Now showing items 1-12 of 12

    • Adjusted hazard rate estimator based on a known censoring probability 

      Gürler, Ü.; Kvam, P. (Taylor & Francis, 2011)
      In most reliability studies involving censoring, one assumes that censoring probabilities are unknown. We derive a nonparametric estimator for the survival function when information regarding censoring frequency is available. ...
    • Coded-reference ultra-wideband systems 

      Gezici, S. (2008)
      Transmitted-reference (TR) and frequency-shifted reference (FSR) ultra-wideband (UWB) systems employ pairs of reference and data signals, which are shifted in the time and frequency domains, respectively, to facilitate ...
    • Determining F2 layer parameters via optimization using IRI model and IONOLAB TEC estimations 

      Şahin O.; Sezen, U.; Arikan F.; Arikan, O. (2011)
      We know that F2 layer of the ionosphere is most important layer in the progaration of high frequency (HF) waves. In this study, The relation of the height (HmF2) and the critical frequency (FoF2) of F2 layer-among the ...
    • Kernel estimation for Time-frequency distribution 

      Deprem, Z.; Cetin, A.E. (Institute of Electrical and Electronics Engineers Inc., 2015)
      In this article a method is introduced to obtain a high-resolution and cross term free Cohen's Class Time-frequency (TF) distribution based on kernel estimation. The kernel is estimated via projecting an initial rough TF ...
    • Novel predistortion algorithm for OFDMA 

      Ali, S.; Markarian G.; Arikan, E. (2009)
      The RF amplifier in a wireless communication system is usually non-linear in nature. If such an amplifier is used in OFDMA based systems, it will cause serious degradation. This degradation will be both in terms of the ...
    • Performance limits on ranging with cognitive radio 

      Dardari, D.; Karisan, Y.; Gezici, S.; D'Amico, A.A.; Mengali, U. (2009)
      Cognitive radio is a promising paradigm for efficient utilization of the radio spectrum due to its capability to sense environmental conditions and adapt its communication and localization features. In this paper, the ...
    • A recursive way for sparse reconstruction of parametric spaces 

      Teke O.; Gurbuz, A.C.; Arikan, O. (IEEE Computer Society, 2015)
      A novel recursive framework for sparse reconstruction of continuous parameter spaces is proposed by adaptive partitioning and discretization of the parameter space together with expectation maximization type iterations. ...
    • Remote sensing and 2-D imaging of ionosphere by IONOLAB group 

      Arikan F.; Toker, C.; Sezen, U.; Deviren, M.N.; Cilibas O.; Arikan, O. (IEEE Computer Society, 2014)
      In this study, research activities of IONOLAB group on remote sensing and 2-D imaging of ionosphere in the last 10 years will be summarized. In TUBITAK EEEAG 105E171 and 109E055 projects, a novel Total Electron Content ...
    • Structured least squares problems and robust estimators 

      Pilanci, M.; Arikan, O.; Pinar, M. C. (IEEE, 2010-10-22)
      A novel approach is proposed to provide robust and accurate estimates for linear regression problems when both the measurement vector and the coefficient matrix are structured and subject to errors or uncertainty. A new ...
    • Structured least squares with bounded data uncertainties 

      Pilanci, M.; Arikan, O.; Oguz, B.; Pinar, M. C. (2009)
      In many signal processing applications the core problem reduces to a linear system of equations. Coefficient matrix uncertainties create a significant challenge in obtaining reliable solutions. In this paper, we present a ...
    • Successive cancelation approach for doppler frequency estimation in pulse doppler radar systems 

      Soǧanci H.; Gezici, S. (2010)
      In this paper, a successive cancelation approach is proposed to estimate Doppler frequencies of targets in pulse Doppler radar systems. This technique utilizes the Doppler domain waveform structure of the received signal ...
    • Theoretical limits on time delay estimation for ultra-wideband cognitive radios 

      Gezici, S.; Celebi H.; Arslan H.; Poor H.V. (2008)
      In this paper, theoretical limits on time delay estimation are studied for ultra-wideband (UWB) cognitive radio systems. For a generic UWB spectrum with dispersed bands, the Cramer-Rao lower bound (CRLB) is derived for ...