simulations are also provided to demonstrate the effectiveness of the theoretical results.展开更多
This paper is concerned with the consensus problems for second-order multi-agent systems with multiple input delays. Different from all standard consensus algorithms with uniform delays, the authors aim to find the la...This paper is concerned with the consensus problems for second-order multi-agent systems with multiple input delays. Different from all standard consensus algorithms with uniform delays, the authors aim to find the largest input-delay margin which can guarantee the consensus for the case when delays are nonuniform. Based on frequency domain analysis and matrix theory, an upper bound for maximum tolerable input-delay is given in terms of the relationship with scaling strengths and largest eigenvalue of the Lapalician matrix. Simulation results are provided to illustrate the obtained results.展开更多
提出了一种基于双交叉耦合电容反馈技术的CMOS共栅低噪声放大器(LNA)。第一个反馈环路利用交叉耦合技术以提高电路跨导;另一个反馈环路在晶体管的源漏两级之间采用交叉耦合共栅技术实现电压电流反馈。提出的LNA在低功耗的前提下取得了...提出了一种基于双交叉耦合电容反馈技术的CMOS共栅低噪声放大器(LNA)。第一个反馈环路利用交叉耦合技术以提高电路跨导;另一个反馈环路在晶体管的源漏两级之间采用交叉耦合共栅技术实现电压电流反馈。提出的LNA在低功耗的前提下取得了优越的性能,基于0.18μm CMOS工艺,对该LNA流片实现并测试。测试结果表明LNA芯片在2.4 GHz频率下的增益为18 d B,噪声系数为2.02 d B,输入三阶截止点IIP3为8.3 d Bm,输入匹配参数S11和输出匹配参数S22均低于-10 d B,在1.1 V电压供电下功耗为2.5 m W。展开更多
针对全盲信道辨识算法无法辨识含公零点信道且对信道阶数误差敏感的问题,本文基于信道的CR相关性提出一种简单有效的半盲信道辨识算法。算法通过输出数据构造相关矩阵W,根据相关矩阵W与信道向量的正交性构造约束方程,并利用少量已知符...针对全盲信道辨识算法无法辨识含公零点信道且对信道阶数误差敏感的问题,本文基于信道的CR相关性提出一种简单有效的半盲信道辨识算法。算法通过输出数据构造相关矩阵W,根据相关矩阵W与信道向量的正交性构造约束方程,并利用少量已知符号和改进的最小二乘(Modified least square,MLS)准则建立额外的约束,通过最小二乘法求得信道响应的闭式解。该算法有效地克服了全盲信道辨识算法的诸多局限性,避免了传统半盲方法面临的最优加权选择问题,算法复杂度较低且性能稳定,对信道噪声及信道阶数具有较强的鲁棒性。仿真实验验证了所提算法的有效性与优越性。展开更多
基金supported by Sichuan Youth Science and Technology Innovation Research Team Project(No.2015TD0022)the Talents Project of Sichuan University of Science and Engineering(No.2017RCL11 and No.2017RCL10)the first batch of science and technology plan key R&D project of Sichuan province(No.2017GZ0068)
文摘To improve the deteriorated capacity gain and source recovery performance due to channel mismatch problem,this paper reports a research about blind separation method against channel mismatch in multiple-input multiple-output(MIMO) systems.The channel mismatch problem can be described as a channel with bounded fluctuant errors due to channel distortion or channel estimation errors.The problem of blind signal separation/extraction with channel mismatch is formulated as a cost function of blind source separation(BSS) subject to the second-order cone constraint,which can be called as second-order cone programing optimization problem.Then the resulting cost function is solved by approximate negentropy maximization using quasi-Newton iterative methods for blind separation/extraction source signals.Theoretical analysis demonstrates that the proposed algorithm has low computational complexity and improved performance advantages.Simulation results verify that the capacity gain and bit error rate(BER) performance of the proposed blind separation method is superior to those of the existing methods in MIMO systems with channel mismatch problem.
基金National Natural Science Foundations of China(Nos.61203147,61374047,61203126,60973095)
文摘This paper is concerned with distributed fault detection of second-order discrete-time multi-agent systems with adversary,where the adversary is regarded as a slowly time-varying signal.Firstly,a novel intrusion detection scheme based on the theory of unknown input observability( UIO) is proposed. By constructing a bank of UIO,the states of the malicious agents can be directly estimated. Secondly,the faulty-node-removal algorithm is provided.Simulations are also provided to demonstrate the effectiveness of the theoretical results.
基金supported by the Defense Industrial Development Program of China under Grant No.JCKY2017212C005
文摘This paper is concerned with the consensus problems for second-order multi-agent systems with multiple input delays. Different from all standard consensus algorithms with uniform delays, the authors aim to find the largest input-delay margin which can guarantee the consensus for the case when delays are nonuniform. Based on frequency domain analysis and matrix theory, an upper bound for maximum tolerable input-delay is given in terms of the relationship with scaling strengths and largest eigenvalue of the Lapalician matrix. Simulation results are provided to illustrate the obtained results.
文摘提出了一种基于双交叉耦合电容反馈技术的CMOS共栅低噪声放大器(LNA)。第一个反馈环路利用交叉耦合技术以提高电路跨导;另一个反馈环路在晶体管的源漏两级之间采用交叉耦合共栅技术实现电压电流反馈。提出的LNA在低功耗的前提下取得了优越的性能,基于0.18μm CMOS工艺,对该LNA流片实现并测试。测试结果表明LNA芯片在2.4 GHz频率下的增益为18 d B,噪声系数为2.02 d B,输入三阶截止点IIP3为8.3 d Bm,输入匹配参数S11和输出匹配参数S22均低于-10 d B,在1.1 V电压供电下功耗为2.5 m W。
文摘针对全盲信道辨识算法无法辨识含公零点信道且对信道阶数误差敏感的问题,本文基于信道的CR相关性提出一种简单有效的半盲信道辨识算法。算法通过输出数据构造相关矩阵W,根据相关矩阵W与信道向量的正交性构造约束方程,并利用少量已知符号和改进的最小二乘(Modified least square,MLS)准则建立额外的约束,通过最小二乘法求得信道响应的闭式解。该算法有效地克服了全盲信道辨识算法的诸多局限性,避免了传统半盲方法面临的最优加权选择问题,算法复杂度较低且性能稳定,对信道噪声及信道阶数具有较强的鲁棒性。仿真实验验证了所提算法的有效性与优越性。
