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Dynamic spectrum access (DSA) has been envisioned to become the key to solving worldwide spectrum shortage. However, the open nature of wireless medium brings severe threats to the DSA system resulting from unauthorized access. Specifically, unauthorized secondary user (SU) utilizes the licensed spectrum by faking/replaying the spectrum permit, which will not only introduce severe interference to...
Localization and asset tracking are key components of the Internet of Things or the fourth industrial revolution called “Industry 4.0”. Current systems using GPS signals cannot be used indoors. Alternative systems for indoor localization exist, but they cannot be battery power with tiny batteries over multiple years. To overcome these drawbacks we propose a new localization concept based on an ultra-low-power...
In order to solve the problem of poor localization accuracy of DV-Hop algorithm, an improved DV-Hop algorithm is proposed in this paper. The proposed algorithm is based on RSSI technology to modify the hop count between nodes. The concept of basic signal strength of node which will be used to modify hop count is proposed in this paper. The hop coefficient and hopsize coefficient are set up to modify...
Localization accuracy with Ultra-Wideband (UWB) in Non-Line-of-Sight (NLOS) environments, which most commonly exist in indoor constructions, is much lower than that in Line-of-Sight (LOS) environments. In this paper, we propose a collaborative localization algorithm to improve the localization accuracy in NLOS environments by maximally utilizing the LOS links among nodes with unknown locations, and...
We present a fully distributed framework for multi-target tracking with bandwidth-limited (wireless) camera networks. Cameras self-organize into coalitions to perform the task of distributed target tracking via local interactions. Each camera joins the coalitions based on considerations of marginal utility, which takes into account tracking confidence and communication performance in the neighborhood...
Recently, 60 GHz technology has become a promising alternative for indoor positioning systems because it can provide very accurate temporal and spatial information for precise time of arrival (TOA) estimation. However, non-line-of-sight (NLOS) propagation in indoor environments can significantly degrade the localization accuracy with 60 GHz signals. To reduce the effects of NLOS propagation, a fingerprinting...
A 60 GHz ranging model is established and a strongest path search ranging algorithm based on beamforming is proposed. The range error caused by a non-line of sight (NLOS) channel is mitigated by modeling the corresponding delay bias. Outlier detection is employed to improve the accuracy. Performance results are presented which show that 60 GHz ranging can achieve centimeter level accuracy in indoor...
WiFi-based localization is a promising candidate for indoor localization because the localization systems can be implemented on WiFi devices widely used today. In this paper, we present a distributed localization system to realize on-demand location-based services. We define characteristics of on-demand from both the service providers' and users' perspectives. From the service providers' perspective,...
Beacon allows Bluetooth [1] devices to broadcast and receive tiny information within short distance, which consists of two parts: a broadcaster (beacon device) and a receiver (smartphone app). So, it is being widely used in URL (Uniform Resource Locator) broadcast, distance measurement, localization etc. However, because of its deviation, measured distance value is not always accuracy. In this paper,...
Diffraction equations are used widely for propagation analysis and they offer a rigorous approach for idealized free space situations. But there is an ongoing need for accurate and fast propagation analysis for real-world problems such as around just one or perhaps two buildings in a cluttered scenario. The diffraction calculations can offer a guideline only because of the clutter. Superimposing a...
The long and complicated preparing procedures, including placement of surface electromyography (sEMG) sensors and intensive training phase before the usage of myoelectric control interface, are key factors inhibiting the extensive applications of sEMG based human-machine interface (HMI). This paper presents an 8-channel sEMG signal acquisition armband (called SJT-iMyo), with the aim of integrating...
This paper proposes high-scalable 3D indoor positioning algorithm in commercial smart-phone by combining two complementary technologies, Wi-Fi and sensor based positioning. Because a smartphone usually has low-grade MEMS sensor and heterogeneous Wi-Fi chipset, it's very difficult to achieve the globally bounded position in scalable indoor environment. Furthermore, the deployment of wireless infrastructure,...
Spectral correlation function (SCF) is an important tool for analyzing cyclostationary signals. Only a few kinds of communication signals have analytic form for their SCF. This paper proposes a simple analytic expression for SCF of the well-known GMSK signal using super-Gaussian function. Numerical results show the validity of our approximation.
In this paper, we propose a method for estimating message diffusion dynamics in epidemic broadcasting called DIFER (Diffusiveness Inference From Epidemic broadcasting Records). Information diffusion in epidemic broadcasting is affected by several factors such as node mobility and the algorithm for epidemic broadcasting. In the literature, properties of epidemic broadcasting have been investigated...
Impulse radio ultra-wideband (IR-UWB) ranging and localization have recently received significant attention due to the high accuracy and precision. This high accuracy can be exploited for many location aware applications in a wide variety of environments. Although most research efforts have focused on location-aware applications for indoor or outdoor environments, there are other environments, such...
Indoor localization by means of GNSS or a cellular-based method is known to be difficult. Potentially, other wireless technologies could address the technical requirements, but they usually imply the end user must carry a device compatible with this additional technology too. In this paper we investigate the feasibility of collecting vibration sensor readings within a building to locate pedestrians...
The optimal jammer placement problem is proposed for a wireless localization network, where the aim is to degrade the accuracy of locating target nodes as much as possible. In particular, the optimal location of a jammer node is obtained in order to maximize the minimum of the Cramér-Rao lower bounds for a number of target nodes under location related constraints for the jammer node. Theoretical results...
The increasing popularity of wireless services led to increased deployment of wireless systems worldwide that operate in adjacent frequency bands. The national regulatory bodies need to address the potential issues of wireless systems mutual interference (either accidental or deliberate) and guarantee their stakeholders efficiently policed national spectrum usage. One of the cornerstones in this aspect...
5G wireless systems are envisioned to provide ultra-high data rates, increased robustness and low latency for new applications such as machine-to-machine (M2M) and car-to-car (C2C) communications. This paper considers high-speed visible light communication (VLC) as a candidate serving technology to fulfill this set of requirements. Synchronization as the first step towards reliable data detection...
In this study, optimal jamming of wireless localization systems is investigated. Two optimal power allocation schemes are proposed for jammer nodes in the presence of total and peak power constraints. In the first scheme, power is allocated to jammer nodes in order to maximize the average Cramér-Rao lower bound (CRLB) of target nodes whereas in the second scheme the power allocation is performed for...
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