Enabling Key Technologies and Emerging Research Challenges Ahead of 5G Networks: An Extensive Survey

C. Amali - Valliammai Engineering College, Chennai, India
B. Ramachandran - SRM University, Chennai, India

Citation Format:

DOI: http://dx.doi.org/10.30630/joiv.2.3.128


The evolution towards 5G networks is expected to slake the growing thirst of internet traffic with improved Quality of Service (QoS) and reduced energy consumption and cost. The increased penetration of smart devices and induction of arising multimedia applications, together with high quality video services are already crafting a milestone on existing cellular networks. These surging demands dictate that radical enhancements need to be made in cellular architecture to drift towards ultra-dense networks. The 5G system is envisioned to achieve improved data rate, increased capacity, decreased latency, and enhanced spectral efficiency in order to provide technical solution for the challenges behind the cellular networks. Thus, the 5G era is emerging to quench the increasing demand for network capacity, to manage explosive growth of traffic patterns and to face the challenges caused by the proliferation of versatile applications and high-end devices. In this paper, we make a broad survey on 5G cellular network architecture and some of the promising key technologies such as cloud RAN (Radio Access Network), Software-Defined Networking (SDN), Network Function Virtualization (NFV) and modulation formats. Finally, this ground-breaking survey highlights major existing research issues and possible future research directions in the next new era of mobile wireless networks.


5G networks; cellular network architecture; key emerging technologies; technical solution

Full Text:



“More than 50 billion connected devices, Ericsson, Plano, TX, USA, White Paper, 2011.

Ericsson Mobility Report: On the Pulse of the Networked Society, Ericsson, 2015. Available:http://www.ericsson.com/res/docs/2015/ericsson-mobility-report-june-2015.pdf.

Cisco. Visual networking index: Global mobile data traffic forecast update 2012–2017, Feb.2013.

[Online].Available:www.cisco.com/en/US/solutions/collateral/ns341/ns525/ns537/ns705/ns827/white paper-c11-520862.html

Cisco, Visual Networking Index, white paper [Online]. Available:www.Cisco.com, Feb. 2015.

Actix. (2013). Data growth will transform mobile infrastructure by 2015 [Online]. Available: www.emlwildfire.com/primages/actssmallcells 2015.

Sukhdeep Singh, Navrati Saxena, Abhishek Roy and HanSeok Kim., “ A Survey on 5G network Technologies from Social Perspectiveâ€, IETE Tech.Rev., 2016, 34(1), 30-39.

A. Osseiran et al., “ The Foundation of the Mobile and Wireless Communications System for 2020 and Beyond: Challenges, Enablers and Technology Solutionsâ€, in Proc. IEEE VTC, 2013, pp. 1–5.

Hafiz Atta Ul Mustafa, Muhammad Ali Imran, Muhammad Zeeshan Shakir, Ali Imran, Rahim Tafazolli., “Separation Framework: An Enabler for Cooperative and D2D Communication for Future 5G Networksâ€, IEEE Commun. Surveys & Tuts, 2016, 18(1), 419 – 445.

X. Zhang, J. Zhang, W. Wang, Y. Zhang, C. I, Z. Pan, G. Li, Y. Chen., “Macro-assisted data-only carrier for 5G green cellular systemsâ€, IEEE Commun. Mag., 2015,53 (5) , 223–231.

NTT Docomo ., “5G Radio Access : Requirements, Concepts Technologies, white paper, 2015.

Nokia Networks., “Looking ahead to 5G: Building a Virtual Zero Latency Gigabit Experience, White paper, 2014.

E. Oh, K. Son and B. Krishnamachari., “Dynamic base station switching on/ off strategies for green cellular networksâ€, IEEE Trans. Wirel. Commun., 2013,12 (5), 2126–2136.

K. Au, L. Zhang, H. Nikopour, E. Yi, A. Bayesteh, U. Vilaipornsawai, J.Ma, P. Zhu., “Uplink Contention Based SCMA For 5G Radio Accessâ€, IEEE GLOBECOM Workshops, 2014, pp. 900–905.

W. Nam, D. Bai, J. Lee and I. Kang., “Advanced Interference Management For 5G Cellular Networksâ€, IEEE Commun. Mag., 2014, 52 (5), 52–60.

Tao Chen, Marja Matinmikko, Xianfu Chen, Xuan Zhou, and Petri Ahokangas., “Software Defined Mobile Networks: Concept, Survey, and Research Directionsâ€, IEEE Commun. Mag., 2015, 53(11),126-133.

L. Gao, J. Acharya and S. Gaur., “ Heterogeneous networks: Theory and Standardizationâ€, Proc. of IEEE Wireless Commun. and Netw. Conference (WCNC 2013), Shangai, China, 2013, pp.7-10.

Roh, W., “5G mobile communications for 2020 and beyond: Vision and key enabling technologiesâ€, Key note: at IEEE WCNC, 2014.

Maria Rita Palattella,et.al., “Internet of Things in the 5G Era: Enablers, Architecture, and Business Modelsâ€, IEEE Journal on Selected Areas in Commun., 2016, 34(3), 510-527.

T.S. Rappaport, W. Roh and K. Cheun., “Wireless Engineers long considered High Frequencies Worthless for Cellular Systems, They couldn’t be more wrongâ€, IEEE Spectrum, 2014, 51(9), 34-58.

PengfeiHu et.al., “Survey on fog computing: architecture, key technologies, applications and open issuesâ€, Journal of Network and Computer Applications, 2017, 98, 27-42.

F. Khan, Z. Pi, S. Rajagopal., “Millimeter-wave Mobile Broadband with Large Scale Spatial Processing For 5G Mobile Communicationâ€, Communication, Control, and Computing (Allerton), 50th Annual Allerton Conference, 2012, pp. 1517-1523.

Marco Giordani, Marco Mezzavilla, and Michele Zorzi., “Initial Access in 5G mmWave Cellular Networksâ€, IEEE Commun. Mag., 2016, 54(11), 40-47.

G - Infrastructure Public-Private Partnership 2013. [Online]. Available: http://5g-ppp.eu/

G Forum, “Make it Happen: creating new values togetherâ€, [Online], Available: http://www.5gforum.org/

P. Pirinen., “A Brief Overview of 5G Research Activitiesâ€, Proc. of 1st International Conference on 5G for Ubiquitous Connectivity (5GU), 2014, pp.17-22.

F. Boccardi, R.W. Heath, A. Lozano, T.L. Marzetta, P. Popovski., “Five Disruptive Technology Directions For 5Gâ€, IEEE Commun. Mag., 2014, 52(2), 74-80.

S. Chen and J. Zhao., “The Requirements, Challenges, and Technologies for 5G of Terrestrial Mobile Telecommunicationâ€, IEEE Commun. Mag., 2014, 52(5), 36-43.

L. Gavrilovska, V. Rakovic, V. Atanasovski., “Visions towards 5G: Technical requirements and Potential Enablersâ€, Wirel. Pers. Commun., 2016,87 (3), 731-757.

C. I, C. Rowell, S. Han, Z. Xu, G. Li, Z. Pan., “Toward Green and Soft: a 5G Perspectiveâ€, IEEE Commun. Mag., 2014, 52 (2),66–73.

Shunqing Zhang, et.al., “Fundamental Green Tradeoffs: Progresses, Challenges, and Impacts on 5G Networksâ€, IEEE Commun. Surveys & Tuts., 2017, 19(1), 33-56.

P.K. Agyapong, M. Iwamura, D. Staehle, W. Kiess, A. Benjebbour., “Design Considerations for a 5G Network Architectureâ€, IEEE Commun. Mag., 2014, 52 (11), 65–75.

Abdelrahim Mohamed, Oluwakayode Onireti, Muhammad Ali Imran, Ali Imran, Rahim Tafazolli., “Control-Data Separation Architecture for Cellular Radio Access Networks: A Survey and Outlookâ€, IEEE Commun. Surveys & Tuts., 2016,18(1), 446 – 465.

S.M. Abd El-atty, Z.M. Gharsseldien., “On performance of HetNet with Coexisting Small Cell Technologyâ€, Proc. of IEEE Conference on Wireless and Mobile Networking, 2013, pp. 1-8.

J. G. Andrews, H. Claussen, M. Dohler, S. Rangan and M.C.Reed., “Femtocells: Past, Present and Futureâ€, IEEE Journal on Selected Areas in Commun., 2012, 30(3), 497-508.

N. Bhushan, L. Junyi, D. Malladi, R. Gilmore, D. Brenner, A. Damnjanovic, R. Sukhavasi, C. Patel and S. Geirhofer., “Network Densification: The Dominant Theme for Wireless Evolution into 5Gâ€, IEEE Commun. Mag., 2014, 52 (2), 82-89.

M. Iwamura., “NGMN View on 5G architecture. Proc. of IEEE 81st Veh. Technol. Conf. (VTC Spring), Glasgow, Scotland, 2015, pp. 1-5.

J. G. Andrews., “Seven Ways that HetNets are a Cellular Paradigm Shiftâ€, IEEE Commun. Mag.,2013, 51(3), 136–144.

Mugen Peng, Yong Li, Zhongyuan Zhao, Chonggang Wang., “System Architecture and Key Technologies for 5G Heterogeneous Cloud Radio Access Networksâ€, IEEE Network., 2015, 29(2), 6 – 14.

J. G. Andrews, S. Singh, Q. Ye, X. Lin, and H. S. Dhillon ., “An overview of load balancing in HetNets: Old myths and open problemsâ€, IEEE Trans. Wireless Commun.,2014, 21(2), 18–25.

Z. Wang, H. Li, H. Wang, S. Ci., “Probability Weighted Based Spectral Resources Allocation Algorithm in Hetnets under Cloud-RAN architecture. Proc. of International Conference on Communications, China- Workshops, 2013, pp. 88-92.

O. Galinina, S. Andreev, M. Gerasimenko, Y. Koucheryavy, N. Himayat, S.P. Yeh, S. Talwar ., “Capturing Spatial Randomness of Heterogeneous Cellular/WLAN Deployments with Dynamic Trafficâ€, IEEE Journal on Selected Areas in Commun., 2014,32(6), 1083-1099.

R. Jain, A. Durresi, and S. Paul., “Future Internet architecturesâ€, IEEE Commun. Mag., 2014, 49(7), 24–25.

Future Internet-PPP. (2013). [Online]. Available: http://www. fi-ppp.eu/

Martin Maier, Mahfuzulhoq Chowdhury,et.al., “The Tactile Internet: Vision, Recent Progress, and Open Challengesâ€, IEEE Commun. Mag., 2016, 54(5), 138-145.

S. Hanly and P. Whiting., “On the capacity of HetNetsâ€, Proc. of Information Theory and Applications,2014, pp. 1–9.

Z. Roth et al., “Vision and Architecture Supporting Wireless Gbit/Sec/Km Capacity Density Deploymentsâ€, Proc. of Future Netw. Mobile Summit, 2010, pp. 1-7.

Ali Y. Al-Zahrani, F. Richard Yu, and Minyi Huang ., “A Joint Cross-Layer and Colayer Interference Management Scheme in Hyperdense Heterogeneous Networks Using Mean-Field Game Theoryâ€, IEEE Trans. on Veh. Tech.,2016, 65(3), 1522-1535.

C. Kosta, B. Hunt, A. Quddus, and R. Tafazolli ., “On Interference Avoidance through Inter-Cell Interference Coordination (ICIC) Based On OFDMA Mobile Systemsâ€, IEEE Commun. Surveys Tuts., 2013, 15(3), 973–995.

Selcuk Bassoy, et.al., “Coordinated Multi-Point Clustering Schemes: A Surveyâ€, IEEE Commun. Surveys Tuts., 2017,19(2) , 743-764.

V. Jungnickel et al. ., “The role of Small Cells, Coordinated Multipoint and Massive MIMO in 5Gâ€, IEEE Commun. Mag., 2014, 52(5), 44-51.

Dantong Liu, Lifeng Wang, Yue Chen, Maged Elkashlan and Kai-Kit Wong., “User Association in 5G Networks: A Survey and an Outlookâ€, IEEE Commun. Surveys Tuts., 2016, 18(2), 1018-1044.

Abdelrahim Mohamed et.al.., “Control-Data Separation Architecture for Cellular Radio Access Networks: A Survey and Outlookâ€, IEEE Commun. Surveys Tuts., 2016,18(1), 446-465.

S. Talwar, D. Choudhury, K. Dimou, E. Aryafar, B. Bangerter, K. Stewart., “Enabling Technologies and Architectures For 5G Wirelessâ€, Proc. of Microwave Symposium (IMS), MTT-S International, 2014, pp: 1-4.

Chungang Yang, Jiandong Li,et.al.., “Advanced Spectrum Sharing in 5G Cognitive Heterogeneous Networksâ€, IEEE Wirel. Commun., 2016, 23(2), 94-101.

Yi Zhong, Tony Q. S. Quek, and Xiaohu Ge., “Heterogeneous Cellular Networks With Spatio-Temporal Traffic: Delay Analysis and Schedulingâ€, IEEE Journal on Selected Areas in Commun., 2017, 35(6), 1373- 1386.

X. Ge, H. Cheng, M. Guizani, T. Han., “5G Wireless Backhaul Networks: Challenges and Research Advancesâ€, IEEE Netw., 2014, 28 (6), 6–11.

Angeliki Alexiou., “Wireless World 2020: Radio Interface Challenges and Technology Enablersâ€, IEEE Veh. Tech., Mag., 2014, 9(1), 46 – 53.

C. J. Bernardos, A. De Domenico, J. Ortin, P. Rost, and D. Wubben., “Challenges of Designing Jointly the Backhaul and Radio Access Network in a Cloud-Based Mobile Networkâ€, Proc. of Future Netw. Mobile Summit (FutureNetworkSummit), 2013, pp. 1-10.

C. Wang, F. Haider, X. Gao, X. You, Y. Yang, D. Yuan, H.M. Aggoune, H. Haas, S. Fletcher, E. Hepsaydir., “Cellular Architecture and Key Technologies For 5G Wireless Communication Networksâ€, IEEE Commun. Mag., 2014, 52 (2), 122–130.

D. C. Chen, T. Q. S. Quek, and M. Kountouris ., “Wireless Backhaul in Small Cell Networks: Modelling and Analysisâ€, Proc. of IEEE Veh. Technol.Conf. (VTC), 2014, pp. 1-6.

G. Zhang, T. Q. S. Quek, M. Kountouris, A. Huang, and H. Shan., “Fundamentals of Heterogeneous Backhaul Design, Analysis and Optimizationâ€, IEEE Trans. Commun.,2016, 64(2), 876-889.

W. Wang, Q. Zhang., “Local Cooperation Architecture for Self-Healing Femto cell Networksâ€, IEEE Wirel. Commun., 2014, 21 (2), 42–49.

X. Duan, X. Wang., “Authentication Handover and Privacy Protection in 5G Hetnets Using Software-Defined Networkingâ€, IEEE Commun. Mag., 2015, 53 (4), 28–35.

C.Amali , Dhanasree Jayaprakash and B.Ramachandran., “Enhanced Media Independent Network Selection for Heterogeneous Wireless Networksâ€, IETE Tech. Rev., 2014, 31(5),392-401.

H. Song, X. Fang, L. Yan., “Handover scheme for 5G C/U Plane Split Heterogeneous Network in High-Speed Railwayâ€, IEEE Trans. Veh. Technol., 2014, 63 (9), 4633–4646.

S. Azodolmolky, P. Wieder, and R. Yahyapour., “Cloud Computing Networking: Challenges and Opportunities for Innovationsâ€, IEEE Commun. Mag., 2013, 51(7), 54–62.

T. Taleb., “Toward Carrier Cloud: Potential, Challenges, and Solutionsâ€, IEEE Wireless Commun., 2014, 21(3), 80–91.

F. Bonomi et al.., “Fog Computing and Its Role in the Internet of Thingsâ€, Proc. of ACM MCC Wksp. Mobile Cloud Computing, 2012, pp. 13–16.

P. Rost, C. J. Bernardos, A. De Domenico, M. Di Girolamo, M. Lalam, A. Maeder, D. Sabella, and D. Wübben., “Cloud technologies for flexible 5G radio access networks,†IEEE Commun. Mag., 2014, 52(5), 68–76.

A. Checko, H.L. Christiansen, Y. Yan, L. Scolari, G. Kardaras, M.S. Berger, L.Dittmann ., “Cloud RAN for mobile networks-a technology overviewâ€, IEEE Commun. Surveys & Tuts., 2015, 17(1), 405-426.

Sabella, D., Rost, P., Sheng, Y., Pateromichelakis, E., Salim, U., Guitton-Ouhamou, P., et al.., “RAN as a service: Challenges of designing a flexible RAN architecture in a cloud-based heterogeneous mobile networkâ€, Proc. of Future network and mobile summit (Future Network Summit), 2013, pp. 1–8.

Haijun Zhang, Yanjie Dong,et.al.., “Front hauling for 5G LT E-U Ultra Dense Cloud Small Cell Networksâ€, IEEE Wirel. Commun., 2016, 23(6), 48-53.

N. Cvijetic., “Optical network evolution for 5G mobile applications and SDN-based controlâ€, Proc. of International Telecommunications Network Strategy and Planning Symposium, 2014, pp. 1-5.

Rui Wang, Honglin Hu, and Xiumei Yang., “Potentials and Challenges of C-RAN Supporting Multi-RATs Toward 5G Mobile Networksâ€, IEEE Access on Recent Advances in Cloud Radio Access Networks., 2014, 2, 1187-1195.

D. Wake, A. Nkansah, and N. J. Gomes ., “Radio over Fiber Link Design for Next Generation Wireless Systemsâ€, IEEE/OSA J. Light wave Technol., 2010, 28(16), 2456–2464.

X. Zhou, Z. Zhao, R. Li, Y. Zhou, T. Chen, Z. Niu, H. Zhang., “Toward 5G: When Explosive Bursts Meet Soft Cloudâ€, IEEE Netw., 2014, 28 (6), 12–17.

K. Chen, C. Cui, Y. Huang, and B. Huang., “C-RAN: A green RAN framework,†Proc. of Green Communications: Theoretical Fundamentals, Algorithms and Applications. CRC Press, 2013, pp. 279–304.

Stefano Buzzi, Chih-Lin I,et.al.., “A Survey of Energy-Efficient Techniques for 5G Networks and Challenges Aheadâ€, IEEE Journal on Selected Areas in Commun., 2016, 34(4), 697-709.

G. Li, S. Zhang, X. Yang, F. Liao, T. Ngai, S. Zhang, and K. Chen., “Architecture of GPP based, scalable, large-scale C-RAN BBU poolâ€, Proc. of Int. Workshop Cloud Base-Station Large-Scale Cooperative Communications, IEEE GLOBECOM 2012 Workshops, Anaheim, CA, 2012, pp. 267–272.

C.X. Mavromoustakis, A. Bourdena, G. Mastorakis, E. Pallis, G.Kormentzas ., “An Energy-Aware Scheme For Efficient Spectrum Utilization in a 5G Mobile Cognitive Radio Network Architectureâ€, Telecommun. Syst., 2015, 59 (1), 63–75.

J. Liu, T. Zhao, S. Zhou, Y. Cheng, Z. Niu ., “CONCERT: a Cloud-Based Architecture for Next-Generation Cellular Systemsâ€, IEEE Wirel.Commun., 2014, 21(6), 14–22.

N. Zhang, N. Cheng, A.T. Gamage, K. Zhang, J.W. Mark, X. Shen ., “Cloud assisted HetNets toward 5G Wireless Networksâ€, IEEE Commun. Mag., 2015, 53(6), 59-65.

Nikos Bizanis And Fernando A. Kuipers., “SDN and Virtualization Solutions for the Internet of Things: A Surveyâ€, IEEE Access, 2016, 4, 5591-5606.

Software-Defined Networking, the New Norm for Networks, Apr. 2012. [Online]. Available: http://www.opennetworking.org

A. Gudipati et al., “SoftRAN: Software Defined Radio Access Network.Proc. of 2nd ACM SIGCOMM Wksp. Hot Topics in Software Defined Networking, 2013, pp. 25–30.

B.A.A. Nunes et al ., A Survey of Software-Defined Networking: Past, Present, and Future of Programmable Networks,†IEEE Commun. Surveys & Tuts., 2014, 16(3), 1617–34.

M. Palkovic et al., “Future Software-Defined Radio Platforms and Mapping Flowsâ€, IEEE Signal Proc. Mag., 2010, 23(4), 22–33.

S. Sezer et al., “Are we ready for SDN? Implementation Challenges for Software-Defined Networksâ€, IEEE Commun. Mag., 2013, 51(7), 36–43.

Bernardos et al.., “An Architecture for Software Defined Wireless Networkingâ€, IEEE Wireless Commun., 2014, 21(3), 52–61.

Lara, A. Kolasani, B. Ramamurthy., “Network innovation using open flow: A surveyâ€, IEEE Commun. Surveys & Tuts., 2014, 16(1), 493-512.

H.H. Cho, C.F. Lai, T.K. Shih, H.C. Chao ., “Integration of SDR and SDN for 5Gâ€, IEEE Access, 2014, 2, 1196-1204.

Songlin Sun, Liang Gong, Bo Rong, and Kejie Lu ., “An Intelligent SDN Framework for 5G Heterogeneous Networksâ€, IEEE Commun. Mag., 2015, 3(11), 142-147.

E. Bjornson, R. Zakhour, D. Gesbert, and B. Ottersten ., “Cooperative multicell precoding: Rate Region Characterization and Distributed Strategies with Instantaneous and Statistical CSIâ€, IEEE Trans. Signal Proc., 2010, 58(8), 4298–4310.

R. Trivisonno et al., “SDN-Based 5G Mobile Networks: Architecture, Functions, Procedures and Backward Compatibilityâ€, Trans. Emerging Telecommun. Tech., 2015, 26(1), 82–92.

M. Arslan, K. Sundaresan, and S. Rangarajan ., “Software- Defined Networking in Cellular Radio Access Networks: Potential and Challengesâ€, IEEE Commun. Mag., 2015, 53(1), 150–56.

B. Han et al., “Network Function Virtualization: Challenges and Opportunities for Innovationsâ€, IEEE Commun.Mag., 2015, 53(2), 90–97.


B. Bangerter et al., “Networks and Devices for the 5G Eraâ€, IEEE Commun. Mag., 2014, 52(2), 90–96.

Network Function Virtualization- An Introduction, Benefit, Enablers, Challenges and Call for Action, whitepaper, Oct.2012.

Panagiotis Demestichas et.al ., “5G on the Horizon: Key Technologies for the Radio Access Networkâ€, IEEE Veh. Tech. Mag., 2013, 8(3), 47-53.

David Muirhead, Muhammad Ali Imran,and Kamran Arshad ., “A Survey of the Challenges, Opportunities and Use of Multiple Antennas in Current and Future 5G Small Cell Base Stationsâ€, IEEE Access, 2016, 4, 2952-2964.

J. Kim, H.W. Lee, S. Chong., “Virtual cell Beam forming in Cooperative Networksâ€, IEEE Journal on Selected Areas in Commun.,2014, 32(6), 1126-1138.

W. Roh, J.Y. Seol, J. Park, B. Lee, J. Lee, Y. Kim, J. Cho, K. Cheun, F. Aryanfar., “Millimeter-wave Beamforming as an Enabling Technology for 5G Cellular Communications: Theoretical Feasibility and Prototype Resultsâ€, IEEE Commun. Mag., 2014, 52(2), 106-113.

Mamta Agiwal, Abhishek Roy and Navrati Saxena., “Next Generation 5G Wireless Networks: A Comprehensive Surveyâ€, IEEE Commun. Surveys & Tuts., 2016, 18 (3), 1617 – 1655.

P. Xia, S.K. Yong, J. Oh, and C. Ngo., “A practical SDMA protocol for 60 GHz Millimeter Wave Communicationsâ€, Proc. of 42nd Asilomar Conference on Signals, Systems and Computers, 2008, pp. 2019-2023.

L. Lu, G.Y. Li, A.L. Swindlehurst, A. Ashikhmin, R. Zhang, R., “An overview of massive MIMO: Benefits and Challengesâ€, IEEE Journal on Sel. Areas in Commun., 2014, 8(5), 742-758.

Jinyoung Jang, et.al., “Smart Small Cell with Hybrid Beamforming for 5G: Theoretical Feasibility and Prototype Resultsâ€, IEEE Wireless Commun., 2016, 23(6),124-131.

Mansoor Shafi, Andreas F. Molisch,et.al. ., “5G: A Tutorial Overview of Standards, Trials, Challenges, Deployment, and Practiceâ€, IEEE Journal on Sel. Areas in Commun., 2017, 35(6), 1201-1221.

Zizheng Cao.et.al., “Advanced Integration Techniques on Broadband Millimeter-Wave Beam Steering for 5G Wireless Networks and Beyondâ€, IEEE Journal of Quantum Electr., 2016, 52(1), 1-7.

T. S. Rappaport et al.., “Millimeter wave mobile communications for 5G cellular: It will work!.â€, IEEE Access, 2013,1, 335–349.

A.Ghosh, T.A.Thomas, M.C.Cudak, R.Ratasuk, P.Moorut, F.W.Vook, T.S.Rappaport, G.R.MacCartney, Shu Sun, Shuai Nie ., “Millimeter-Wave Enhanced Local Area Systems: A High-Data-Rate Approach for Future Wireless Networksâ€, IEEE Journal on Sel. Areas in Commun., 2014, 32(6),1152-1163.

E. Larsson, O. Edfors, F. Tufvesson, T. Marzetta., “Massive MIMO for Next Generation Wireless Systemsâ€, IEEE Commun. Mag., 2014, 52(2), 186-195.

H. Q. Ngo, E. G. Larsson, and T. L. Marzetta ., “Energy and Spectral Efficiency of Very Large Multiuser MIMO systemsâ€, IEEE Trans. Commun., 2013, 61(4), 1436–1449.

Y. Mehmood, W. Afzal, F. Ahmad, U. Younas, I. Rashid, I. Mehmood ., “Large scaled multi-user MIMO system so called massive MIMO systems for Future Wireless Communication Networksâ€, Proc. of International Conference on Automation and Computing, 2013, pp. 1-4.

Z. Xiang, M. Tao, X. Wang., “Massive MIMO multicasting in Non-Cooperative Cellular Networksâ€, IEEE Journal on Sel. Areas in Commun., 2014, 32(6), 1180-1193.

J. Hoydis, S. ten Brink, and M. Debbah., “Massive MIMO in the UL/DL of cellular networks: How many antennas do we need?.â€, IEEE J. Sel. Areas Commun., 2013, 31(2), 160–171.

Olakunle Elijah et.al., “A Comprehensive Survey of Pilot Contamination in Massive MIMO-5G Systemâ€, IEEE Commun. Surveys & Tuts., 2016, 18(2), 905-923.

W. Liu, S. Han, C. Yang, C. Sun., “Massive MIMO or small cell network: Who is more Energy Efficient?.â€, Proc. of IEEE Wireless Commun. and Netw. Conference Workshops, 2013, pp. 24-29.

E. Björnson, L. Sanguinetti, J. Hoydis, and M. Debbah ., “Optimal design of energy-efficient multi-user MIMO systems: Is massive MIMO the answer?.â€, IEEE Trans. Wireless Commun., 2015, 14(6), 3059-3075.

Feng Zheng,et.al. ., “An Efficient CSI Feedback Scheme for Dual-Polarized MIMO Systems Using Layered Multi-Paths Informationâ€, China Commun., 2017, 14(5), 91-104.

L. Sanguinetti, A.L. Moustakas, M.Debbah ., “Interference management in 5G reverse TDD HetNets with Wireless Backhaul: A Large System Analysisâ€, IEEE Journal on Sel. Areas in Commun., 2015, 33(6), 1187-1200.

Anqi He, Lifeng Wang, Yue Chen, Kai-Kit Wong, and Maged Elkashlan., “Uplink Interference Management in Massive MIMO Enabled Heterogeneous Cellular Networksâ€, IEEE Wireless Commun. Letters, 2016, 5(5), 560-563.

Shanzhi Chen,et.al., “Adaptive Beamforming in TDD-Based Mobile Communication Systems: State of the Art and 5G Research Directionsâ€, IEEE Wireless Commun., 2016, 23(6), 81-87.

Vidhya Sridhar, Thibaud Gabillard, and Athanassios Manikas., “Spatiotemporal-MIMO Channel Estimator and Beamformer for 5Gâ€, IEEE Trans. on Wireless Commun., 2016, 15(12), 8025-8038.

G. Andrews, S. Buzzi, W. Choi, S. Hanly, A. Lozano, A. C.K. Soong, and J. C. Zhang ., “What will 5G be?.â€, IEEE J. Select. Areas in Commun., 2014, 32(6), 1065–1082.

Akhil Gupta and Rakesh Kumar Jha ., “A Survey of 5G Network: Architecture and Emerging Technologiesâ€, IEEE Access, 2015, 3, 1206-1232.

Y. Li and G. Stüber, Eds.., “Orthogonal Frequency Division Multiplexing for Wireless Communications, Boston, MA, USA: Springer,2006.

T. Hwang, C. Yang, G. Wu, S. Li, and G. Ye Li ., “OFDM and its Wireless Applications: A Survey. IEEE Trans. Veh. Technol., 2009, 58(4), 1673–1694.

M. Morelli., “Timing and frequency synchronization for the uplink of an OFDMA system. IEEE Trans. Commun., 2004, 52(2), 296–306.

H. Ochiai and H. Imai., “On the distribution of the peak-to-average power ratio in OFDM signals. IEEE Trans. Commun., 2001, 49(2), 282–289.

Ertugrul Basar., “On Multiple-Input Multiple-Output OFDM with Index Modulation for Next Generation Wireless Networksâ€, IEEE Trans. On Signal Proc., 2016, 64(15), 3868-3878.

R. Irmer, H. Droste, P. Marsch, M.Grieger, G. Fettweis, S. Brueck, H.-P.Mayer, L. Thiele, and V. Jungnickel ., “Coordinated multipoint: Concepts, Performance, and Field Trial Resultsâ€, IEEE Commun. Mag., 2011, 49(2), 102–111.

K. Lee, S.-R. Lee, S.-H. Moon, and I. Lee., “MMSE-based CFO compensation for uplink OFDMA Systems with Conjugate Gradient. IEEE Trans. Wireless Commun., 2012, 11(8), 2767–2775.

S. Hong et al., “Frequency and Quadrature-Amplitude Modulation for Downlink Cellular OFDMA Networksâ€, IEEE J. Sel. Areas Commun., 2014, 32(6), 1256-1267.

D. Huang and K. B. Letaief ., “An Interference-Cancellation Scheme for Carrier Frequency Offsets Correction in OFDMA systemsâ€, IEEE Trans. Commun., 2005, 53(7), 1155–1165.

H. Saeedi-Sourck, Y. Wu, J. W. M. Bergmans, S. Sadri, and B. Farhang-Boroujeny., “Complexity and Performance Comparison of Filter Bank Multicarrier and OFDM in Uplink of Multicarrier Multiple Access Networksâ€, IEEE Trans. Signal Process, 2011, 59(4), 1907–1912.

Behrouz Farhang-Boroujeny and Hussein Moradi., “OFDM Inspired Waveforms for 5Gâ€, IEEE Commun. Surveys & Tuts., 2016, 18(4), 2474-2492.

S. N. Premnath, D. Wasden, S. Kasera, N. Patwari, and B. Farhang-Boroujeny., “Beyond OFDM: Best-effort Dynamic Spectrum Access Using Filter bank Multicarrierâ€, IEEE/ACM Trans. Netw., 2013, 21(3), 869–882.

B. Farhang-Boroujeny., “OFDM versus filter bank multicarrierâ€, IEEE Signal Proc. Mag., 2011, 28(3), 92–112.

M. Payaró, A. Pascual-Iserte, and M. Najar., “Performance comparison between FBMC and OFDM in MIMO systems under Channel Uncertaintyâ€, Proc. of Eur. Wireless Conf. (EW), Lucca, Italy, 2010, pp. 1023–1030.

T. Ihalainen, A. Ikhlef, J. Louveaux, and M. Renfors., “Channel equalization for multi-antenna FBMC/OQAM receivers. IEEE Trans. Veh. Tech., 2011, 60(5), 2070–2085.

J.-B. Dore, V. Berg, D. Ktenas., “Performance of FBMC Multiple Access for Relaxed Synchronization Cellular Networksâ€, IEEE Globe Com Workshop on Broadband Wireless Access, Austin, TX, USA, 2014, pp. 983 – 988.

G. Fettweis, M. Krondorf, and S. Bittner., “GFDM—Generalized frequency division multiplexingâ€, Proc. of IEEE 69th Veh. Technol. Conf. (VTC), Barcelona, Spain, 2009, pp. 1–4.

M. Matthe, L. L. Mendes, and G. Fettweis., “Generalized Frequency Division Multiplexing in a Gabor Transform Settingâ€, IEEE Commun. Lett., 2014, 18(8), 1379–1382.

N. Michailow, I. Gaspar, S. Krone, M. Lentmaier, G. Fettweis., “Generalized Frequency Division Multiplexing: Analysis of an Alternative Multicarrier Technique for Next Generation Cellular Systemsâ€, Proc. of International Symposium on Wireless Communication Systems, Paris, France, 2012, pp. 171-175.

N. Michailow et al.., “Generalized Frequency Division Multiplexing For 5th Generation Cellular Networksâ€, IEEE Trans. Commun., 2014, 62(9), 3045–3061.

H. Lin and P. Siohan., “An advanced multi-carrier modulation for future radio systemsâ€, Proc. of IEEE Int. Conf. Acoust. Speech Signal Process. (ICASSP), Florence, Italy, 2014, pp. 8097–8101.

V. Vakilian, T. Wild, F. Schaich, S. ten Brink, and J.-F. Frigon., “Universal-Filtered Multi-Carrier Technique for Wireless Systems beyond LTEâ€, Proc. of IEEE Globecom Workshops (GC Wkshps), Atlanta, GA, USA, 2013, pp. 223–228.

T. Wild, F. Schaich, and Y. Chen., “5G Air Interface Design based on universal filtered (UF-OFDM) “, Proc. 19th Int. Conf. Digit. Signal Process. (DSP), Hong Kong, 2014, pp. 699–704.

F. Schaich and T. Wild., “Relaxed Synchronization Support of Universal Filtered Multi-Carrier including Autonomous Timing Advanceâ€, Proc. of 11th Int. Symp. Wireless Commun. Syst. (ISWCS), Barcelona, Spain, 2014, pp. 203–208.

E. Basar, U. Aygolu, E. Panayirci, and H. V. Poor., “Orthogonal Frequency Division Multiplexing with Index Modulationâ€, IEEE Trans. Signal Proc., 2013, 61(22), 5536–5549.

E. Basar., “OFDM with Index Modulation Using Coordinate Interleavingâ€, IEEE Wireless Commun., Lett., 2015, 4(4), 381–384.

R. Fan, Y. Yu, and Y. Guan., “Generalization of Orthogonal Frequency Division Multiplexing with Index Modulationâ€, IEEE Trans. Wireless Commun., 2015, 14(10), 5350–5359.

M. Wen et al., “On the Achievable Rate of OFDM with Index Modulationâ€, IEEE Trans. Signal Proc., 2016, 64(8), 1919–1932.

Ertugrul Basar., “Index Modulation Techniques for 5G Wireless Networksâ€, IEEE Commun. Mag., 2016, 54(7), 168-175.

Yinsheng Liu et.al., “Waveform Design for 5G Networks: Analysis and Comparisonâ€, IEEE Access, 2017, PP(99), 1-9., y

Van Minh Nguyen, Member, IEEE, and Marios Kountouris., “Performance Limits of Network Densificationâ€, IEEE J. Select. Areas Commun.,2017, 35(6), 1294-1308.

Mona Jaber,et.al., “5G Backhaul Challenges and emerging Research Directions: A Surveyâ€, IEEE Access, 2016, 4, 1743-1766.

Gongzheng Zhang, Tony Q. S. Quek,et.al., “Fundamentals of Heterogeneous Backhaul Design-Analysis and Optimizationâ€, IEEE Trans. on Commun., 2016, 64(2), 876-889.