2,200 research outputs found

    Optimizing Indoor Location Based Tracking through Proper Filter Selection and Wireless Sensor Network Design

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    Indoor positioning system (IPS) is a topic that is coming up more and more for various reasons, such as allowing companies to track important objects using radio frequency identification (RFID) and employees with Bluetooth devices inside a facility. Geofencing is one of the biggest topics with IPS and is meant to limit access to a network in specified areas. Devices that incorporate indoor tracking are not initially precise when objects and employees are on the move. This movement requires devices to have a reliable filter for noise and package lose. For this paper, the comparison between extended Kalman filters and unscented Kalman filter in a controlled environment will help indicate which is ideal for IPS tracking. Both filters will be applied and compared on location accuracy metrics. The proper design of the wireless network is also crucial for having an effective IPS method. This will show the difference in wireless networks and how the initial design will lead to greater chance of success for IPS

    A Survey of Positioning Systems Using Visible LED Lights

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    © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.As Global Positioning System (GPS) cannot provide satisfying performance in indoor environments, indoor positioning technology, which utilizes indoor wireless signals instead of GPS signals, has grown rapidly in recent years. Meanwhile, visible light communication (VLC) using light devices such as light emitting diodes (LEDs) has been deemed to be a promising candidate in the heterogeneous wireless networks that may collaborate with radio frequencies (RF) wireless networks. In particular, light-fidelity has a great potential for deployment in future indoor environments because of its high throughput and security advantages. This paper provides a comprehensive study of a novel positioning technology based on visible white LED lights, which has attracted much attention from both academia and industry. The essential characteristics and principles of this system are deeply discussed, and relevant positioning algorithms and designs are classified and elaborated. This paper undertakes a thorough investigation into current LED-based indoor positioning systems and compares their performance through many aspects, such as test environment, accuracy, and cost. It presents indoor hybrid positioning systems among VLC and other systems (e.g., inertial sensors and RF systems). We also review and classify outdoor VLC positioning applications for the first time. Finally, this paper surveys major advances as well as open issues, challenges, and future research directions in VLC positioning systems.Peer reviewe

    Robust Sensor Fusion for Indoor Wireless Localization

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    Location knowledge in indoor environment using Indoor Positioning Systems (IPS) has become very useful and popular in recent years. Indoor wireless localization suffers from severe multi-path fading and non-line-of-sight conditions. This paper presents a novel indoor localization framework based on sensor fusion of Zigbee Wireless Sensor Networks (WSN) using Received Signal Strength (RSS). The unknown position is equipped with two or more mobile nodes. The range between two mobile nodes is fixed as priori. The attitude (roll, pitch, and yaw) of the mobile node are measured by inertial sensors (ISs). Then the angle and the range between any two nodes can be obtained, and thus the path between the two nodes can be modeled as a curve. Through an efficient cooperation between two or more mobile nodes, this framework effectively exploits the RSS techniques. This constraint help improve the positioning accuracy. Theoretical analysis on localization distortion and Monte Carlo simulations shows that the proposed cooperative strategy of multiple nodes with extended Kalman filter (EKF) achieves significantly higher positioning accuracy than the existing systems, especially in heavily obstructed scenarios

    A novel wideband dynamic directional indoor channel model based on a Markov process

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    Personal Navigation Based on Wireless Networks and Inertial Sensors

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    Tato prĂĄce se zaměƙuje na vĂœvoj navigačnĂ­ho algoritmu pro systĂ©my vhodnĂ© k lokalizaci osob v budovĂĄch a městskĂœch prostorech. Vzhledem k poĆŸadovanĂœm nĂ­zkĂœm nĂĄkladĆŻm na vĂœslednĂœ navigačnĂ­ systĂ©m byla uvaĆŸovĂĄna integrace levnĂœch inerciĂĄlnĂ­ch senzorĆŻ a určovĂĄnĂ­ vzdĂĄlenosti na zĂĄkladě měƙenĂ­ v bezdrĂĄtovĂœch sĂ­tĂ­ch. DĂĄle bylo pƙedpoklĂĄdĂĄno, ĆŸe bezdrĂĄtovĂĄ sĂ­Ć„ bude určena k jinĂœm ĂșčelĆŻm (napƙ: měƙenĂ­ a regulace), neĆŸ lokalizace, proto bylo pouĆŸito měƙenĂ­ sĂ­ly bezdrĂĄtovĂ©ho signĂĄlu. KvĆŻli snĂ­ĆŸenĂ­ značnĂ© nepƙesnosti tĂ©to metody, byla navrhnuta technika mapovĂĄnĂ­ ztrĂĄt v bezdrĂĄtovĂ©m kanĂĄlu. Nejprve jsou shrnuty rĆŻznĂ© modely senzorĆŻ a prostƙedĂ­ a ty nejvhodnějĆĄĂ­ jsou potĂ© vybrĂĄny. Jejich efektivnĂ­ a novĂ© vyuĆŸitĂ­ v navigačnĂ­ Ășloze a vhodnĂĄ fĆŻze vĆĄech dostupnĂœch informacĂ­ jsou hlavnĂ­ cĂ­le tĂ©to prĂĄce.This thesis deals with navigation system based on wireless networks and inertial sensors. The work aims at a development of positioning algorithm suitable for low-cost indoor or urban pedestrian navigation application. The sensor fusion was applied to increase the localization accuracy. Due to required low application cost only low grade inertial sensors and wireless network based ranging were taken into account. The wireless network was assumed to be preinstalled due to other required functionality (for example: building control) therefore only received signal strength (RSS) range measurement technique was considered. Wireless channel loss mapping method was proposed to overcome the natural uncertainties and restrictions in the RSS range measurements. The available sensor and environment models are summarized first and the most appropriate ones are selected secondly. Their effective and novel application in the navigation task, and favorable fusion (Particle filtering) of all available information are the main objectives of this thesis.

    Hybrid Dy-NFIS & RLS equalization for ZCC code in optical-CDMA over multi-mode optical fiber

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    For long haul coherent optical fiber communication systems, it is significant to precisely monitor the quality of transmission links and optical signals. The channel capacity beyond Shannon limit of Single-mode optical fiber (SMOF) is achieved with the help of Multi-mode optical fiber (MMOF), where the signal is multiplexed in different spatial modes. To increase single-mode transmission capacity and to avoid a foreseen “capacity crunch”, researchers have been motivated to employ MMOF as an alternative. Furthermore, different multiplexing techniques could be applied in MMOF to improve the communication system. One of these techniques is the Optical Code Division Multiple Access (Optical-CDMA), which simplifies and decentralizes network controls to improve spectral efficiency and information security increasing flexibility in bandwidth granularity. This technique also allows synchronous and simultaneous transmission medium to be shared by many users. However, during the propagation of the data over the MMOF based on Optical-CDMA, an inevitable encountered issue is pulse dispersion, nonlinearity and MAI due to mode coupling. Moreover, pulse dispersion, nonlinearity and MAI are significant aspects for the evaluation of the performance of high-speed MMOF communication systems based on Optical-CDMA. This work suggests a hybrid algorithm based on nonlinear algorithm (Dynamic evolving neural fuzzy inference (Dy-NFIS)) and linear algorithm (Recursive least squares (RLS)) equalization for ZCC code in Optical-CDMA over MMOF. Root mean squared error (RMSE), mean squared error (MSE) and Structural Similarity index (SSIM) are used to measure performance results
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