60,986 research outputs found
Asymptotic Performance Analysis of Time-Frequency-Domain Spread MC DS-CDMA Systems Employing MMSE Multiuser Detection
No full textIn this contribution the asymptotic signal-to-interference-plus-noise ratio (SINR) performance of multicarrier direct-sequence code-division multiple-access systems employing time-frequency-domain spreading, i.e., of the TF/MC DS-CDMA systems, is studied, when separate minimum mean-square error multiuser detection (MMSE-MUD) is considered. The separate MMSE-MUD detects signals first in the time (T)-domain and then in the frequency (F)-domain. Based on random matrix theory, closed-form expressions for the asymptotic SINR of the TF/MC DS-CDMA systems using separate MMSE-MUD is derived, when communicating over additive white Gaussian noise (AWGN) channels. The closed-form expressions show that the asymptotic SINR performance is only depended on the T- and F-domain user load factors as well as noise variance. Hence, they are beneficial to evaluation. Furthermore, our simulation and numerical results show that in most cases the asymptotic SINR can provide a good approximation to the SINR achieved by realistic TF/MC DS-CDMA systems employing separate MMSE-MUD
Asymptotic Spectral-Efficiency of MIMO-CDMA Systems with Arbitrary Spatial Correlation
No full textIn this contribution, we analyze the asymptotic spectral-efficiency (ASE) of multiuser MIMO-CDMA systems, when assuming communications over flat fading channels with arbitrary spatial correlation. Our analysis is built on the operator-valued free probability theory, which is applied to obtain the limit distribution of the correlation matrix's eigenvalues, as the MIMO-CDMA systems' size tends to infinity. The spectral-efficiency (SE) performance of the MIMO-CDMA systems is investigated via both analysis and simulations. Our simulation and numerical results show that the ASE is capable of providing a good measure of the SE achieved by the corresponding realistic MIMO-CDMA systems
Compressive Sensing for PAN-Sharpening
No full textBased on compressive sensing framework and sparse reconstruction technology, a new pan-sharpening method, named Sparse Fusion of Images (SparseFI, pronounced as sparsify), is proposed in [1]. In this paper, the proposed SparseFI algorithm is validated using UltraCam and WorldView-2 data. Visual and statistic analysis show superior performance of SparseFI compared to the existing conventional pan-sharpening methods in general, i.e. rich in spatial information and less spectral distortion. Moreover, popular quality assessment metrics are employed to explore the dependency on regularization parameters and evaluate the efficiency of various sparse reconstruction toolboxes
Portrait of Cindy Pan, 2001 [picture] /
No full textCondition: Good.; Part of the collection of photographs of the Chinese community living in Australia by William Yang.; Photographer's stamp on photograph.; Title devised by cataloguer based on caption and accompanying notes. See acquisition file number 204/26/00003.; Photograph signed by artist.; "2/10"--Inscription below title
Near-Optimum Iterative Multiuser Detection in Time-Frequency-Domain Spread Multicarrier DS-CDMA Systems
No full textIn this contribution we propose and study a novel iterative time-frequency-domain (TF-domain) multiuser detector (MUD) for the multicarrier direct-sequence code-division multiple-access system employing both T-domain and F-domain spreading, which, for brevity, is referred to as the TF/MC DS-CDMA system. The proposed iterative TF-domain MUD consists of a set of T-domain soft-input soft-output MUDs (SISO-MUDs) and a set of F-domain SISO-MUDs, which exchange information through two multiuser interference (MUI) cancellation units. Both the T-domain and F-domain SISO-MUDs are operated under the maximum {\em a-posteriori} (MAP) principles. In this contribution the complexity and bit error rate (BER) performance of the TF/MC DS-CDMA employing the proposed iterative TF-domain MUD are investigated and also compared with the other existing MUD schemes, including the optimum MUD and the joint/separate minimum mean-square error (MMSE) MUDs. Our study shows that the iterative TF-domain MUD is capable of achieving nearly the same BER performance as the optimum MUD, but at much lower complexity
Spatially modulated code-division multiple-access for high-connectivity multiple-access
No full textIn order to take the advantages of spatial modulation (SM) and support the multiple access (MA) communications requiring high-connectivity, we integrate the SM with DS-CDMA to propose a SM/DS-CDMA scheme, which is in favor of attaining both antenna diversity and frequency diversity. Associated with the SM/DS-CDMA scheme, a range of linear and nonlinear multiuser detectors (MUDs) are proposed and studied. Specifically, for linear MUDs, both minimum mean-square error aided joint spatial demodulation (MMSE-JSD) and MMSE-aided separate spatial demodulation (MMSE-SSD) are introduced. For nonlinear MUDs, we first present the joint maximum-likelihood MUD (JML-MUD) for demonstrating the potential of SM/DS-CDMA systems. Then, the MMSE-relied iterative interference cancellation (MMSE-IIC) is suggested, and associated with which two types of low-complexity high-efficiency reliability measurement schemes are proposed. In this paper, we mathematically analyze both the single-user average bit error rate (ABER) of the SM/DS-CDMA systems employing joint spatial demodulation (JSD), and the approximate ABER of the SM/DS-CDMA systems employing the MMSE-JSD. We investigate and compare the ABER performance of the SM/DS-CDMA systems with various detection schemes, and also with some legacy schemes. Our studies and performance results show that the SM/DS-CDMA systems in conjunction with appropriate MUD schemes are capable of providing a desirable trade-off among the number of users supportable, implementation complexity and the ABER performance
Zhang Li, Ye Yang, Edoardo Bruno, Pan Yi, Wen Zishen, Zhang Jingqiu, “Bridge: Dream and Nightmare”
No full textOverview of the Author Profiling Task at PAN 2013
No full text[EN] This overview presents the framework and results for the Author Profiling
task at PAN 2013. We describe in detail the corpus and its characteristics,
and the evaluation framework we used to measure the participants performance to
solve the problem of identifying age and gender from anonymous texts. Finally,
the approaches of the 21 participants and their results are described.The author profiling task @PAN-2013 was an activity of the WIQ-EI IRSES project (Grant No. 269180) within the FP 7 Marie Curie People Framework of the European Commission. We want to thank the Forensic Lab of the Universitat Pompeu Fabra Barcelona for sponsoring the award for the winner team. The work of the first author was partially funded by Autoritas Consulting SA and by Ministerio de Economía y Competitividad de España under grant ECOPORTUNITY IPT-2012-1220-430000. The work of the second author was in the framework the DIANA-APPLICATIONS-Finding Hidden Knowledge in Texts: Applications (TIN2012-38603-C02-01) project, and the VLC/CAMPUS Microcluster on Multimodal Interaction in Intelligent Systems. The work of fifth author was funded in part by the Swiss National Science Foundation (SNF) project "Mining Conversational Content for Topic Modelling and Author Identification (ChatMiner)" under grant number 200021_130208.Rangel, F.; Rosso, P.; Koppel, M.; Stamatatos, E.; Inches, G. (2013). Overview of the Author Profiling Task at PAN 2013. CLEF Conference on Multilingual and Multimodal Information Access Evaluation. 352-365. https://riunet.upv.es/handle/10251/46636S35236
Ide dan perjuangan Jamaluddin Al-Afghaniy dalam mewujudkan Pan Islamisme
No full textSkripsi ini menunjukkan bahwa Jamaluddin Al-Afghaniy adalah tokoh Islam yang terkemuka pada abad ke 19. Dia berusaha melahirkan ide-ide pembaruan untuk membangkitkan dan menyatukan kaum muslimin akibat dominasi Barat yang telah menciptakan desintegrasi politik dunia Islam. Pan Islamisasi terletak pada ide bahwa Islam adalah satu-satunya ikatan kesatuan kaum muslimin yang menjadikan Islam sebagai ideologi anti-kolonialis yang menyerukan aksi politik menetang Barat. Islam adalah faktor yang paling esensial untuk perjuangan kaum muslimin melawan Eropa, dan Barat pada umumnya.ix, 63 hlm.; 29 c
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