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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...
Despite the fact that cooperative localization approaches stand well in Wireless Sensor Networks (WSNs), they impose challenge of increased energy consumption resulting from the important communication overhead required to accomplish the localization task. In this paper, we developed an Energy Aware Cooperative Localization approach (EACL) based on using a recursive localization system. Obviously,...
With the rapid growth of social media and Internet-of-Things, real-time processing of big data has become a core operation in various business areas. It is of paramount importance that big-data analyses are executed timely with specified accuracy guarantees. However, workloads in the wild are highly bursty with skewed contents and often present the conundrum of meeting latency and accuracy requirements...
We consider a range estimation algorithm based on the time-of-arrival differences between multipath replicas of a signal transmitted by an anchor node of known location to a silent node that needs to localize itself. We consider the geometry of the problem in the simplified case of a constant sound speed profile (SSP), and argue that the more realistic case of a non-constant SSP can be still tackled...
The concept of Precise Point Positioning (PPP) for Global Navigation Satellite System (GNSS) technology was introduced in 1976, however it took until the 1990s for PPP to generate interest amongst the greater GNSS community. In order to evaluate the performance of PPP and its uses for CORSs Network definition, data collected from geodetic receivers belonging to permanent stations of Nigeria network...
A common approach for improving application performance is to process its working set from memory. For datasets that do not fit into DRAM of a single machine this leads to a design of scale-out applications, where the application dataset is partitioned and processed by a cluster of machines. Performance of distributed memory applications, implemented using MPI (Message Passing Interface), inherently...
This paper presents an accurate source number detection method for low-cost array system based on nested array and Khatri-Rao product approaches. Source number estimation accuracy can be enhanced by increasing the number of array elements, but it is often limited due to hardware and software cost. The authors have already proposed a low-cost array receiver system using switches which can reduce receiver...
In this paper we present an indoor-localization system using sound signals which are outside of the audible range with an error in the range of centimeters. The innovative distinctive feature of the proposed system is based on the high accuracy due to the acoustic run-time measurements. Therefore this approach is more precise than other indoor-localization systems based on Wi-Fi or Bluetooth. Furthermore,...
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...
This paper is concerned with a dilution of precision (DOP) simulation considering line-of-sight (LOS) and non-line-of-sight (NLOS). Multilatelation (MLAT) system is used for estimating the position of the aircraft on an airport surface, and its basic principle is equivalent to GPS positioning. DOP is the standard value for the accuracy of the positioning. In the system deployment, we have so far computed...
Motivated by the emergence of the Internet of Things (IoT), and by the importance that location information has on many complex systems scenarios, we propose a hybrid scheme for user positioning in an urban scenario. The system uses both a Global Navigation Satellite System (GNSS) and a Magnetic Positioning System (MPS). To maintain receiver complexity and cost at a minimum, the location scheme combines...
Unmanned aerial vehicles, such as Multicopters, are becoming ubiquitous. One newer field is in electromagnetic (EM) metrology [1] [2]. For such applications the vehicles are relatively complex, housing multiple subsystems with associated wiring and metallic surfaces. The galvanically interconnected subsystems have bearing on the on-board antennas and therefore the integrity of measurements.
This document presents a brief overview of the Sferics Timing and And Ranging NETwork (STARNET) measurements over South America in the last 9 years. Since its beginning, STARNET measured more than 610 millions of sferics in the entire South America. The main hot spots are found over Maracaibo - Venezuela, northern Argentina, Paraguay, Bolivia, and Corumbá and Amazon basin in Brazil. The detection...
This paper describes a possible usage of Radio Frequency Identification as a mean of asset localisation. The development of the working solution of asset localisation system based on the Radio Frequency Identification measured distance between the emitter and the receiver is presented also. The crucial part of the research was the design and development of the algorithms responsible for the processing...
For the GNSS receiver, when the satellite navigation signal is weak, the traditional tracking accuracy of GNSS receiver tracking loops will decline sharply which will lead to the deterioration of the Carrier frequency error. Aiming at improving the Velocity Determination accuracy of GNSS receiver, we propose the GNSS Precise Velocity Determination Algorithm Based on Chaotic Oscillator. The proposed...
The wireless channel in mobile communications changes the transmitted signal and thus must be properly modeled. If a multiple-input multiple-output (MIMO) system is considered, the modeling procedure becomes more challenging. In this paper, a novel radio channel model is implemented and validated using measurement data. On one hand, statistical properties of MIMO channels are modeled by geometry-based...
Aiming at the problem of how to make use of the atomic clocks offered by Micro-PNT to make Global Navigation Satellite System (GNSS) receivers fulfill fast positioning with the recovery of the satellite navigation signal, this paper discusses the fast positioning method which omits the step of frame synchronization and proposes a constellation-triangle selecting algorithm based on high-precision clock...
This study is aimed at evaluating the trade-off between Global Positioning System (GPS) accuracy and power saving from reduction of number of channels. The study is conducted for number of GPS receiver channels of 4 to 12 for two scenarios: 1) Normal scenario with full range of available GPS satellites; 2) Obstruction scenario with GPS satellite elevation cutoff of 20°. It is observed that increase...
A method for electromagnetic radiation source identification is proposed. The spatial characteristic of a radiation source is taken as the unique parameter for support vector machines (SVMs) to identify. First, the location of radiation source is determined by the triangulation method, and then its spatial characteristic is collected by a band receiver array with simulation, which removes the limit...
Some tactual communication tools which conveys emotions during face-to-face oral conversation have been developing. In the present study, to diagnose the mental condition of the institutionalized elderly person using the tactual communication tool, an algorithm of emotion recognition was developed. The emotion recognition algorithm recognized six emotions (surprise, joy, anger, sadness, disgust and...
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