Chamchoy, Monchai
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Item type:Publication, Evaluation of WUWB Transmission with LOS and NLOS for Smart Home(2018-07-02); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Accuracy Analysis of Indoor Positioning Using Min-Max Method(2025-01-01); ; In this paper, the accuracy analysis of indoor positioning using min-max method is proposed. The distance error model is applied to estimate the distance between the transmitter and user's position with different path loss exponent and fading amount of indoor channel. The total $\mathbf{1 0 0}$ coordinates of user's positions are estimated using min-max method. The distance error at each position, probability density function (PDF) and cumulative distribution function (CDF) of distance errors are illustrated. The mean of analysis distance error corresponds with the mean of measurement distance error with same path loss exponent and fading amount of indoor channel. The results show that it is possible to use this accuracy analysis to estimate the distance error in an indoor environment. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Study on RSRP of LTE Mobile Phone on Thailand's National Highway(2018-07-02); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Study on Accuracy of Min-Max Method Using Distance Error Model for Indoor Positioning(2022-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The impact of path loss on cooperative MIMO transmission scheme for intelligent transport system(2006-12-01); Intelligence transport system (ITS) is the system which needs an effective cooperate between local base stations, vehicles and other communication networks in order to create an efficient communication and high-speed data transfer. The cooperative MIMO transmission scheme for ITS is proposed to solve the correlated fading channel. The impact of path losses in inter-vehicle communication and road to vehicle communication are investigated and discussed in the text. As the result, the path loss and correlated fading channel have become the cause of distorting the efficient communication. © 2006 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Investigation of ultra-wideband pulse distortion due to the body shadowing(2005-12-01); ; In this paper, the distortion of ultra-wideband (UWB) pulse due to the human body shadowing is investigated. The frequency responses of the radio channels are acquired by using a vector network analyzer (VNA) over the frequency bandwidth of 3 GHz to 11 GHz. The experimental channels are taken for several T-R separation distances in the indoor environment. Consequently, the characteristics of the UWB pulse distortion including the effect of transmitter/receiver antennas and human body are examined. The pulse distortion is considered by using the percentage of the correlation coefficient between the transmitted signal and the received signal. As the results, the distortion of UWB pulse increases as the T-R separation distance increases, especially when the fully shadowing is observed. © 2005 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Ground reflection model in rough surface forUWB impulse radio(2005-12-01); ; ; Keawmechai, SompophUltra-wideband (UWB) is currently wide interesting technology of wireless communication technology in building and home entertainment. In order to be the most effective wireless communications, we have to consider the parameters which are vital signal transmission factors of UWB. As a consequent, imitation of UWB signal transmission in two-part model so as to notice reflected signal from several rough types of ground such as Brick and Limestone is demonstrated in this abstracts. Friis' transmission formula and Rayleigh equation are used to calculate in this model for searching any effects happened by reflection of rough ground and analyzed in path loss, path gain and time dispersion as RMS delay spread. © 2005 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Rayleigh performance of transmitter preceding based-multiuser detection for DS-CDMA over Rayleigh fading environments(2004-09-27); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Characteristics of UWB propagation through building materials(2005-12-01); UWB system is the one type of several wireless communication that can be used in home networking, which have any probably obstruct by building material. Then the influences of the obstructions are considered. In this paper, the time dispersion and penetration loss are studied. The glass, gypsum, dry wood and partition board are considered the obstruction materials. The channels with these materials are measured in a fully anechoic chamber by using the vector network analyzer. The measurement frequency range is set to be 3-11 GHz, which covered the full band of UWB specified by FCC. The biconical antennas are used for both transmitter and receiver. The time dispersion and penetration loss for each material are evaluated based on the measurement channels. The data of theses results is useful for considering the UWB link budget. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A simple method of synthesis design for generating UWB pulse based on wavelet(2005-12-01); This paper proposes the simple method of synthesis design for generating UWB pulse based on wavelet. This study consider the characteristics of Haar wavelet, which are digital and simple method for synthesizing. By using discrete wavelet transform, the synthesis signal is similar with mother signal and simple to implement. In our study, the modulated Gaussian waveform is involved as the UWB pulse for synthesizing. The synthesis signal method based on Haar wavelet which is the mother wavelet is presented. Moreover, the comparison for the performance between the mother signal and the synthesis signal on the additive white Gaussian noise (AWGN) channel are given. © 2005 IEEE.