Prof. Dr. Hikmet Sari

Prof. Dr. Hikmet Sari

Professor of Telecommunications Department SUPELEC
Plateau de Moulon
3rue Joliot-Curie

Hari/Tanggal : Rabu, 20 Maret 2013
Waktu : 10.50 – 11.10 WIB
Tempat : The Trans Luxury Hotel Bandung
Agenda : Multiple Access and Power Efficiency in Wireless Communications


In this talk, we address the critical issues related to nonlinear amplifier problems in wireless communications and the developments in multiple access techniques to face these issues and increase power efficiency. First of all, we review the Orthogonal Frequency-Division Multiplexing (OFDM) vs. Single-Carrier Transmission with Frequency-Domain Equalization (SC-FDE) issue, which first came up in Digital Audio and Video Broadcasting and continued later in wireless communications. Then, we discuss the birth and the principle of Orthogonal Frequency-Division Multiple Access (OFDMA) and of Single-Carrier Frequency-Division Multiple Access (SC-FDMA) and compare these multiple access techniques in a cellular environment using the Long-Term Evolution (LTE) standard and assuming a linear channel. Finally, we give a comprehensive presentation of the effect of nonlinear power amplifiers on the transmitted signal and the methods used to compensate for the resulting distortion. A comparison is then made between OFDMA and SC-FDMA using nonlinear power amplifiers. Our analysis indicates that OFDMA performs better on linear channels, particularly with high-level signal constellations, but that SC-FDMA reduces high-power amplifier back-off by 1.5 – 2.0 dB. The final conclusion in that it is better to use OFDMA for users close to the base station in order to increase cell capacity, and in contrast it is better to use SC-FDMA for users near the cell edge to increase the cell range.


  • Chair, Communication Theory Symposium (ICC 2002, New York)
  • Technical Program Chair, 2004 IEEE International Conference on Communications (ICC 2004), Paris, June 2004
  • Vice General Chair, ICC 2006, Istanbul, June 2006
  • General Chair, PIMRC 2010, Istanbul, September 2010
  • General Chair, WCNC 2012, Paris, April 2012
  • Executive Chair, WCNC 2014, Istanbul, April 2014
  • General Chair, ICUWB 2014, Paris, September 2014
  • Executive Co-Chair, ICC 2016, Kuala Lumpur, May 2016
  • Executive Chair, ICC 2017, Paris, May 2017


  • IEEE Fellow (since 1995
  • André Blondel Medal (1995)
  • Distinguished Lecturer of the IEEE Communications Society (2001 – 2006) : Numerous invited talks in Europe, North America, Asia-Pacific, and Latin America
  • Edwin H. Armstrong Award (2003)
  • Elected to Academia Europaea (2012)
  • Harold Sobol Award (2012)
  • Elected to the Science Academy of Turkey (2012)