Browsing by Author "Dogan, Hakan"
Now showing items 1-11 of 11
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Channel Estimation for SM Systems over Time-Varying Rayleigh Fading Channels
This paper is concerned with the challenging and timely problem of channel estimation for spatial modulated systems in the presence of time varying channels. Recently estimation of channel state information for SM systems is investigated by the recursive least square (RLS) algorithm for slow fading channels. However it is clear that the RLS based receiver will have a performance degradation for fast fading channels. Therefore we developed iterative channel estimation based on detected symbols and ...
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Data Detection Based Iterative Channel Estimation for Coded SM-OFDM Systems
Authors:Acar, Yusuf; Leblebici, M. Merih; Dogan, Hakan; Panayırcı, Erdal
Publisher and Date:(IEEE, 2016)The combination of spatial modulation (SM) and orthogonal frequency division multiplexing (OFDM) as SM-OFDM is a recently proposed efficient modulation scheme with exploiting the index of transmit antenna to convey information bits for multiple-input multiple-output (MIMO) wireless communication systems due to its low complexity feature. The pioneering works assume that the perfect channel state information (P-CSI) or pilot symbols aided channel estimation (PSA-CE) is available at the receiver. ...
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Interpolation Based Pilot-Aided Channel Estimation for STBC Spatial Modulation and Performance Analysis Under Imperfect CSI
Authors:Acar, Yusuf; Dogan, Hakan; Basar, Ertugrul; Panayirci, Erdal
Publisher and Date:(Inst Engineering Technology-IET, 2016)A combination of space-time block coding and spatial modulation (STBC-SM) has been recently proposed for multiple input-multiple output systems to obtain both spatial diversity gain and more capacity simultaneously while assuming the perfect channel state information (P-CSI) was available at the receiver. However in practical scenarios the CSI is unknown to the receiver and should be estimated in order to detect the transmitted data in a reliable way. Therefore channel estimation (CE) is a major ...
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Iterative channel estimation techniques for uplink MC-CDMA systems
In this work maximum likelihood (ML) channel estimation for uplink multicarrier code-division multiple-access (MC-CDMA) systems is considered in the presence of frequency fading channel. The expectation-maximization (EM)- and a space-alternating generalized expectation-maximization (SAGE) algorithm are introduced to avoid matrix inversion for the ML channel estimation problem. We compare the both algorithms in terms of the number of used iteration and show that the proposed algorithms converge the ...
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Iterative joint data detection and channel estimation for uplink MC-CDMA systems in the presence of frequency selective channels
Authors:Panayirci, Erdal; Dogan, Hakan; Cirpan, Hakan Ali; Kocian, Alexander; Fleury, Bernard Henri
Publisher and Date:(2010)This paper is concerned with joint multiuser detection and multichannel estimation (JDE) for uplink multicarrier code-division multiple-access (MC-CDMA) systems in the presence of frequency selective channels. The detection and estimation implemented at the receiver are based on a version of the expectation maximization (EM) algorithm and the space-alternating generalized expectation-maximization (SAGE) which are very suitable for multicarrier signal formats. The EM-JDE receiver updates the data ...
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Iterative receiver for DS-CDMA systems in the presence of time-varying channels
In this paper we present an efficient iterative receiver structure of tractable complexity for joint multiuser detection and multichannel estimation (JDE) ofdirect-sequence code-division multiple-access systems operating in the presence of timevarying flat fading channel. The tilne-varying channel is assumed to be modeled according to a piece-wise constant channel. An optimality criterion is defined and analytical expressions for the corresponding optimized weight coefficients are given. Monte-Carlo ...
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Low-complexity joint data detection and channel equalisation for highly mobile orthogonal frequency division multiplexing systems
This study is concerned with the challenging and timely problem of channel equalisation and data detection for orthogonal frequency division multiplexing (OFDM) systems in the presence of frequency-selective and very rapidly time-varying channels. The algorithm is based on the space alternating generalised expectation-maximisation (SAGE) technique which is particularly well suited to multicarrier signal formats and can be easily extended to multi-input multi-output-OFDM systems. In fast fading ...
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Low-Complexity MAP-Based Successive Data Detection for Coded OFDM Systems Over Highly Mobile Wireless Channels
Authors:Panayırcı, Erdal; Dogan, Hakan; Poor, H. Vincent
Publisher and Date:(IEEE-INST Electrical Electronics Engineers Inc, 2011)This paper is concerned with the challenging and timely problem of data detection for coded orthogonal frequency-division multiplexing (OFDM) systems in the presence of frequency-selective and very rapidly time varying channels. New low-complexity maximum a posteriori probability (MAP) data detection algorithms are proposed based on sequential detection with optimal ordering (SDOO) and sequential detection with successive cancellation (SDSC). The received signal vector is optimally decomposed into ...
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On Channel Estimation in DC Biased Optical OFDM Systems Over VLC Channels
Authors:Sayli, Osman; Dogan, Hakan; Panayirci, Erdal
Publisher and Date:(IEEE Computer Society, 2016)Visible Light Communication(VLC) has been considered as a potential access option for 5G wireless systems to solve performance limitation due to bandwidth shortage at radio frequency (RF) band. In (VLC) system illumination infrastructure has dual usage at the same time namely illumination and wireless data transmission. DC Biased optical (DCO)-OFDM has been proposed for VLC systems to provide optically power efficient solution and easy implementation. Wireless communication systems generally require ...
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Spline based channel estimation for STBC-SM systems over fast-varying rician fading channels
Authors:Acar, Yusuf; Dogan, Hakan; Panayirci, Erdal
Publisher and Date:(Institute of Electrical and Electronics Engineers Inc., 2015)In the STBC-SM systems the information is carried both by STBC symbols and indices of the transmit antennas from which these symbols are transmitted. Channel estimation is a critical process at the receiver during the coherent detection of the transmitted STBC symbols and indices of the transmit antennas. In this paper a spline interpolation and pilot symbols based channel estimation has been proposed for the space-time block coded spatial modulation (STBC-SM) systems to track the channel variations ...
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Spline Interpolation Based Channel Estimation for ACO-OFDM Over Visible Light Channels
Authors:Sayli, Osman; Dogan, Hakan; Panayirci, Erdal
Publisher and Date:(Institute of Electrical and Electronics Engineers Inc., 2016)Visible light communication has been considered one of promising candidate technology to solve performance limitation due to bandwidth shortage at radio frequency (RF) band. In VLC system the visible light is used not only for illuminating rooms but also for an optical data transmission. ACO-OFDM is a power efficient modification of OFDM to use in VLC systems. Wireless communication systems generally require estimating and tracking the fading channel in order to detect transmitted data coherently. ...