Chutchavong, Vanvisa

Preferred name

Alternative Name

Chutchavong, V.

Main Affiliation

School of Engineering

vanvisa.ch@kmitl.ac.th

Now showing 1 - 9 of 9

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On approximation of linear gain equalizer by q-Bernstein-Stancu operators and Möbius transformation
(2018-07-02)
Chutchavong, V.
;
Dokyam, T.
;
Janchitrapongvej, K.
;
Benjangkaprasert, C.
This paper presents the design of linear gain equalizer by using Bernstein polynomials including q-Bernstein-Stancu operator and Möbius transformation. This method has the adjustable parameters more than the many types of Bernstein operators, these parameters can use to adjust the important characteristics of a linear gain equalizer for the best result. The simulation results show maximally flat magnitude, non-minimum linear phase and nearly constant delay for both of low-gain and high-gain equalizer. Furthermore, the Mikhailov's criterion has been used to guarantee the stability of desired transfer function.
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Approximation of sine-squared pulse with additional transmission zero using bessel polynomials
(2017-11-24)
Chutchavong, V.
;
Anuwongpinit, T.
;
Benjangkaprasert, C.
;
Janchitrapongvej, K.
In this paper, the approximation of sine-squared pulse based on Bessel polynomials with additional transmission zero is presented. The additional transmission zero has a parameter alpha to control the attenuation response. The simulation results show the additional transmission zero can control the peak of attenuation response close to the ideal response. In addition, the orders of Bessel polynomials are decreased that confirm a performance is better than the previous works.
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Circularly polarized right angle slot antennas for WLAN of IEEE 802.11b/g
(2008-12-01)
Pomsathit, A.
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Benjangkaprasert, C.
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Anantrasirichai, N.
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Chutchavong, V.
;
Wakabayashi, T.
In this paper, the design consideration for right-hand (clockwise) and left-hand (counterclockwise) circularly polarized microstrip slot antennas are presented. The circularly polarized antenna consists of two right angle slot antennas that is two orthogonal modes in phase quadrature or an array of linearly polarized slot with proper orientations and phases. This antenna can generate circular polarization by radiating orthogonal field components from two slots with equal amplitude but in phase quadrature. Two orientations for circularly polarized are investigated in this paper from simulation and measurement results are shown at resonance frequency 2.45 GHz on return loss, VSWR and radiation patterns.I © 2008 IEEE.
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A new method for design of the linear gain equalizer based on stancu’s including bernstein polynomials
(2017-11-24)
Chutchavong, V.
;
Dokyam, T.
;
Benjangkaprasert, C.
;
Janchitrapongvej, K.
This paper presents an approximation of transfer function for gain equalizer based on the Bernstein-Stancu polynomials operators, which used to equalize the linear gain distortion. As the well-known that the Bernstein-Stancu polynomials have an adjustable parameter more than the classical Bernstein polynomials, it can be used to adjust a response for the best result. As the result, the proposed method to design gain equalizer has a good performance both of low-gain distortion and high-gain distortion. In addition, the stability of desired transfer function is verified by using the Mikhailov’s criterion.
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Performance of a robust variable step-size LMS adaptive algorithm for multiple echo cancellation in telephone network
(2006-12-01)
Tingchan, W.
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Chutchavong, V.
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Benjangkaprasert, C.
The used of adaptive echo canceller is to estimate the impulse response of echo path and synthesizes an echo replica to subtracted from the echo signal in telephone network. Moreover, most echo paths change their characteristics frequency according to the noisy environment. To cancel multiple echoes, the number of tap coefficients of a conventional echo canceller must be large. The length of the echo canceller will directly affect both the degree of accuracy and the convergence speed the adaptation process. In this paper presents the comparison of the performance of the robust variable step-size LMS adaptive algorithm and the LMS adaptive algorithm for cancels multiple echoes signal in telephone networks. The core of this paper is a multiple delay estimator, which estimates and distributes delays to each individual fixed length short echo canceller. The simulation results are show that with the delays given, the robust variable step-size LMS adaptive algorithm can update the echo path accurately. © 2006 ICASE.
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A variable luminance-chrominance gain equalizer
(2010-07-30)
Chutchavong, V.
;
Poungpayom, S.
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Sangaroon, O.
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Benjangkaprasert, C.
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Janchitrapongvej, K.
This paper presents a variable luminance-chrominance gain equalizer for correcting the linear chrominance gain distortion in color TV transmission system. The new technique shows that the chrominance signal amplitude at 4.43 MHz can be controlled by using a delay line network in parallel with a variable resistor R<inf>T</inf>. Therefore, the proposed gain equalizer can be controlled by means of variable resistor R<inf>T</inf> and R<inf>Y</inf> for correction of the chrominance gain distortion. It is also proved to be efficient in equalizing because it offers more advantages. Among the advantages obtained using a delay line network in parallel with a variable resistor when compared to the gain equalizer provide by the other filters. First of all, it can provide a wide range of gain control. Secondly, the circuit of the proposed gain equalizer is simple with low cost. Next, it is also low complexity. At last, the chrominance gain distortion can be easily corrected without much serious delay error. Additionally, a modulated 20T sine-squared pulse test signal is used to test the performance of the proposed gain equalizer.
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On design of video equalizer for distorted chrominance based on the Bernstein Polynomials
(2006-12-01)
Chutchavong, V.
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Benjangkaprasert, C.
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Janchitrapongvej, K.
In this paper, we propose a design of video equalizer for compensating the amplitude of chrominance signal based on the Bernstein Polynomials. The use of Bernstein Polynomials in analog filter obtain the advantages are linear phase filter, several parameters that control the amount of phase and magnitude, and flexible for variable of phase. In addition, experimental results are carried out by using the modulated 20T sine squared signal. It is shown that the proposed video equalizer can be enhanced or compressed the amplitude chrominance distortion in color television transmission. © 2006 IEEE.
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Adaptive equalization of the distorted chrominance signal using VSQLMp error criterion
(2004-12-01)
Chutchavong, V.
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Rukluea, P.
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Benjangkaprasert, C.
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Sangaroon, O.
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Janchitrapongvej, K.
This paper presents an adaptive equalizer using FIR Filter and variable step-size quantize least mean p-power error criterion (VSQLMp) algorithm for compensating the amplitude of Chrominance signal. The proposed equalizer can be enhanced and compressed the chrominance signal at color subcarrier and it is not taken into account how the signal is distorted. In addition, experimental results are carried out by using the modulated 20T sine squared signal.
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Sine-Squared Pulse Approximation for Matched Filter Design Using Generalized Bessel Polynomials and Particle Swarm Optimization
(2022-01-01)
Chutchavong, V.
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Anuwongpinit, T.
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Pumee, T.
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Benjangkaprasert, C.
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Janchitrapongvej, K.
This paper presents the study of mathematical characteristics of generalized Bessel polynomial that can be applied to approximate a sine-squared pulse for designing matched filters in communication systems. The proposed pulse can be designed by using the transfer function, in which the numerator is the five pairs of a transmissions zero pairs, and the generalized Bessel polynomial is used as the denominator. A parameters of generalized Bessel polynomials can be adjusted by particle swarm optimization to find the best parameter value. From the simulation results can be found that a parameter can be adjusted. A proposed pulse is close to the ideal response in mainlobe, and one sidelobe to four sidelobes with stability, which outperformed previous research.

Chutchavong, Vanvisa

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