Now showing 1 - 10 of 34
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    Item type:Publication,
    Comparison of UWB fingerprinting with vertical and horizontal polarizations for indoor localization
    (2010-07-30)
    Sangthong, Jirapat
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    The indoor localization system has been extensively researched because of its various applications. This system requires high accuracy in indoor environments which absence line of sight and dense multipath. Ultra wideband (UWB) fingerprinting is developed for this purpose. This paper discuss about indoor localization using a fingerprinting concept based on UWB signal and compares between vertical and horizontal polarization cases. All of the measurements used biconical antennas as both transmitter (Tx) and receiver (Rx) antennas. The channel frequency transfer functions of corridor environment were measured at frequencies ranging from 3 GHz to 11 GHz. The path loss and delay time of first three-path is investigated to perform the fingerprints and signatures. The accuracy of estimated distances is shown in terms of cumulative distribution function (CDF). From the results, horizontal polarization provides greater accuracy than vertical polarization.
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    Simple waveforms satisfying MIC spectral mask for UWB communications
    (2006-12-01)
    Wansiang, Kritsana
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    Takada, Jun Ichi
    In this paper, the simple waveforms for ultra wideband (UWB) communications are presented to satisfy the Ministry of Internal Affairs and Communications (MIC) spectral mask. The rectangular passband, modulated rectangular and modulated Gaussian waveforms are considered. They are optimized to maximized bandwidth, amplitude and average power in the MIC spectral mask bandwidth ranging from 3.4 to 4.8 GHz for low passband and 7.25 to 10.25 GHz for high passband. The maximum average power spectral density (PSD) limit of MIC spectral mask is considered. The binary pulse amplitude modulation (PAM) with balance binary data independent identically distributed (i.i.d.) random sequence is considered to easily derive the PSD of the waveforms. The PSD and parameters of each optimized waveforms are shown. The optimized results are discussed in the conclusion. © 2006 IEEE.
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    Path loss and matched filter gain of free space and ground reflection channels for UWB radio systems
    (2004-12-01) ;
    Takada, Jun Ichi
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    Tangtisanon, Prakit
    In this paper, the path loss and matched filter gain of free space and ground reflection channels for UWB radio systems are proposed. The passband rectangular pulse with specific center frequency and bandwidth is used as the transmitted signal. The complex form Friis transmission formula is used for the UWB channel. The received signal is evaluated. The UWB path loss is defined as the ratio between the maximum amplitude of the transmitted and received signal waveforms. At the receiver, the matched filter detection with its frequency transfer junction satisfying the constant noise power condition is used. The UWB matched filter gain is defined as the ratio between the maximum amplitude of the signal waveform at the output of the matched filter and that of the received signal waveform. The closed form path loss and matched filter gain expressions are derived. The characteristics of the path loss and matched filter gain are shown and discussed in this paper. © 2004IEEE.
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    Item type:Publication,
    Accuracy Analysis of Indoor Positioning Using Min-Max Method
    (2025-01-01) ;
    Vinicchayakul, Wipassorn
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    Tabsombat, Sirinya
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    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.
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    Theoretical ground re. ection model for UWB communication systems
    (2004-12-01) ;
    Takada, Jun Ichi
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    Tangtisanon, Prakit
    In this paper, the theoretical ground re. ection model for UWB communication systems is proposed. The pass-band rectangular pulse with speci. c center frequency and bandwidth is used as the transmitted signal. Complex form Friis' transmission formula is applied for the UWB ground re. ection channel. The received signal is evaluated. The UWB path loss is de. ned as the ratio between the maximum amplitude of the transmitted and received signal waveforms. The closed form path loss expression is derived. For the data processing, the path loss and rms delay spread of ground re. ection model are considered for the 1.00, 0.10 and 0.01 m antenna heights. The double linear regression for the path loss is modeled by using the. rst Fresnel zone and MMSE break points. The rms delay spread as the function of the antenna height and the path loss is investigated. The characteristics of the path loss and rms delay spread are discussed in the paper.
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    Regression models of ultra wideband ground reflection path loss based on peak power loss
    (2007-12-01) ;
    Pokang, Apiradee
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    Noppanakeepong, Suthichai
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    Takada, Jun Ichi
    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. ©2007 IEEE.
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    Distortion analysis of ultra wideband pulse waveforms with meander line antenna
    (2006-12-01)
    Kiphairoj, Auttaphol
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    Takada, Jun Ichi
    In this paper, the distortion of ultra wideband (UWB) pulse waveforms with meander line antenna (MLA) is analyzed. The rectangular passband, modulated rectangular and modulated Gaussian waveforms, which satisfied the Federal Communications Commission (FCC) definition of UWB signal and FCC spectral masks for the indoor and outdoor limits, are considered. The frequency transfer function of MLA is evaluated by using measurement scheme. The correlation coefficient of each waveform at the specific angle is illustrated. From the results, we can see the distortion effect of each waveform caused by MLA along the specific angle. © 2006 IEEE.
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    Ground reflection path loss based on average power loss for ultra wideband communications
    (2007-12-01) ;
    Kaewsirisin, Sarunya
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    Noppanakeepong, Suthichai
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    Takada, Jun Ichi
    In this paper, the ground reflection path loss based on average power loss for ultra wideband (UWB) communications is proposed. The expression is derived from the rectangular passband waveform and extension of Friis" transmission formula in the terms of the closed form formula based on average power loss. The results are compared with other models and verified with the measurement result. From the results, this proposed model corresponds with compared models and measurement result.
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    Performance evaluation scheme of SNR gain for UWB impule radio receivers
    In this paper, we evaluated the signal to noise ratio (SNR) gains of ultra wideband (UWB) for UWB receivers performance. The optimum and isotropic matched filter receivers are considered. The biconical antennas are used as the transmitter (Tx) and receiver (Rx) antennas. The rectangular passband, which is satisfied the full band of UWB signal definition and Federal Communications Commission (FCC) indoor and outdoor limit spectral masks, is used as the transmitted UWB signal. The channels are measured in an anechoic chamber by using a vector network analyzer (VNA). The SNR gains of optimal and isotropic matched filter receivers are shown and compared in results.
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    Performance Evaluation of Artificial Megneto-Dielectric Metamaterial with Microstrip Patch Antenna for Wireless System
    (2018-07-02)
    Pinsakul, Atcharaporn
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    This paper we presents the performance evaluation of artificial magneto dielectric substrate with microstrip patch antenna for wireless system. From the result, at the resonance frequency 2.45 GHz have the radiation efficiency and the real gain are 88.87% and 6.89 dBi, respectively. The microstrip patch antenna on finite artificial magneto dielectric substrate by used metamaterial structure. The unit cell consist of multi square loop pinned in the dielectric material. The feature of the antenna can be rectify with controlling permeability (boldsymbolmu-eff) and permittivity (boldsymbolvarepsilon-eff).