Sampled-Data $$H_{\infty }$$ Synchronization of Chaotic Lur’e Systems with Time Delay

This paper deals with the problem of robust \(H_{\infty }\) synchronization of chaotic Lur’e systems with time-varying delays via sampled-data control. In order to make full use of the information about sampling intervals, nonlinear functions and time-varying delays, an improved Lyapunov–Krasovskii (L–K) functional is introduced. Based on reciprocal convex combination technique, sufficient conditions are derived in terms of linear matrix inequalities (LMIs) to ensure the asymptotic synchronization of the considered Lur’e system with a guaranteed \(H_{\infty }\) performance. By solving the obtained LMIs, the required sampled-data control gain matrix is obtained, which assures the asymptotic stability of the error system and reduces the effect of external disturbance according to \(H_{\infty }\) norm. Finally, the effectiveness and less conservatism of the proposed method are verified through numerical simulations of the Chua’s circuit and neural networks.     

Asymptotical Synchronization of Chaotic Lur’e Systems Under Time-Varying Sampling

This paper investigates the problem of sampled-data synchronization of chaotic Lur’e systems with time-varying sampling. A novel Lyapunov functional, which is continuous in time and makes full use of the available information about the sampling pattern, is constructed to synchronize the chaotic Lur’e systems. By using a free-weighting matrix approach and solving a set of linear matrix inequalities (LMIs), a sampled-data controller is obtained. The effectiveness and the validity of the proposed theoretical result are illustrated by two numerical examples.     

Synchronization for Time-Delay Lur’e Systems with Sector and Slope Restricted Nonlinearities Under Communication Constraints

This paper presents a new approach to the output feedback control problem of master-slave synchronization of time-delay chaotic Lur’e systems with sector and slope restricted nonlinearities under communication constraints. The communication constraints involve measurement quantization and signal transmission delay. By constructing an appropriate Lyapunov functional with the idea of a discretized Lyapunov–Krasovskii functional method and utilizing the sector bound of the logarithmic quantizer, a delay-dependent synchronization criterion is derived. The desired synchronization controller can be obtained by solving a set of linear matrix inequalities. Finally, numerical simulations for Chua’s circuit are proposed to show the effectiveness of the proposed approach.     

Networked Reliable Synchronization of Chaotic Lur’e Systems with Sector- and Slope-Restricted Nonlinearities

This paper investigates the networked reliable synchronization problem of chaotic Lur’e systems containing the sector- and slope-restricted nonlinearities. The reliable synchronization of chaotic Lur’e systems is achieved based on networked control techniques. Moreover, some sufficient conditions are obtained and these conditions depend on various network-related parameters, fault indicating matrices, sector and slope bounds. Finally, a numerical example is provided to illustrate the validity of the proposed method.     

Further Criteria on Master–Slave Synchronization in Chaotic Lur’e Systems Using Delay Feedback Control

This paper is concerned with designing delay feedback controllers of master–slave synchronization for Lur’e systems. Through dividing the delay interval into two parts and choosing two augmented Lyapunov–Krasovskii functionals, some delay-dependent synchronization criteria are formulated in terms of linear matrix inequalities (LMIs), in which the conservatism can be effectively reduced based on adjusting some useful parameters. The proposed conditions can be easily checked, and the controller gains can be achieved by solving the derived LMIs. Finally, two numerical examples are given to illustrate the presented results.     

Implementation of Synchronized Chaotic Lü Systems and Its Application in Secure Communication Using PSO-Based PI Controller

This paper investigates the synchronization of chaotic systems and its application in secure communication. First, a particle swarm optimization (PSO)-based proportional -integral (PI) controller is proposed for synchronization of general chaotic systems. By using the PSO algorithm, optimal control gains in PI controller are derived such that a performance index of integrated squared error (ISE) is as minimal as possible and synchronization can be achieved. Then a chaotic secure communication system based on synchronized coupled Lü systems is implemented using basic electronic components. Finally, both simulation results and the experimental results demonstrate the proposed PSO-based PI scheme’s success in the secure communication application.     

Global Synchronization for Coupled Lur’e Dynamical Networks

This paper studies the global exponential synchronization for coupled Lur’e dynamical networks. Based on Lyapunov stability theory and novel matrix techniques, several sufficient conditions are established to ensure the global synchronization of the proposed network model. These conditions are expressed in terms of matrix and algebraic inequalities, which can be verified and solved easily. It is noted that, unlike existing approaches which may involve heavy computation when the number of subsystems is large, the method developed in this paper can be applied to tackle this case efficiently. Finally, the coupled chaotic Chua system is used to show the effectiveness of the obtained results.     

Synchronization and Parameters Identification of Chaotic Systems via Adaptive Control

Based on Lyapunov stability theory, a novel adaptive controller is designed for a class of chaotic systems. The parameters identification and synchronization of chaotic systems can be carried out simultaneously. The controller and the updating law of parameters identification are directly constructed by analytic formula. Simulation results with Chen‘s system and Roessler system show the effectiveness of the proposed controller.     

Design of Secure Distributed Intrusion Detection Systems

1　ＩｎｔｒｏｄｕｃｔｉｏｎＷｉｔｈｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆＩｎｔｅｒｎｅｔ,ｖａｒｉｏｕｓｎｅｔ ｗｏｒｋｉｎｃｉｄｅｎｔｓｈａｖｅｄｏｎｅｇｒｅａｔｈａｒｍｔｏｎｅｔｗｏｒｋｉｎ ｆｏｒｍａｔｉｏｎｓｙｓｔｅｍｓａｎｄｕｓｅｒｓ.Ｍａｎｙｓｅｃｕｒｉｔｙｐｒｏｄ ｕｃｔｓ[1 ] ａｌｓｏａｐｐｅａｒｓｕｃｈａｓｆｉｒｅｗａｌｌ,ＶｉｒｔｕａｌＰｒｉｖａｔｅＮｅｔｗｏｒｋ (ＶＰＮ)ａｎｄＩｎｔｒｕｓｉｏｎＤｅｔｅｃｔｉｏｎＳｙｓｔｅｍｓ(ＩＤＳ) .Ｉｎｔｒｕｓｉｏｎｄｅｔｅｃｔｉｏｎｓｙｓｔｅｍｓ…     

Robust Absolute Stability Criterion for Uncertain Lur’e Differential Inclusion Systems with Time Delay

This paper deals with uncertain Lur’e differential inclusion systems with time delay. The set-valued mappings considered are upper semi-continuous, non-empty, closed, convex and bounded. It is proved that original systems can be reduced to their equivalent systems by introducing the dynamic multiplier. Based on the Lyapunov–Krasovskii functional, delay-dependent stability criterion is given to guarantee the robust absolute stability of the systems by LMI method. The result is new to the previous literature. Numerical examples are provided to show the effectiveness of the proposed stability condition.     

Performance Evaluation of Wireless Communication Systems over Weibull/q-Lognormal Shadowed Fading Using Tsallis’ Entropy Framework

Wireless Personal Communications - In wireless communication channels, the signals arriving at the receiver may be of stochastic nature or be superpositioned due to non-uniform scattering and...     

The User-level Security of Mobile Communication Systems

1　ＩｎｔｒｏｄｕｃｔｉｏｎＢｏｔｈｔｈｅｆｉｘｅｄｔｅｌｅｐｈｏｎｅｎｅｔｗｏｒｋａｎｄｔｈｅｍｏ ｂｉｌｅｓｙｓｔｅｍｓ (ｅ .ｇ .,ＧＳＭ )ａｒｅｂｅｉｎｇｕｓｅｄｉｎｃｒｅａｓ ｉｎｇｌｙｆｏｒｎｏｔｏｎｌｙｓｐｅｅｃｈａｎｄｆａｘｃｏｍｍｕｎｉｃａｔｉｏｎｂｕｔａｌｓｏＩｎｔｅｒｎｅｔｓｅｒｖｉｃｅ .ＴｈｅｄｅｍａｎｄｆｏｒｔｈｅｆｉｘｅｄＩｎ ｔｅｒｎｅｔｓｅｒｖｉｃｅ ,ｎａｍｅｌｙｔｈｅＷｏｒｌｄＷｉｄｅＷｅｂ(ＷＷＷ ) ,ｈａｓｂｅｅｎｓｐｅｃｔａｃｕｌａｒ.Ｔｈｅｓｅｒｖｉｃｅｉｓｎｏｗ…     

Performance of High Speed Coherent Optical Communication Systems

Ｐｅｒｆｏｒｍａｎｃｅｏｆｈｉｇｈｓｐｅｅｄｃｏｈｅｒｅｎｔｏｐｔｉｃａｌｃｏｍｍｕｎｉｃａｔｉｏｎｓｙｓｔｅｍｓｈａｓｂｅｅｎｉｎｖｅｓｔｉｇａｔｅｄ．Ａｎｏｖｅｌｆｒｅｑｕｅｎｃｙｔｒａｃｋｉｎｇ／ｌｏｃｋｉｎｇａｕｔｏｍａｔｉｃａｌｆｒｅｑ...     

An Asynchronous Implementation of Add-Compare-Select Processor for Communication Systems

A novel asynchronous ACS(add-compare-select) processor for Viterbi decoder is described.It is controlled by local handshake signals instead of the globe clock.The circuits of asynchronous adder unit,asynchronous comparator unit,and asynchronous selector unit are proposed.A full-custom design of asynchronous 4bit ACS processor is fabricated in CSMC-HJ 0.6μm CMOS 2P2M mixed-mode process.At a supply voltage of 5V,when it operates at 20MHz,the power consumption is 75.5mW.The processor has no dynamic power consumption when it awaits an opportunity in sleep mode.The results of performance test of asynchronous 4bit ACS processor show that the average case response time 19.18ns is only 82% of the worstcase response time 23.37ns.Compared with the synchronous 4bit ACS processor in power consumption and performance by simulation,it reveals that the asynchronous ACS processor has some advantages than the synchronous one.     

A Solution of Secure Communication in the Current and Future Mobile Network

1　Introduction　The mobile network is making people s lives more conve nient. Using mobile terminals people can talk to anyone atany time and at any places. And we want more. People willask if I can send short messages to Tom without others beingable to obtain their meanings. When I use my mobile phonetransferring my credit card, can anyone filch my credit cardpassword? Can I safely using my mobile phone to exchangestock? And so on…　Unfortunately, the answer is no nowadays. People canno…     

The Stability Analysis of Multimedia Playout Synchronization Using Buffer Level Control

1　Introduction　Multimediareferstothepresentationofcollectionsofbothstaticanddynamicdatainaspecifiedorderandtime[5] .Therefore ,therearewelldefinedtemporalrela tionshipsbetweenMediaUnits(MUs) .Mediacanbeonlyplayedwellwhenthesetemporalrelationshipsarepreservedatpresentationtime .Unfortunately ,afterthetransportationoverbest effortnetworks,thedelayjitterdestroysthetemporalrelationshipsbetweenperiodicallytransmittedMUs .Network jitter ,end systemjitter,clockdriftandchangingnetworkconditionsof…     

Circuit Topology Analysis of CMOS LNA in Mobile Communication Systems

1　Introduction　Now ,mostoftheLNAinRFreceiversarede signedwithGaAsorbipolartechnologies,whichhavealargepowerdissipationandunfavorableper formanceofintegration .CMOStechnologiestakeincreasinglyadvantagesoftechnologyadvances,whichhaveverylow powerconsumptionandmakepossibletheintegrationofcompletecommunicationsystems[1 ] .Forexample ,mobilecommunicationsystemreceiversemployextensivedigitalsignalpro cessingtoperformacquisition ,tracking ,anddecod ingfunctions.TheuseofCMOStechnologiesforimpl…     

H ∞ Control of Piecewise-Linear Systems Under Unreliable Communication Links

This paper considers the problem of H _∞ control of piecewise-linear control systems under unreliable communication links. Due to the limited bandwidth of the channels, signal transmission delays and data packet losses can occur between the plant and the controller. In the presence of random signal transmission delays and data packet losses, a piecewise controller is designed to stabilize the piecewise-linear system in the sense of mean square and also achieve a prescribed H _∞ disturbance attenuation performance based on piecewise-quadratic Lyapunov–Krasovskii functionals. It is shown that the H _∞ controllers can be designed by solving a set of linear matrix inequalities (LMIs) that are numerically feasible. Moreover, the controller design method is further extended to uncertain case where the system matrices’ uncertainties are represented in polytopic frameworks. Finally, an example is provided to illustrate the effectiveness of the developed theoretical results.