ZTE Communications ›› 2017, Vol. 15 ›› Issue (S1): 11-20.DOI: 10.3969/j.issn.1673-5188.2017.S1.002

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Enhanced OFDM for 5G RAN

Zekeriyya Esat Ankaralı1, Berker Peköz1, Hüseyin Arslan1,2   

  1. 1. Department of Electrical Engineering, University of South Florida, FL 33620, USA
    2. College of Engineering, Istanbul Medipol University, Istanbul 34810, Turkey
  • Received:2016-11-30 Online:2017-06-25 Published:2020-04-14
  • About author:Zekeriyya Esat Ankaralı (zekeriyya@mail.usf.edu) received his B.Sc. degree in control engineering from Istanbul Technical University (ITU), Turkey in 2011 with honors degree and M.Sc. in electrical engineering from University of South Florida (USF), USA in December 2012. Since January 2013, he has been pursuing his Ph.D. as a member of the Wireless Communication and Signal Processing (WCSP) Group at USF. His current research interests are waveform design, multicarrier systems, physical layer security and in vivo communications.|Berker Peköz (pekoz@mail.usf.edu) received his B.Sc. degree in electrical and electronics engineering from Middle East Technical University (METU), Turkey in 2015 with high honors degree. Since August 2015, he has been pursuing his Ph.D. as a member of the Wireless Communication and Signal Processing (WCSP) Group at University of South Florida (USF), USA. His current research interests are mmWave communications, multidimensional modulations and waveform design.|Huseyin Arslan (arslan@usf.edu) received his B.S. degree from Middle East Technical University (METU), Turkey in 1992; M.S. and Ph.D. degreesfrom Southern Methodist University (SMU), USA in 1994 and 1998. From January 1998 to August 2002, he was with the research group of Ericsson Inc., USA, where he was involved with several project related to 2G and 3G wireless communication systems. Since August 2002, he has been with the Electrical Engineering Dept. of University of South Florida (USF), USA. Also, he has been the dean of the College of Engineering and Natural Sciences of Istanbul Medipol University, Turkey since 2014. In addition, he has worked as part time consultant for various companies and institutions including Anritsu Company (USA) and The Scientific and Technological Research Council of Turkey. His current research interests include physical layer security, mmWave communications, small cells, multi-carrier wireless technologies, co-existence issues on heterogeneous networks, aeronautical (high altitude platform) communications and in vivo channel modeling, and system design.


Support of many different services, approximately 1000x increase of current data rates, ultra-low latency and energy/cost efficiency are among the expectations from the upcoming 5G standards. In order to meet these expectations, researchers investigate various potential technologies involving different network layers and discuss their tradeoffs for possible 5G scenarios. As one of the most critical components of communication systems, waveform design plays a vital role here to achieve the aforementioned goals. Basic features of the 5G waveform can be given in a nutshell as more flexibility, support of multiple access, the ability to co-exist with different waveforms, low latency and compatibility with promising future technologies such as massive MIMO and mmWave communications. Orthogonal frequency division multiplexing (OFDM) has been the dominant technology in many existing standards and is still considered as one of the favorites for broadband communications in 5G radio access network (RAN). Considering the current interest of industry and academia on enhancing OFDM, this paper drafts the merits and shortcomings of OFDM for 5G RAN scenarios and discusses the various approaches for its improvement. What is addressed in this paper includes not only enhancing the waveform characteristics, out of band leakage and peak to average power ratio in particular, but also methods to reduce the time and frequency redundancies of OFDM such as cyclic prefix and pilot signals. We present how the requirements of different 5G RAN scenarios reflect on waveform parameters, and explore the motivations behind designing frames that include multiple waveforms with different parameters, referred to as numerologies by the 3GPP community, as well as the problems that arise with such coexistence. In addition, recently proposed OFDM-based signaling schemes will also be discussed along with a brief comparison.

Key words: 5G waveform, 5G RAN, eMBB, multicarrier systems, OFDM