scholarly journals A Hybrid RSS/TOA Method for 3D Positioning in an Indoor Environment

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Smita Tiwari ◽  
Donglin Wang ◽  
Michel Fattouche ◽  
Fadhel Ghannouchi
Keyword(s):  
Indoor Environment ◽  
Signal Strength ◽  
Least Square ◽  
Line Of Sight ◽  
Time Of Arrival ◽  
Nakagami Distribution ◽  
University Of Calgary ◽  
Multipath Effects ◽  
3D Positioning ◽  
The University

This paper investigates 3D positioning in an indoor line of sight (LOS) and nonline of sight (NLOS) combined environment. It is a known fact that time-of-arrival-(TOA-) based positioning outperforms other techniques in LOS environments; however, multipath in an indoor environment, especially NLOS multipath, significantly decreases the accuracy of TOA positioning. On the other hand, received-signal-strength-(RSS-) based positioning is not affected so much by NLOS multipath as long as the propagation attenuation can be correctly estimated and the multipath effects have been compensated for. Based on this fact, a hybrid weighted least square (HWLS) RSS/TOA method is proposed for target positioning in an indoor LOS/NLOS environment. The identification of LOS/NLOS path is implemented by using Nakagami distribution. An experiment is conducted in the iRadio lab, in the ICT building at the University of Calgary, in order to (i) demonstrate the availability of Nakagami distribution for the identification of LOS and NLOS path, (ii) estimate the pass loss exponent for RSS technique, and (iii) verify our proposed scheme.

scholarly journals Estimation of the number of people in an indoor environment based onWiFi received signal strength indicator

2021 ◽  
Vol 10 (3) ◽  
pp. 1475-1483
Author(s):  
Hakam Marwan Zaidan ◽  
Emad Ahmed Mohammed ◽  
Dheyaa Hussein Alhelal
Keyword(s):  
Indoor Environment ◽  
Polynomial Regression ◽  
Signal Strength ◽  
Received Signal Strength ◽  
Line Of Sight ◽  
Concrete Wall ◽  
Received Signal Strength Indicator ◽  
The People ◽  
Two Stages ◽  
Non Line Of Sight

WiFi access points are widely spread everywhere in all our daily life routines. Using these devices to provide services other than the Internet is becoming familiar nowadays.This paper conducts an experimental study to estimate the number of people in an indoor environment through two system setups, line of sight, and non-line of sight. Relationship modeling between WiFi received signal and the number of people uses polynomial regression. The experiment comprised of two stages: first is the data collection from a controlled number of people. Then, the collected data used to train the system through polynomial regression. The second is testing the system’s effectiveness by applying it to an uncontrolled environment. Testing results revealed efficiency in using WiFi received signal strength to do the people counting (up to 60) because of the accuracy achievements of 93.17% in the line of sight system. The non-line of sight system disclosed randomness in the received signal strength indicator regardless of the change in the number of people. The  randomness is mainly caused by the fading effect of the concrete wall. Therefore it is inefficient to use the non-line of sight system in concrete buildings.

scholarly journals Indoor 3-D Localization Based on Received Signal Strength Difference and Factor Graph for Unknown Radio Transmitter

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 338 ◽  
Author(s):  
Liyang Zhang ◽  
Taihang Du ◽  
Chundong Jiang
Keyword(s):  
Measurement Errors ◽  
Signal Strength ◽  
Received Signal Strength ◽  
Least Square ◽  
Practical Significance ◽  
Factor Graph ◽  
Line Of Sight ◽  
Localization Algorithm ◽  
Radio Transmitter ◽  
Strength Difference

Accurate localization of the radio transmitter is an important work in radio management. Previous research is more focused on two-dimensional (2-D) scenarios, but the localization of an unknown radio transmitter under three-dimensional (3-D) scenarios has more practical significance. In this paper, we propose a novel 3-D localization algorithm with received signal strength difference (RSSD) information and factor graph (FG), which is suitable for both line-of-sight (LOS) and non-line-of-sight (NLOS) condition. Considering the stochastic properties of measurement errors caused by the indoor environment, RSSD measurements are processed with mean and variance in the form of Gaussian distribution in the FG framework. A new 3-D RSSD-based FG model is constructed with the relationship between RSSD and location coordinates by local linearization technique. The soft-information computation and iterative process of the proposed model are derived by using the sum-product algorithm. In addition, the impacts of different grid distances and number of signal receivers on positioning accuracy are explored. Finally, the performance of our proposed approach is experimentally evaluated in a real scenario. The results show that the positioning performance of the proposed algorithm is not only superior to the k-nearest neighbors (kNN) algorithm and least square (LS) algorithm, but also it can achieve a mean localization error as low as 1.15 m. Our proposed scheme provides a good solution for the accurate detection of an unknown radio transmitter under indoor 3-D space and has a good application prospect.

Node Localization in Ad-hoc Networks

2011 ◽  
pp. 115-135
Author(s):  
Zhonghai Wang ◽  
Seyed (Reza) Zekavat
Keyword(s):  
Ad Hoc Networks ◽  
Wireless Channels ◽  
Ad Hoc ◽  
Signal Strength ◽  
Received Signal Strength ◽  
Line Of Sight ◽  
Time Of Arrival ◽  
Node Localization ◽  
Mitigation Techniques ◽  
Hoc Networks

This chapter introduces node localization techniques in ad-hoc networks including received signal strength (RSS), time-of-arrival (TOA) and direction-of-arrival (DOA). Wireless channels in ad-hoc networks can be categorized as LOS and NLOS. In LOS channels, the majority of localization techniques perform properly. However, in NLOS channels, the performance of these techniques reduces. Therefore, non-line-of-sight (NLOS) identification and mitigation techniques, and localization techniques for NLOS scenarios are briefly reviewed.

scholarly journals Enhanced TOA Estimation Using OFDM over Wide-Band Transmission Based on a Simulated Model

2021 ◽  
Author(s):  
Huthaifa A. Obeidatat ◽  
Imran Ahmad ◽  
Mohammad R. Rawashdeh ◽  
Ali A. Abdullah ◽  
Wafa S. Shuaieb ◽  
...  
Keyword(s):  
Indoor Environment ◽  
Wide Band ◽  
Line Of Sight ◽  
Time Of Arrival ◽  
Localization Accuracy ◽  
Access Points ◽  
Simulated Model ◽  
Toa Estimation ◽  
Localization Errors ◽  
Wide Band Transmission

AbstractThis paper presents the advantages of using a wideband spectrum adopting multi-carrier to improve targets localization within a simulated indoor environment using the Time of Arrival (TOA) technique. The study investigates the effect of using various spectrum bandwidths and a different number of carriers on localization accuracy. Also, the paper considers the influence of the transmitters’ positions in line-of-sight (LOS) and non-LOS propagation scenarios. It was found that the accuracy of the proposed method depends on the number of sub-carriers, the allocated bandwidth (BW), and the number of access points (AP). In the case of using large BW with a large number of subcarriers, the algorithm was effective to reduce localization errors compared to the conventional TOA technique. The performance degrades and becomes similar to the conventional TOA technique while using a small BW and a low number of subcarriers.

Combining the Love of Art, Science, Business and Medicine to Innovate and Enhance Patient Health. Highlights from the 7th Annual Leaders in Medicine Symposium of the Cummings School of Medicine, Calgary, AB

2018 ◽  
pp. E51-E54
Author(s):  
Jennifer Beatty ◽  
Michael Peplowski ◽  
Noreen Singh ◽  
Craig Beers ◽  
Evan M Beck ◽  
...  
Keyword(s):  
Hospital Admissions ◽  
Clinical Care ◽  
Clinical Problem ◽  
Faculty Members ◽  
Guest Speaker ◽  
School Of Medicine ◽  
University Of Calgary ◽  
Patient Health ◽  
The University ◽  
Care Costs

The Leader in Medicine (LIM) Program of the Cumming School of Medicine, University of Calgary, hosted its 7th Annual LIM Research Symposium on October 30, 2015 and participation grew once again, with a total of six oral and 99 posters presentations! Over 45 of our Faculty members also participated in the symposium. This year’s LIM Symposium theme was “Innovations in Medicine” and the invited guest speaker was our own Dr. Breanne Everett (MD/MBA). She completed her residency in plastic surgery at University of Calgary and holds both a medical degree and an MBA from the University of Calgary. In her inspiring talk, entitled “Marrying Business and Medicine: Toe-ing a Fine Line”, she described how she dealt with a clinical problem (diabetic foot ulcers), came up with an innovation that optimized patient care, started her own company and delivered her product to market to enhance the health of the community. She clearly illustrated how to complete the full circle, from identifying a clinical problem to developing and providing a solution that both enhances clinical care and patient health as well as reduces health care costs and hospital admissions. The research symposium was an outstanding success and the abstracts are included in companion article in CIM.

scholarly journals An Indoor Visible Light Positioning System Using Tilted LEDs with High Accuracy

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 920
Author(s):  
Neha Chaudhary ◽  
Othman Isam Younus ◽  
Luis Nero Alves ◽  
Zabih Ghassemlooy ◽  
Stanislav Zvanovec ◽  
...  
Keyword(s):  
Visible Light ◽  
Polynomial Regression ◽  
Power Level ◽  
Least Square ◽  
Line Of Sight ◽  
Received Power ◽  
Strength Based ◽  
Complex Linear ◽  
Linear Least Square ◽  
First Time

The accuracy of the received signal strength-based visible light positioning (VLP) system in indoor applications is constrained by the tilt angles of transmitters (Txs) and receivers as well as multipath reflections. In this paper, for the first time, we show that tilting the Tx can be beneficial in VLP systems considering both line of sight (LoS) and non-line of sight transmission paths. With the Txs oriented towards the center of the receiving plane (i.e., the pointing center F), the received power level is maximized due to the LoS components on F. We also show that the proposed scheme offers a significant accuracy improvement of up to ~66% compared with a typical non-tilted Tx VLP at a dedicated location within a room using a low complex linear least square algorithm with polynomial regression. The effect of tilting the Tx on the lighting uniformity is also investigated and results proved that the uniformity achieved complies with the European Standard EN 12464-1. Furthermore, we show that the accuracy of VLP can be further enhanced with a minimum positioning error of 8 mm by changing the height of F.

scholarly journals Barriers on Establishing Passive Strategies in Office Spaces: A Case Study in a Historic University Building

2021 ◽  
Vol 13 (8) ◽  
pp. 4563
Author(s):  
Nuno Baía Baía Saraiva ◽  
Luisa Dias Dias Pereira ◽  
Adélio Rodrigues Gaspar ◽  
José Joaquim da Costa
Keyword(s):  
Thermal Comfort ◽  
Indoor Environment ◽  
Hvac Systems ◽  
Heritage Buildings ◽  
Full Capacity ◽  
Free Cooling ◽  
Passive Strategies ◽  
The University ◽  
Indoor Conditions

The adaptation of spaces to different usage typologies can be complex in heritage buildings. Facilities were initially planned for a specific type of use that, when changed, require additional measures to ensure a suitable indoor environment. Passive strategies—e.g., free cooling—are commonly used as an alternative without requiring equipment installation. However, its implementation often leads to unsatisfactory conditions. Therefore, it is important to clarify the main barriers to achieving thermal comfort in readapted historic buildings. The present work investigates the thermal comfort conditions reported by workers in office spaces of a historic building in the University of Coimbra. A monitoring campaign was carried out between May and September 2020 to assess indoor conditions’ quality. Due to the current pandemic of COVID-19, offices were not occupied at full capacity. A one-day evaluation of thermal comfort was made using a climate analyzer and six occupants were surveyed on 19 August 2020. The main results highlighted discomfort due to overheating of spaces. The causes were related to the combination of inadequate implementation of the free cooling actions and the building use. Furthermore, it was recommended the installation of HVAC systems in case of full capacity.

Marketing Love: Romance Publishers Mills & Boon and Harlequin Enterprises, 1930–1990

2021 ◽  
pp. 1-31
Author(s):  
DENISE HARDESTY SUTTON
Keyword(s):  
Consumer Goods ◽  
Marketing Strategies ◽  
Direct Mail ◽  
Popular Romance ◽  
British Publisher ◽  
Product Standardization ◽  
University Of Calgary ◽  
Standard Practices ◽  
The University ◽  
Book Publishers

When Harlequin Enterprises acquired British publisher Mills & Boon in 1972, the merged firm became the world’s dominant publisher of popular romance novels. Little is known, however, about the role that innovative marketing strategies played in the growth of these two romance publishing companies, especially their use of product sampling, direct mail, product standardization, and what was known at Mills & Boon as the “personal touch.” Through research in the Mills & Boon company archive at the University of Reading, the Grescoe Archive at the University of Calgary, as well as an analysis of company histories, trade publications, interviews, and marketing techniques, this study reveals how Harlequin and Mills & Boon took a different approach to product promotion than traditional publishers. Their innovation was to incorporate consumer goods marketing strategies, familiar to other industries, that disrupted and redefined standard practices of book publishers.

scholarly journals Target Localization via Integrated and Segregated Ranging Based on RSS and TOA Measurements

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 230 ◽  
Author(s):  
Slavisa Tomic ◽  
Marko Beko
Keyword(s):  
State Of The Art ◽  
Hybrid Approach ◽  
Critical Distance ◽  
Heuristic Approach ◽  
Target Localization ◽  
Line Of Sight ◽  
Time Of Arrival ◽  
Individual Measurement ◽  
New Approach ◽  
Non Line Of Sight

This work addresses the problem of target localization in adverse non-line-of-sight (NLOS) environments by using received signal strength (RSS) and time of arrival (TOA) measurements. It is inspired by a recently published work in which authors discuss about a critical distance below and above which employing combined RSS-TOA measurements is inferior to employing RSS-only and TOA-only measurements, respectively. Here, we revise state-of-the-art estimators for the considered target localization problem and study their performance against their counterparts that employ each individual measurement exclusively. It is shown that the hybrid approach is not the best one by default. Thus, we propose a simple heuristic approach to choose the best measurement for each link, and we show that it can enhance the performance of an estimator. The new approach implicitly relies on the concept of the critical distance, but does not assume certain link parameters as given. Our simulations corroborate with findings available in the literature for line-of-sight (LOS) to a certain extent, but they indicate that more work is required for NLOS environments. Moreover, they show that the heuristic approach works well, matching or even improving the performance of the best fixed choice in all considered scenarios.

Sign in / Sign up

Export Citation Format

Share Document