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, Empirically based path loss and penetration loss models for UWB communication in residential environment(2005-12-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Evaluation of DVB-T2 transmission channel in Bangkok, Thailand(2017-04-19); This paper describes the evaluation of DVB-T2 transmission channel in Bangkok Thailand. The DVB-T2 test signal is transmitted in Bangkok Thailand. Type of transmission channel were used including Gaussian, Rician for fix rooftop reception. The measurements are consisting of a several environments such as open area, urban area, high building area. The measurement result are include Power Output from transmitter after combiner, LBER, bBER, NsMAR (Noise Margin), MER (Modulation Error Ratio), SNR (Signal to Noise Ratio), CNR (Carrier to Noise Ratio), and Signal. The measurement result of this paper lead to the evaluation of DVB-T2 transmission channel for environment of Bangkok, Thailand and could be useful to improve and to design the digital television broadcasting network in Thailand especially in urban area like Bangkok. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A body-shadowing model for indoor UWB communication environments(2008-10-06); Radio channel characteristic is a very important factor for designing indoor UWB communication network. As we know, the indoor communication channel is limited by geometry of room and some obstruction in that room such as furniture, human operator, etc. These obstructions directly affect to quality of received signal, especially human who usually obstruct receiving signal. To efficient the network designing, the influence of human body shadowing on radio propagation in building UWB communication is investigated by involving propagation prediction model. This model will predict characteristics of the received signal affected from body shadowing by considering many wave propagation phenomenons such as reflection, refraction, absorption, etc. based on ray-tracing technique. The predicted results are shown in various forms such as power loss of received signal, mean excess delay and power delay profile. To verify the validation of the model, these results will be compared with the measured results. It is found that the measurement and prediction results are closely related. ©2008 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Characterization of in-home UWB channel with different antenna directivity(2004-12-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Experimental evaluation scheme of UWB radio propagation channel with human body(2005-12-01); ; This paper presents the evaluation scheme to investigate the pulse distortion, propagation loss due to human body shadowing. The matched filter is employed at the UWB receiver to maximize the SNR. The propagation loss and matched filter gain of the passband rectangular pulse are simulated for comparing with the experiment results. The experimental channels are taken for several T-R separation distances in an indoor environment. 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. From the results, the distortion and the propagation loss of the UWB pulse increase as the T-R separation distance increases, especially when the fully shadowing is occurred. © 2005 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Study on QoS routing for pulse based UWB ad-hoc network(2006-12-01); Ultra wideband (UWB) is a prospective radio technology for wireless ad-hoc networks. In this paper we propose the Quality of Service (QoS) routing for pulse based UWB ad-hoc network. The performance of TH-UWB on the AWGN channel is studied. The PPM scheme with data rate of 110 Mbps is considered. As the simulation results, the information sent by single-hop transmission has error more than that sent by multihop communication. For the data transmission, TCP is useful for this system. The notion of QoS is a quarantee by network to the best satisfy. © 2006 IEEE. - 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.