Eleftherios KOFIDIS

Additional Info

  • Full Name:

    Kofidis Eleftherios

  • Role:

    Associate Professor

  • Department:

    Department of Statistics and Actuarial Science

  • Office:

    601/Lam 126

  • Phone/Fax:

    +30 210 4142475

  • E-mail:

  • Education

    • 1996 , Ph.D., University of Patras, Dept. of Computer Engineering and Informatics, Signal and Image Processing
    • 1990 , Dipl. Ing, University of Patras, Dept. of Computer Engineering and Informatics

     

    Research Interests

    • Signal processing
    • Applied linear and multilinear algebra
    • Digital communications
  • Teaching

    • Introduction to Computer Programming (2nd semester)
    • Numerical Analysis (3rd semester)
    • Operations Research (4th semester)
  • Books / Book chapters

    1. E. Kofidis, Ν. Kolokotronis, A. Vassilarakou, S. Theodoridis, and D. Cavouras, “Medical image compression,” pp. 369–406 in Advanced Infrastructures for Future Healthcare, A. Marsh et al. (Eds.), IOS Press, 2000.
    2. Ε. Kofidis and P. A. Regalia, “Tensor approximation and signal processing applications,” in Structured Matrices in Mathematics, Computer Science, and Engineering I, V. Olshevsky (Ed.), Contemporary Mathematics Series, American Mathematical Society, 2001.
    3. Μ. Renfors, X. Mestre, E. Kofidis, and F. Bader (Eds.), Orthogonal Waveforms and Filter Banks for Future Communication Systems, Academic Press, 2017.
    4. Ε. Kofidis, L. G. Baltar, X. Mestre, F. Bader, and V. Savaux, “FBMC channel estimation techniques,” Chapter 11 in [3].
    5. Ε. Kofidis, M. Renfors, J. Louveaux, X. Mestre, D. Gregoratti, D. Le Ruyet, and R. Zakaria, “MIMO-FBMC receivers,” Chapter 14 in [3].
    6. Μ. Haardt, Y. Cheng, F. Rottenberg, J. Louveaux, and E. Kofidis, “FBMC distributed and cooperative systems,” Chapter 16 in [3].

     

    Journal papers

    1. Ε. Kofidis, S. Theodoridis, and N. Kalouptsidis, “On the perfect-reconstruction problem in N-band maximally-decimated multirate FIR filter banks,” IEEE Transactions on Signal Processing, vol. 44, no. 10, pp. 2439–2455, Oct. 1996.
    2. Ε. Kofidis, S. Theodoridis, C. Kotropoulos and I. Pitas, “Nonlinear adaptive filters for speckle suppression in ultrasonic images,” Signal Processing, vol. 52, no. 3, pp. 357–372, 1996.
    3. Ε. Kofidis, S. Theodoridis, and N. Kalouptsidis, “Mirror-image symmetric perfect reconstruction FIR filter banks: Parametrization and design,” Signal Processing, vol. 68, no. 1, pp. 1–21, 1998.
    4. Ε. Kofidis, N. Kolokotronis, A. Vassilarakou, S. Theodoridis, and D. Cavouras, “Wavelet-based medical image compression,” Future Generation Computer Systems, vol. 15, no. 2, pp. 223–243, 1999.
    5. Ε. Kofidis and P. A. Regalia, “On the best rank-1 approximation of higher-order super-symmetric tensors,” SIAM Journal on Matrix Analysis and Applications, vol. 23, no. 3, pp. 863–884, 2002.
    6. P. A. Regalia and E. Kofidis, “Monotonic convergence of fixed-point algorithms for ICA,” IEEE Transactions on Neural Networks, vol. 14, no. 4, pp. 943–949, July 2003.
    7. E. Kofidis, “Designing Ν-band biorthogonal FIR systems given several of the analysis and synthesis filters,” Signal Processing, vol. 85, pp. 1335-1331, July 2005.
    8. E. Kofidis, Y. Kopsinis, and S. Theodoridis, “On the least-squares performance of a novel efficient center estimation method for clustering-based MLSE equalization,” IEEE Transactions on Signal Processing, vol. 54, no. 4, pp. 1459-1471, April 2006.
    9. Y. Kopsinis, S. Theodoridis, and E. Kofidis, “An efficient low complexity cluster-based MLSE equalizer for frequency-selective fading channels,” IEEE Transactions on Wireless Communications, vol. 5, no. 4, pp. 705-711, April 2006.
    10. E. Kofidis, V. Dalakas, Y. Kopsinis, and S. Theodoridis, “A novel efficient cluster-based MLSE equalizer for satellite channels with M-QAM signaling,” EURASIP Journal on Applied Signal Processing, vol. 2006, Article ID 34343, 2006.
    11. D. Katselis, E. Kofidis, and S. Theodoridis, “Training-based estimation of correlated MIMO fading channels in the presence of colored interference,” Signal Processing, vol. 87, no. 9, pp. 2177-2187, Sept. 2007.
    12. D. Katselis, E. Kofidis, and S. Theodoridis, “On training optimization for estimation of correlated MIMO channels in the presence of multiuser interference,” IEEE Transactions on Signal Processing, vol. 56, no. 10, pp. 4892-4904, Oct. 2008.
    13. C. Rizogiannis, E. Kofidis, C. B. Papadias, and S. Theodoridis, “Semi-blind maximum-likelihood joint channel / data estimation for correlated channels in multiuser MIMO networks,” Signal Processing, vol. 90, no. 4, pp. 1209-1224, April 2010.
    14. D. Katselis, E. Kofidis, A. Rontogiannis, and S. Theodoridis, “Preamble-based channel estimation for CP-OFDM and OFDM/OQAM systems: A comparative study,” IEEE Transactions on Signal Processing , vol. 58, no. 5, pp. 2911-2916, May 2010.
    15. C. Rizogiannis, E. Kofidis, A. A. Rontogiannis, and S. Theodoridis, “Adaptive BLAST-type decision-feedback equalization in DS-CDMA systems,” Signal Processing, vol. 92, pp. 977-988, 2012.
    16. E. Kofidis, D. Katselis, A. A. Rontogiannis, and S. Theodoridis, “Preamble-based channel estimation in OFDM/OQAM systems: A review,” Signal Processing, July 2013.
    17. C. Mavrokefalidis, E. Kofidis, A. Rontogiannis, and S. Theodoridis, “Preamble-based channel estimation in single-relay networks using FBMC/OQAM,” EURASIP Journal on Advances in Signal Processing, 2014:66 (doi: 10.1186/1687-6180-2014-66).
    18. A. I. Pérez-Neira, M. Caus, R. Zakaria, D. Le Ruyet, E. Kofidis, X. Mestre, M. Haardt, and Y. Cheng, “MIMO signal processing in offset-QAM based filter bank multicarrier systems,” IEEE Transactions on Signal Processing, vol. 64, no. 21, pp. 5733-5762, Nov. 2016.
    19. E. Kofidis, “Preamble-based estimation of highly frequency selective channels in FBMC/OQAM systems,” IEEE Transactions on Signal Processing, vol. 65, no. 7, pp. 1855-1868, April 2017.

     

    Working papers / Technical reports / Submitted papers

    1. E. Kofidis, “Blind source separation: Fundamentals and recent advances,” (tutorial overview presented at SBrT’01), arXiv: 1603.03089v1 [stat.ML] (2016).
    2. D. Katselis, E. Kofidis, A. Rontogiannis, and S. Theodoridis, “Preamble-based channel estimation for CP-OFDM and OFDM/OQAM systems: A comparative study,” arXiv: 0910.3928v1 [cs.IT] (2009).
    3. E. Kofidis, “Preamble-based channel estimation in OFDM/OQAM systems: A time-domain approach,” arXiv: 1306.2581v2 [cs.IT] (2014).
    4. E. Kofidis, C. Chatzichristos, and A. L. F. de Almeida, “Joint channel estimation / data detection in MIMO-FBMC/OQAM systems – A tensor-based approach,” arXiv:1609.09661v1 [cs.IT], Sept. 2016.
    5. C. Chatzichristos, E. Kofidis, Y. Kopsinis, and S. Theodoridis, “Higher-order block term decomposition for spatially folded fMRI data,” arXiv:1607.05073v1 [cs.NA], July 2016.
    6. K. Maliatsos, E. Kofidis, and A. Kanatas, “A unified multicarrier modulation framework,” arXiv:1607.03737v1 [cs.IT], July 2016.
    7. V. Dalakas and E. Kofidis, “Filter bank-based multicarrier modulation for multiple access in satellite uplinks: A DVB-RCS2 based experimental study,” hal-01381072, Oct. 2016.
    8. M. Morante Moreno, Y. Kopsinis, E. Kofidis, C. Chatzichristos, and S. Theodoridis, “Assisted dictionary learning for fMRI data analysis” arXiv: 1610.03276v1 [stat.ML], Oct. 2016.
    9. M. Bellanger et al., “FBMC physical layer: A primer,” http://www.ict-phydyas.org/teamspace/internal-folder/FBMC-Primer_06-2010.pdf. June 2010.

     

    Conference papers

    1. E. Kofidis, S. Theodoridis, C. Kotropoulos and I. Pitas, “Segmentation-based L-filtering of speckle noise in ultrasonic images,” Nonlinear Image Processing V, SPIE’94, San Diego, CA, USA, Feb. 1994.
    2. E. Kofidis, S. Theodoridis and N. Kalouptsidis, “On perfect-reconstruction FIR filter banks,” Signal Processing VIII: Theories and Applications (EUSIPCO-96), Trieste, Italy, Sept. 1996.
    3. E. Kofidis, S. Theodoridis and N. Kalouptsidis, “Perfect-reconstruction FIR filter banks with mirror-image symmetry,” IEEE Int’l Conference on Electronics, Circuits and Systems (ICECS’96), Rhodes, Greece, Oct. 1996.
    4. E. Kofidis, S. Theodoridis, C. Kotropoulos and I. Pitas, “Application of neural networks and order statistics filters to speckle noise reduction in remote sensing imaging,” pp. 45–57 in Neurocomputation in Remote Sensing Data Analysis, I. Kanellopoulos, D. G. Wilkinson, F. Roli, and J. Austin (Eds.), Springer-Verlag, 1997.
    5. E. Kofidis, S. Theodoridis and N. Kalouptsidis, “Designing FIR perfect-reconstruction systems given several of the analysis and synthesis filters,” 13th Int’l Conference on Digital Signal Processing (DSP-97), Santorini, Greece, July 1997.
    6. P. A. Regalia and E. Kofidis, “The higher-order power method revisited: Convergence proofs and effective initialization,” IEEE Int’l Conference on Acoustics, Speech and Signal Processing (ICASSP-2000), Istanbul, Turkey, June 2000.
    7. P. A. Regalia and E. Kofidis, “A “unimodal” blind equalization criterion,” Signal Processing X: Theories and Applications (EUSIPCO-2000), Tampere, Finland, Sept. 2000.
    8. E. Kofidis and P. A. Regalia, “Design of biorthogonal multi-band FIR filter banks given several of the analysis and synthesis filters,” Signal Processing X: Theories and Applications (EUSIPCO-2000), Tampere, Finland, Sept. 2000.
    9. E. Kofidis and P. A. Regalia, “Spreading sequence design via perfect reconstruction filter banks,” 19th Brazilian Telecommunications Symposium (SBrT-2001), Fortaleza, Brazil, Sept. 2001.
    10. E. Kofidis, Y. Kopsinis, and S. Theodoridis, “On the least-squares performance of a novel efficient center estimation method for clustering-based MLSE equalization,” Signal Processing VIII: Theories and Applications (EUSIPCO-2004), Vienna, Austria, Sept. 2004.
    11. Y. Kopsinis, S. Theodoridis, and E. Kofidis, “An efficient low complexity cluster-based MLSE equalizer for frequency-selective fading channels,” Signal Processing VIII: Theories and Applications (EUSIPCO-2004), Vienna, Austria, Sept. 2004.
    12. C. Rizogiannis, E. Kofidis, C. B. Papadias, and S. Theodoridis, “Semi-blind maximum likelihood joint channel estimation / data detection for MIMO fading channels,” 7th IEEE Int’l Workshop on Signal Processing Advances in Wireless Communications (SPAWC-2006), Cannes, France, July 2006.
    13. D. Katselis, E. Kofidis, and S. Theodoridis, “Training-based estimation of correlated MIMO fading channels in the presence of colored interference,” Proc. IEEE Int’l Symposium on Circuits and Systems (ISCAS-2007), New Orleans, LA, USA, May 2007.
    14. D. Katselis, E. Kofidis, and S. Theodoridis, “A low-cost approach to training-based MIMO channel estimation in interference-limited environments,” Proc. 8th IEEE Int’l Workshop on Signal Processing Advances in Wireless Communications (SPAWC-2007), Helsinki, Finland, June 2007.
    15. E. Kofidis and A. A. Rontogiannis, “Adaptive BLAST decision feedback equalizer for MIMO-FBMC/OQAM systems,” Proc. 21st Personal, Indoor, and Mobile Radio Communications Conf. (PIMRC-2010), Istanbul, Turkey, Sept. 2010.
    16. C. Rizogiannis, E. Kofidis, A. A. Rontogiannis, and S. Theodoridis, “Adaptive BLAST-type decision-feedback equalizers for DS-CDMA systems,” Proc. IEEE Int’l Conf. on Communication Systems (ICCS-2010), Singapore, Nov. 2010.
    17. E. Kofidis and D. Katselis, “Improved interference approximation method for preamble-based channel estimation in FBMC/OQAM,” Proc. 19th European Signal Processing Conf. (EUSIPCO-2011), Barcelona, Spain, Sept. 2011.
    18. D. Katselis, M. Bengtsson, C. Rojas, H. Hjalmarsson, and E. Kofidis, “On preamble-based channel estimation in OFDM/OQAM systems,” Proc. 19th European Signal Processing Conf. (EUSIPCO-2011), Barcelona, Spain, Sept. 2011.
    19. E. Kofidis and D. Katselis, “Preamble-based channel estimation in MIMO-OFDM/OQAM systems,” Proc. IEEE Int’l Conf. on Signal and Image Processing Applications (ICSIPA-2011), Kuala Lumpur, Malaysia, Nov. 2011.
    20. D. Katselis, E. Kofidis, and S. Theodoridis, “On OFDM/OQAM receivers,” Proc. 20th European Signal Processing Conf. (EUSIPCO-2012), Bucharest, Romania, Aug. 2012.
    21. C. Mavrokefalidis, E. Kofidis, A. Rontogiannis, and S. Theodoridis, “Optimal training design for channel estimation in OFDM/OQAM cooperative systems,” Proc. 14th IEEE Int’l Workshop on Signal Processing Advances in Wireless Communications (SPAWC-2013), Darmstadt, Germany, June 2013.
    22. C. Mavrokefalidis, E. Kofidis, A. Rontogiannis, and S. Theodoridis, “Preamble design for channel estimation in OFDM/OQAM cooperative systems,” Proc. 10th IEEE Int’l Symposium on Wireless Communication Systems (ISWCS-2013), Ilmenau, Germany, Aug. 2013.
    23. Ε. Kofidis, “Short preamble-based estimation of highly frequency selective channels in FBMC/OQAM,” 39th IEEE Int’l Conf. Acoustics, Speech, and Signal Processing (ICASSP-2014), Florence, Italy, May 2014.
    24. E. Kofidis, “Channel estimation in filter bank-based multicarrier systems: Challenges and solutions,” Proc. 6th IEEE Int’l Symp. Communications, Control, and Signal Processing (ISCCSP-2014), Special session on “Signal processing techniques for future mobile networks,” Athens, Greece, May 2014.
    25. C. Mavrokefalidis, A. Rontogiannis, E. Kofidis, A. Beikos, and S. Theodoridis, “Efficient adaptive equalization of doubly dispersive channels in MIMO-FBMC/OQAM systems,” Proc. 11th IEEE Int’l Symposium on Wireless Communication Systems (ISWCS-2014), Barcelona, Spain, Aug. 2014.
    26. E. Kofidis, “Preamble-based estimation of highly frequency selective channels in MIMO-FBMC/OQAM systems,” Proc. 21st European Wireless Conf. (EW-2015), Budapest, Hungary, May 2015.
    27. F. Rottenberg, Y. Medjahdi, E. Kofidis, and J. Louveaux, “Preamble-based channel estimation in asynchronous FBMC-OQAM distributed MIMO systems,” Proc. 12th IEEE Int’l Symposium on Wireless Communication Systems (ISWCS-2015), Brussels, Belgium, Aug. 2015.
    28. E. Kofidis, “On optimal multi-symbol preambles for highly frequency selective FBMC/OQAM channel estimation,” Proc. 12th IEEE Int’l Symposium on Wireless Communication Systems (ISWCS-2015), Brussels, Belgium, Aug. 2015.
    29. E. Kofidis, C. Chatzichristos, and A. L. F. de Almeida, “Tensor-based processing of filter bank-based multicarrier signals,” poster in Workshop on Tensor Decompositions and Applications (TDA-2016), Leuven, Belgium, Jan. 2016.
    30. X. Mestre and E. Kofidis, “Pilot-based FBMC/OQAM channel estimation under strong frequency selectivity,” Proc. IEEE Int’l Conf. Acoustics, Speech and Signal Processing (ICASSP-2016), Shanghai, China, March 2016.
    31. F. Rottenberg, F. Horlin, E. Kofidis, and J. Louveaux, “Generalized optimal pilot allocation for channel estimation in multicarrier systems,” Proc. 17th IEEE Int’l Workshop on Signal Processing Advances in Wireless Communications (SPAWC-2016), Edinburgh, UK, July 2016.
    32. C. Chatzichristos, E. Kofidis, Y. Kopsinis, M. Morante Moreno, and S. Theodoridis, “Higher-order block term decomposition for spatially folded fMRI data,” Proc. 13th Int’l Conf. Latent Variable Analysis and Signal Separation (LVA/ICA-2017), Grenoble, France, Feb. 2017.
    33. M. Morante Moreno, Y. Kopsinis, E. Kofidis, C. Chatzichristos, and S. Theodoridis, “Assisted dictionary learning for fMRI data analysis,” Proc. IEEE Int’l Conf. Acoustics, Speech and Signal Processing (ICASSP-2017), New Orleans, LA, March 2017.
    34. E. Kofidis, C. Chatzichristos, and A. L. F. de Almeida, “Joint channel estimation / data detection in MIMO-FBMC/OQAM systems – A tensor-based approach,” Proc. 25th European Signal Processing Conf. (EUSIPCO-2017), Kos, Greece, 28 Aug. - 2 Sept. 2017.
    35. C. Chatzichristos, E. Kofidis, and S. Theodoridis, “PARAFAC2 and its block term decomposition analog for blind fMRI source unmixing,” Proc. 25th European Signal Processing Conf. (EUSIPCO-2017), Kos, Greece, 28 Aug. - 2 Sept. 2017.
    36. L. De Lathauwer and E. Kofidis, “Coupled matrix-tensor factorizations - The case of partially shared factors,” Proc. 51st Asilomar Conference on Signals, Systems and Computers (ACSSC-2017), Asilomar Conference Grounds, Pacific Grove, CA, 29 Oct. – 1 Nov. 2017.

     

     

    • M. Renfors, X. Mestre, E. Kofidis, and F. Bader (Eds.), Orthogonal Waveforms and Filter Banks for Future Communication Systems, Acacemic Press, 2017.
    • S. Theodoridis, K. Berberidis, and E. Kofidis. Introduction to Signal and System Theory, 2nd ed., Typotheto, 2003 (in Greek).
  • Monday, 09:00-11:00

    Thursday, 12:30-13:30