Massive MIMO-based Localization and Mapping Exploiting Phase Information of Multipath Components

In this paper, we present a robust multipath-based localization and mapping framework that exploits the phases of specular multipath components (MPCs) using a massive multiple-input multiple-output (MIMO) array at the base station. Utilizing the phase information related to the propagation distances of the MPCs enables the possibility of localization with extraordinary accuracy even with limited bandwidth. The specular MPC parameters along with the parameters of the noise and the dense multipath component (DMC) are tracked using an extended Kalman filter (EKF), which enables to preserve the distance-related phase changes of the MPC complex amplitudes. The DMC comprises all non-resolvable MPCs, which occur due to finite measurement aperture. The estimation of the DMC parameters enhances the estimation quality of the specular MPCs and therefore also the quality of localization and mapping. The estimated MPC propagation distances are subsequently used as input to a distance-based localization and mapping algorithm. This algorithm does not need prior knowledge about the surrounding environment and base station position. The performance is demonstrated with real radio-channel measurements using an antenna array with 128 ports at the base station side and a standard cellular signal bandwidth of 40 MHz. The results show that high accuracy localization is possible even with such a low bandwidth.Comment: 14 pages (two columns), 13 figures. This work has been submitted to the IEEE Transaction on Wireless Communications for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Sensor Networks TDOA Self-Calibration: 2D Complexity Analysis and Solutions

Given a network of receivers and transmitters, the process of determining their positions from measured pseudo-ranges is known as network self-calibration. In this paper we consider 2D networks with synchronized receivers but unsynchronized transmitters and the corresponding calibration techniques,known as TDOA techniques. Despite previous work, TDOA self-calibration is computationally challenging. Iterative algorithms are very sensitive to the initialization, causing convergence issues.In this paper, we present a novel approach, which gives an algebraic solution to three previously unsolved scenarios. Our solvers can lead to a position error <1.2% and are robust to noise

Great Powers, the Persian Gulf, and Global Oil: A Comparative Analysis

Using original data, this study explores the changing capabilities of the United States, China, and Russia in the conflict-ridden Persian Gulf since 1980. It reveals what such shifts mean for American hegemony, the international distribution of capabilities in the region, relations among the great powers, and global oil security

Molybdenum - a scoping review for Nordic Nutrition Recommendations 2023

Molybdenum is an essential element in the form of the molybdenum cofactor (Moco). In humans, Moco is required for four enzymes: xanthine oxidase (XO), aldehyde oxidase, sulfite oxidase (SO), and mitochondrial amidoxime-reducing component (mARC). The enzymes are involved in the oxidation of purines to uric acid, metabolism of aromatic aldehydes and heterocyclic compounds, and in the catabolism of sulfur amino acids. Molybdenum cofactor deficiency is a rare autosomal recessive syndrome due to a defective synthesis of Moco, resulting in a deficiency of all the molybdoenzymes. There are no reports on clinical signs of dietary molybdenum deficiency in otherwise healthy humans. Water-soluble molybdate is efficiently absorbed from the digestive tract. The body retention is regulated by urinary excretion. Plasma molybdenum reflects long-term intake and 24-h urinary excretion is related to recent intake. There are no biochemical markers of molybdenum status. Cereal products are the main contributors to molybdenum dietary intake, estimated to 100-170 mu g/day in Nordic studies. Little data are available on molybdenum toxicity in humans. A tolerable upper intake level of molybdenum has been based on reproductive toxicity in rats, but the effects have not been reproduced in more recent studies. The U.S. Institute of Medicine (IOM, present National Academy of Sciences, Engineering, and Medicine; NASEM) established a Recommended Dietary Allowance of 45 mu g/day in adult men and women in 2001, based on a small study reporting urinary excretion in balance with intake at 22 mu g/day. The European Food Safety Authority (EFSA) considered in 2013 the evidence to be insufficient to derive an Average Requirement and a Population Reference Intake, but proposed an Adequate Intake of 65 mu g/day for adults

Landlock

Landlock: Paralysing Dispute over Minerals on Adivasi Land in India explores the ways in which political controversy over a bauxite mining and refining project on constitutionally protected tribal lands in Andhra Pradesh descended into a state of paralysis where no productive outcome was possible. Long-running support for Adivasi (or tribal) land rights motivated a wide range of actors to block the project’s implementation by recourse to India’s dispersed institutional landscape, while project proponents proved adept in proposing workarounds to prevent its outright cancellation. In the ensuing deadlock, the project was unable to move towards completion, while marginalised Adivasi groups were equally unable to repossess their land. Such a ‘landlock’ is argued to be characteristic of India’s wider inability to deal with conflicts over land matters, despite the crucial importance of land for smallholder livelihoods and various economic processes in an intensely growth-focused country. The result has been frequent yet grindingly slow processes of contestation in which powerful business and state interests are, at times, halted in their tracks, but mostly seem able to slowly exhaust local resistance in their pursuit of large-scale projects that produce no benefits for the rural poor