Showing papers on "Bessel filter published in 2014"

Improved Vowel Onset and offset points detection using bessel features

Abstract: This work presents a method for improving accuracy of Vowel Onset Point (VOP) and Vowel End Point (VEP) detection in continuous speech. VOP and VEP are the instants at which the onset and offset of vowel takes place, respectively, during speech production. Speech signal is represented using Bessel functions with their damped sinusoid-like basis functions. Bessel expansion is used to emphasize the vowel regions by appropriate consideration of the range of Bessel coefficients. Bandpass filtered narrow-band signal is modeled as a monocomponent amplitude modulated-frequency modulated (AM-FM) signal. The amplitude envelope (AE) function of this vowel emphasized AM-FM signal gives strong evidence for the VOP and VEP. This evidence after adding with some of the existing evidences having source and system information, increases the detection rate as well as the accuracy of detection.

Bessel Function and Damped Simple Harmonic Motion

Abstract: A glance at Bessel functions shows they behave similar to the damped sinusoidal function. In this paper two physical examples (pendulum and spring-mass system with linearly increasing length and mass respectively) have been used as evidence for this observation. It is shown in this paper how Bessel functions can be approximated by the damped sinusoidal function. The numerical method that is introduced works very well in adiabatic condition (slow change) or in small time (independent variable) intervals. The results are also compared with the Lagrange polynomial.

Wdm based fso link optimizing for 180km using bessel filter

Abstract: Free space optical link is a growing field in communication due to its advantage of wide bandwidth, high security and easy installation. A wavelength division multiplexing (WDM) access network using free space optical (FSO) communication in different weather conditions like haze and rain are discussed in this article and find out the possibility of communication link up to 180 km in clear weather with 2.5 Gbps data rate on the wavelength of 1550 nm and up to 54 km in haze condition using same data rate & wave length. Further the effect of using two different low pass filter (Gaussian and Bessel) at the receiver are discussed and conclude that Bessel filter is better on 2.5 Gbps data rate for WDM based FSO link.

Bessel-Butterworth transitional filters

Abstract: The paper considers a new class of polynomial filters with transfer functions calculated via a recurrent relationship. The procedure starts choosing two kernel algebraic ratios u 0 (s) = 1 and u 1 (s) = 1 + 1 / s where s is the complex variable. Further ratios are obtained via the recurrent relationship u n+1 (s) = [(2n + d) / s]u n (s) + u n-1 (s) where n ≥ 1 and d is a parameter. The numerators of these ratios are taken as denominator polynomials for filter transfer functions. When d = 1 these polynomials are coinciding with the Bessel polynomials. The corresponding filters (or Bessel filters) have a very small step-response overshoot (less than 1%). When d ≠ 1 (the paper considers the range of 0 ≤ d ≤ 1), and is decreasing, the step-response overshoot is increasing. For d = 0 it becomes about 10% as in Butterworth filters. The proposed filters are transitional between Bessel and Butterworth and called here as BeBut filters.

Analog quantity merging unit transient state delay test method based on frequency scanning

Abstract: The invention discloses an analog quantity merging unit transient state delay test method based on frequency scanning. Sudden-change quantities of a received standard source signal and a signal to be measured are judged in real time, a starting moment of a transient state process is determined, waveform signals are collected, the amplitude and the phase angle of each harmonic are calculated, the transient state delay corresponding to each harmonic is calculated, and ultimately, the ultimate transient state delay is calculated according to the amplitude of each harmonic and the transient state delay corresponding to each harmonic. Transient state transmission time is calculated through a weighting coefficient, test currents do not need to be output specially, universality is high, and the method is suitable for all merging units with low-pass filter coefficients, port modes and port protocols currently. A high-precision constant-temperature crystal oscillator is used for controlling timing sequence and eliminating errors, the transient state starting moment of tested data is guaranteed, and sampling precision of higher harmonics is improved by means of a four-step Bessel filter. The analog quantity merging unit transient state delay test method based on frequency scanning can be widely used in the field of relay protection and verification.

Electronic transformer collector based on 4-order Bessel filtration and software integration

Abstract: The invention discloses an electronic transformer collector based on 4-order Bessel filtration and software integration The collector comprises a 4-order Bessel filter, a high-speed sampling module, an integration element and an FT3 sending module After low pass filtering is carried out on signals output by a sensing element of an electronic transformer through the 4-order Bessel filter, the high-speed sampling module samples the filtered signals at a high speed, then integral restoring is carried out on the sampling signals through the integration element, measurement of currents and voltage at one time is achieved, and the FT3 sending module sends data to a merging unit The electronic transformer collector effectively solves the problems that at present, antijamming capability is insufficient, distortion of the software integration element occurs, higher harmonic cut-off frequency is too low, hardware integral accuracy is not high, and damage is easily caused, and improves accuracy and reliability of measurement of the currents and voltage

Quantifying the Q-Factor and Minimizing BER in 32-Channel DWDM System Design Using EDFA and RAMAN Amplifiers

Abstract: In this work we have designed, modeled and simulated a 32-channel DWDM (Dense Wavelength Division Multiplexing) system using OptiSystem photonic simulator. The system is tested for external transmitter with NRZ (Non-Return Zero) encoder using Mech-Zehnder modulator, which accepts input from CW (Continuous Wave) laser array and low pass Bessel filter that supports PIN photodiode at receiver end. System performance for optical channels has been compared by varying channel length of EDFA (Erbium Doped Fiber Amplifier) and Raman amplifiers to identify its impact in the sense of eye diagram, QF (Quality Factor) and minimum BER (Bit Error Rate). Experimental setup was done by varying channel lengths of 60, 100, 120, 150 and 170Kms. It was found that EDFA has better performance in the sub-low ranges of 60Kms, whereas Raman offers better performance at wider channel lengths i.e. more than 100Kms. The proposed work can be extend for the avoidance of amplifier utilization at wider ranged.

Gain equalizer approximation by using q-Bessel polynomials

Abstract: A linear slope gain equalizer with MAXFLAT delay is presented based on using q-Bessel polynomials. As it is known that the q-Bessel polynomial has more parameter to adjust than does the simple Bessel polynomials. The proposed gain equalizer has the important features; maximally flat group delay, non-minimum phase network, and transmission zeros possess quadrant symmetry. The simulation is carried out to investigate the performance of the proposed equalizer. As the result, the proposed gain equalizer can correct both low-gain distortion and high-gain distortion and agrees with the theoretical ones.

Simple proofs of classical results on zeros of $\mathbf{J_\nu(x)}$ and $\mathbf{J_\nu'(x)}$

Abstract: The Bessel functions $J_{ u}(x)$ and their derivatives $J_{ u}^{\prime}(x)$ can be represented by infinite series and infinite products. Using these representations we give very simple proofs for known results concerning the zeros of the above functions.

q-Bessel polynomials for linear phase matched filter

Abstract: In this paper, q-Bessel polynomials for linear phase matched filter is presented. In order to approximate a receiver filter with optimum performance, a raised-cosine test pulse is utilized. A transfer function of the proposed matched filter at receiver consists of transmission zero pairs and q-Bessel polynomials used as a linear phase denominator. Simulation results show that the performance of the matched filter is better than the one obtained from conventional Bessel polynomials.

Floor vibration isolation of a coriolis mass-flow meter using filtering techniques

Abstract: In this research, floor vibration isolation using filtering techniques is evaluated. A Bronkhorst Coriolis Mass Flow Meter, CMFM, for low flows is used as a platform for testing the resistance against external disturbances. The robustification of this CMFM consists of both predicting the disturbance at the sensing frequency and removing as much of the other disturbances as possible. The first part, the prediction, starts with estimating the transfer from floor vibrations to mass- flow. Once this transfer is obtained, it is modeled using a state space model. The measured floor vibrations are fed to this model and subtracted from the measured mass-flow. The second part is the removal of the remaining disturbances (floor vibrations and higher harmonics) left. This is done using a band-pass and a Bessel filter. The band-pass filter enhances the measured data and improves the signal to noise ratio. A second order Bessel filter removes any high-frequent noise still present in the flow signal.

EDFA WDM Optical Network using GFF

Abstract: This paper describes the model and simulation of EDFA WDM optical network using GFF (Gain flattening filter). The proposed model consists of input source, pumping sources, isolators, EDFA, WDM multiplexers, GFF, pin photo detector, low pass Bessel filter, 3R generator, BER analyzer. The proposed model is simulated on optisystem 7.In this paper the proposed model represent EDFA flattened gain dynamics and reduced noise figure. This is useful in network reconfiguration and Multi-vendor networks.

Design of 4-way crossover network by using bernstein polynomial

Abstract: This paper presents the design of a 4-way crossover network by using bernstein polynomial. This crossover can be created by combining a high-pass filter, low-pass filter, and Band-pass filter the three frequencies range. Simulation results are using MATLAB. The simulation results can be seen that good slope for magnitude responses of high-pass filter, low-pass filter and band-pass filter the Second frequencies range. And phase responses of the total filter have the zero phases. The crossover is unique, in that it sums with the flat magnitude response and phase response of all band.

Detecting Bessel beams

Abstract: We propose a 2-dimensional method for Bessel Gaussian beam azimuthal and radial decomposition using digital holograms. We illustrate the reconstruction of a Bessel Gaussian beam after encountering an obstruction. From the measured decomposition we show the reconstruction of the amplitude, phase and azimuthal index of the field with high degree of accuracy.

Investigate the Performance of QAM Communication System by Transforming Linear Phase Filter Design using Parks-Mcclellan Algorithm into Minimum Phase Filter

Abstract: n this paper, the design of a low-pass minimum phase equiripple finite impulse response (FIR) digital filter from the given low-pass linear phase equiripple. The initial linear phase transfer function is obtained by standard Parks- Mcclellan algorithm. The shorter group delay should be minimal for efficient performance of digital pulse shaping filter like it improves the performance parameters like increased Capacity, reduced BER, better S/N ratio, and Reduced ISI (noise). The small group delay minimum phase filter coefficients were subjected to QAM (32, 64, and 128) system. The minimum phase filter performed well in terms of bit error rate (BER) parameter.