Search Results

We propose and analyze new impedance matching schemes to enhance applied voltage to an optical modulator and light modulation for a subcarrier multiplexed light transmitter or a radio-on-fiber transmitter that carries radio-frequency signal through an optical fiber. Our proposal includes two methods using a quarter-wavelength impedance transformer and a tapered microstrip line for impedance matching…

Modulation type classification is a part of waveform estimation required to employ spectrum sharing scenarios like dynamic spectrum access that allow more efficient spectrum utilization. In this work multiple classification features, feature extraction, and classification algorithms for modulation type classification have been studied and compared in terms of classification speed and accuracy to suggest the…

The problem of Pulse Width Modulated (PWM) DC-DC converter simulation is faced in this paper. It is shown how the analysis of this kind of circuits, nonlinear and switching for their nature, can be easily and quickly executed by using symbolic analysis techniques. The paper also presents the program SapWinPE, which performs an automatic symbolic…

Wireless Body Area Networks support the operation within multiple frequency bands. Thus, they can be integrated in several applications, one of which is on-body medical monitoring applications, as concerned in this paper. Therefore, the purpose of this study is to present the impact of transmission power and both of Differential Binary Phase Shift Keying and…

Electrostatic suspension systems have great potential applications in contactless transportation objects since they allow many different materials to be suspended. The electrostatic suspension will be widely applied in practice if the system cost is inexpensive. This paper presents an electrostatic suspension system controlled by using pulse width modulation (PWM). The use of PWM in electrostatic…

FM broadcast stations generate reverse intermodulation signals that cause communication problems between ATC controllers and pilots in the Air Traffic Control systems (ATC) in Thailand. In this paper proposes a balanced RF power amplifier using the improvement 3-dB quadrature hybrid couplers to reduce the reverse intermodulation of FM broadcasting systems. The mathematics analysis of the…

The Internet of Things (IOT) is a revolutionary communication technology which enables numerous heterogeneous objects to be inter-connected. In such a wireless system, interference management between the operating devices is an important challenge. Cognitive Radio (CR) seems to be a promising enabler transmission technology for the 5G-IOT system. The “sense-and-adapt” smart transmission strategy in CR…

The track circuits are very important equipments used in the railway transportation system. Today these are used to send vital information, to the running train, in the same time with the integrity checking of the rail. The actual track circuits have a small problem due to the use of the same transmission medium by the…

In this paper, a spatial modulation (SM) which provides no synchronization between the transmitting antennas and avoids inter-channel interference (ICI) at the receiver input while maintaining high spectral efficiency is applied to filtered-orthogonal frequency division multiplexing (F-OFDM) transmission. The SM technique maps a block of information bits into two information carrying units, namely, a symbol…

Direction dependent antenna modulation (DAM), as a potential physical-layer security technique, is able to enhance the security of wireless communication systems by virtue of the capability of its direction-dependent signal modulation format transmission. In this paper, DAM using frequency diverse array (FDA) to produce the modulation is presented. By phase shifting each element, the desired…

Carbon nanotube field effect transistor (CNTFET) has a huge advantage over the Si- MOSFET. In MOSFET switching occurs by altering channel resistivity whereas in CNTFET switching occurs by modulation contact resistance. CNTFET generates three to four times of drive current than MOSFET. Transconductance of CNTFET is four times higher than the MOSFET. The average carrier…

With the significant spread of 5G telecommunication systems, the demand for high quality of service and better coverage is growing rapidly. Multiple-input–multiple-output is planned to be among the key technologies in 5G telecommunication’s field. In this article, a new fully digital 2×2 MIMO testbed is implemented, using USRP B210 and 2 pairs of microstrip antennas…

Induction motors (IM) are used widely in high energy applications where high torque is required such as ships/ aircrafts manufacturing industry. Those motor drivers are populated in many advantages especially their wide control strategies. However, new technology is invented for enhancing efficiency and smoothing the torque curve by increasing number of phases in the motor…

Higher efficiency and lower losses are widely considered as the best metrics to optimize, in a high-power converter performance context. To provide a solution to the ever-increase of high switching frequencies challenges, we must explore soft-switching technologies to resolve interface issues and reduce the switching losses. This manuscript describes a comparative analysis between the fixed-bandwidth…

This paper covers a new topology, a synchronous wind turbine generator, and a solar photovoltaic generator. The Permanent Magnet Synchronous Generator is linked to the grid by back-to-back voltage source converters (BtB VSC), consisting of a two-stage rectifier and a five-stage Neutral Point Clamped inverter, operated by the Space Vector Pulse Width Modulation technique. A…

Advances in optimizing optical fiber communications have been on the rise these recent years due to the increasing demand for larger data bandwidths and overall better efficiency. Coherent optics have focused on many kinds of research due to its ability to transport greater amounts of information, have better flexibility in network implementations, and support different…

The main advantage of software-defined visible light communication (VLC) systems is that they allow us to reuse modulation, coding, synchronization and medium access techniques used in conventional radio systems. This article focuses on the implementation of an uplink alternative using an infrared (IR) light communication system. For this goal, analog front-ends are designed and implemented.…

This paper represents analysis of principles providing maximally reliable delay estimation of signal synchronization devices in telecommunication. Clock synchronization schemes on the base of stochastic models, graph-analytic interpretation, analytical functional description and their parameters selection in case of real complex hindrance are analyzed. Dependences between dispersion of maximally reliable estimation of synchronization devices and signal…

In fast charging station for Battery Electric Vehicles (BEVs) the three-phase PWM (Pulse Width Modulation) inverters generate parasitic Differential-Mode Voltages (DMV) and Common-Mode Voltages (CMV). Parasitic voltages are a side effect of using the width modulation to shape the phase-to-phase inverter’s voltage. In this article the authors present a mathematical description of the differential-mode (DM)…

Orthogonal Frequency Division Multiplexing (OFDM) is a modulation format that has recently attracted lots of consideration interior the long-haul fiber-optic transmission community. The most important advantage of optical OOFDM is its unlimited capability of canceling Inter-Symbol Interference (ISI) caused by Chromatic Dispersion (CD) and Polarization-Mode Dispersion (PMD). Specifically, Coherent OOFDM (CO-OFDM) presents a good and…

An experimental transmission between two XBee modules using Radio over Fiber technique is demonstrated. Data issued from an XBee module coded on a wireless microwave carrier at 2.44GHz is transmitted through an optical link of 25.24 km. The optical transmission is based on an external modulation scheme over a dispersive channel. Frequency response of the…

The article proposes a Digital Predistortion (DPD) methodology that substantially meliorates the linearity of limited range Mobile Front Haul links for the extant Long-Term Evolution (LTE) and future (5G) networks. Specifically, the DPD is employed to Radio over Fiber links that contrive of Vertical Cavity Surface Emitting Lasers (VCSELs) working at 850 nm. Both, Memory…

This work extends the development of the nonuniform Parallel Digital Ramp Pulse Position Modulation Analog-to-Digital Converter (PDRADC) architecture. The continuous to discrete transform of the PDRADC is achieved by partitioning the signal amplitude axis into P nonoverlapping partitions that sample the analog input at input signal driven instances. Each partition contains L uniform levels with…

In densely located loosely coupled wireless charger environments, cross-connection errors can occur when wireless chargers operate at the same time within the same wireless communication range. In this work, an effective algorithm is proposed to prevent cross-connection error. The algorithm based on the cross-connection abatement technique with the received signal strength indicator of out-band BLE…

Requirement for pole-changing motors emerged at the very early times of asynchronous motor design. Different solutions have been elaborated and some of them are generally used. One of these solutions in use is the so called pole phase modulation method. The so called 3 Y / 3 Y pole-changing winding being subject of this paper…