Article

Probability characteristics of the sum of a deterministic signal and noise with mean frequency equal to multiple signal frequency

April 1995

Authors:

In transmission of a harmonic signal through radioengineering sections and media differing by their amplitude-phase-frequency and dispersion characteristics a random process is realized which can be approximately represented as a sum of a deterministic harmonic signal and higher harmonics with random amplitudes and phases. There are determined statistical characteristics of envelope and phase of the sum of a deterministic harmonic signal and a narrow-band random process with frequency equal to multiple signal frequency. One-dimensional probability density, the first initial and second central moments of sum envelope and phase are obtained.

ResearchGate has not been able to resolve any citations for this publication.

ResearchGate has not been able to resolve any references for this publication.

Chapter

Power Spectral Density of Standard Random Processes—Part 1

March 2003

Roy Howard

Chapter 5 details the power spectral density of the standard random processes which are encountered in communications and electronics. The generality and importance of ?signalling random processes? is clearly outlined. The power spectral density of communication signals, DAC quantization noise, jitter, shot noise, and shot noise with dead time are detailed.

Article

Surface topography as nonstationary random process

February 1978

TOPOGRAPHY is often considered as a narrow bandwidth of features covering the form or shape of the surface. After detailed study of many measurements we consider that as well as the possibility of a dominant range of features there is always an underlying random structure where undulations in surface height continue over as broad a bandwidth as the surface size will allow. We consider this a ... [Show full abstract] result of many physical effects each confined to a specific waveband but no band being dominant. We invoke the central limit theorem and show through Gaussian statistics that the variance of the height distribution of such a structure is linearly related to the length of sample involved. In another form, the power spectral density, this relationship is shown to agree well with measurements of structures taken over many scales of size, and from throughout the physical universe.

Article

A numerical study of the existence and stability of some chaotic attractors by path integration

December 2008 · Journal of Vibroengineering

The response of a harmonically excited Duffing oscillator with chaotic response is studied by replacing the excitation by harmonic excitation plus added noise, a harmonic motion with phase perturbations, and a narrow-band filtered noise. The mean frequency and excitation energy for all the models are the same, assuming that these are basic parameters for the response of the oscillator. The ... [Show full abstract] resulting probability densities in the state space show that the chaotic attractor is very stable for the different kinds of perturbations. Also, a new conditional path integration method is described, which is shown to be robust and accurate while the CPU time is kept at a minimum.

Article

Full-text available

Limitations of red noise in analysing Dansgaard-Oeschger events

July 2009 · Climate of the Past Discussions

During the last glacial period, climate records from the North Atlantic region exhibit a pronounced spectral component corresponding to a period of about 1470 years, which has attracted much attention. This spectral peak is closely related to the recurrence pattern of Dansgaard-Oeschger (DO) events. A red noise random process was used to evaluate the statistical significance of this peak, with a ... [Show full abstract] reported significance of more than 99%. Here we use a simple two-state model of DO events, which itself was derived from a much more sophisticated ocean-atmosphere model of intermediate complexity, to numerically evaluate the spectral properties of random (i.e., solely noise-driven) events. This way we find that the power spectral density of random DO events differs fundamentally from a simple red noise random process. These results question the applicability of linear spectral analysis for estimating the statistical significance of highly non-linear processes such as DO events.

Article

Microscopic Study of Proton-Nucleus Total Reaction Cross Sections

January 1991 · Indian Journal of Physics

Mohamed Assad Abdel-Raouf

In this work, the modified Glauber theory (Glauber 1959) is applied to study the effect of the repulsive potential (Coulomb plus centrifugal) on the cross section of protons scattered from 12C and 208Pb in the energy range 5-2500 MeV. This potential is introduced in the calculations when the impact is replaced by the distance of closest approach. The effect of the central dispersion in the target ... [Show full abstract] density on the reaction cross section is investigated by comparing the cross section calculated with Fermi density and the one calculated with three parameter density.

Article

Quantum solutions for the harmonic-parabola potential system

March 2000 · Physical review A, Atomic, molecular, and optical physics

The quantum harmonic-parabola system, whose potential energy is the negative harmonic potential, is analyzed and applied to the cases of a quantum well, barrier, and periodic lattices. The eigenstate of the quantum Hamiltonian of the harmonic-parabola system is obtained. It is shown that any function may be expanded in terms of the eigenfunctions of the system in a finite interval, and the ... [Show full abstract] propagator of the system can be obtained from the eigenfunctions. The energy eigenvalues, uncertainty, and probability density for the first few states are treated for the infinite harmonic-parabola well. The energy eigenvalues and their enumeration, the energy band, and the probability density for the first few states are obtained for a well composed of the parabola and constant potentials. The transmission coefficients and each potential interval dependence are determined for this well and the barrier of the parabola-constant potential structure. Periodic lattices composed of the parabola potential and parabola-constant potentials are constructed, and their dispersion relations, energy states, and bands are obtained.

Conference Paper

Estimation of linear frequency drift coefficient of frequency standards

July 1996

Random errors of linear frequency drift coefficient measurements of frequency standards in the presence of disturbing noises for different estimation methods are discussed

Article

Search Control Algorithm Based on Random Step Size Hill-Climbing Method for Adaptive PMD Compensatio...

August 2009 · IEICE Transactions on Communications

Adaptive polarization mode dispersion (PMD) compensation is required for the speed-up and advancement of the present optical communications. The combination of a tunable PMD compensator and its adaptive control method achieves adaptive PMD compensation. In this paper, we report an effective search control algorithm for the feedback control of the PMD compensator. The algorithm is based on the ... [Show full abstract] hill-climbing method. However, the step size changes randomly to prevent the convergence from being trapped at a local maximum or a flat, unlike the conventional hill-climbing method. The randomness depends on the Gaussian probability density functions. We conducted transmission simulations at 160Gb/s and the results show that the proposed method provides more optimal compensator control than the conventional hill-climbing method.

Article

Full-text available

Theory of Interferometric Analysis of Laser Phase Noise

August 1966 · Journal of the Optical Society of America

J. A. Armstrong

The line width of a well-stabilized laser operating far above threshold is determined by random fluctuations of the phase. This paper discusses several types of experiments which can give information about the details of this phase random process. In order to study the laser phase noise experimentally the laser signal (containing phase noise only) must be passed through some type of ... [Show full abstract] interferometer which will convert the phase noise to intensity noise. The various properties of this derived intensity noise which may then be determined are its probability density, first and second moments, autocorrelation function, and spectrum. These measurable quantities depend on two factors; the first and more fundamental is the joint probability distribution for the change in phase in a given time. The second factor is the manner of operation of the interferometer in changing phase to intensity noise. We discuss both two-beam and multiple-beam interferometers and derive theoretical expressions for the above-mentioned properties of the output intensity fluctuations. It is interesting that although in both cases the output intensity fluctuations are nongaussian random processes, it is nevertheless possible to derive a number of useful theoretical results.

Article

On the motion of gyroscopic devices under the influence of random forces

December 1960 · Journal of Applied Mathematics and Mechanics

Ia.N. Roitenberg

The motion of gyroscopic devices under ship's rolling coniditions was usually considered assuming the roll sinusoidal. The works of Sveshnikov [1] showed that the rolling motion of a ship can be considered a stationary random process, and obtained the correlation function and spectral density for this process. The motion of some ship devices under these conditions was studied by Rivkin [2].The ... [Show full abstract] present paper considers the motion of a powered gyrostabilizer, plane gyropendulum and a gyrocompass subject to irregular ship rolling; determines the dispersion of a stabilization angle for the powered gyrostabilizer; and derives an expression for intercardinal deviation of the gyrocompass.

Article

Full-text available

Spectral features of the alternating cluster process

September 2010 · Fluctuation and Noise Letters

Ferdinand Grüneis

The alternating cluster process is a Poisson process the rate of which is modulated by an underlying two-state process. We derive the power spectral density of the alternating cluster process; besides random noise we obtain excess noise due to the impact of modulation.

Article

Impact of polarisation mode dispersion on the statistics of Q factor in optical transmission systems

September 2000 · Electronics Letters

The authors calculate the probability density function of the Q factor for optically amplified transmission IM-DD systems, in the presence of a randomicity given by the polarisation mode dispersion. Theoretical and experimental results obtained in a soliton field trial 500 km long at 40 Gbit/s show a satisfactory agreement