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Odd clipping optical orthogonal frequency division multiplexing for VLC system

The Orthogonal Frequency Division Multiplexing (OFDM) has emerged as one of the promising techniques because of its robustness to multipath fading with high-speed data transmission. Classical bipolar OFDM cannot be used in intensity modulated with direct detection (IM/DD) optical communication systems, as visible light communication (VLC), so many optical modulation techniques as asymmetrical

Circuit Theory and Applications
Software and Communications

All Possible Topologies of the Fractional-Order Wien Oscillator Family Using Different Approximation Techniques

This paper introduces all the possible topologies of the Wien bridge oscillator family. This family has 72 topologies, 24 of them contain only RC or RL pairs, and the rest contain mixed pairs. The complete mathematical analysis of all twelve possible capacitive-based topologies is proposed in the fractional-order domain. The investigated circuits can be categorized into two groups, each with a

Circuit Theory and Applications

FPGA implementation of sound encryption system based on fractional-order chaotic systems

This paper introduces design and FPGA implementation of sound encryption system based on a fractional-order chaotic system. Also, it presents the FPGA implementation of Tang, Yalcin, and Özoǧuz fractional order chaotic systems. The Grunwald-Letnikov (GL) definition is used to generalize the investigated systems into the fractional-order domain. Also, the variation of parameters for each system is

Circuit Theory and Applications

A Simple BJT Inverse Memristor Emulator and Its Application in Chaotic Oscillators

A generalized inverse memristor emulator is proposed based on two BJT transistors as a diode connected with a first order parallel RC filter. The mathematical model of the circuit is presented where the pinched hysteresis loops (PHLs) with different periodic stimuli are analyzed. The numerical, P-Spice simulations and experimental results are presented indicating that the introduced emulator is a

Circuit Theory and Applications

Control of continuous-time chaotic (hyperchaotic) systems: F-M synchronisation

In this paper, a new type of chaos synchronisation between different dimensional chaotic systems is proposed. The novel scheme is called F-M synchronisation, since it combines the inverse generalised synchronisation with the matrix projective synchronisation. In particular, the proposed approach enables F-M synchronisation to be achieved between n-dimensional master system and m-dimensional slave

Circuit Theory and Applications

Fractional X-shape controllable multi-scroll attractor with parameter effect and FPGA automatic design tool software

This paper proposes a new fractional-order multi-scrolls chaotic system. More complex systems and flexible ranges of the chaotic behavior are obtained due to the extra parameters added by the fractional-order. The proposed system has novel complex chaotic behaviors. The effect of changing the system parameters on the system behavior is investigated and their bifurcation diagrams have been provided

Circuit Theory and Applications

Multifunction fractional inverse filter based on otra

This paper proposes a generalized topology of a fractional-order inverse filter (FOF) using operational transresistance amplifiers (OTRA) block. Seven different configurations are extracted from the introduced topology employing generalized admittances. The generalized admittances increase the flexibility to provide different types of FOFs such as inverse fractional high pass filter (FHPF)

Circuit Theory and Applications

Fractional-order mihalas-niebur neuron model implementation using current-mirrors

A simple realization of the fractional-order Mihalas-Niebur neuron model is presented in this work. The required low-pass filter is implemented using current-mirrors offering simple circuitry and, also, electronic tunability of the realized time-constant. Due to the limited bandwidth required for this application, the necessary fractional-order capacitor is realized using an appropriately

Circuit Theory and Applications

Partial fraction expansion–based realizations of fractional-order differentiators and integrators using active filters

Approximations of the fractional-order differentiator and integrator operators s±r are proposed in this work. These approximations target the realization of these operators using standard active filter transfer functions. Hence, circuit implementations in integrated circuit form or in discrete component form are significantly facilitated. Complementary metal-oxide-semiconductor (CMOS) realizations

Circuit Theory and Applications

Using Meta-heuristic Optimization to Extract Bio-impedance Parameters from an Oscillator Circuit

This paper introduces a method for extracting the Cole-impedance model parameters using a meta-heuristic optimization technique. The method is based on a single proposed resistor controlled oscillator (SRCO) where the unknown bio-impedance is embedded. At two different oscillation frequencies, the start-up oscillation condition is recorded. Then the corresponding nonlinear equations are solved

Circuit Theory and Applications