Browsing Elektrik-Elektronik Mühendisliği / Electrical - Electronics Engineering by Access Type "Panayirci, Erdal"
Now showing items 1-7 of 7
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A low-complexity time-domain MMSE channel estimator for space-time/frequency block-coded OFDM systems
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Publisher and Date:(Hindawi Publishing Corporation, 2006)Focusing on transmit diversity orthogonal frequency-division multiplexing (OFDM) transmission through frequency-selective channels this paper pursues a channel estimation approach in time domain for both space-frequency OFDM (SF-OFDM) and space-time OFDM (ST-OFDM) systems based on AR channel modelling. The paper proposes a computationally efficient pilot-aided linear minimum mean-square-error (MMSE) time-domain channel estimation algorithm for OFDM systems with transmitter diversity in unknown ...
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Blind-phase noise estimation in OFDM systems by sequential Monte Carlo method
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Publisher and Date:(John Wiley and Sons Ltd, 2006)One of the main drawbacks of orthogonal frequency division multiplexing (OFDM) systems is the phase noise (PN) caused by the oscillator instabilities. Unfortunately due to the PN the most valuable feature namely orthogonality between the carriers is destroyed resulting in a significant degradation in the performance of OFDM systems. In this paper based on a sequential Monte Carlo method (particle filtering) a computationally efficient algorithm is presented for estimating the residual phase noise ...
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Linear expansions for frequency selective channels in OFDM
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Publisher and Date:(Elsevier GMBH Urban & Fischer Verlag, 2006)Modeling the frequency selective fading channels as random processes we employ a linear expansion based on the Karhumen-Loeve (KL) series representation involving a complete set of orthogonal deterministic vectors with a corresponding uncorrelated random coefficients. Focusing on OFDM transmissions through frequency selective fading this paper pursues a computationally efficient pilot-aided linear minimum mean square error (MMSE) uncorrelated KL series expansion coefficients estimation algorithm. ...
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New channel estimation techniques for cooperative underwater acoustic OFDM systems
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Publisher and Date:Cooperative underwater acoustic communication systems come into prominence in recent years. Since underwater channels are sparse and additive noise entering the system is colored Gaussian noise it is very difficult to estimate the underwater channels and theoretically makes it interesting. in the first part of the thesis the transmission from source to the target recipient is realized by means of a relay system. Orthogonal frequency division multiplexing (OFDM)-based channel estimation problem is ...
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Orthogonal Frequency Division Multiplexing With Index Modulation
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Publisher and Date:(IEEE-INST Electrical Electronics Engineers Inc, 2013)In this paper a novel orthogonal frequency division multiplexing (OFDM) scheme called OFDM with index modulation (OFDM-IM) is proposed for operation over frequency-selective and rapidly time-varying fading channels. In this scheme the information is conveyed not only by M-ary signal constellations as in classical OFDM but also by the indices of the subcarriers which are activated according to the incoming bit stream. Different low complexity transceiver structures based on maximum likelihood ...
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Space-Time Block Coding for Spatial Modulation
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Publisher and Date:(IEEE, 2010)Space-time block coded spatial modulation (STBC-SM) which employs space-time block coding (STBC) for spatial modulation (SM) is proposed as a new multiple-input multiple-output (MIMO) transmission scheme. In the STBC-SM scheme the transmitted information symbols are expanded not only to the space and time domains but also to the spatial (antenna) domain therefore both core STBC and antenna indices carry information. A general framework is presented for the design of the STBC-SM scheme for any ...
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Synchronization in Wireless Communications
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Publisher and Date:(Hindawi Publishing Corporation, 2009)