Pichaya Supanakoon

Indoor measurement results of UWB impulse radio for shot-range wireless systems with RMS delay spread and path loss

In this paper, we describe a simple method for measurement of the ultra-wideband (UWB) frequency response for evaluation of the path loss and RMS delay spread which are the important parameters for the wireless communications, probability and cumulative density of rms delay spread and path loss are evaluated based on the measurement of UWB indoor environment. For the measurement, the frequency responses of the UWB channel are acquired by using a vector network analyzer (VNA) over the frequency bandwidth of 3/spl sim/11 GHz. The biconical antennas are used for both the transmitter (Tx) and receiver (Rx) antennas. The probability density function and cumulative distribution function of the rms delay spread and path loss are shown. The results are discussed in this paper.

Performance study of dynamic framed slotted ALOHA for RFID systems

When more than two tags respond to a reader request at same time slot, the tag collision occurs. This is one of disadvantages in radio frequency identification (RFID) system. The performance of anti-collision algorithms is important to overcome this problem. In this paper, the performance of dynamic framed slotted ALOHA (DFSA) is studied. The DFSA with mute tags is considered and compared with framed slotted ALOHA (FSA) with mute tags. The average used time slot, probabilities of ideal time slot, collision time slot and successful time slot are shown. The results are discussed in the conclusion.

Statistical Model RMS Delay Spread in UWB Ground Reflection Channel Based on Peak Power Loss

We establish the statistical models of the root mean square (RMS) delay spread for ultra wideband (UWB) communications. The received signal in the UWB ground reflection channel based on peak power loss is evaluated. The RMS delay spread is calculated by using the delayed times and the peak powers of the received signals from the direct and reflected paths. The RMS delay spread with the different signal bandwidths and the antenna heights are demonstrated. The histograms and the probability density functions (PDFs) are illustrated and compared. The parameters of the statistical models are shown. The results are discussed in the conclusion

Experimental evaluation scheme of UWB propagation channel with human body

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.

Study on performance of ultra wideband and narrow band propagation for an indoor positioning

This paper studies ultra wideband (UWB) and narrow band (NB) propagation in the frequency range of 3 GHz to 11 GHz. The UWB signal was used to follow the standard of IEEE802.15.4a in order to find the position in line of sight (LOS) and non-line of sight (NLOS) environment. Then, the sinusoidal frequency was tested in the frequency range of 3 GHz to 11 GHz, changing 1 GHz per step in order to analyze and compare with the UWB standard. The experiments were done by using vector network analyzer (VNA). Four conditions were studied in LOS and NLOS environment for indoor positioning. The four condition are the parameters; UWB standard; polarizations; and the frequencies. For the positioning determination, a location pattern technique was used with a minimum root mean square (RMS) error matching algorithm to find the position. Finally, a suitable condition is shown, and it has an accuracy of 91.11% at 1 meter.

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.

Path Loss Expressions of Ultra Wideband Ground Reflection Channel

In this paper, the path loss expressions of ultra wideband (UWB) ground reflection channel are proposed. The expressions are derived from the integral formula in the terms of the closed form formula and double linear regression model based on average power loss. The break point distance are expressed in the exacted formula. The results are compared with other models and verified with the measurement result. The results are discussed in the conclusion

Simple Implement of Home Agent Reliability for Mobile IPv6 Network

This paper studies the home agent (HA) reliability with TCP. The experiments are performed with two HAs and a backup HA. When the main mobile IPv6 HA fails, the backup HA is used for standby and recovery services instead. The goal of this paper is to minimize the recovery time

Quantitative Measurement of Path Loss Model Adaptation Using the Least Squares Method in an Urban DVB-T2 System

The aim of this paper was to propose quantitative measurement of path loss model adaptation in urban radio propagation for a second-generation, terrestrial digital video broadcasting standard (DVB-T2) system. The measurement data was analyzed using data processing based on the least squares (LS) method to verify the probabilistic quantitation of realistic data measurement such as mean error (ME), root mean square error (RMSE), and standard deviation of error (SD), as well as relative error (RE). To distinguish the experimental evaluation, the researchers compared between the conventional Hata path loss model and the proposed model. The result showed that path loss based on the proposed model was more accurate in predicting the quantitative measurement of propagation data properly.

Study of UWB indoor localization using fingerprinting technique with different number of antennas

Wireless sensor networks (WSNs) have been applied in various applications. Each application is developed in order to increase security, increase convenience to life and property. In this work, we have analyzed the application of WSNs to locate with fingerprinting technique on the standard of IEEE802.15.4a (Ultra wideband (UWB)) in terms of the number of antennas required when using line of sight (LOS) environment. The experiment was done by using a vector network analyzer (VNA) with biconical antennas. The frequency transfer function of the channel was measured at various locations. As a result, the use of delay time parameter of the UWB standard gave the best result. It was able to use only one antenna pair to identify areas accurately. Moreover, it saved time for doing the database, reduced size of the database and reduced some cost because the number of antennas was decreased.