This paper presents two methods for designing special purpose controllers for permanent magnet synchronous motor. The main target of the designed controllers is to reduce torque ripples of this type of motors. The first proposed adaptive method is based on two loop controllers (current controller and speed controller) in addition to using space vector pulse width modulation to maximize fundamen...

This paper presents an evaluation of the spectral characteristics of switching converters with a chaotic carrier-frequency modulation scheme (CCFMS). By incorporating a Chua’s circuit (CC) into the pulsewidth modulator for driving the switches, three modulation schemes, including the standard pulsewidth modulation scheme, periodic carrier-frequency modulation scheme, and CCFMS, can be realized ...

This work represents the synthesis of the 211 pulse sequence for the study of electron spin-echo envelope modulation ~ESEEM! with the technique of spin-echo correlated spectroscopy ~SECSY!, which has previously been used to study nuclear modulation by two-dimensional Fourier transform ESR methods. This example of ‘‘pulse adjustable’’ spectroscopy, wherein the pulse width and pulse amplitude of ...

We propose a simple method for secure digital signal transmission by making some modifications in the single-step parameter modulation technique proposed earlier into overcome certain inherent deficiencies. In the modified method, the parameter modulation is effectively regulated or controlled by the chaotic signal obtained from the transmitting chaotic system so that it has the maximum securit...

This paper describes various block waveform encoded (M-ary) signal designs using pulse-position-modulation (PPM) that are useful in pulse-based ultra wideband (UWB) communications inwireless, cable and twisted-pair wire channels, and in other systems based on PPM (not necessarily of UWB nature). This work is focused in four interesting M-ary PPM signal designs: Orthogonal, Equicorrelated, N-ort...

Pulse width modulation strategies have been developed for indirect matrix converters (IMCs) in order to improve their performance. In indirect matrix converters, the LC input filter is used to remove input current harmonics and electromagnetic interference problems. Unfortunately, due to the existence of the input filter, the input power factor is diminished, especially during operation at low ...

Optical wireless communication has the potential for extremely high data rates of up to tens of Gb/s. In this study, a hybrid modulation technique named adaptive differential amplitude pulse-position modulation (DAPPM) is proposed to improve channel immunity by utilising optimised modulation to channel. The unit transmission rate, channel capacity, peak-to-average power ratio, bandwidth require...

Unfortunately, traditional RF pulse measurements become less effective predictors of performance in radars that use pulse compression. For example, the width of an uncompressed radar pulse is directly related to spatial resolution. In contrast, the resolution depends on pulse width, chirp bandwidth and chirp linearity in a compressed radar system that uses linear frequency modulated (LFM) chirp...

Significant misrepresentation of both 1-bit SDM and multi-bit LPCM coding paradigms persist within both professional and commercial arenas that impacts directly upon the perception of DVD-A and SACD formats. A balanced appraisal of these schemes is presented in order to expose the core differences in the technology both in the theoretical and instrumentation domains. Some observations are made ...

We study cumulative scattering effects on wave front propagation in time dependent randomly layered media. It is well known that the wave front has a deterministic characterization in time independent media, aside from a small random shift in the travel time. That is, the pulse shape is predictable, but faded and smeared as described mathematically by a convolution kernel determined by the auto...