The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform
Hong-chuan Yang - One of the best experts on this subject based on the ideXlab platform.
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Rate-Energy Outage Analysis of MISO SWIPT With Multiple Energy Harvesting Sensors
IEEE Access, 2019Co-Authors: Minchul Ju, Hong-chuan YangAbstract:We study a multi-input-single-output (MISO) transmission system consisting of a multi-Antenna basestation (BS) and a single-Antenna user in the presence of multiple single-Antenna Radio frequency (RF) energy harvesting (EH) sensor nodes, where the user decodes information and multiple EH sensor nodes accumulate energy through the received signal from the BS. The sensor nodes coordinate their transmissions to perform virtual MISO beamforming, which requires sufficient individual and sum transmission power across multiple sensor nodes. For this reason, we consider simultaneously both the individual and sum EH constraints for SWIPT networks. Specifically, under both the individual and sum EH constraints, we propose beam selection of random unitary beamforming to maximize the transmission rate of the MISO system. Then we derive the exact rate-energy outage probability in closed-form for the system with identical average value of harvested energy across all sensor nodes and the exact probability in recursive form for the system with distinct average value of harvested energy at each sensor node. Numerical results confirm that the analyses are exact and the outage performance improves as the number of Antennas at the BS increases and/or as the average received power at the user and sensor nodes increases.
Minchul Ju - One of the best experts on this subject based on the ideXlab platform.
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Rate-Energy Outage Analysis of MISO SWIPT With Multiple Energy Harvesting Sensors
IEEE Access, 2019Co-Authors: Minchul Ju, Hong-chuan YangAbstract:We study a multi-input-single-output (MISO) transmission system consisting of a multi-Antenna basestation (BS) and a single-Antenna user in the presence of multiple single-Antenna Radio frequency (RF) energy harvesting (EH) sensor nodes, where the user decodes information and multiple EH sensor nodes accumulate energy through the received signal from the BS. The sensor nodes coordinate their transmissions to perform virtual MISO beamforming, which requires sufficient individual and sum transmission power across multiple sensor nodes. For this reason, we consider simultaneously both the individual and sum EH constraints for SWIPT networks. Specifically, under both the individual and sum EH constraints, we propose beam selection of random unitary beamforming to maximize the transmission rate of the MISO system. Then we derive the exact rate-energy outage probability in closed-form for the system with identical average value of harvested energy across all sensor nodes and the exact probability in recursive form for the system with distinct average value of harvested energy at each sensor node. Numerical results confirm that the analyses are exact and the outage performance improves as the number of Antennas at the BS increases and/or as the average received power at the user and sensor nodes increases.
Wright Brittany - One of the best experts on this subject based on the ideXlab platform.
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The Dipole Antenna Radio Telescope (DART)
Scholarly Commons, 2018Co-Authors: Wright BrittanyAbstract:The Dipole Antenna Radio Telescope (DART) array consists of 48, dual-polarization, dipole Antennas optimized for the 80 – 300 MHz range of frequency, being used to do Radio astronomy. Radio Astronomy is a field of astronomy that studies celestial objects through Radio waves. Radio waves have a long wavelength and a low frequency, thus allowing them to travel through the cosmic dust in the universe. This array of Antennas is special because it is fully steerable without any moving parts. Having steerable Antennas allows for a larger range of viewing, and with this particular telescope, it is fully steerable above 30 degrees. These Antennas are arranged in the form of three 4 x 4 arrays, and are spread around Embry-Riddle’s Radio observatory. The main goal of DART is to detect pulsars, which are highly magnetized rotating neutron stars that emit a beam of electromagnetic radiation from its poles, usually in the form of Radio waves. Pulsars show extreme physical concepts of density, gravity, magnetic fields, and electric fields, which make them a very elaborate object to study. Poster Presentation IGNITE Grant Awar
Ranveer Chandra - One of the best experts on this subject based on the ideXlab platform.
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Enabling Reliable , Asynchronous , and Bidirectional Communication in Sensor Networks over White Spaces
In Proceedings of SenSys '17, 2017Co-Authors: Abusayeed Saifullah, Chenyang Lu, St. Louis, Ranveer ChandraAbstract:Low-Power Wide-Area Network (LPWAN) heralds a promising class of technology to overcome the range limits and scalability challenges in traditional wireless sensor networks. Recently pro-posed Sensor Network over White Spaces (SNOW) technology is particularly attractive due to the availability and advantages of TV spectrum in long-range communication. This paper proposes a new design of SNOW that is asynchronous, reliable, and robust. It represents the first highly scalable LPWAN over TV white spaces to support reliable, asynchronous, bi-directional, and concurrent communication between numerous sensors and a base station. This is achieved through a set of novel techniques. This new design of SNOW has an OFDM based physical layer that adopts robust mod-ulation scheme and allows the base station using a single Antenna-Radio (1) to send different data to different nodes concurrently and (2) to receive concurrent transmissions made by the sensor nodes asynchronously. It has a lightweight MAC protocol that (1) effi-ciently implements per-transmission acknowledgments of the asyn-chronous transmissions by exploiting the adopted OFDM design; (2) combines CSMA/CA and location-aware spectrum allocation for mitigating hidden terminal effects, thus enhancing the flexibility of the nodes in transmitting asynchronously. Hardware experiments through deployments in three Radio environments -in a large met-ropolitan city, in a rural area, and in an indoor environment -as well as large-scale simulations demonstrated that the new SNOW design drastically outperforms other LPWAN technologies in terms of scalability, energy, and latency.
Roope Vehkalahti - One of the best experts on this subject based on the ideXlab platform.
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dense mimo matrix lattices a meeting point for class field theory and invariant theory
Applicable Algebra in Engineering Communication and Computing, 2007Co-Authors: Jyrki Lahtonen, Roope VehkalahtiAbstract:The design of signal constellations for multi-Antenna Radio communications naturally leads to the problem of finding lattices of square complex matrices with a fixed minimum squared determinant. Since [5] cyclic division algebras, their orders and related structures have become standard material for researchers seeking to construct good MIMO-lattices. In recent submissions [3], [8] we studied the problem of identifying those cyclic division algebras that have the densest possible maximal orders. That approach was based on the machinery of Hasse invariants from class field theory for classifying the cyclic division algebras. Here we will recap the resulting lower bound from [3], preview the elementary upper bounds from [4] and compare these with some suggested constructions. As the lattices of the shape E8 are known to be the densest (with respect to the usual Euclidean metric) in an 8-dimensional space it is natural to take a closer look at lattices of 2×2 complex matrices of that shape. We derive a much tighter upper bound to the minimum determinant of such lattices using the theory of invariants.