Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
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Conference Object Adaptive Limited Feedback Scheme for Stream Selection Based Interference Alignment in Heterogeneous Networks(IEEE, 2016) Beyazıt, Esra Aycan; Özbek, Berna; Le Ruyet,D.This paper presents a stream selection based interference alignment approach with imperfect channel state information for heterogeneous networks. The proposed algorithm performs the selection of a stream sequence among a predetermined set of sequences. Those selected sequences are the ones that mostly contribute to the sum rate when performing the exhaustive search. These stream sequences form a regular structure where the first stream is associated to a pico user. The effect of imperfect channel state information on the proposed algorithm is analyzed and a bit allocation scheme is proposed by deriving an upper bound on the rate loss due to quantization. © 2016 IEEE.Conference Object Citation - WoS: 15Citation - Scopus: 20Adaptive Control of Redundant Robot Manipulators With Sub-Task Objectives [proceedings Paper](Institute of Electrical and Electronics Engineers Inc., 2008) Tatlıcıoğlu, Enver; Braganza, David; Burg, Timothy C.; Dawson, Darren M.In this paper, adaptive control of kinematically redundant robot manipulators is considered. An end-effector tracking controller is designed and the manipulator's kinematic redundancy is utilized to integrate a general sub-task controller for self-motion control. The control objectives are achieved by designing a feedback linearizing controller that includes a least-squares estimation algorithm to compensate for the parametric uncertainties.Conference Object Citation - Scopus: 1Interference Management for Multiuser Multiantenna Ofdma Underlaying Device-To Communications(IEEE, 2017) Özbek, Berna; Pischella, Mylene; Le Ruyet, DidierUnderlaying device-to-device (D2D) transmission in cellular wireless systems is one of the promising transmission techniques for fifth generation (5G) and beyond 5G applications. Nevertheless, the interference between the D2D pairs, the interference from cellular users to D2D receivers and the interference that affects the cellular communications should be mitigated to increase the overall system performance. In this paper, we propose interference management techniques for D2D underlaying communications in multiuser multiantenna orthogonal frequency division multiple access (OFDMA) systems. Our goal is to increase the data rate of both the cellular users and D2D pairs by performing interference management in frequency, power and spatial dimensions. The performance evaluations illustrate the effectiveness of the proposed algorithm in terms of average data rate and average transmitted power for both cellular users and D2D pairs.Conference Object Citation - WoS: 3Citation - Scopus: 3Space-Frequency Grouping Based Key Extraction for Mimo-Ofdm Systems(IEEE, 2017) Topal, Ozan Alp; Karabulut Kurt, Güneş; Özbek, BernaLatest developments in wireless communication networks push the limits of conventional security methods. Security can be improved with a secret key that is dynamically generated based on the surrounding physical environment. With this objective, physical layer security approaches can be implemented by means of simple signal processing methods. In this paper, we propose novel key extraction approaches based on spatial and frequency characteristics of the wireless environment. In a 2x2 MIMO-OFDM system, low key disagreement rates and key error rates are observed, proving the potential of physical layer key extraction techniques.Conference Object Matching Aerial Coastline Images With Map Data Using Dynamic Programming(Institute of Electrical and Electronics Engineers Inc., 2006) Kahraman, Metin; Gümüştekin, ŞevketMatching aerial images with map data is an important task in several remote sensing applications such as autonomous navigation, cartography, oceanography. The unique and distinctive shapes of coastlines can be effectively utilized to solve this problem. In this study a completely automatic scheme is proposed to detect coastlines using multiresolution texture analysis and to match the detected coastlines to a map database. A shape matching method using dynamic programming is used and tested on the satellite images of the western coast of Turkey.Conference Object Citation - WoS: 3Citation - Scopus: 4Neural Network Based Repetitive Learning Control of Robot Manipulators(Institute of Electrical and Electronics Engineers Inc., 2017) Çobanoğlu, Necati; Tatlıcıoğlu, Enver; Zergeroğlu, ErkanControl of robot manipulators performing periodic tasks is considered in this work. The control problem is complicated by presence of uncertainties in the robot manipulator's dynamic model. To address this restriction, a model free repetitive learning controller design is aimed. To reduce the heavy control effort, a neural network based compensation term is fused with the repetitive learning controller. The convergence of the tracking error to the origin is ensured via Lyapunov based techniques. Numerical simulations and experiments are performed to demonstrate the viability of the proposed controller.Conference Object Citation - WoS: 3Citation - Scopus: 3Load Based Cell Selection Algorithm for Digital Mobile Radio(Institute of Electrical and Electronics Engineers Inc., 2016) Yılmaz, Simay; Özbek, Berna; Taş, Murat; Bardak, Erinç DenizDigital mobile radio is one of a digital radio standard for Professional Mobile Radio and it is commonly used for emergency services. The cell selection is very important for digital mobile radio based systems to improve system performance in terms of delay and bit error rate. In this work, we propose an efficient cell selection algorithm for Digital Mobile Radio. In the proposed algorithm, each user selects the base station according to the proposed utility value determined based on both cell load and signal-to-interference-noise ratio. The goal of the proposed algorithm is to balance the distribution of the users among the cells to reduce the waiting time for connection while establishing reliable transmission link. We illustrate the performance results for different scenarios and applications in terms of cell load, signal-to-interference-noise ratio and bit error rate. © 2016 IEEE.Article Citation - Scopus: 8Wideband Printed Planar Monopole Antenna for Pcs, Uwb and X-Band Applications(EMW Publishing, 2015) Bozdağ, Göksenin; Kuştepeli, AlpIn this paper, a printed planar monopole antenna (PPMA) is presented for PCS, UWB and X-band. The antenna is designed in two stages. In the design of the preliminary PPMA used to obtain the proposed PPMA, the structure is divided into sections, and they are optimized in the sense of bottom to up strategy. The bandwidth is enhanced by employing tapered transitions and inset feed. The resulting antenna operates between 2.37 GHz and 12 GHz with VSWR < 2 and an average peak realized gain of 4.95 dB. Therefore, the preliminary antenna can be considered to be suitable for Bluetooth, WLAN, WiMAX, UWB and X-band. The proposed PPMA is designed by implementing slots on the preliminary PPMA to include PCS, and to suppress Bluetooth and commonly used WLAN and WiMAX bands, the ones allocated out of UWB. The proposed antenna operates in the 1.67 GHz– 1.91 GHz and 3GHz–15 GHz bands with VSWR < 2. The peak realized gain (Gpr) in PCS is 1.32 dB at 1.8GHz, and the average Gpr is 5 dB for the 3 GHz–15 GHz band. The group delay performances are also examined, and the maximum group delay deviations of preliminary and proposed PPMAs are observed as 1 ns and 1.25 ns, respectively.Conference Object Citation - WoS: 6Citation - Scopus: 7Lyapunov-Based Output Feedback Learning Control of Robot Manipulators(Institute of Electrical and Electronics Engineers Inc., 2015) Doğan, Kadriye Merve; Tatlıcıoğlu, Enver; Zergeroğlu, Erkan; Çetin, KamilThis paper address the output feedback learning tracking control problem for robot manipulators with repetitive desired joint level trajectories. Specifically, an observer-based output feedback learning controller for periodic trajectories with known period have been proposed. The proposed learning controller guarantees semi-global asymptotic tracking despite the existence of parametric uncertainties associated with the robot dynamics and lack of velocity measurements. A learning-based feedforward term in conjunction with a novel observer formulation is designed to obtain the aforementioned result. The stability of the controller-observer couple is guaranteed via Lyapunov based arguments. Numerical studies performed on a two link robot manipulator are also presented to demonstrate the viability of the proposed method. © 2015 American Automatic Control Council.Conference Object Citation - WoS: 4Citation - Scopus: 6A Robust Tracking Controller for Dynamically Positioned Surface Vessels With Added Mass(Institute of Electrical and Electronics Engineers Inc., 2014) Bidikli, B.; Tatlicioglu, E.; Zergeroglu, E.This work concentrates on tracking control of dynamically positioned surface vessels with asymmetric added mass terms affecting the system model at the acceleration level. Specifically, we propose a novel continuous robust controller for surface vessels that, in addition to asymmetric added mass in its inertia matrix, contains unstructured uncertainties in all its system matrices. The proposed controller compensates the overall system uncertainties and ensures asymptotic tracking, while requiring only the knowledge of the sign of the leading principle minors of the input gain matrix. Lyapunov based approaches are applied in order to prove the stability of the closed-loop system and asymptotic convergence of the tracking error signal. © 2014 IEEE.
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