Suthichai Noppanakeepong

Adaptive OFDM modulation techniques over fading channel for wireless communication systems with an 80 MHz bandwidth

The orthogonal frequency division multiplexing (OFDM) is one of the promising technologies to improve the spectral efficiency, enhance system capacity and mitigate inter-symbol interference in the wireless communication system. In this paper, we aim at the study on adaptive modulation and coding technologies for wireless system over frequency selective fading channel. This adaptive allocation algorithm assigns the sub-carriers. We are applied adaptive modulation technique to each sub-carrier to keep required BER and PER performance. The system chooses modulation among BPSK, QPSK, 16QAM and 64QAM which the estimated SNR of the sub-carrier inhabits. Adaptive modulation can improve communication performance under small SNR. The computer simulation result shows the BER, PER and Throughput performance can be improved under 30 dB of SNR region.

Regression models of ultra wideband ground reflection path loss based on peak power loss

In this paper, the regression models of ultra wideband (UWB) ground reflection path loss are proposed. The UWB ground reflection path loss is defined as the ratio between the maximum amplitude of the transmitted and received signal waveforms. The polarizations of transmitted signal and ground characteristics are considered. The double and triple linear regression models are derived from the closed form expression of ground reflection path loss based on peak power loss. The regression models are shown and compared with the closed form expression. From the results, the double and triple linear regression models are appropriate for conductor and dielectric grounds, respectively. Therefore, these proposed regression models are the one choice for modeling the UWB ground reflection path loss.

THz light pulse generation and storage within an embedded optical waveguide system

We propose the interesting results of high frequency generation method, which is required to use in the THz regime. A generated system consists of two micro and a nano rings that can be integrated into a signal system which can be employed to generate the large bandwidth by a Gaussian pulse propagating within the ring resonator system. The selected signals can be filtered by using the optical add/drop filter. By controlling the ring parameters, the appropriate output power can be obtained, which can be modified to be suitable in either imaging or communication applications. Moreover, the very wide band of wavelength can be generated and controlled for various applications.

THz LIGHT PULSE GENERATION AND STORAGE WITHIN AN EMBEDDED OPTICAL WAVEGUIDE SYSTEM

We propose the interesting results of high frequency generation method, which is required to use in the THz regime. A generated system consists of two micro and a nano rings that can be integrated into a signal system which can be employed to generate the large bandwidth by a Gaussian pulse propagating within the ring resonator system. The selected signals can be filtered by using the optical add/drop filter. By controlling the ring parameters, the appropriate output power can be obtained, which can be modified to be suitable in either imaging or communication applications. Moreover, the very wide band of wavelength can be generated and controlled for various applications.

The analysis of cause from fusion splice in single mode optic fiber for reducing splicing loss between fusion splicing

This article is study on loss from fusion splice for single mode optic fibers from any errors in order to find out the actual loss cause. The loss from fusion splicing is compared with the loss obtained from simulation. The result can predict the error caused by fusion splicing. It is an actual error at junction, so fusion splicing loss of fiber optic can be reduced. Sometimes, the technician just notices that fusion splicing has some loss but he does not know the actual cause. Researcher want to find out and prepare the Microsoft access program for checking loss and cause from any errors. It is useful for the technician to train and to decrease any errors from fusion splice. The heat to be radiated from fusion splice and parameters of fusion splice are important to be considered. The comparison involves the development of optic fiber to the gateway of data high speed. This simulation is technically easy and can do actual performance and can be adapted to telecommunications system.

The Analysis of IRBUS Channel Allocation for decrease Four-Wave Mixing in DWDM System

This paper presents a new model of optical channel allocation named “IRBUS” for improving the operation of a DWDM light source multiplexing by not have to use an optical filter in the DWDM de-multiplexer device. By our method can reduce transmission loss in case of the number of channels are plentiful and each of the channels is nearby that be found in Dense Wavelength Division Multiplexing (DWDM) Systems. The transmission loss is called “Four-Wave Mixing (FWM)” caused by the nonlinearity of the optical fiber signal. The results of numerical computation shown that the IRBUS model can decrease average FWM efficiency from -12.03dBm to -28.27dBm indicated that the remains FWM value are less than other methods and can also reduce the BER probabilities from - 5dBm to -19.75 dBm.

Dynamic optical tweezers: Experiment

We have experimentally generated the optical tweezers in the form of a dark soliton pulse using the Stimulated Brillouin Scattering (SBS) system. This is the first time ever found on the use of the highly intense pulse in the form of a dark soliton to perform the dynamic light trapping probe known as a “dynamic optical tweezers”. The advantage of the generated tweezers is that it can be used to transmit and transport the trapping atom/molecule into the optical device and communication network, which can be claimed as the dynamic optical tweezers transportation, for used in many frontier applications. The multi-optical tweezers generated, with high capacity regime can then be used for multi-optical tweezers transmission. The various applications to form the frontier research using photon, atom, molecule, DNA, electron and ion trapping for atomic tools, tiny synchrotron, molecular networks, bottom up atom/molecule assembly, ozone repair etc. are described. The experimental details and model of the optical tweezers generation and related characteristics are described. The interesting simulation results of a dark soliton generation for the optical tweezers are also analyzed and discussed in various applications.

Electrical equivalent circuit model and impedance of euglena sanguinea stimulated by multi-level electromagnetic fields

This research studied the characteristic of electrical properties of E. sanguinea by evaluation of complex impedance and complex permittivity. Apply Cole-Cole plot technique to explain the behavior of RC impedance form simulation and measurement. The objective of this study was to build up a new electrical equivalent circuit model from RC circuit model of E. sanguinea with MLEMF. The results revealed that there were a correlation between impedance from measurement and simulation with correlation value equal to 0.83 at 95% confidence interval. The RC impedance of E. sanguinea of each chemical component, i.e., protein, chlorophyll, carbohydrate, lipid and phosphorus was behavioral in semicircle varied to frequency which give the correlation with complex permittivity. The model can be used for design of water supply system by MLEMF for treating algae bloom water. This is an innovative electric simulation applicable to the electric engineering and other related fields of study.

Histogram compensation to improve blind modulation detection in adaptive OFDM

This paper proposes a blind modulation detection technique for adaptive orthogonal frequency division multiplexing (Adaptive OFDM) communications. Adaptive modulations are applied to improve communication performance in OFDM over complicated multi-path fading channels. This paper proposes a new method which reduces detection errors in blind modulation and improves communication throughput in adaptive OFDM systems. The new proposed is based on statistical methods using a combination of distance histogram and phase histogram methods. It can improve communication performance and increases a data rate by not sending side information about modulation modes. The proposed method has showed better blind detection performance at lower SNR regions than the previous method.

Rainfall Rate and Rain Attenuation Model in Bangkok Thailand

This paper describes the measurement of rainfall rate at King Mongkuts Institute of Technology Ladkrabang (KMITL), Bangkok, Thailand, by using satellite signal from Thaicom5. Three years measurement of rainfall rate are presented. The experimental results indicate that the measured rainfall rate are 90mm/hr in 2005, 94 mm/hr in 2006 and 102 mm/hr in 2007. Moreover, we have developed new modify prediction model of rain attenuation by ITU-R rain attenuation model. The model provides for prediction of annual and for expected year to year variations. This model applied to collecte data compared with ITU-R model. From the results of prediction model at KMITL, we found that the highest rainfall rate 102 mm/hr in 2007 cause to signal attenuate 14.34 dB.