Receiver Orientation Research Articles

Methodology for the design of multi-source transmitters dedicated to perpendicular dynamic wireless power transfer: theoretical study

In this paper, a theoretical study for the design of multi-source transmitters suitable for perpendicular dynamic wireless power transfer is presented. Unlike conventional systems, the concept presented here overcomes the traditional limitation on the receiver's orientation by providing an optimal distribution of the transmitted energy obtained by using different sources. For this purpose, a theoretical study of different transmitters has been achieved by solving the inverse problem. Comparison with conventional single-source transmitters carrying the same total current as the multi-source transmitters, shows a significant enhancement of the power gain when a Genetic Algorithm is used. The obtained theoretical results show power gain levels over 7.5 dB for different path lengths at different heights. At the end, a solution for a path of an infinite length is presented.

A Single LED Positioning System Based on Circle Projection

A simple and efficient visible light positioning (VLP) system based on a single LED lamp is proposed and demonstrated. In our system, a common circular LED lamp with a point marker is used as a transmitter and a smartphone camera serves as a receiver. The LED image is no longer treated as a point as in the existing works, but as an image whose geometric features are exploited to determine the receiver's orientation and location relative to the reference LED lamp. The expressions for determining the receiver's orientation and location are derived in terms of the geometric parameters. Our algorithm enhances the system robustness by overcoming the possible interruptions in conventional VLP systems, which require multiple LEDs. Meanwhile, it avoids the usage of angular sensors, which are unable to provide reliable and accurate measurements on receiver's orientation in mobile indoor environment. We experimentally evaluate and analyze the performance of the proposed VLP system. A centimeter-level positioning accuracy is achieved in an area of 3 m × 3 m.

Fast and Efficient Adaptation Algorithms for Multi-Gigabit Wireless Infrared Systems

Multibeam angle adaptive systems (MBAAS) have been shown to offer performance improvements over traditional spot-diffusing optical wireless systems. However, an increase in the computational cost is incurred. This paper introduces a method to speed up the adaptation process through efficient use of a divide and conquer algorithm by recursively breaking down the scanning process and focusing it into a smaller region in each iteration. The new, fast and efficient angle adaptation algorithm offers the advantages of optimizing the number and pattern (positions) of the spots so as to maximize the receiver's signal-to-noise ratio (SNR), regardless of the transmitter's position, the receiver's orientation and its field of view. It can also adapt to environmental changes, providing a robust link against shadowing and signal blockage. Furthermore, a beam delay adaptation method is used to reduce the effect of multipath dispersion and inter-symbol interference. The combination of angle and delay adaptation adds a degree of freedom to the link design, resulting in a compact impulse response and a system that is able to achieve higher data rates (15 Gbit/s). Significant improvements in the SNR, with optical wireless channel bandwidths of more than 15 GHz are obtained, and eye safety is considered while operating at 15 Gbit/s with full mobility in a realistic environment where shadowing exists.

Dolphin pointing is linked to the attentional behavior of a receiver.

In 2001, Xitco et al. (Anim Cogn 4:115-123) described spontaneous behaviors in two bottlenose dolphins (Tursiops truncatus) that resembled pointing and gaze alternation. The dolphins' spontaneous behavior was influenced by the presence of a potential receiver, and the distance between the dolphin and the receiver. The present study adapted the technique of Call and Tomasello [(1994) J Comp Psychol 108:307-317], used with orangutans to test the effect of the receiver's orientation on pointing in these same dolphins. The dolphins directed more points and monitoring behavior at receivers whose orientation was consistent with attending to the dolphins. The results demonstrated that the dolphins' pointing and monitoring behavior, like that of apes and infants, was linked to the attentional behavior of the receiver.