-
[show abstract]
[hide abstract]
ABSTRACT: This paper presents a coplanar waveguide (CPW) fed rectangular slot antenna with tuning stub and pi-strip for WLAN and WiMAX (2-6 GHz) applications. Simulation results show that the impedance matching for the proposed antenna depends on the location of the tuning stub and pi-strip, and the impedance bandwidth is mainly determined by the width and length of tuning stub. The bandwidth of slot antenna can achieve 116% (1.8-6.75 GHz). The radiation patterns are bi-directional and maximum gain is 4.8 dBi at 5.8 GHz.
Intelligent Signal Processing and Communications Systems, 2008. ISPACS 2008. International Symposium on; 03/2009
-
[show abstract]
[hide abstract]
ABSTRACT: Video equalizer design for compensated the distortion of the chrominance amplitude in color television transmission system is presented. The approximation is based on the Bernstein polynomials and generalized bilinear transformation to obtain the transfer function. This approach has several parameters can be varied satisfying stability conditions. And the advantages of the Bernstein polynomials when compared to the Butterworth, Chebyshev and Thomson polynomials are three parameters available control the amount of phase and magnitude, linear phase, and flexible for variable of phase. Among all referred advantages so that these methodologies were applied in this paper. In addition, the pulse and bar test signal which has been used to measure linear waveform distortion in TV system is special the modulated 20T sine squared pulse with color sub-carrier 4.43 MHz for PAL system. As a result, the proposed digital video equalizer can be enhance and compress the gain chrominance distortion without degraded it phase characteristic.
Control, Automation and Systems, 2008. ICCAS 2008. International Conference on; 11/2008
-
[show abstract]
[hide abstract]
ABSTRACT: This paper presents the slot antenna fed by microstrip line with inset U-strip for dual frequency operates in WLAN applications. The rectangular slot antenna is proposed for comparison between with and without U-strip in slot antenna by using three configurations of slot antenna. This antenna is designed for dual frequency used in WLAN system coverage IEEE 802.11 b/g (2.4-2.4835 GHz), IEEE 802.11j (4.90-5.091), IEEE 802.11a (5.15-5.35 GHz) and WiMAX of IEEE802.16d (5.7-5.9 GHz). The PCB-FR4 substrate with dielectric constant (epsiv<sub>r</sub>) 4.5 of thickness 1.6 mm is chose for low cost. The simulation results of these slot antennas are analyzed by using Method of Moment (MoM) from IE3D Software. Finally, the result of bandwidth at low frequency and high frequency of the desirable antenna are 9.76% and 31.6% at frequency range 2.3-2.58 GHz and 4.76-6.34 GHz, respectively.
Control, Automation and Systems, 2008. ICCAS 2008. International Conference on; 11/2008
-
[show abstract]
[hide abstract]
ABSTRACT: The coplanar waveguide fed slot antenna with inset L-stripe tuning stub is proposed for UWB applications. The antenna consists of two rectangular slots separated by center strip with CPW feed line. This antenna is design for match impedance with 50 ohm of characteristic impedance of transmission line by using inset L-stripe tuning stub for wideband matching. By adjusting dimension of inset L-strip tuning stub, the range of bandwidth can be achieved 144.6% (1.80 GHz - 11.2 GHz) of the center band coverage standard of IEEE 802.15a for ultra wideband operation. The characteristics of antenna are proposed and analyzed for instance input impedance, return loss, bandwidth, VSWR, and far field radiation patterns.
SICE Annual Conference, 2008; 09/2008
-
[show abstract]
[hide abstract]
ABSTRACT: An extend bi-directional arbitrated decision feedback equalizer (E-BAD) was developed from BAD which shown that performance is improved at low error rate. BAD detector can be replaced for the high-complexity detector in turbo equalization for a coded magnetic recording channel which the performance is closed. This paper considers a performance evaluation of EBAD detector in turbo equalization with selected LDPC code which the performance is improved while keep low-complexity structure.
Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology, 2008. ECTI-CON 2008. 5th International Conference on; 06/2008
-
[show abstract]
[hide abstract]
ABSTRACT: The traffic prediction are mainly used to improve the performance of telecommunication network management. This paper improved model for telephone traffic prediction in Thailand by using artificial neural network (ANN) with back propagation learning algorithms. By applied data which is collected at different node in main routes of TOT, Thailand telephone network for learning process and testing. The neural network structure and input/output musters are descried in detail. We present the comparatively results of simulation with another methods, the results shows traffic fluctuation prediction by the method of ANN is accurately.
Control, Automation and Systems, 2007. ICCAS '07. International Conference on; 11/2007
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper presents the comparison of the performance of the variable step-size LMS adaptive algorithm and the fixed step-size 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. It is shown that the variable step-size LMS adaptive algorithm yields the performances over the fixed step-size LMS algorithm. Computer simulation results are provided to confirm the performances of the variable step-size LMS algorithm.
Control, Automation and Systems, 2007. ICCAS '07. International Conference on; 11/2007
-
[show abstract]
[hide abstract]
ABSTRACT: This paper presents a study of using artificial neural network (ANN) in predicting IP traffic fluctuation in IP based next generation network (NGN) in Thailand. By analyzing the time level correlation of traffic flow over TOT IP core network, monitor by the Multi Router Traffic Grapher (MRTG) from January,2006 to December, 2006 at Latya and Phrakhanong exchange. For comparison purposes, the back propagation learning algorithms are considered, in particular ,optimization techniques with statistical methods prediction such us Double Exponential smoothing, Lest Square Methods and Adaptive response rate simple exponential smoothing method are applied for predicting the same node of problems. Computational results by using the data monitoring at Latya exchange for training and actual traffic in Phrakhanong area to check prediction correctness show that the based ANN method obtained better results, it can be prediction more precisely.
Control, Automation and Systems, 2007. ICCAS '07. International Conference on; 11/2007
-
[show abstract]
[hide abstract]
ABSTRACT: The design of search algorithm is an important as more complex model is developed for improving has been recognition accuracy. The intelligent searching with multi-display strategies have been used for the searching with three language character, sound and picture in the same time by binary search tree algorithm can reduce the time for searching and more accuracy
SICE-ICASE, 2006. International Joint Conference; 11/2006
-
[show abstract]
[hide abstract]
ABSTRACT: Threads class is represented as object the oriented design in programming languages. The multi-threaded execution collides from the same data access. This problem is fixed by synchronization critical section method in every thread, when the process is finished its behavior of terminated time of multithreading. Another problem arises due to threads class does not concurrent terminate execution. This paper also presents an object-oriented design using message control to solve concurrent terminated execution problem. By using a concept that every thread can be communicate to the center of object class. The main object decides to handle on every thread with stability executions. The benefit of handle during run time is broken and continue execute of threads. Using Delphi programming carries out an experimental result
SICE-ICASE, 2006. International Joint Conference; 11/2006
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper, a new class of a variable step-size algorithm for a second-order lattice form structure adaptive IIR notch filter for detection of sinusoids in noise environments is presented. The proposed algorithm is adjusting two variable coefficients of the adaptive IIR notch filter: one is variable notch frequency and the other is variable notch bandwidth. By the proposed method, the optimization of the coefficients of the filter is obtained. The computer simulation results are shown that the proposed algorithm provides fast convergence speed, low mean square error, low variance of filter coefficients and high impulsive noise robustness. Moreover, to verify the new adaptive algorithm by application to reducing 50-Hz interference in ECG signal. As results, it is evident that the new algorithm gives a good performance
Communications, Circuits and Systems Proceedings, 2006 International Conference on; 07/2006
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper proposes an addition of a variable step-size modified memoryless nonlinear gradient (MNG) algorithm for a second-order adaptive IIR notch filter for detection of sinusoids in noise environment. The structure of the adaptive IIR notch filter is based on direct form structure and lattice form structure. The objective of variable step-size (VSS) algorithm is to optimize the filter coefficient. The computer simulation results are shown that the proposed algorithm provides fast convergence speed, low mean square error, low variance of filter coefficients and high impulsive noise robustness.
Intelligent Signal Processing and Communication Systems, 2005. ISPACS 2005. Proceedings of 2005 International Symposium on; 01/2006
-
[show abstract]
[hide abstract]
ABSTRACT: This paper presents a new variable step-size algorithm on soft output adaptive decision feedback equalizer for turbo coded direct-sequence code division multiple access (DS/CDMA) systems. The proposed adaptive equalizer utilizes a performance of the system or by means of bit error rate to control the adaptation process of the equalizer and the new structure is based on the decision feedback equalizer. By this method, the performances of the proposed adaptive equalizer cooperate with the attractive log-maximum a posteriori (Log-MAP) algorithm of turbo decoder for the DS/CDMA system. It provides a good statistical in non-stationary channel condition scenario. The simulation results are shown the superior bit error rate performances of the proposed adaptive equalizer over other equalizers such as the finite impulse response equalizer and conventional decision feedback equalizer.
Intelligent Signal Processing and Communication Systems, 2005. ISPACS 2005. Proceedings of 2005 International Symposium on; 01/2006
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper, a new implementation of an adaptive noise canceller based upon a parallel block structure is proposed. The objective is to increase the processing and convergence rates and to improve the steady-state performance. First, an IIR bandpass filter with a variable center angular frequency using adaptive Q-factor control and two adaptive control signal generators are realized by the parallel block structure. Secondly, an algorithm for adaptive Q-factor control with parallel block structure is proposed to improve the convergence characteristic. Furthermore, by using the normalized transfer function and the continuously variable step-size parameter for adaptive control of the center frequency to stabilize the steady-state performance of the filter. Finally, simulation results are given to demonstrate the convergence performance.
TENCON 2004. 2004 IEEE Region 10 Conference; 12/2004
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper, the combination algorithm for a second-order adaptive IIR notch filter is presented. The proposed algorithm is based on the genetic algorithm as an initial stage of adaptation process, as we approach the optimum step-size parameter, we using the new variable step-size algorithm. By this technique, the new algorithm achieves the optimum step-size parameter of the filter coefficient for an adaptive IIR notch filter. The results of computer simulation show that the new algorithm provides a good performance such as fast convergence rate, low mean square error and noise robustness. In addition, the new algorithm is also applied to cancel 50-Hz power line interference in the recording of electrocardiograms signal.
Neural Networks and Signal Processing, 2003. Proceedings of the 2003 International Conference on; 01/2004
-
[show abstract]
[hide abstract]
ABSTRACT: This paper examines a method for converting among scintillation expression methods, peak to peak values method and standard deviation values method, by using local measurement of meteorological parameters. Part 1 focuses on tropospheric scintillation related to 12.260 GHz measurements at an elevation angle of 59.9°. Part 2 focuses on ionospheric scintillation at 3.916 GHz; observations were made at KMITL, Bangkok, Thailand. The principle techniques find a good correlation coefficient ranging from 0.900 to 0.999. As a result the relationship between two methods is given by σ<sub>x</sub>=α(p-p)+β, where α is 0.14.
Electromagnetic Compatibility, 2002 3rd International Symposium on; 06/2002
-
[show abstract]
[hide abstract]
ABSTRACT: This paper aims to improved the convergence speed, steady-state mean square error and variance of the filter coefficient. The proposed adaptive algorithm is for a second-order adaptive IIR notch filter based on gradient algorithm. The simulation results shown that the proposed algorithm provides fast convergence speed, and has low steady-state mean square error and low variance of filter coefficient.
Circuits and Systems, 2002. APCCAS '02. 2002 Asia-Pacific Conference on; 02/2002
-
[show abstract]
[hide abstract]
ABSTRACT: This paper proposes a different approach to control step-size
adaptation. The objective is to ensure large step-size when the
algorithm is far from the optimum with step-size decreasing as we
approach the optimum. The proposed algorithm achieves this objective by
employing the output signal energy to control step-size update. In the
early stage of adaptation the estimate of the output signal energy is
large, resulting in a large step-size. As we approach the optimal, the
output signal energy approaches zero, resulting in a small step-size.
This provides the fast convergence due to large initial step-size while
ensuring low gradient noise due to the small final step-size, resulting
in low variance of the filter coefficient
Circuits and Systems, 2000. IEEE APCCAS 2000. The 2000 IEEE Asia-Pacific Conference on; 02/2000
