scholarly journals Performance Comparison of OFDM-UWB Radio Signals Distribution in Long-Reach PONs Using Mach-Zehnder and Linearized Modulators

2011 ◽  
Vol 29 (6) ◽  
pp. 1311-1320 ◽  
Author(s):  
Tiago Alves ◽  
Maria Morant ◽  
Adolfo Cartaxo ◽  
Roberto Llorente
Keyword(s):  
Performance Comparison ◽  
Radio Signals ◽  
Uwb Radio

UWB and MEMS Based Indoor Navigation

2008 ◽  
Vol 61 (3) ◽  
pp. 369-384 ◽  
Author(s):  
Sylvain Pittet ◽  
Valérie Renaudin ◽  
Bertrand Merminod ◽  
Michel Kasser
Keyword(s):  
Indoor Navigation ◽  
Ultra Wideband ◽  
Indoor Environments ◽  
Selection Methods ◽  
Pedestrian Navigation ◽  
Radio Signals ◽  
Uwb Radio ◽  
Mechanical Sensors ◽  
Inertial Measurements ◽  
Reference Trajectories

Thanks to its physical characteristics, Ultra-wideband (UWB) is one of the most promising technologies for indoor pedestrian navigation. UWB radio localisation systems however experience multipath phenomena that decrease the precision and the reliability of the user's location. To cope with complex indoor environments, UWB radio signals are coupled with inertial measurements from Micro Electro Mechanical Sensors (MEMS) in an extended Kalman filter. Improved performances of the filter are presented and compared with reference trajectories and with pure inertial solutions. Only specific selection methods enable this improvement by detecting and removing outliers in the raw localisation data.

scholarly journals Improving the Accuracy of Decawave’s UWB MDEK1001 Location System by Gaining Access to Multiple Ranges

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1787
Author(s):  
Antonio R. Jiménez ◽  
Fernando Seco
Keyword(s):  
Mobile User ◽  
Position Estimation ◽  
Indoor Environments ◽  
Outlier Removal ◽  
Estimation Algorithms ◽  
Advantages And Disadvantages ◽  
Major Disadvantage ◽  
Radio Signals ◽  
Iot Devices ◽  
Uwb Radio

The location of people, robots, and Internet-of-Things (IoT) devices has become increasingly important. Among the available location technologies, solutions based on ultrawideband (UWB) radio are having much success due to their accuracy, which is ideally at a centimeter level. However, this accuracy is degraded in most common indoor environments due to the presence of obstacles which block or reflect the radio signals used for ranging. One way to circumvent this difficulty is through robust estimation algorithms based on measurement redundancy, permitting to minimize the effect of significantly erroneous ranges (outliers). This need for redundancy often conflicts with hardware restraints put up by the location system’s designers. In this work, we present a procedure to increase the redundancy of UWB systems and demonstrate it with the help of a commercial system made by Decawave. This system is particularly easy to deploy, by configuring a network of beacons (anchors) and devices (tags) to be located; however, its architecture presents a major disadvantage as each tag to be located can only measure ranges to a maximum of four anchors. This limitation is embedded in the Positioning and Networking Stack (PANS) protocol designed by Decawave, and therefore is not easy to bypass without a total redesign of the firmware. In this paper, we analyze the strategies that we have been able to identify in order to provide this equipment with multiple range measurements, and thus enable each tag to be positioned with more than four measured ranges. We will see the advantages and disadvantages of each of these strategies, and finally we will adopt a solution that we implemented to be able to measure up to eight ranges for each mobile device (tag). This solution implies the duplication of the tags at the mobile user, and the creation of a double interleaved network of anchors. The range among tags and the eight beacons is obtained through an API via a wireless BLE protocol at a 10 Hz rate. A robustified Extended Kalman filter (EKF) is designed to estimate, by trilateration, the position of the pair of mobile tags, using eight ranges. Two different scenarios are used to make localization experimentation: a laboratory and an apartment. Our position estimation, which exploits redundant information and performs outlier removal, is compared with the commercial solution limited to four ranges, demonstrating the need and advantages of our multi-range approach.

scholarly journals Ultrawideband Technology in Medicine: A Survey

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
R. Chávez-Santiago ◽  
I. Balasingham ◽  
J. Bergsland
Keyword(s):  
Surgical Procedures ◽  
Medical Services ◽  
Medical Applications ◽  
Wireless Technology ◽  
Less Invasive ◽  
Research Perspectives ◽  
Radio Signals ◽  
Enhanced Mobility ◽  
Uwb Radio ◽  
Positive Effect

The utilization of wireless technology in traditional medical services provides patients with enhanced mobility. This has a positive effect on the recovery speed of a person after major surgical procedures or prolonged illness. Ultrawideband (UWB) radio signals have inherent characteristics that make them highly suitable for less invasive medical applications. This paper surveys our own and related recent research on UWB technology for medical sensing and communications. Some research perspectives in the aforementioned topics are suggested too.

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