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, Analysis of RC Quadcopter RCS Estimation in indoor and Outdoor Environments with L-Band Primary Surveillance Radar(2022-01-01) - 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, Accuracy Study of Indoor Positioning with Bluetooth Low Energy Beacons(2020-03-01); Currently, Bluetooth low energy (BLE) beacons are widely used for positioning, especially an indoor environment. However, there is still high error due to dense multipath fading that often occurs in the indoor environment. This paper presents the accuracy study of indoor positioning with BLE beacons. The indoor environment is the room of 91.8 m<sup>2</sup> with 3 BLE beacons. The user equipment (UE), iPhone XS Max, with Beacon Analyzer application is used to measure the received signal strength (RSS) of each BLE beacon. Fingerprinting technique with least root mean square (RMS) error matching is used to estimate the position of UE. The accuracy that obtained from single measurement and average five measurements is studied. The RSS fingerprint of each BLE beacon is shown. The cumulative distribution function (CDF) of distance error is evaluated and illustrated. From the results, the average five measurements can reduce the average distance error about 0.86 m. - 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.