Empirical Modeling of Ducting Effects on a Mobile Microwave Link Over a Sea Surface

In this paper, signal enhancement due to the ducts over a sea surface is experimentally investigated and modeled. The investigation is carried out through the study of air-to-ground mobile microwave links over a tropical ocean with low airborne altitudes (0.37 - 1.83 km) at C band (5.7 GHz). The distance-dependence of the ducting induced enhancement (with reference to the free-space propagation) is linearly modeled, and the physical variations of the ducts are found to be Gaussian distributed. Empirical ducting coefficients and parameters for the Gaussian function are estimated and provided for the prediction of the distance-dependent signal enhancement due to the ducts in similar scenarios

A hybrid model approach for strange and multi-strange hadrons in 2.76 A TeV Pb+Pb collisions

Using the VISHNU hybrid model, we calculate the multiplicity, spectra, and elliptic flow of $\Lambda$, $\Xi$ and $\Omega$ in 2.76 A TeV Pb+Pb collisions. Comparisons between our calculations and the ALICE measurements show that the model generally describes the soft hadron data of these strange and multi-strange hadrons at several centrality bins. Mass ordering of elliptic flow among $\pi$, K, p, $\Lambda$, $\Xi$ and $\Omega$ has also been studied and discussed. With a nice description of the particle yields, we explore chemical and thermal freeze-out of various hadrons species at the LHC within the framework of the VISHNU hybrid model.Comment: version 2: with several references added, published in PR

Correlating Satellite Cloud Cover with Sky Cameras

The role of clouds is manifold in understanding the various events in the atmosphere, and also in studying the radiative balance of the earth. The conventional manner of such cloud analysis is performed mainly via satellite images. However, because of its low temporal- and spatial- resolutions, ground-based sky cameras are now getting popular. In this paper, we study the relation between the cloud cover obtained from MODIS images, with the coverage obtained from ground-based sky cameras. This will help us to better understand cloud formation in the atmosphere - both from satellite images and ground-based observations.Comment: Published in Proc. Progress In Electromagnetics Research Symposium (PIERS), 201

Research on SLM Algorithm for PAPR reduction in MB-OFDM UWB Systems

AbstractMultiband orthogonal frequency division multiplexing (MB-OFDM) is one of the key techniques of ultra wideband (UWB) systems. A major drawback of MB-OFDM technique is the high peak-to-average power ratio (PAPR) of the transmit signal. In this paper, a novel phase sequence of selected mapping algorithm which makes the side information not needed is designed to lower the PAPR of MB-OFDM UWB signals. It is also shown that comparable PAPR reduction performance with the original SLM algorithm can be achieved with a small increase in signal power. Simulation results show that there must be equilibriums between SLM computational complexity and PAPR performance. The objective of the new algorithm is to lower PAPR close to ordinary SLM technique with reduced computational complexity with little performance degradation and achieves better system resource utilization