WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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2004 - 20053

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Publisher: search.filters.publisher.Institute of Electrical and Electronics Engineers Inc.Subject: search.filters.subject.Algorithms

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  • Conference Object
    Approximate Best Linear Unbiased Channel Estimation for Frequency Selective Channels With Long Delay Spreads: Robustness To Timing and Carrier Offsets
    (Institute of Electrical and Electronics Engineers Inc., 2005) Özen, Serdar; Nerayanuru, Sreenivasa M.; Pladdy, Christopher; Fimoff, Mark J.
    We provide an iterative and a non-iterative channel impulse response (CIR) estimation algorithm for communication systems which utilize a periodically transmitted training sequence within a continuous stream of information symbols. The iterative procedure calculates the (semi-blind) Best Linear Unbiased Estimate (BLUE) of the CIR. The non-iterative version is an approximation to the BLUE CIR estimate, denoted by a-BLUE, achieving almost similar performance, with much lower complexity. Indeed we show that, with reasonable assumptions, a-BLUE channel estimate can be obtained by using a stored copy of a pre-computed matrix in the receiver which enables the use of the initial CIR estimate by the subsequent equalizer tap weight calculator. Simulation results are provided to demonstrate the performance of the novel algorithms for 8-VSB ATSC Digital TV system. We also provide a simulation study of the robustness of the a-BLUE algorithm to timing and carrier phase offsets.
  • Conference Object
    Citation - WoS: 6
    Citation - Scopus: 11
    Dynamically Adaptive Partition-Based Data Distribution Management
    (Institute of Electrical and Electronics Engineers Inc., 2005) Kumova, Bora İsmail
    Performance and scalability of distributed simulations depends primarily on the effectiveness of the employed data distribution management (DDM) algorithm, which aims at reducing the overall computational and messaging effort on the shared data to a necessary minimum. Existing DDM approaches, which are variations and combinations of two basic techniques, namely region-based and grid-based techniques, perform purely in the presence of load differences. We introduce the partition-based technique that allows for variable-size partitioning shared data. Based on this technique, a novel DDM algorithm is introduced that is dynamically adaptive to cluster formations in the shared data as well as in the physical location of the simulation objects. Since the re-distribution is sensitive to inter-relationships between shared data and simulation objects, a balanced constellation has the additional advantage to be of minimal messaging effort. Furthermore, dynamic system scalability is facilitated, as bottlenecks are avoided.
  • Conference Object
    Rank Kestirim Yöntemi Kullanarak Svd Tabanlı Gürültü Filtreleme
    (Institute of Electrical and Electronics Engineers Inc., 2004) Çek, Mehmet Emre; Savacı, Ferit Acar
    In this paper, an algorithm which performs the singular values decomposition of a noisy matrix has been presented in order to make noise reduction by rank estimation of the noise free data matrix. In this study the rank estimation methodis done by finding ratios of among all consecutive singular values and selecting the maximum of these ratios as the noise threshold.