Dynamic spectrum access and spectrum sharing lie at the heart of cognitive radio networks. As such, developing new multiple access techniques along with exploiting unconventional frequency bands are necessary steps needed to ensure the wide-scale deployment of cognitive radio networks. In this regard, this TCCN Newsletter will delve into two key emerging technologies in this regard: a) non-orthogonal multiple access (NOMA) and b) Millimeter wave communications (mmWave). Both NOMA and mmWave are considered as major components of emerging 5G networks and, as such, exposing their challenges and opportunities is essential. In order to do so, this second issue of the TCCN Newsletter of 2017 will bring together two feature topics on NOMA and mmWave. Within each feature topic, we review the state of the art and provide an in-depth exposition of some of the recent research contributions. For NOMA, we also provide a position paper from Dr. Zhiguo Ding’s group who has been the driving force behind many of the key contributions in NOMA. In addition to these two feature topics, we discuss the theme of “Spectrum Scarcity”, which has been driving much of the research in wireless networks, in general, and cognitive radio networking, in particular, over the past few years. Within the context of this theme, we get expert opinions from Drs. Akbar Sayeed and Mérouane Debbah along with two position papers from the groups of Dr. Danijela Cabric and Dr. George K. Karagiannidis, that expose various research challenges within this theme.
That said, we would like to thank our two feature topic editors: Dr. Daniel Benevides da Costa from UFC – Brazil and Dr. Omid Semiari, from Georgia Southern University, for their efforts in arranging the paper reviews, positions papers, and expert opinion. Moreover, we want to thank all authors and interviewees for contributing their significant research works to the two feature topics and sharing with us their useful experience and future outlook on the area. I would finally like to acknowledge the gracious support from the TCCN chair, Dr. Jianwei Huang and all TCCN officers. As always, if you have any suggestions, feel free to contact me at: email@example.com. We hope that you enjoy the material provided here!
Dr. Walid Saad
Vice Chair, IEEE ComSoc TCCN
Department of Electrical and Computer Engineering
Virginia Tech, USA