scholarly journals Lab-Based Evaluation of Device-Free Passive Localization Using Multipath Channel Information

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2383
Author(s):  
Jonas Ninnemann ◽  
Paul Schwarzbach ◽  
Andrea Jung ◽  
Oliver Michler
Keyword(s):  
Wide Band ◽  
Location Based Services ◽  
Radio Communication ◽  
Communication Signals ◽  
Environmental Mapping ◽  
Wireless Signal ◽  
Elliptical Model ◽  
Em Method ◽  
Multipath Detection ◽  
Passive Localization

The interconnection of devices, driven by the Internet of Things (IoT), enables a broad variety of smart applications and location-based services. The latter is often realized via transponder based approaches, which actively determine device positions within Wireless Sensor Networks (WSN). In addition, interpreting wireless signal measurements also enables the utilization of radar-like passive localization of objects, further enhancing the capabilities of WSN ranging from environmental mapping to multipath detection. For these approaches, the target objects are not required to hold any device nor to actively participate in the localization process. Instead, the signal delays caused by reflections at objects within the propagation environment are used to localize the object. In this work, we used Ultra-Wide Band (UWB) sensors to measure Channel Impulse Responses (CIRs) within a WSN. Determining an object position based on the CIR can be achieved by formulating an elliptical model. Based on this relation, we propose a CIR environmental mapping (CIR-EM) method, which represents a heatmap generation of the propagation environment based on the CIRs taken from radio communication signals. Along with providing imaging capabilities, this method also allows a more robust localization when compared to state-of-the-art methods. This paper provides a proof-of-concept of passive localization solely based on evaluating radio communication signals by conducting measurement campaigns in an anechoic chamber as a best-case environment. Furthermore, shortcomings due to physical layer limitations when using non-dedicated hardware and signals are investigated. Overall, this work lays a foundation for related research and further evaluation in more application-oriented scenarios.

Exploring LoRa for Sensing

2021 ◽  
Vol 25 (2) ◽  
pp. 33-37
Author(s):  
Fusang Zhang ◽  
Zhaoxin Chang ◽  
Jie Xiong ◽  
Daqing Zhang
Keyword(s):  
Long Range ◽  
Small Range ◽  
Wireless Sensing ◽  
60 Ghz ◽  
Wireless Technologies ◽  
Sensing Range ◽  
Wireless Signal ◽  
New Applications ◽  
Passive Localization ◽  
Activity Sensing

Wireless sensing received a great amount of attention in recent years and various wireless technologies have been exploited for sensing, including WiFi [1], RFID [2], ultrasound [3], 60 GHz mmWave [4] and visible light [5]. The key advantage of wireless sensing over traditional sensing is that the target does not need to be equipped with any sensor(s) and the wireless signal itself is being used for sensing. Exciting new applications have been enabled, such as passive localization [6] and contactless human activity sensing [7]. While promising in many aspects, one key limitation of current wireless sensing techniques is the very small sensing range. This is because while both direct path and reflection path signals are used for communication, only the weak target-reflection signals can be used for sensing. Take Wi-Fi as an example: the communication range can reach 20 to 50 meters indoors but its sensing range is merely 4 to 8 meters. This small range further limits the through-wall sensing capability of Wi-Fi. On the other hand, many applications do require long-range and through-wall sensing capability. In a fire rescue scenario, the sensing device cannot be placed close to the building, and the long-range through-wall sensing capabilities are critical for detecting people deep inside the building. Table I summarizes the sensing range of existing wireless technologies. We can see that long-range through-wall sensing is still missing with wireless sensing.

scholarly journals Frequency-Selective Wallpaper for Indoor Interference Reduction and MIMO Capacity Improvement

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 695
Author(s):  
José-Víctor Rodríguez ◽  
Mats Gustafsson ◽  
José-María Molina-García-Pardo ◽  
Leandro Juan-Llácer ◽  
Ignacio Rodríguez-Rodríguez
Keyword(s):  
Mimo Systems ◽  
Radio Channel ◽  
Multiple Input Multiple Output ◽  
Singular Values ◽  
Indoor Environments ◽  
Radio Communication ◽  
Single Input Single Output ◽  
Communication Signals ◽  
Frequency Selective ◽  
5 Ghz

This paper presents the design and features of frequency-selective wallpaper—based on periodic and symmetric metallic hexagons—intended to be attached to standard walls for filtering out 5 GHz signals (e.g., IEEE 802.11a systems) without blocking other selected radio communication services (e.g., cellular mobile communication signals). It analyzes the characteristics of the radio channel—as found within standard indoor environments—with both regular walls and walls with the proposed frequency-selective wallpaper, examined using a ray-launching program for single-input single-output (SISO) and multiple-input multiple-output (MIMO) systems. This allows the harvesting of parameters, including channel capacity, power delay profile, and signal-to-interference ratio, for proper comparison between the two environments under study: with and without the presented wallpaper. The achieved results clearly show that the use of the proposed frequency-selective wallpaper in an indoor scenario reduces interference levels by an additional attenuation of up to 20 dB in comparison to an unpapered wall. Additionally, with MIMO systems, radio channel characteristics, such as capacity, are improved due to the increase in the magnitude of all singular values of the channel transfer matrix compared to the unpapered wall case, thereby leading to the existence of more relevant subchannels.

scholarly journals An Algorithm for Accurate and Robust Indoor Localization Based on Nonlinear Programming

Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 65 ◽  
Author(s):  
Stefania Monica ◽  
Federico Bergenti
Keyword(s):  
Nonlinear Programming ◽  
Mobile Devices ◽  
Optimization Problem ◽  
Indoor Localization ◽  
Wide Band ◽  
Location Based Services ◽  
Experimental Results ◽  
Indoor Environments ◽  
Anchor Nodes ◽  
The Impact

The study of techniques to estimate the position of mobile devices with a high level of accuracy and robustness is essential to provide advanced location based services in indoor environments. An algorithm to enable mobile devices to estimate their positions in known indoor environments is proposed in this paper under the assumption that fixed anchor nodes are available at known locations. The proposed algorithm is specifically designed to be executed on the mobile device whose position is under investigation, and it allows the device to estimate its position within the environment by actively measuring distance estimates from the anchor nodes. In order to reduce the impact of the errors caused by the arrangement of the anchor nodes in the environment, the proposed algorithm first transforms the localization problem into an optimization problem, and then, it solves the derived optimization problem using techniques inspired by nonlinear programming. Experimental results obtained using ultra-wide band signaling are presented to assess the performance of the algorithm and to compare it with reference alternatives. The presented experimental results confirm that the proposed algorithm provides an increased level of accuracy and robustness with respect to two reference alternatives, regardless of the position of the anchor nodes.

scholarly journals Wide-Band High-Gain DGS Antenna System for Indoor Robot Positioning

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Lu Bai ◽  
Chenglie Du
Keyword(s):  
Antenna Array ◽  
Mutual Coupling ◽  
Wide Band ◽  
High Gain ◽  
Antenna System ◽  
Fusion Technology ◽  
Positioning Systems ◽  
Signal Fusion ◽  
Wireless Signal ◽  
Robot Positioning

Based on multisource wireless signal fusion technology, the autonomous positioning systems of robots have been widely employed. How to design a compact compostable antenna array for indoor robot positioning is still a problem. In this study, we proposed a compact ultrathin antenna unit that effectively reduces the mutual coupling between any adjacent units, while covering most of the existing communication bands, including 2G/3G/4G/Wi-Fi, which will greatly reduce the size of the positioning antenna array. The proposed antenna system has been employed for positioning purpose with high-gain, wide-frequency band and limited size. It necessarily improves the accuracy of positioning signal from various unknown sources and finally accomplishes its autonomous positioning function.

PDR-Aided Algorithm with WiFi Fingerprint Matching for Indoor Localization

2014 ◽  
Vol 701-702 ◽  
pp. 989-993
Author(s):  
Wen Bin Yu ◽  
Peng Li ◽  
Zhi Chen ◽  
Chang Li
Keyword(s):  
Social Network ◽  
Indoor Localization ◽  
Dead Reckoning ◽  
Location Based Services ◽  
Fingerprint Matching ◽  
Network Applications ◽  
Wireless Signal ◽  
Signal Fluctuation ◽  
Pedestrian Dead Reckoning ◽  
Wifi Fingerprint

Recently, indoor localization is essential to enable location-based services for many mobile and social network applications. Due to fluctuation of the wireless signal, the accuracy of a simple WiFi fingerprint-based localization is not high. In this paper, we first exploit Pedestrian Dead Reckoning (PDR) technology to overcome the problem of the wireless signal fluctuation, then propose a PDR-aided algorithm with WiFi fingerprint matching for indoor localization, which using the PDR technology aided indoor localization. Experiments show that our algorithm has better accuracy than other indoor localization methods.

scholarly journals Multi-task Learning Approach for Automatic Modulation and Wireless Signal Classification

2021 ◽  
Author(s):  
Anu Jagannath ◽  
Jithin Jagannath
Keyword(s):  
State Of The Art ◽  
Spectrum Management ◽  
Signal Classification ◽  
Electromagnetic Spectrum ◽  
Signal Recognition ◽  
Single Task ◽  
Communication Signals ◽  
Spectrum Monitoring ◽  
Task Learning ◽  
Wireless Signal

Wireless signal recognition is becoming increasingly more significant for spectrum monitoring, spectrum management, and secure communications. Consequently, it will become a key enabler with the emerging fifth-generation (5G) and beyond 5G communications, Internet of Things networks, among others. State-of-the-art studies in wireless signal recognition have only focused on a single task which in many cases is insufficient information for a system to act on. In this work, for the first time in the wireless communication domain, we exploit the potential of deep neural networks in conjunction with multi-task learning (MTL) framework to simultaneously learn modulation and signal classification tasks. The proposed MTL architecture benefits from the mutual relation between the two tasks in improving the classification accuracy as well as the learning efficiency with a lightweight neural network model. Additionally, we consider the problem of heterogeneous wireless signals such as radar and communication signals in the electromagnetic spectrum. Accordingly, we have shown how the proposed MTL model outperforms several state-of-the-art single-task learning classifiers while maintaining a lighter architecture and performing two signal characterization tasks simultaneously. Finally, we also release the only known open heterogeneous wireless signals dataset that comprises of radar and communication signals with multiple labels.

scholarly journals PREDICTION OF SIGNAL ATTENUATION DUE TO DUSTSTORMS USING MIE SCATTERING

2010 ◽  
Vol 11 (1) ◽  
pp. 71-87 ◽  
Author(s):  
Md. Rafiqul Islam ◽  
Zain Elabdin Omer Elshaikh ◽  
Othman O. Khalifa ◽  
Ahm Zahirul Alam ◽  
Sheroz Khan ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Wide Band ◽  
Mie Scattering ◽  
Dust Particles ◽  
Signal Attenuation ◽  
Communication Signals ◽  
Proposed Model ◽  
Desert Areas ◽  
Signal Path ◽  
Predicted Values

The present trend in radio design calls for the use of frequencies above 40 GHz for short links carrying wide-band digital communication signals. In order to utilize the new frequency band efficiently, signal attenuation studies due to duststorms is needed urgently for desert areas. This paper presents a mathematical model which has been developed to predict the signal attenuation due to duststorm. The proposed model enables the convenient calculation of the signal path attenuation based on Mie solution of Maxwell's equations for the scattering of electromagnetic wave by dust particles. The predicted values from the proposed mathematical model are compared with the measured values observed in Saudi Arabia and Sudan and show relatively close agreement.

The Wireless Network Positioning Strategies Basing on Mobile Terminal

2012 ◽  
Vol 546-547 ◽  
pp. 1124-1129
Author(s):  
Lei Xu ◽  
Yu Feng Zhang ◽  
Jian Guo ◽  
Lian Gao
Keyword(s):  
Implementation Strategies ◽  
Value Added ◽  
Mobile Terminal ◽  
Base Station ◽  
Location Based Services ◽  
Radio Communication ◽  
Cellular Radio ◽  
Wireless Data ◽  
Location Services ◽  
Code Division Multiple

With the continuous development of terminal technologies, the use of mobile terminals is becoming more and more diverse. Many value-added services brought by such applications gradually become to be the firm's new profit opportunity. The location itself has great value; with the display of electronic map or with the support of geographic information database, a variety of information can be shown, tracked and handled. Such location-based services (LBS) is widely used in the field of public wireless data, and mobile location services is recognized as the most attractive wireless data value-added business in 3G network. This paper discusses three positioning standards of the 3GPP first; and then combined with the existing GSM/GPRS cellular radio communication network, it mainly gives specific positioning implementation strategies of single base station in the TD-SCDMA (Time Division Synchronous Code Division Multiple Access) system.

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