Surachet Kanprachar

Learn More
The number of users in a limited-bandwidth channel can be increased if code division multiple access (CDMA) technique is adopted. This technique has been widely used for wireless communication systems. As the number of users in the system increases, the achieved performance in terms of bit-error-rate (BER) does not increase significantly and is in the(More)
This paper proposes a new technique of edge detection for inspecting edge and perfection of soldering joint in the pre-amplifier circuit, which is an important part in hard disk drive. Summation of error between the actual value and the measured value from the designed system of several data sets is formulated as the objective function. Genetic Algorithm(More)
Multimode fiber (MF) has been used as a medium for transmitting a high data rate signal up to 10 Gbps over its high frequency region. This high frequency region of multimode fiber contains many passbands, which can be adopted as channels for sending many subcarrier signals. These passbands are located at different frequencies and vary from fiber to fiber(More)
1 Abstract – Multimode fiber (MF) has recently been considered as a high data rate medium for signals transmitted at its high frequency region. This high data rate transmission is made possible since there are many many passbands, which can be adopted as channels for sending many subcarrier signals. These passbands are located at different frequencies and(More)
A rigorous approach yielding high accuracy is proposed for the solution of the tapered discontinuity in a planar dielectric waveguide. The method models tapered portion as a sequence of step discontinuities to which the mode-matching technique is imposed extending over infinite range. Partial field is established for TE wave polarization. An iterative(More)
Multimode fiber is one of two major types of optical fibers used in practice. Its capacity in terms of the available bandwidth for signal transmission can be increased significantly if the signal is transmitted over the passbands at high frequency range. However, it has been shown that as the frequency increases, the magnitude response of multimode fibers(More)
Electrical Engineering (ABSTRACT) In digital communication systems, several types of impairments may be introduced to the signal. These impairments result in degraded system performance; for example, high bit-error-rate or power penalty. For optical communication systems, in this thesis, these impairments are categorized into four types; that is, thermal(More)
.................................................................................... ii ACKNOWLEDGEMENT.................................................................. iv TABLE OF CONTENTS..................................................................... v LIST OF FIGURES......................................................................... viii(More)