Bhuvaneswari P, Nithyanandan L (2018) Improving energy efficiency in backhaul of LTE-A network with base station cooperation. Proc Comput Sci 143. https://doi.org/10.1016/j.procs.2018.10.378

Saad W, Bennis M, Chen M (2019) A vision of 6G wireless systems: applications, trends, technologies, and open research problems. IEEE Netw. https://doi.org/10.1109/MNET.001.1900287

Ngo HQ, Ashikhmin A, Yang H, Larsson EG, Marzetta TL (2017) Cell-free massive MIMO versus small cells. IEEE Transact Wireless Commu 16(3):1834–1850. https://doi.org/10.1109/TWC.2017.2655515

Article
Google Scholar

Gangakhedkar S, Cao H, Ali AR, Ganesan K, Gharba M, Eichinger J (2018) Use cases, requirements and challenges of 5G communication for industrial automation. https://doi.org/10.1109/ICCW.2018.8403588

Book
Google Scholar

Gandotra P, Jha RK (2017) A survey on green communication and security challenges in 5G wireless communication networks. J Network Comp Appl 96. https://doi.org/10.1016/j.jnca.2017.07.002

Imoize AL, Adedeji O, Tandiya N, Shetty S (2021) 6G enabled smart infrastructure for sustainable society: opportunities, challenges, and research roadmap. Sensors 21(5):1709. https://doi.org/10.3390/s21051709

Article
Google Scholar

Bhat JR, AlQahtani SA (2021) 6G ecosystem: current status and future perspective. IEEE Access 10(6). https://doi.org/10.1109/access.2021.3054833

Rajatheva N et al (2020) White paper on broadband connectivity in 6G, pp 1–46

Google Scholar

Chataut R, Akl R (2020) Massive MIMO systems for 5G and beyond networks—overview, recent trends, challenges, and future research direction. Sensors (Switzerland) 20(10). https://doi.org/10.3390/s20102753

Hoang TM, Ngo HQ, Duong TQ, Tuan HD, Marshall A (2018) Cell-free massive MIMO networks: optimal power control against active eavesdropping. IEEE Trans Commun 66(10):4724–4737. https://doi.org/10.1109/TCOMM.2018.2837132

Article
Google Scholar

Bjornson E, Sanguinetti L (2019) A new look at cell-free massive MIMO: making it practical with dynamic cooperation. https://doi.org/10.1109/PIMRC.2019.8904101

Book
Google Scholar

Demir ÖT, Björnson E, Sanguinetti L (2021) Foundations of user-centric cell-free massive MIMO. Found Trends Signal Process 14(3–4). https://doi.org/10.1561/2000000109

Akyildiz IF, Han C, Nie S (2018) Combating the distance problem in the millimeter wave and terahertz frequency bands. IEEE Commun Mag 56(6):102–108. https://doi.org/10.1109/MCOM.2018.1700928

Article
Google Scholar

Sun J, Chang H, Gao X, Wang CX, Huang J (2020) Multi-frequency multi-scenario millimeter wave MIMO channel measurements and modeling for B5G wireless communication systems. IEEE J Sel Areas Commun 38(9):2010–2025

Article
Google Scholar

MacCartney GR, Rappaport TS (2019) Millimeter-wave base station diversity for 5G coordinated multipoint (CoMP) applications. IEEE Trans Wirel Commun 18(7):3395–3410. https://doi.org/10.1109/TWC.2019.2913414

Article
Google Scholar

Akyildiz IF, Jornet JM, Han C (2014) Terahertz band: next frontier for wireless communications. Phys Commun 12:16–32. https://doi.org/10.1016/j.phycom.2014.01.006

Article
Google Scholar

Petrov V, Pyattaev A, Moltchanov D, Koucheryavy Y (2016) Terahertz band communications: applications, research challenges, and standardization activities. Int Congr Ultra Mod Telecommun Control Syst Work 2016:183–190. https://doi.org/10.1109/ICUMT.2016.7765354

Article
Google Scholar

Chaccour C, Soorki MN, Saad W, Bennis M, Popovski P, Debbah M (2021) Seven defining features of terahertz (THz) wireless systems: a fellowship of communication and sensing. 1(4) Available: http://arxiv.org/abs/2102.07668

Nawaz SJ, Sharma SK, Wyne S, Patwary MN, Asaduzzaman M (2019) Quantum machine learning for 6G communication networks: state-of-the-art and vision for the future. IEEE Access 7(c):46317–46350. https://doi.org/10.1109/ACCESS.2019.2909490

Article
Google Scholar

Cacciapuoti AS, Caleffi M, Tafuri F, Cataliotti FS, Gherardini S, Bianchi G (2020) Quantum internet: networking challenges in distributed quantum computing. IEEE Netw 34(1):137–143. https://doi.org/10.1109/MNET.001.1900092

Article
Google Scholar

Wu Q, Zhang R (2020) Towards smart and reconfigurable environment: intelligent reflecting surface aided wireless network. IEEE Commun Mag 58(1):106–112. https://doi.org/10.1109/MCOM.001.1900107

Article
Google Scholar

Wu Q, Zhang R (2019) Intelligent reflecting surface enhanced wireless network via joint active and passive beamforming. IEEE Trans Wirel Commun 18(11):5394–5409. https://doi.org/10.1109/TWC.2019.2936025

Article
Google Scholar

Huang C, Zappone A, Alexandropoulos GC, Debbah M, Yuen C (2019) Reconfigurable intelligent surfaces for energy efficiency in wireless communication. IEEE Trans Wirel Commun 18(8):4157–4170. https://doi.org/10.1109/twc.2019.2922609

Article
Google Scholar

Tang W, Chen MZ, Chen X, Dai JY, Han Y, di Renzo M, Zeng Y, Jin S, Cheng Q, Cui TJ (2021) Wireless communications with reconfigurable intelligent surface: path loss modeling and experimental measurement. IEEE Trans Wirel Commun 20(1):421–439. https://doi.org/10.1109/TWC.2020.3024887

Article
Google Scholar

Ngo HQ, Ashikhmin A, Yang H, Larsson EG, Marzetta TL (2015) Cell-free massive MIMO: uniformly great service for everyone. https://doi.org/10.1109/SPAWC.2015.7227028

Book
Google Scholar

Interdonato G, Björnson E, Quoc Ngo H, Frenger P, Larsson EG (2019) Ubiquitous cell-free massive MIMO communications. EURASIP J Wirel Commun Netw 1(1):2019. https://doi.org/10.1186/s13638-019-1507-0

Article
Google Scholar

Buzzi S, D’andrea C, Zappone A, D’elia C (2020) User-centric 5G cellular networks: resource allocation and comparison with the cell-free massive MIMO approach. IEEE Trans Wirel Commun. https://doi.org/10.1109/TWC.2019.2952117

Ngo HQ, Tran LN, Duong TQ, Matthaiou M, Larsson EG (2017) Energy efficiency optimization for cell-free massive MIMO. https://doi.org/10.1109/SPAWC.2017.8227722

Book
Google Scholar

Zhu WP, Ajib W, Amarasuriya G, Kusaladharma S (2019) Achievable rate analysis of NOMA in cell-free massive MIMO: a stochastic geometry approach. https://doi.org/10.1109/ICC.2019.8761506

Book
Google Scholar

Lu L, Li GY, Swindlehurst AL, Ashikhmin A, Zhang R (2014) An overview of massive MIMO: benefits and challenges. IEEE J Selected Topics Signal Process 8(5):742–758. https://doi.org/10.1109/JSTSP.2014.2317671

Article
Google Scholar

Björnson E, Zakhour R, Gesbert D, Ottersten B (2010) Cooperative multicell precoding: rate region characterization and distributed strategies with instantaneous and statistical CSI. IEEE Trans Signal Process. https://doi.org/10.1109/TSP.2010.2049996

Nayebi E, Ashikhmin A, Marzetta TL, Yang H, Rao BD (2017) Precoding and power optimization in cell-free massive MIMO systems. IEEE Trans Wirel Commun. https://doi.org/10.1109/TWC.2017.2698449

Nayebi E, Ashikhmin A, Marzetta TL, Yang H (2016) Cell-free massive MIMO systems. https://doi.org/10.1109/ACSSC.2015.7421222

Book
Google Scholar

Boughaci D (2021) Solving optimization problems in the fifth generation of cellular networks by using meta-heuristics approaches. Proc Comput Sci 182. https://doi.org/10.1016/j.procs.2021.02.008

Hamdi R, Driouch E, Ajib W (2017) Energy management in hybrid energy large-scale MIMO systems. IEEE Trans Veh Technol 66(11). https://doi.org/10.1109/TVT.2017.2757401

Alamu O, Gbenga-Ilori A, Adelabu M, Imoize A, Ladipo O (2020) Energy efficiency techniques in ultra-dense wireless heterogeneous networks: an overview and outlook. Eng Sci Technol an Int J 23(6):1308–1326. https://doi.org/10.1016/j.jestch.2020.05.001

Article
Google Scholar

Hamdi R, Qaraqe M (2020) Power allocation and cooperation in cell-free massive MIMO systems with energy exchange capabilities. https://doi.org/10.1109/VTC2020-Spring48590.2020.9129410

Book
Google Scholar

Piovesan N, Fernandez Gambin A, Miozzo M, Rossi M, Dini P (2018) Energy sustainable paradigms and methods for future mobile networks: a survey. Comput Commun 119. https://doi.org/10.1016/j.comcom.2018.01.005

Mahapatra R, Nijsure Y, Kaddoum G, Ul Hassan N, Yuen C (2016) Energy efficiency tradeoff mechanism towards wireless green communication: a survey. IEEE Commun Surv Tutorials 18(1):686–705. https://doi.org/10.1109/COMST.2015.2490540

Article
Google Scholar

Zuo J, Zhang J, Yuen C, Jiang W, Luo W (2016) Energy efficient downlink transmission schemes for multi-cell massive distributed antenna systems. IEEE Vehicular Technol Conf 2016. https://doi.org/10.1109/VTCSpring.2016.7504221

Hamdi R, Qaraqe M (2019) Energy cooperation in renewable- powered cell-free massive MIMO systems. https://doi.org/10.1109/APCC47188.2019.9026523

Book
Google Scholar

Le QN, Nguyen VD, Dobre OA, Zhao R (2021) Energy efficiency maximization in RIS-aided cell-free network with limited backhaul. IEEE Commun Lett. https://doi.org/10.1109/LCOMM.2021.3062275

Li S, Duo B, Yuan X, Liang Y-C, Di Renzo M (2020) Reconfigurable intelligent surface assisted UAV communication: joint trajectory design and passive beamforming. IEEE Wirel Commun Lett 2337(c):1–720. https://doi.org/10.1109/lwc.2020.2966705

Article
Google Scholar

Amarasuriya G, Larsson EG, Poor HV (2016) Wireless information and power transfer in multiway massive MIMO relay networks. IEEE Trans Wirel Commun 15(6). https://doi.org/10.1109/TWC.2016.2530067

Varshney LR (2008) Transporting information and energy simultaneously. https://doi.org/10.1109/ISIT.2008.4595260

Book
Google Scholar

Ding Z et al (2015) Application of smart antenna technologies in simultaneous wireless information and power transfer. IEEE Commun. Mag 53(4). https://doi.org/10.1109/MCOM.2015.7081080

Xia X, Zhang D, Xu K, Ma W, Xu Y (2015) Hardware impairments aware transceiver for full-duplex massive MIMO relaying. IEEE Trans Signal Process. 63(24). https://doi.org/10.1109/TSP.2015.2469635

Zhang J, Wei Y, Bjornson E, Han Y, Jin S (2018) Performance analysis and power control of cell-free massive MIMO systems with hardware impairments. IEEE Access. https://doi.org/10.1109/ACCESS.2018.2872715

Zhang Y, Cao H, Zhou M, Li L, Yang L (2020) Power optimization in cell-free massive MIMO with non-ideal hardware transceiver. Chin J Electron 29(1). https://doi.org/10.1049/cje.2019.12.005

Zhang J, Dai L, He Z, Jin S, Li X (2017) Performance analysis of mixed-ADC massive MIMO systems over rician fading channels. IEEE J Sel Areas Commun 35(6). https://doi.org/10.1109/JSAC.2017.2687278

Zhang J, Dai L, Sun S, Wang Z (2016) On the spectral efficiency of massive MIMO systems with low-resolution ADCs. IEEE Commun Lett 20(5). https://doi.org/10.1109/LCOMM.2016.2535132

Alonzo M, Buzzi S, Zappone A, D’Elia C (2019) Energy-efficient power control in cell-free and user-centric massive MIMO at millimeter wave. https://doi.org/10.1109/TGCN.2019.2908228

Book
Google Scholar

Mai TC, Ngo HQ, Egan M, Duong TQ (2018) Pilot power control for cell-free massive MIMO. IEEE Trans Veh Technol. https://doi.org/10.1109/TVT.2018.2867606

Chen Z, Bjornson E (2018) Channel hardening and favorable propagation in cell-free massive MIMO with stochastic geometry. IEEE Trans Commun. https://doi.org/10.1109/TCOMM.2018.2846272

Mai TC, Quoc Ngo H, Duong TQ (2019) Cell-free massive MIMO systems with multi-antenna users. https://doi.org/10.1109/GlobalSIP.2018.8646330

Book
Google Scholar

Gkonis PK, Trakadas PT, Kaklamani DI (2020) A comprehensive study on simulation techniques for 5G networks: state of the art results, analysis, and future challenges. Electronics (Switzerland) 9(3). https://doi.org/10.3390/electronics9030468

Memon ML, Maheshwari MK, Saxena N, Roy A, Shin DR (2019) Artificial intelligence-based discontinuous reception for energy saving in 5G networks. Electron. 8(7). https://doi.org/10.3390/electronics8070778

Alkhateeb A, Alex S, Varkey P, Li Y, Qu Q, Tujkovic D (2018) Deep learning coordinated beamforming for highly-mobile millimeter wave systems. IEEE Access 6. https://doi.org/10.1109/ACCESS.2018.2850226

Lee W, Kim M, Cho DH (2018) Deep power control: transmit power control scheme based on convolutional neural network. IEEE Commun Lett 22(6). https://doi.org/10.1109/LCOMM.2018.2825444

Luo C, Ji J, Wang Q, Yu L, Li P (2018) Online power control for 5G wireless communications: a deep q-network approach. IEEE Int Conf Commun 2018. https://doi.org/10.1109/ICC.2018.8422442

Zhou P, Fang X, Wang X, Long Y, He R, Han X (2019) Deep learning-based beam management and interference coordination in dense mmWave networks. IEEE Trans Veh Technol 68(1). https://doi.org/10.1109/TVT.2018.2882635

Chen Z, Bjoernson E (2018) Can We Rely on Channel Hardening in Cell-Free Massive MIMO? https://doi.org/10.1109/GLOCOMW.2017.8269162

Book
Google Scholar

Ojo S, Imoize A, Alienyi D (2021) Radial basis function neural network path loss prediction model for LTE networks in multitransmitter signal propagation environments. Int J Commun Syst 34(e4680):1–26. https://doi.org/10.1002/dac.4680

Article
Google Scholar

Polegre AA, Riera-Palou F, Femenias G, Armada AG (2020) New insights on channel hardening in cell-free massive MIMO networks. https://doi.org/10.1109/ICCWorkshops49005.2020.9145215

Book
Google Scholar

Tu LT, Di Renzo M (2017) Analysis of millimeter wave cellular networks with simultaneous wireless information and power transfer. https://doi.org/10.1109/SIGTELCOM.2017.7849792

Book
Google Scholar

Liao Y, Zhang J, Zhang Y, Chen M, Li Q, Han T (2016) Performance analysis of K-tier cellular networks with time-switching energy harvesting. https://doi.org/10.1109/PIMRC.2016.7794611

Book
Google Scholar

Di Renzo M, Lu W (2017) System-level analysis and optimization of cellular networks with simultaneous wireless information and power transfer: stochastic geometry modeling. IEEE Trans Veh Technol. https://doi.org/10.1109/TVT.2016.2574811

Shrestha R, Amarasuriya G (2018) SWIPT in cell-free massive MIMO. https://doi.org/10.1109/GLOCOM.2018.8648129

Book
Google Scholar

Kusaladharma S, Zhu WP, Ajib W, Amarasuriya G (2020) Performance of SWIPT in cell-free massive MIMO: a stochastic geometry based perspective. https://doi.org/10.1109/CCNC46108.2020.9045726

Book
Google Scholar

Liu A, Lau VKN (2017) Joint BS-user association, power allocation, and user-side interference cancellation in cell-free heterogeneous networks. IEEE Trans Signal Process. https://doi.org/10.1109/TSP.2016.2620962

Interdonato G, Frenger P, Larsson EG (2019) Scalability aspects of cell-free massive MIMO. https://doi.org/10.1109/ICC.2019.8761828

Book
Google Scholar

Li T, Sahu AK, Talwalkar A, Smith V (2020) Federated learning: challenges, methods, and future directions. IEEE Signal Process Mag. https://doi.org/10.1109/MSP.2020.2975749

Brendan McMahan H, Moore E, Ramage D, Hampson S, Agüera y Arcas B (2017) Communication-efficient learning of deep networks from decentralized data

Google Scholar

Tran NH, Bao W, Zomaya A, Nguyen MNH, Hong CS (2019) Federated learning over wireless networks: optimization model design and analysis. https://doi.org/10.1109/INFOCOM.2019.8737464

Book
Google Scholar

Wang S, Tuor T, Salonidis T, Leung KK, Makaya C, He T, Chan K (2019) Adaptive federated learning in resource constrained edge computing systems. IEEE J Sel Areas Commun 37(6):1205–1221. https://doi.org/10.1109/JSAC.2019.2904348

Article
Google Scholar

Yang K, Jiang T, Shi Y, Ding Z (2020) Federated learning via over-the-air computation. IEEE Trans Wirel Commun. https://doi.org/10.1109/TWC.2019.2961673

Zhang X, Guo D, An K, Zhang B (2020) Secure communications over cell-free massive MIMO networks with hardware impairments. IEEE Syst J. https://doi.org/10.1109/JSYST.2019.2919584

Yang H, Marzetta TL (2018) Energy efficiency of massive MIMO: cell-free vs. cellular. https://doi.org/10.1109/VTCSpring.2018.8417645

Book
Google Scholar

Bashar M, Cumanan K, Burr AG, Ngo HQ, Debbah M, Xiao P (2019) Max-min rate of cell-free massive MIMO uplink with optimal uniform quantization. IEEE Trans Commun 67(10). https://doi.org/10.1109/TCOMM.2019.2926706

Mai TC, Ngo HQ, Duong TQ (2019) Uplink spectral efficiency of cell-free massive MIMO with multi-antenna users. https://doi.org/10.1109/SIGTELCOM.2019.8696221

Book
Google Scholar

D’Andrea C, Zappone A, Buzzi S, Debbah M (2019) Uplink power control in cell-free massive MIMO via deep learning. https://doi.org/10.1109/CAMSAP45676.2019.9022520

Book
Google Scholar

Ajani TS, Imoize AL, Atayero AA (2020) An overview of machine learning within embedded and mobile devices – optimizations and applications, pp 1–44

Google Scholar

Ngo HQ, Tran LN, Duong TQ, Matthaiou M, Larsson EG (2018) On the total energy efficiency of cell-free massive MIMO. https://doi.org/10.1109/TGCN.2017.2770215

Book
Google Scholar

Zhang Y, Zhou M, Cheng Y, Yang L, Zhu H (2020) RF impairments and low-resolution ADCs for nonideal uplink cell-free massive MIMO systems. IEEE Syst J. https://doi.org/10.1109/JSYST.2020.2990709

Fan W, Zhang J, Bjornson E, Chen S, Zhong Z (2019) Performance analysis of cell-free massive MIMO over spatially correlated fading channels. https://doi.org/10.1109/ICC.2019.8762051

Book
Google Scholar

Interdonato G, Ngo HQ, Larsson EG, Frenger P (2016) On the performance of cell-free massive MIMO with short-term power constraints. https://doi.org/10.1109/CAMAD.2016.7790362

Book
Google Scholar

Li Y, Aruma Baduge GA (2018) NOMA-aided cell-free massive MIMO systems. IEEE Wirel Commun Lett. https://doi.org/10.1109/LWC.2018.2841375

Bashar M, Cumanan K, Burr AG, Ngo HQ, Larsson EG, Xiao P (2019) On the energy efficiency of limited-backhaul cell-free massive MIMO. https://doi.org/10.1109/ICC.2019.8761134

Book
Google Scholar

Imoize AL, Ibhaze AE, Atayero AA, Kavitha KVN (2021) Standard propagation channel models for MIMO communication systems. Wirel Commun Mob Comput 2021(8838792):36. https://doi.org/10.1155/2021/8838792

Article
Google Scholar

Ogbebor JO, Imoize AL, Atayero AA-A (2020) Energy efficient design techniques in next-generation wireless communication networks: emerging trends and future directions. Wirel Commun Mob Comput 2020(7235362):19. https://doi.org/10.1155/2020/7235362

Article
Google Scholar

Marzetta TL, Larsson EG, Yang H, Ngo HQ (2016) Fundamentals of massive MIMO. Cambridge: Cambridge University Press. https://doi.org/10.1017/CBO9781316799895

Björnson E, Hoydis J, Sanguinetti L (2017) Massive MIMO networks: spectral, energy, and hardware efficiency. Foundations Trends in Signal Process 11(3–4) Now Publishers Inc:154–655. https://doi.org/10.1561/2000000093

Article
Google Scholar

Larsson EG, Edfors O, Tufvesson F, Marzetta TL (2014) Massive MIMO for next generation wireless systems. IEEE Commun Mag 52(2):186–195. https://doi.org/10.1109/MCOM.2014.6736761

Article
Google Scholar

Marzetta TL (2010) Noncooperative cellular wireless with unlimited numbers of base station antennas. IEEE Trans Wirel Commun. https://doi.org/10.1109/TWC.2010.092810.091092

Ngo HQ, Larsson EG, Marzetta TL (2013) Energy and spectral efficiency of very large multiuser MIMO systems. IEEE Trans Commun 61(4):1436–1449. https://doi.org/10.1109/TCOMM.2013.020413.110848

Article
Google Scholar

Rusek F, Persson D, Buon Kiong Lau, Larsson EG, Marzetta TL, Tufvesson F (2013) Scaling up MIMO : opportunities and challenges with very large arrays. IEEE Signal Process Mag 30(1):40–60. https://doi.org/10.1109/MSP.2011.2178495

Article
Google Scholar

Truong KT, Heath RW (2013) The viability of distributed antennas for massive MIMO systems. https://doi.org/10.1109/ACSSC.2013.6810508

Book
Google Scholar

Venkatesan S, Lozano A, Valenzuela R (2007) Network MIMO: overcoming intercell interference in indoor wireless systems. https://doi.org/10.1109/ACSSC.2007.4487170

Book
Google Scholar

Gesbert D, Hanly S, Huang H, Shamai Shitz S, Simeone O, Yu W (2010) Multi-cell MIMO cooperative networks: a new look at interference. IEEE J Sel Areas Commun. https://doi.org/10.1109/JSAC.2010.101202

Zhang J, Dai L, Li X, Liu Y, Hanzo L (2018) On low-resolution ADCs in practical 5G millimeter-wave massive MIMO systems. IEEE Commun Mag 56(7). https://doi.org/10.1109/MCOM.2018.1600731

Björnson E, Larsson EG, Debbah M (2016) Massive MIMO for maximal spectral efficiency: how many users and pilots should be allocated? https://doi.org/10.1109/TWC.2015.2488634

Book
Google Scholar

Yang H, Marzetta TL (2013) Total energy efficiency of cellular large scale antenna system multiple access mobile networks. https://doi.org/10.1109/OnlineGreenCom.2013.6731024

Book
Google Scholar

Zhang J, Chen S, Lin Y, Zheng J, Ai B, Hanzo L (2019) Cell-free massive MIMO: a new next-generation paradigm. IEEE Access. https://doi.org/10.1109/access.2019.2930208

Bjornson E, Sanguinetti L (2020) Making cell-free massive MIMO competitive with MMSE processing and centralized implementation. IEEE Trans Wirel Commun. https://doi.org/10.1109/TWC.2019.2941478

Dai L, Wang B, Ding Z, Wang Z, Chen S, Hanzo L (2018) A survey of non-orthogonal multiple access for 5G. IEEE Commun Surv Tutorials 20(3):2294–2323. https://doi.org/10.1109/COMST.2018.2835558

Article
Google Scholar

Yang K, Yang N, Ye N, Jia M, Gao Z, Fan R (2019) Non-orthogonal multiple access: achieving sustainable future radio access. IEEE Commun Mag. https://doi.org/10.1109/MCOM.2018.1800179

An J, Yang K, Wu J, Ye N, Guo S, Liao Z (2017) Achieving sustainable ultra-dense heterogeneous networks for 5G. IEEE Commun Mag 55(12). https://doi.org/10.1109/MCOM.2017.1700410

Zhang Z, Sun H, Hu RQ, Qian Y (2016) Stochastic geometry based performance study on 5G non-orthogonal multiple access scheme. https://doi.org/10.1109/GLOCOM.2016.7842300

Book
Google Scholar

Saito Y, Kishiyama Y, Benjebbour A, Nakamura T, Li A, Higuchi K (2013) Non-orthogonal multiple access (NOMA) for cellular future radio access. https://doi.org/10.1109/VTCSpring.2013.6692652

Book
Google Scholar

Sun Q, Han S, Chin-Lin I, Pan Z (2015) On the ergodic capacity of MIMO NOMA systems. IEEE Wirel Commun Lett 4(4). https://doi.org/10.1109/LWC.2015.2426709

Burr A, Bashar M, Maryopi D (2018) Ultra-dense radio access networks for smart cities: cloud-RAN, fog-RAN and ‘cell-free’ massive MIMO. arXiv

Gustavsson U et al (2014) On the impact of hardware impairments on massive MIMO. https://doi.org/10.1109/GLOCOMW.2014.7063447

Book
Google Scholar

Bacha MN, Evans JS, Hanly SV (2006) On the capacity of MIMO cellular networks with macrodiversity. https://doi.org/10.1109/ausctw.2006.1625264

Book
MATH
Google Scholar

Xiang Z, Tao M, Wang X (2014) Massive MIMO multicasting in noncooperative cellular networks. IEEE J Sel Areas Commun. https://doi.org/10.1109/JSAC.2014.2328144

Ngo HQ, Larsson EG, Marzetta TL (2014) Aspects of favorable propagation in massive MIMO. https://doi.org/10.5281/zenodo.43970

Book
Google Scholar

Liu P, Luo K, Chen D, Jiang T (2020) Spectral efficiency analysis of cell-free massive MIMO systems with zero-forcing detector. IEEE Trans Wirel Commun. https://doi.org/10.1109/TWC.2019.2948841

Huh H, Caire G, Papadopoulos HC, Ramprashad SA (2012) Achieving ‘massive MIMO’ spectral efficiency with a not-so-large number of antennas. IEEE Trans Wirel Commun. https://doi.org/10.1109/TWC.2012.070912.111383

Imoize AL, Orolu K, Atayero AA-A (2020) Analysis of key performance indicators of a 4G LTE network based on experimental data obtained from a densely populated smart city. Data Br 29(105304):1–17. https://doi.org/10.1016/j.dib.2020.105304

Article
Google Scholar

Shuaifei Chen BA, Zhang J, Zhang J, Björnson E (2021) A survey on user-centric cell-free massive MIMO systems

Google Scholar

Kumar S, Chandrasekaran G, Kalyani S (2015) Analysis of outage probability and capacity for κ-μ/η-μ faded channel. IEEE Commun Lett 19(2). https://doi.org/10.1109/LCOMM.2014.2371051

Beiranvand J, Meghdadi H (2018) Analytical performance evaluation of MRC receivers in massive MIMO systems. IEEE Access 6. https://doi.org/10.1109/ACCESS.2018.2866795

Atapattu S, Dharmawansa P, Tellambura C, Evans J (2017) Exact outage analysis of multiple-user downlink with MIMO matched-filter precoding. IEEE Commun Lett 21(12). https://doi.org/10.1109/LCOMM.2017.2749302

Interdonato G, Ngo HQ, Larsson EG, Frenger P (2016) How much do downlink pilots improve cell-free massive MIMO? https://doi.org/10.1109/GLOCOM.2016.7841875

Book
Google Scholar

Elhoushy S, Hamouda W (2020) Performance of distributed massive MIMO and small-cell systems under hardware and channel impairments. IEEE Trans Veh Technol. https://doi.org/10.1109/TVT.2020.2998405

Francis J, Baracca P, Wesemann S, Fettweis G (2019) Downlink power control in cell-free massive MIMO with partially distributed access points. https://doi.org/10.1109/VTCFall.2019.8891216

Book
Google Scholar

Vu TT, Ngo DT, Tran NH, Ngo HQ, Dao MN, Middleton RH (2020) Cell-free massive MIMO for wireless federated learning. IEEE Trans Wirel Commun. https://doi.org/10.1109/TWC.2020.3002988

Vu TT, Ngo DT, Ngo HQ, Le-Ngoc T (2019) Full-duplex cell-free massive MIMO. https://doi.org/10.1109/ICC.2019.8761711

Book
Google Scholar

Rezaei F, Tellambura C, Tadaion AA, Heidarpour AR (2020) Rate analysis of cell-free massive MIMO-NOMA with three linear precoders. IEEE Trans Commun. https://doi.org/10.1109/TCOMM.2020.2978189

Nguyen TK, Nguyen HH, Tuan HD (2020) Max-min QoS power control in generalized cell-free massive MIMO-NOMA with optimal backhaul combining. IEEE Trans Veh Technol. https://doi.org/10.1109/TVT.2020.3006054

Galappaththige DL, Amarasuriya G (2020) NOMA-aided cell-free massive MIMO with underlay spectrum-sharing. https://doi.org/10.1109/ICC40277.2020.9149105

Book
Google Scholar

Bashar M et al (2020) Uplink spectral and energy efficiency of cell-free massive MIMO with optimal uniform quantization. IEEE Trans Commun. https://doi.org/10.1109/tcomm.2020.3028305

Van Chien T, Bjornson E, Larsson EG (2020) Optimal design of energy-efficient cell-free massive MIMO: joint power allocation and load balancing. https://doi.org/10.1109/ICASSP40776.2020.9054083

Book
Google Scholar

Interdonato G, Ngo HQ, Larsson EG (2021) Enhanced normalized conjugate beamforming for cell-free massive MIMO. IEEE Trans Commun. https://doi.org/10.1109/TCOMM.2021.3055522

Masoumi H, Emadi MJ (2020) Performance analysis of cell-free massive MIMO system with limited fronthaul capacity and hardware impairments. IEEE Trans Wirel Commun. https://doi.org/10.1109/TWC.2019.2950316

Zheng J, Zhang J, Zhang L, Zhang X, Ai B (2020) Efficient receiver design for uplink cell-free massive MIMO with hardware impairments. IEEE Trans Veh Technol. https://doi.org/10.1109/TVT.2020.2975354

Verenzuela D, Bjornson E, Matthaiou M (2021) Optimal per-antenna ADC bit allocation in correlated and cell-free massive MIMO. IEEE Trans Commun. https://doi.org/10.1109/TCOMM.2021.3067699

Zhang J, Wei Y, Bjornson E, Han Y, Li X (2017) Spectral and energy efficiency of cell-free massive MIMO systems with hardware impairments. In: 2017 9th International Conference on Wireless Communications and Signal Processing, WCSP 2017 - Proceedings, 2017. https://doi.org/10.1109/WCSP.2017.8171057

Chapter
Google Scholar

Chakraborty S, Bjornson E, Sanguinetti L (2019) Centralized and distributed power allocation for max-min fairness in cell-free massive MIMO. https://doi.org/10.1109/IEEECONF44664.2019.9048903

Book
Google Scholar

Nuwanthika Rajapaksha ML, Shashika Manosha KB, Rajatheva N (2021) Deep learning-based power control for cell-free massive MIMO networks. Cent Wirel Commun Univ Oulu Finl

Palhares VMT, Flores A, De Lamare RC (2021) Robust MMSE precoding and power allocation for cell-free massive MIMO systems. IEEE Trans Veh Technol. https://doi.org/10.1109/tvt.2021.3072828

Bashar M, Cumanan K, Burr AG, Ngo HQ, Poor HV (2018) Mixed quality of service in cell-free massive MIMO. IEEE Commun Lett 22(7). https://doi.org/10.1109/LCOMM.2018.2825428

Buzzi S, Zappone A (2018) Downlink power control in user-centric and cell-free massive MIMO wireless networks. In: IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC, vol 2017. https://doi.org/10.1109/PIMRC.2017.8292293

Chapter
Google Scholar

Demir ÖT, Björnson E (2021) Joint power control and LSFD for wireless-powered cell-free massive MIMO. IEEE Trans Wirel Commun 20(3). https://doi.org/10.1109/TWC.2020.3036281

Bashar M, Cumanan K, Burr AG, Debbah M, Ngo HQ (2018) Enhanced max-min SINR for uplink cell-free massive MIMO systems. arXiv. p. 1-6. https://doi.org/10.1109/ICC.2018.8422577.

Bashar M, Cumanan K, Burr AG, Debbah M, Ngo HQ (2019) On the uplink max-min SINR of cell-free massive MIMO systems. IEEE Trans Wirel Commun 18(4). https://doi.org/10.1109/TWC.2019.2892463

Zhang Y, Cao H, Yang L (2019) Max-min power optimization in multigroup multicast cell-free massive MIMO. IEEE Wirel Commun Networking Conf 2019. https://doi.org/10.1109/WCNC.2019.8885776

Zhou A, Wu J, Larsson EG, Fan P (2020) Max-min optimal beamforming for cell-free massive MIMO. IEEE Commun Lett 24(10). https://doi.org/10.1109/LCOMM.2020.3000067

Nikbakht R, Jonsson A, Lozano A (2019) Unsupervised-learning power control for cell-free wireless systems. In: IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC, 2019. https://doi.org/10.1109/PIMRC.2019.8904394

Chapter
Google Scholar

Zhao Y, Niemegeers IG, De Groot SH (2020) Power allocation in cell-free massive MIMO: a deep learning method. IEEE Access 8. https://doi.org/10.1109/ACCESS.2020.2992629

Nguyen LD, Duong TQ, Ngo HQ, Tourki K (2017) Energy efficiency in cell-free massive MIMO with zero-forcing precoding design. IEEE Commun Lett 21(8). https://doi.org/10.1109/LCOMM.2017.2694431

Bashar M, Cumanan K, Burr AG, Ngo HQ, Larsson EG, Xiao P (2019) Energy efficiency of the cell-free massive MIMO uplink with optimal uniform quantization. IEEE Trans Green Commun Netw 3(4). https://doi.org/10.1109/TGCN.2019.2932071

Nikbakht R, Lozano A (2019) Uplink fractional power control for cell-free wireless networks. IEEE Int Conf Commun 2019. https://doi.org/10.1109/ICC.2019.8761096

Papazafeiropoulos AK, Bjornson E, Kourtessis P, Chatzinotas S, Senior JM (2020) Scalable cell-free massive MIMO systems with hardware impairments. https://doi.org/10.1109/PIMRC48278.2020.9217151

Book
Google Scholar

Chen S, Zhang J, Bjornson E, Zhang J, Ai B (2021) Structured massive access for scalable cell-free massive MIMO systems. IEEE J Sel Areas Commun 39(4). https://doi.org/10.1109/JSAC.2020.3018836

Tripathi SC, Trivedi A, Rajoria S (2018) Power optimization of cell free massive MIMO with zero-forcing beamforming technique. https://doi.org/10.1109/INFOCOMTECH.2018.8722368

Book
Google Scholar

Nguyen TH, Nguyen TK, Han HD, Nguyen VD (2018) Optimal power control and load balancing for uplink cell-free multi-user massive MIMO. IEEE Access 6. https://doi.org/10.1109/ACCESS.2018.2797874

Zhang Y, Cao H, Guo Y, Yang L (2018) SCA power optimization in cell-free massive MIMO with short-term power constraints. https://doi.org/10.1109/WCSP.2018.8555614

Book
Google Scholar

Bashar M et al (2020) Exploiting deep learning in limited-fronthaul cell-free massive MIMO uplink. IEEE J Sel Areas Commun 38(8). https://doi.org/10.1109/JSAC.2020.3000812

Liang F, Shen C, Yu W, Wu F (2020) Towards optimal power control via ensembling deep neural networks. IEEE Trans Commun 68(3). https://doi.org/10.1109/TCOMM.2019.2957482

Bashar M, Cumanan K, Burr AG, Ngo HQ, Hanzo L, Xiao P (2019) NOMA/OMA mode selection-based cell-free massive MIMO. https://doi.org/10.1109/ICC.2019.8761072

Book
Google Scholar

Rezaei F, Heidarpour AR, Tellambura C, Tadaion A (2020) Underlaid spectrum sharing for cell-free massive MIMO-NOMA. IEEE Commun Lett. https://doi.org/10.1109/LCOMM.2020.2966195

Ashikhmin A, Li L, Marzetta TL (2018) Interference reduction in multi-cell massive MIMO systems with large-scale fading precoding. IEEE Trans Inf Theory 64(9). https://doi.org/10.1109/TIT.2018.2853733

GÜL BK, TAŞPINAR N (2021) Application of intelligent optimization techniques to spectral and energy efficiencies in massive MIMO systems at different circuit power levels. Mühendislik Bilim ve Araştırmaları Derg 3(1):102–111. https://doi.org/10.46387/bjesr.893643

Article
Google Scholar

Jin SN, Yue DW, Nguyen HH (2021) Spectral efficiency of a frequency-selective cell-free massive MIMO system with phase noise. IEEE Wirel Commun Lett 10(3). https://doi.org/10.1109/LWC.2020.3035364

Wang X, Zhou M, Qiao X, Zhang Y, Ruan X, Yang L (2019) Energy efficiency of downlink cell-free massive MIMO system with full-pilot zero-forcing. https://doi.org/10.1109/ICCC47050.2019.9064337

Book
Google Scholar

Zhang Y, Cao H, Zhou M, Yang L (2019) Power optimization for energy efficiency in cell-free massive MIMO with ZF receiver. https://doi.org/10.23919/ICACT.2019.8702035

Book
Google Scholar

Wang Z, Lin Z, Lv T, Ni W (2021) Energy-efficient resource allocation in massive MIMO-NOMA networks with wireless power transfer: a distributed ADMM approach. IEEE Internet Things J. https://doi.org/10.1109/JIOT.2021.3068721

Björnson E, Sanguinetti L, Hoydis J, Debbah M (2015) Optimal design of energy-efficient multi-user MIMO systems: is massive MIMO the answer? 14(IEEE Trans. Wirel. Commun, 6). https://doi.org/10.1109/TWC.2015.2400437

Falconetti L, Yassin E (2014) Towards energy efficiency with uplink cooperation in heterogeneous networks. https://doi.org/10.1109/WCNC.2014.6952477

Book
Google Scholar

Fehske AJ, Marsch P, Fettweis GP (2010) Bit per joule efficiency of cooperating base stations in cellular networks. https://doi.org/10.1109/GLOCOMW.2010.5700169

Book
Google Scholar

Bjornson E, Hoydis J, Kountouris M, Debbah M (2014) Massive MIMO systems with non-ideal hardware: energy efficiency, estimation, and capacity limits. IEEE Trans Inf Theory 60(11):7112–7139. https://doi.org/10.1109/TIT.2014.2354403

Article
MathSciNet
MATH
Google Scholar

Hassan K, Masarra M, Zwingelstein M, Dayoub I (2020) Channel estimation techniques for millimeter-wave communication systems: achievements and challenges. IEEE Open J Commun Soc 1. https://doi.org/10.1109/ojcoms.2020.3015394

Ke M, Gao Z, Wu Y, Gao X, Schober R (2020) Compressive sensing-based adaptive active user detection and channel estimation: massive access meets massive MIMO. IEEE Trans Signal Process 68. https://doi.org/10.1109/TSP.2020.2967175

Mei K, Liu J, Zhang X, Wei J (2019) Machine learning based channel estimation: a computational approach for universal channel conditions

Google Scholar

Chun CJ, Kang JM, Kim IM (2019) Deep learning-based channel estimation for massive MIMO systems. IEEE Wirel Commun Lett 8(4). https://doi.org/10.1109/LWC.2019.2912378

Waseem A, Naveed A, Ali S, Arshad M, Anis H, Qureshi IM (2019) Compressive sensing based channel estimation for massive mimo communication systems. Wirel Commun Mob Comput 2019:15. https://doi.org/10.1155/2019/6374764

Article
Google Scholar

Wang M, Zhu T, Zhang T, Zhang J, Yu S, Zhou W (2020) Security and privacy in 6G networks: new areas and new challenges. Digit Commun Networks 6(3). https://doi.org/10.1016/j.dcan.2020.07.003

Albreem MA, Juntti M, Shahabuddin S (2019) Massive MIMO detection techniques: a survey. IEEE Commun Surv Tutorials 21(4):3109–3132. https://doi.org/10.1109/COMST.2019.2935810

Article
Google Scholar

Jeon YS, Lee N, Hong SN, Heath RW (2018) One-bit sphere decoding for uplink massive MIMO systems with one-bit ADCs. IEEE Trans Wirel Commun 17(7). https://doi.org/10.1109/TWC.2018.2827028

Elghariani A, Zoltowski M (2015) Successive interference cancellation for large-scale MIMO OFDM. IEEE Int Conf Electro Inform Techn 2015. https://doi.org/10.1109/EIT.2015.7293412

Akbar N, Yan S, Yang N, Yuan J (2018) Location-aware pilot allocation in multicell multiuser massive MIMO networks. IEEE Trans Veh Technol. https://doi.org/10.1109/TVT.2018.2831224

Liu H, Zhang J, Zhang X, Kurniawan A, Juhana T, Ai B (2020) Tabu-search-based pilot assignment for cell-free massive MIMO systems. IEEE Trans Veh Technol. https://doi.org/10.1109/TVT.2019.2956217

Liu H, Zhang J, Jin S, Ai B (2020) Graph coloring based pilot assignment for cell-free massive MIMO systems. IEEE Trans Veh Technol. https://doi.org/10.1109/TVT.2020.3000496

You X et al (2021) Towards 6G wireless communication networks: vision, enabling technologies, and new paradigm shifts. Sci China Inform Sci 64(1). https://doi.org/10.1007/s11432-020-2955-6