In this paper, we present a new scheme for the realization of a wide-band chaotic RADAR system. The remarkable characteristics of such scheme are: (1) Wide-band chaotic signal generated from microwave chaotic Colpitts oscillator is directly used as the RADAR signal; (2) Chaos synchronization is used to recover the chaotic signal from the back-scattered signal by targets; (3) The intrinsic sensitivities of the chaotic signal to the parameters of the chaotic circuit and to the initial conditions are used to realize the “multi-user” property. System simulations show that such RADAR can still work in an environment when the signal-to-noise ratio (SNR) is lower than −20 dB. † Also with Zhejiang University City College, Hangzhou, 310025, China.

/pdf/a-new-architecture-of-uwb-radar-utilizing-microwave-chaotic-aclrol3hj6.pdf

A new architecture of uwb radar utilizing microwave chaotic signals and chaos synchronization

We solve the problem of master-slave synchronization of fourth-order Lu's hyperchaotic systems via feedback control. We use only one control input that enters in the slave system. We show that this simple feedback suffices to synchronize both systems exponentially fast. We provide a proof of stability and convergence (hence, that synchronization takes place) via Lyapunov's second stability method. We provide some numeric simulations that illustrate our findings.

/pdf/master-slave-synchronization-of-fourth-order-lu-chaotic-2yh94143cp.pdf

Master–Slave Synchronization of Fourth-Order Lü Chaotic Oscillators via Linear Output Feedback

In this paper, synchronization of chaotic Colpitts circuits using a particle filter (PF) to combat the additive white Gaussian noise (AWGN) channel effect is studied by numeric simulations. A novel PF algorithm suitable for chaos synchronization is proposed. With this algorithm, chaos synchronization of Colpitts circuits can be achieved and maintained in AWGN channels. Parameters in the proposed PF algorithm are studied to understand their effects on synchronization performance. The synchronization performance using the proposed PF algorithm is compared with those using other digital filters, such as the extended Kalman filter and the generic PF. It is found that the proposed PF algorithm performs better than the other digital filters. Simulation results also show that the particle number is not very critical to the synchronization performance when this PF algorithm is used.

Particle Filter-Based Synchronization of Chaotic Colpitts Circuits Combating AWGN Channel Distortion

In this paper, we present a new scheme for the realization of a wide-band noisesignal RADAR utilizing wide-band chaotic signal generated from microwave chaotic Colpitts oscillator. System simulations show that such RADAR can still work in an environment when the signal-to-noise ratio (SNR) is −20 dB.

https://piers.org/piersonline/pdf/Vol3No8Page1326to1329.pdf

Ultra-wide Band Noise-signal Radar Utilizing Microwave Chaotic Signals and Chaos Synchronization

In this work, synchronization of chaotic Colpitts circuits, using adaptive controllers to combat circuit parameter mismatches and channel distortions, is studied by numerical simulations. Synchronization errors caused by different main circuit components are compared, and compensation for time-constant and time-varying circuit parameter mismatches is demonstrated. Different kinds of channel distortions, including time-constant and time-varying channel attenuation, Additive White Gaussian Noise (AWGN) are all investigated by numerical simulations and discussed. Simulation results indicated that the synchronization performance of chaotic Colpitts circuits can be greatly improved by applying adaptive controllers when parameter mismatches and channel attenuation are considered as time-constant or time-varying, but have no obvious enhancements regarding the effect on AWGN channel.

Adaptive synchronization of chaotic Colpitts circuits against parameter mismatches and channel distortions

The synchronization performance of the Pecora-Carroll scheme and the error feedback scheme was investigated for two coupled chaotic Colpitts circuits. Both the mathematical derivation and numeric simulations indicate that the error feedback synchronization scheme outperforms the Pecora-Carroll synchronization scheme when the chaotic signal is transmitted over a noisy channel in which there exist an additive white Gaussian noise source and a channel filter. As a result, the information embedded in the chaotic signal, which passes a noisy channel from the transmitter to the receiver, can be recovered in a better way when the error feedback synchronization scheme is used.

http://ieeexplore.ieee.org/iel5/9294/29544/01340842.pdf

Zhiguo Shi

Papers

Performance comparison of two synchronization schemes for Colpitts circuits based chaotic communication system over noise channel