Current Issue : January - March Volume : 2019 Issue Number : 1 Articles : 5 Articles
The fractional Fourier transform (FRFT) method has emerged in response to the demand for high-performance time-frequency\nprocessing technology. Next, the weighted fractional Fourier transform (WFRFT) method was developed, especially the\nsingle-parameter 4-weighted fractional Fourier transform (SP-4-WFRFT), which is most suitable for applications in digital\ncommunication systems. Therefore, in receiving systems, research on the scanningmethod of transformation order has also become\nthe focus of research under the condition of unknown transformation order. However, in the process of inverse transformation,\nthere are many problems, such as long scanning times and slow scanning speed. Thus, to improve the characteristics of a digital\ncommunication system based on SP-4-WFRFT, a cross-hierarchical scanning (CHS) method is established. A large number of test\nresults show that the CHS method can achieve fast recovery of data and estimation of transformation order....
Color independency is an important factor in visible light communication (VLC) systems.\nThis paper aims to review and summarize recent achievements in color-independent visible light\ncommunication based on color space, with the main focus being on color-space-based modulation\n(CSBM), termed as generalized color modulation (GCM), which allows VLC to adapt to any target\ncolor. The main advantages of GCM are its color independency, reasonable bit error rate (BER)\nperformance during color variation, and dimming control. We also address our past research works\nthat aimed to achieve a color-independent visual MIMO system by incorporating the advantages\nof GCM, which can lead to higher data rates over longer distances and improved performance,\nusing image processing in addition to color independency. Finally, two case studies are introduced\nto demonstrate the potential applicability of a color-independent visual-MIMO system using\ncolor-space-based modulation techniques....
In this paper we present an experimental validated system for measuring\nrainfall due to radio frequency (RF) signal attenuation at 2 GHz. Measurements\ntook place in Ioannina, NW Greece, starting in April 2015 and lasting for\ntwelve months. The primary acquired extensive results have shown reliable and\naccurate measurements for rainfall amounts smaller than 1 mm for 5 min periods.\nThe very important innovation is that this paper presents significant\nearth-to-earth measurements due to rainfall attenuation (at 2 GHz) in order\nto act as a map for future investigation and as a prior knowledge for the behavior\nof other systems operating at frequencies around S-band....
To detect perimeter intrusion accurately and quickly, a stream computing technology was\nused to improve real-time data processing in perimeter intrusion detection systems. Based on the\ntraditional density-based spatial clustering of applications with noise (T-DBSCAN) algorithm, which\ndepends on manual adjustments of neighborhood parameters, an adaptive parameters DBSCAN\n(AP-DBSCAN) method that can achieve unsupervised calculations was proposed. The proposed\nAP-DBSCAN method was implemented on a Spark Streaming platform to deal with the problems of\ndata stream collection and real-time analysis, as well as judging and identifying the different types of\nintrusion. A number of sensing and processing experiments were finished and the experimental data\nindicated that the proposed AP-DBSCAN method on the Spark Streaming platform exhibited a fine\ncalibration capacity for the adaptive parameters and the same accuracy as the T-DBSCAN method\nwithout the artificial setting of neighborhood parameters, in addition to achieving good performances\nin the perimeter intrusion detection systems....
The quaternion linear canonical transform (QLCT) is defined in this paper,\nwith proofs given for its reversibility property, its linear property, its\nodd-even invariant property and additivity property. Meanwhile, the quaternion\nconvolution (QCV), quaternion correlation (QCR) and product theorem\nof LCT are deduced. Their physical interpretation is given as classical\nconvolution, correlation and product theorem. Moreover, the fast algorithm\nof QLCT (FQLCT) is obtained, whose calculation complexity for different\nsignals is similar to FFT. In addition, the paper presents the relationship between\nthe convolution and correlation in LCT domains, and the convolution\nand correlation can be calculated via product theorem in Fourier transform\ndomain using FFT....
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