Ahmet Bastug

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Cees van Westen

University of Twente, Faculty of Geoinformation Science and Earth Observation (ITC)

Stefano R L Campana

University of Siena / Università di Siena

Pierfrancesco Lombardo

Università degli Studi "La Sapienza" di Roma

Md Ashraful Islam

University of Dhaka, Bangladesh

Fusun Balik Sanli

Yildiz Technical University

Roland Linck

Bayerisches Landesamt für Denkmalpflege

amrit mandal

West Bengal University Of Technology

Prof. Mahendra S I N G H Sevda

Central Agricultural University (CAU), Imphal

Harijono Djojodihardjo

Institut Teknologi Bandung

Daniel Condurache

Technical University of Iasi

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Papers by Ahmet Bastug

Procédé et appareil pour ajuster les champs de mouvement dans une mémoire - moyen efficace d'accès aux structures d'interpolation de cadre

Méthode d'adaptation niveau symbole, mémoire, égaliseur et récepteur pour implémenter cette méthode

Methode d'adaptation niveau symbole pour adapter au moins un coefficient d'un egaliseur, ... more Methode d'adaptation niveau symbole pour adapter au moins un coefficient d'un egaliseur, la methode comprenant les etapes suivantes : a) determiner (144) l'existence d'un code de canalisation de pilote raccourci dont le facteur d'etalement est plus court que le facteur d'etalement d'un code de canalisation de pilote complet et qui demeure, simultanement, orthogonal a tout autre code de canalisation simultanement actif, et b) s'il existe un code de canalisation de pilote raccourci, desetaler (162) le canal de pilote en utilisant le code de canalisation de pilote raccourci pour obtenir une estimation de symbole de pilote, et c) adapter (168) la valeur du coefficient d'egaliseur en fonction de l'erreur entre l'estimation de symbole de pilote obtenue a l'etape b) et un symbole de pilote attendu correspondant.

Verfahren und Vorrichtung zur Einstellung von Bewegungsfeldern in einem Speicher, zugriffseffizienter Weg zu Rahmeninterpolations-Frameworks

Occlusion adaptive frame rate up-conversion

2011 IEEE International Conference on Consumer Electronics -Berlin (ICCE-Berlin), 2011

ABSTRACT This paper presents a novel occlusion adaptive frame rate up-conversion method. The prop... more ABSTRACT This paper presents a novel occlusion adaptive frame rate up-conversion method. The proposed method consists of two main steps; true motion estimation and directionally adaptive motion compensated interpolation. In order to reliably estimate the motion vectors of occlusion regions without increasing the number of frames, forward and backward directed motion vectors are merged recursively. Following the motion estimation step, a motion compensated interpolation is done by determining the temporal interpolation source directions under an OBMC framework. The experimental results show that the proposed approach improves the frame rate up-conversion performance and reduce the occlusion related halo artifacts compared to the conventional approaches. The motion compensated Frame Rate Up-Conversion (FRUC) approaches estimate the motion vector field of the frame and makes a motion compensated interpolation between the original frames of the video. The correctness of the estimated motion vector field directly affects the quality of the temporal interpolation of the video hence the temporal flow of the output video. Although true motion estimation techniques are developed in the literature for FRUC applications, the motion estimation errors at occlusion regions brings the annoying hot air like artifact, called as halo artifact, around the object boundaries. Various halo artifact reducing FRUC approaches are introduced in the literature and they can be classified into two main approaches. The first approach detects the occlusion regions and corrects the erroneous motion vectors explicitly (1) and the second approach implicitly tries to correctly estimate the motion vectors of the occlusion regions at the motion estimation step (2). After acquiring the motion vector field estimate, the motion compensated interpolation step is also done by taking care of the occlusion regions. In the forthcoming sections a novel occlusion handling motion compensated FRUC algorithm will be introduced. The motion estimation and the motion compensated interpolation steps will be mentioned in sections 2 and 3 respectively. The experimental results will be given in section 4 and section 5 will conclude the paper.

Improving the Payload of Watermarking Channels via LDPC Coding

The payload increase of watermarking channels via the use of low-density parity check (LDPC) code... more The payload increase of watermarking channels via the use of low-density parity check (LDPC) codes is considered. The bit error rate and payload size problem is addressed in the light of the performance of typical transform-domain spread-spectrum watermarking techniques. Simulation results indicate that the information payload can be doubled via judicious use of LDPC codes vis--vis the performance of the Bose-- Chaudhuri--Hochquenghem and repetition codes.

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An apparatus for estimating filter coefficients with one of the HSDSCH symbol rate corresponding update rate for an operating symbol-level equalizer

Watermarking Capacity Improvement by Low Density Parity Check Codes

WATERMARKING CAPACITY IMPROVEMENT BY LOW DENSITY PARITY CHECK CODES Digital image watermark is an... more WATERMARKING CAPACITY IMPROVEMENT BY LOW DENSITY PARITY CHECK CODES Digital image watermark is an imperceptible, robust, secure message embedded into the image, which identifies one or more of the owner, distributor or recipient of the image, origin or status of the data or transaction dates. Watermarking is also used for data hiding, content labeling, broadcast monitoring and integrity control applications. Digital image watermarking resembles communication systems. Watermark is the sent message. Image is the watermark channel or carrier. Image pixels and possible attacks on the marked image constitute the noise. Only the authorized parties extract the watermark message from the marked image by using detectors.

Advanced receivers for high speed downlink packet access in UMTS

Advanced Receivers for High Speed Downlink Packet Access in UMTS

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Generalized pilot assisted channel estimation for WCDMA

2005 13th European Signal Processing Conference, Sep 1, 2005

A general method for user dedicated downlink channel estimation in WCDMA receivers is addressed, ... more A general method for user dedicated downlink channel estimation in WCDMA receivers is addressed, particularly suited in the presence of dedicated channel transmit beamforming. A three-step dedicated channel estimation procedure is derived which exploits all the existing pilot sequences as well as the structured dynamics of the channel. In the first step, least squares (LS) estimates of the channels associated with dedicated and common pilots are built. In the second step, an improved unbiased minimum mean square error (UMMSE) estimate of the dedicated channel is obtained by optimally combining the initial LS estimates exploiting the correlation between dedicated and common pilot channels. In the last step, the improved dedicated channel estimate is further refined via Kalman filtering by exploiting the channel temporal correlation.

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Receiver with Chip-Level Equalisation

Downlink WCDMA receivers based on combined chip and symbol level equalization

In this paper, we consider iterative receiver techniques for the downlink in WCDMA systems (UMTS ... more In this paper, we consider iterative receiver techniques for the downlink in WCDMA systems (UMTS FDD mode). We start from the linear minimum mean square error (MMSE) receiver (at symbol level), which is time varying and hence too complex to implement. By applying polynomial expansion (PE) to the LMMSE receiver, an iterative solution is obtained in which the complexity per iteration becomes comparable to twice that of the Rake receiver. Our one contribution is to replace the channel matched filter by a channel equaliser within this PE to accelerate the convergence of the iterations. We also investigate various scenarios for the introduction of non-linearities in the PE scheme that are particularly applicable to the multicode case of the high speed downlink packet access (HSDPA) mode since it is well known that non-linearities in the PE scheme lead, in fact, to the parallel interference canceler (PIC).

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Method and Apparatus for Estimating Noise Varience

Down-Sampled Impulse Response Channel Estimation

Method and apparatus for estimating noise variance

Symbol-Level Adaptation Method for Equalizer Coefficients, Memory, Equalizer and Receiver for Implementing the Method

Filter weight estimation device with update at HSDSCH symbol rate, for a symbol level equaliser

Développement de récepteurs avancés pour les systèmes de communication mobile de type WCDMA et HSDPA

Http Www Theses Fr, 2006

Channel estimation using common and dedicated pilots

Symbol-Level Adaptation Method, Memory, Equalizer and Receiver for Implementing This Method

Determination of active spreading codes and their powers

Procédé et appareil pour ajuster les champs de mouvement dans une mémoire - moyen efficace d'accès aux structures d'interpolation de cadre