Performance of free space optical communication using M-array receivers at atmospheric conditions

Abstract: In free space optical (FSO) communication links, atmospheric parameters including absorption, scattering and turbulence have significant impacts on the quality of laser beams propagating through the atmosphere. Absorption and/or scattering, due to atmospheric particles result in optical losses, whereas turbulence contributes to the intensity scintillation that can severely impair the operation of FSO communications systems. In this paper, using a modified model we analyze the atmospheric effects on the signal-to-noise ratio (SNR) and the bit error rate (BER) of an FSO system. We show that there is an improvement in BER when using M-array receivers instead of one a single receiver

Efficient Entanglement Measure for Graph States

In this paper, we study the multipartite entanglement properties of graph states up to seven qubits. Our analysis shows that the generalized concurrence measure is more efficient than geometric entanglement measure for measuring entanglement quantity in the multi-qubit graph states.Comment: 10 pages, 4 table

Knowledge, Treatment, Control, and Risk Factors for Hypertension among Adults in Southern Iran

Hypertension is the first and the most common risk factor to diseases such as cardiovascular, stroke, and renal diseases. The aim of this study was to determine the factors relevant to hypertension knowledge, treatment, and control in southern Iran. In this cross-sectional study, conducted in Kohgiluye Boyer-Ahmad province, south of Iran, a total of 1836 hypertension patients were randomly selected to participate voluntarily in the study. Hypertension treatment and its control were defined during study. In addition, knowledge about hypertension was measured by hypertension knowledge level scale (HK-LS). Treatment rates were 75.5 and 37.7 percent for female and male, respectively. Habitat, education, income, family history with hypertension, smoking, and time of diagnosis to the disease were found to be related to the treatment of the disease. Control rates were 30.7 and 31.4 for males and females, respectively. Habitat, education, and time of diagnosis to the disease were related to control. Over 50 percent of patients had average knowledge on hypertension. Considering the low rate of control and knowledge on hypertension among patients, health care providers should reinforce their services to improve appropriate knowledge level among elders and, also, plan comprehensive programs to promote health in order to encourage patients change and reform their life style

A modified model of the atmospheric effects on the performance of FSO links employing single and multiple receivers

In free space optical (FSO) communication links, atmospheric effects including absorption, scattering and turbulence have significant impacts on the quality of the laser beam propagating through the free space channel. Absorption and/or scattering due to the atmospheric particles result in optical losses, whereas turbulence contributes to the intensity scintillation which can severely impair the operation of FSO links. In this paper, using a modified model we analyze the atmospheric effects on the signal-to-noise ratio (SNR) and the bit error rate (BER) performance of an FSO system. We show that for multiple detectors with the same surface area as a single detector there is a critical link range less than which the SNR decreases for larger values of M

Blickling homily 7

In free space optical (FSO) communication links, atmospheric turbulence has a significant impact on the quality of a laser beam propagating through the atmosphere. Turbulence results in intensity scintillation, which can severely impair the operation of target designation and FSO communications systems. Two important parameters for describing quality of FSO communications systems are the signal-to-noise ratio (SNR) and the bit error rate (BER). In this paper, using a modified model we analyze the effect of atmospheric turbulence on the SNR and BER for an FSO system in both weak and strong turbulence conditions