Now showing items 1-8 of 8

    • Antenna analysis 

      Tunç, Celal Alp (Bilkent University, 2009)
      Multiple-input-multiple-output (MIMO) wireless communication systems have been attracting huge interest, since a boost in the data rate was shown to be possible, using multiple antennas both at the transmitter and receiver. ...
    • Application of spectral acceleration forward-backward method for propagation over terrain 

      Tunç, Celal Alp (Bilkent University, 2003)
      Mobile radio planning requires the accurate prediction of electromagnetic eld strengths over large terrain pro les. However, numerical methods, like MoM, become not suitable for electrically large surfaces, because of ...
    • Investigation of planar and conformal printed arrays for MIMO performance analysis 

      Tunç, Celal Alp; Ircı, Erdinç; Bakır, Onur; Aktaş, Defne; Ertürk, Vakur B.; Altıntaş, Ayhan (IEEE, 2006)
      MIMO channel capacity of printed arrays with dipole elements is analyzed. A MIMO channel model based on electric fields is used. The effects of mutual interactions among the array elements through space and surface waves ...
    • A model with electric fields for the inclusion of mutual coupling effects in the MIMO channel 

      Tunç, Celal Alp; Ircı, Erdinç; Bakır, Onur; Aktaş, Defne; Ertürk, Vakur B.; Altıntaş, Ayhan (IEEE, 2007)
      Multiple input multiple output (MIMO) wireless communication systems have been a focus of interest, due to their ability to increase the capacity in rich scattering environments by using multi-element antenna arrays both ...
    • On the number of clusters in channel model 

      Akkaya, Keziban; Tunç, Celal Alp; Aktaş, Defne; Altıntaş, Ayhan (IEEE, 2006-08)
      Typically, scatterers in an environment are not distributed uniformly but rather observed to occur in clusters. Identification of clusters is an issue under discussion. To this end, we study the effect of number of clusters ...
    • Optimization of linear wire antenna arrays to increase MIMO capacity using swarm intelligence 

      Olgun, Uğur; Tunç, Celal Alp; Aktaş, Defne; Ertürk, Vakur B.; Altıntaş, Ayhan (Institution of Engineering and Technology, 2007)
      Free standing linear arrays (FSLA) are analyzed and optimized to increase MIMO capacity. A MIMO channel model based on electric fields is used. The effects of mutual interactions among the array elements are included into ...
    • Particle swarm optimization for SAGE maximization step in channel parameter estimation 

      Bodur, Harun; Tunç, Celal Alp; Aktaş, Defne; Ertürk, Vakur .B.; Altıntaş, Ayhan (IET, 2007-11)
      This paper presents an application of particle swarm optimization (PSO) in space alternating generalized expectation maximization (SAGE) algorithm. SAGE algorithm is a powerful tool for estimating channel parameters like ...
    • Use of characteristic basis function method for scattering from terrain profiles 

      Yağbasan, Atacan; Tunç, Celal Alp; Ertürk, Vakur B.; Altıntaş, Ayhan; Mittra, R. (TÜBİTAK, 2008)
      An integral equation (IE) based solution procedure is presented for the rigorous analysis of scattering from terrain profiles. The procedure uses characteristic basis function method (CBFM), which is hybridized with the ...