Multipath channel identification by using global optimization in ambiguity function domain

Cataloged from PDF version of article.A new transform domain array signal processing technique is proposed for identification of multipath communication channels. The received array element outputs are transformed to delay-Doppler domain by using the cross-ambiguity function (CAF) for efficient exploitation of the delay-Doppler diversity of the multipath components. Clusters of multipath components can be identified by using a simple amplitude thresholding in the delay-Doppler domain. Particle swarm optimization (PSO) can be used to identify parameters of the multipath components in each cluster. The performance of the proposed PSO-CAF technique is compared with the space alternating generalized expectation maximization (SAGE) technique and with a recently proposed PSO based technique at various SNR levels. Simulation results clearly quantify the superior performance of the PSO-CAF technique over the alternative techniques at all practically significant SNR levels. (C) 2011 Elsevier B.V. All rights reserved

PENGARUH MODEL PEMBELAJARAN KOOPERATIF TIPE TALKING STICK TERHADAP HASIL BELAJAR SISWA PADA PELAJARAN IPAS DI KELAS IV SD NEGERI 104243 LUBUK PAKAM TAHUN PEMBELAJARAN 2023/2024

Penelitian ini bertujuan untuk mengetahui pengaruh model pembelajaran kooperatif tipe Talking Stick  terhadap hasil belajar IPAS siswa kelas IV di SD Negeri 104243 Lubuk Pakam. Pada penelitian ini menggunakan metode penelitian kuantitatif dan jenis penelitian pre eksperimen, populasi penelitian ini adalah seluruh peserta didik SD Negeri 104243 Lubuk Pakam yang berjumlah sebanyak 6 kelas. Pengambilan sampel dengan menggunakan sampel non probality jenis purposive sampling dengan sampel seluruh siswa kelas IV SD Negeri 104243 Lubuk Pakam yang berjumlah 30 siswa. Untuk mengetahui kemampuan awal siswa, peneliti melakukan prestest dengan nilai rata-rata 59,93 kategori tidak baik. Setelah penelitian menggunakan model pembelajaran kooperatif tipe Talking Stick menunjukkan bahwa hasil belajar siswa mengalami peningkatan terhadap posttest dengan nilai rata-rata 82,93 kategori baik. Tingkatan keberhasilan hasil belajar siswa meningkat dibuktikan dengan hasil perhitungan uji korelasi yang diperoleh sebesar 0,64

On the MIMO Channel Capacity of Multi-Dimensional Signal Sets

In this contribution we evaluate the capacity of Multi-Input Multi-Output (MIMO) systems using multi-dimensional PSK/QAM signal sets. It was shown that transmit diversity is capable of narrowing the gap between the capacity of the Rayleigh-fading channel and the AWGN channel. However, since this gap becomes narrower when the receiver diversity order is increased, for higher-order receiver diversity the performance advantage of transmit diversity diminishes. A MIMO system having full multiplexing gain has a higher achievable throughput than the corresponding MIMO system designed for full diversity gain, although this is attained at the cost of a higher complexity and a higher SNR. The tradeoffs between diversity gain, multiplexing gain, complexity and bandwidth are studied

Special investigation of the City of Scarville for the period January 1, 2006 through March 31, 2011

Special investigation of the City of Scarville for the period January 1, 2006 through March 31, 201

Highlights of the 1999 Growing Season

Frequently I am asked, how does this growing season compare to previous years? In reality, there are certain generalizations that can be drawn regarding the similarities among all growing seasons. Rainfall, temperatures, weeds, insects, diseases, frost, all seem to have some degree of impact on every growing season. As I review the conditions of the 1999 growing season, there are many similarities to what was experienced in the 1998 growing season. Too cool, too wet, too warm, too dry, high winds, early frost ... all played significant roles in influencing the 1999 crop. However, given all the adverse conditions that occurred throughout the season, the crop still managed to weather them pretty well and yields have been remarkably good considering all factors. Let\u27s take a look at what happened during the 1999 growing season and attempt to explain why things turned out the way they did

The Medicare Prescription Drug, Improvement, & Modernization Act of 2003: Are We Playing the Lottery With Healthcare Reform?

With millions of Americans unable to cope with the rising costs of prescription drugs, and many even forced to go without health insurance, the mounting pressure on Congress to enact major healthcare reform culminated in the Medicare Prescription Drug, Improvement, & Modernization Act of 2003. This iBrief examines this legislation, and concludes that it provides elusive benefits for seniors and merely creates a windfall for the pharmaceutical and insurance industries

Galaxy Clusters in the IRAC Dark Field II: Mid-IR Sources

We present infrared luminosities, star formation rates, colors, morphologies, locations, and AGN properties of 24 micron-detected sources in photometrically detected high-redshift clusters in order to understand the impact of environment on star formation and AGN evolution in cluster galaxies. We use three newly-identified z=1 clusters selected from the IRAC dark field; the deepest ever mid-IR survey with accompanying, 14 band multiwavelength data including deep HST imaging and deep wide-area Spitzer MIPS 24 micron imaging. We find 90 cluster members with MIPS detections within two virial radii of the cluster centers, of which 17 appear to have spectral energy distributions dominated by AGN and the rest dominated by star formation. We find that 43 of the star forming are luminous infrared galaxies (LIRGs). The majority of sources (81%) are spirals or irregulars. A large fraction (at least 25%) show obvious signs of interactions. The MIPS -detected member galaxies have varied spatial distributions as compared to the MIPS-undetected members with one of the three clusters showing SF galaxies being preferentially located on the cluster outskirts, while the other 2 clusters show no such trend. Both the AGN fraction and the summed SFR of cluster galaxies increases from z=0 to 1, at a rate that is a few times faster in clusters than over the same redshift range in the field. Cluster environment does have an effect on the evolution of both AGN fraction and SFR from redshift one to the present, but does not effect the infrared luminosities or morphologies of the MIPS sample. Star formation happens in the same way regardless of environment making MIPS sources look the same in the cluster and field, however the cluster environment does encourage a more rapid evolution with time as compared to the field.Comment: 18 pages, 9 figures, ApJ accepte