{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,7]],"date-time":"2026-04-07T16:19:31Z","timestamp":1775578771308,"version":"3.50.1"},"reference-count":81,"publisher":"Institute of Electrical and Electronics Engineers (IEEE)","issue":"10","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IEICE Trans. Commun."],"published-print":{"date-parts":[[2022,10,1]]},"DOI":"10.1587\/transcom.2021mei0001","type":"journal-article","created":{"date-parts":[[2022,4,27]],"date-time":"2022-04-27T22:09:57Z","timestamp":1651097397000},"page":"1107-1116","source":"Crossref","is-referenced-by-count":18,"title":["A Survey on Research Activities for Deploying Cell Free Massive MIMO towards Beyond 5G"],"prefix":"10.23919","volume":"E105.B","author":[{"given":"Issei","family":"KANNO","sequence":"first","affiliation":[{"name":"KDDI Research Inc."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kosuke","family":"YAMAZAKI","sequence":"additional","affiliation":[{"name":"KDDI Research Inc."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yoji","family":"KISHI","sequence":"additional","affiliation":[{"name":"KDDI Research Inc."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Satoshi","family":"KONISHI","sequence":"additional","affiliation":[{"name":"KDDI Research Inc."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"263","reference":[{"key":"1","unstructured":"[1] Hexa-X, https:\/\/hexa-x.eu\/"},{"key":"2","unstructured":"[2] Next-G-Alliance, https:\/\/nextgalliance.org\/"},{"key":"3","unstructured":"[3] 6G flagship, https:\/\/www.oulu.fi\/6gflagship\/"},{"key":"4","unstructured":"[4] ITU-T Focus Group on Technologies for Network 2030, https:\/\/www.itu.int\/en\/ITU-T\/focusgroups\/net2030\/Pages\/default.aspx"},{"key":"5","doi-asserted-by":"publisher","unstructured":"[5] H.Q. Ngo, A. Ashikhmin, H. Yang, E.G. Larsson, and T.L. Marzetta, \u201cCell-free massive MIMO versus small cells,\u201d IEEE Trans. Wireless Commun., vol.16, no.3, pp.1834-1850, March 2017. 10.1109\/twc.2017.2655515","DOI":"10.1109\/TWC.2017.2655515"},{"key":"6","doi-asserted-by":"publisher","unstructured":"[6] I.K. Jain, R. Kumar, and S.S. Panwar, \u201cThe Impact of mobile blockers on millimeter wave cellular systems,\u201d IEEE J. Sel. Areas Commun., vol.37, no.4, pp.854-868, April 2019. 10.1109\/jsac.2019.2898756","DOI":"10.1109\/JSAC.2019.2898756"},{"key":"7","doi-asserted-by":"publisher","unstructured":"[7] T.S. Rappaport, Y. Xing, G.R. MacCartney, A.F. Molisch, E. Mellios, and J. Zhang, \u201cOverview of millimeter wave communications for fifth-generation (5G) wireless networks with a focus on propagation models,\u201d IEEE Trans. Antennas Propag., vol.65, no.12, pp.6213-6230, Dec. 2017. 10.1109\/tap.2017.2734243","DOI":"10.1109\/TAP.2017.2734243"},{"key":"8","doi-asserted-by":"publisher","unstructured":"[8] J. Zhang, S. Chen, Y. Lin, J. Zheng, B. Ai, and L. Hanzo, \u201cCell-free massive MIMO: A new next-generation paradigm,\u201d IEEE Access, vol.7, pp.99878-99888, 2019. 10.1109\/access.2019.2930208","DOI":"10.1109\/ACCESS.2019.2930208"},{"key":"9","doi-asserted-by":"publisher","unstructured":"[9] J. Zhang, E. Bj\u00f6rnson, M. Matthaiou, D.W. Kwang, H. Yang, and D.J. Love, \u201cProspective multiple antenna technologies for beyond 5G,\u201d IEEE J. Sel. Areas Commun., vol.38, no.8, pp.1637-1660, Aug. 2020. 10.1109\/jsac.2020.3000826","DOI":"10.1109\/JSAC.2020.3000826"},{"key":"10","doi-asserted-by":"crossref","unstructured":"[10] H.Q. Ngo, A. Ashikhmin, H. Yang, E.G. Larsson, and T.L. Marzetta, \u201cCell-free massive MIMO: Uniformly great service for everyone,\u201d Proc. IEEE SPAWC 2015, June 2015. 10.1109\/SPAWC.2015.7227028","DOI":"10.1109\/SPAWC.2015.7227028"},{"key":"11","unstructured":"[11] KDDI, KDDI Research Inc., \u201cBeyond 5G\/6G white paper ver. 2.0,\u201d http:\/\/www.kddi-research.jp\/english\/tech\/whitepaper_b5g_6g\/assets\/pdf\/KDDI_B5G6G_WhitePaperEN_2.0_rev2.pdf, Oct. 2021."},{"key":"12","doi-asserted-by":"publisher","unstructured":"[12] O.T. Demir, E. Bj\u00f6rnson, and L. Sanguinetti, \u201cFoundations of user-centric cell-free massive MIMO,\u201d Foundations and Trends\u00ae in Signal Processing, vol.14, no.3-4, pp.162-472, 2021. 10.1561\/2000000109","DOI":"10.1561\/2000000109"},{"key":"13","doi-asserted-by":"publisher","unstructured":"[13] S. Elhoushy, M. Ibrahim, and W. Hamouda, \u201cCell-free massive MIMO: A survey,\u201d IEEE Commun. Surveys Tuts., vol.24, no.1, pp.492-523, Oct. 2021. 10.1109\/comst.2021.3123267","DOI":"10.1109\/COMST.2021.3123267"},{"key":"14","doi-asserted-by":"crossref","unstructured":"[14] S. Kumagai, T. Kobayashi, T. Oyama, C. Akiyama, M. Tsutsui, D. Jitsukawa, T. Seyama, T. Dateki, H. Seki, M. Minowa, T. Okuyama, J. Mashino, S. Suyama, and Y. Okumura, \u201cExperimental trials of 5G ultra high-density distributed antenna systems,\u201d Proc. VTC fall 2019, Sept. 2019. 10.1109\/vtcfall.2019.8891604","DOI":"10.1109\/VTCFall.2019.8891604"},{"key":"15","unstructured":"[15] NEC, \u201cNEC millimeter-wave distributed-MIMO technique triples the number of simultaneous connections and transmission capacity in a real office setting,\u201d Jan. 2021. (Press Release) https:\/\/www.nec.com\/en\/press\/202101\/global_20210125_01.html"},{"key":"16","unstructured":"[16] Huawei, \u201cHuawei&apos;s 5G indoor distributed massive MIMO \u2014 \u201cBest solution case\u201d by ICT China 2021,\u201d Sept. 2021. (Press Release) https:\/\/www.huawei.com\/en\/news\/2021\/9\/ubiquitous-gigabit-5g-indoor-dmm-wins-award"},{"key":"17","unstructured":"[17] 3GPP TR 38.801, \u201cStudy on new radio access technology; radio access architecture and interfaces,\u201d V2.0.0, 2017."},{"key":"18","doi-asserted-by":"publisher","unstructured":"[18] T.L. Marzetta, \u201cNoncooperative cellular wireless with unlimited numbers of base station antennas,\u201d IEEE Trans. Wireless Commun., vol.9, no.11, pp.3590-3600, Nov. 2010. 10.1109\/twc.2010.092810.091092","DOI":"10.1109\/TWC.2010.092810.091092"},{"key":"19","doi-asserted-by":"publisher","unstructured":"[19] E.G. Larsson, O. Edfors, and T.L. Marzetta, \u201cMassive MIMO for next generation wireless systems,\u201d IEEE Commun. Mag., pp.186-195, Feb. 2014. 10.1109\/mcom.2014.6736761","DOI":"10.1109\/MCOM.2014.6736761"},{"key":"20","doi-asserted-by":"publisher","unstructured":"[20] F. Rusek, D. Persson, B. Lau, E. Larsson, T. Marzetta, O. Edfors, and F. Tufvesson, \u201cScaling up MIMO: Opportunities and challenges with very large arrays,\u201d IEEE Signal Process. Mag., vol.30, no.1, pp.40-60, Jan. 2013. 10.1109\/msp.2011.2178495","DOI":"10.1109\/MSP.2011.2178495"},{"key":"21","doi-asserted-by":"crossref","unstructured":"[21] E. Nayebi, A. Ashikhmin, T.L. Marzetta, and H. Yang, \u201cCell-free massive MIMO systems,\u201d Proc. 49th Asilomar Conf. Signals, Syst. Comput., Nov. 2015. 10.1109\/acssc.2015.7421222","DOI":"10.1109\/ACSSC.2015.7421222"},{"key":"22","doi-asserted-by":"publisher","unstructured":"[22] Y. Zhang, H. Cao, M. Zhou, and L. Yang, \u201cCell-free massive MIMO: Zero forcing and conjugate beamforming receivers,\u201d J. Commun. Netw., vol.21, no.6, pp.529-538, Dec 2019. 10.1109\/jcn.2019.000053","DOI":"10.1109\/JCN.2019.000053"},{"key":"23","doi-asserted-by":"crossref","unstructured":"[23] E. Nayebi, A. Ashikhmin, T.L. Marzetta, and B.D. Rao, \u201cPerformance of cell-free massive MIMO systems with MMSE and LSFD receivers,\u201d Proc. 50th Asilomar Conf. Signals, Syst. Comput., Nov. 2016. 10.1109\/acssc.2016.7869024","DOI":"10.1109\/ACSSC.2016.7869024"},{"key":"24","doi-asserted-by":"publisher","unstructured":"[24] G. Interdonato, M. Karlsson, E. Bj\u00f6rnson, and E.G. Larsson, \u201cLocal partial zero-forcing precoding for cell-free massive MIMO,\u201d IEEE Trans. Wireless Commun., vol.19, no.7, pp.4758-4774, July 2020. 10.1109\/twc.2020.2987027","DOI":"10.1109\/TWC.2020.2987027"},{"key":"25","doi-asserted-by":"publisher","unstructured":"[25] E. Bj\u00f6rnson and L. Sanguinetti, \u201cMaking cell-free massive MIMO competitive with MMSE processing and centralized implementation,\u201d IEEE Trans. Wireless Commun., vol.19, no.1, pp.77-90, Jan. 2020. 10.1109\/twc.2019.2941478","DOI":"10.1109\/TWC.2019.2941478"},{"key":"26","doi-asserted-by":"crossref","unstructured":"[26] M. Attarifar, A. Abbasfar, and A. Lozano, \u201cRandom vs structured pilot assignment in cell-free massive MIMO wireless networks,\u201d Proc. IEEE Int. Conf. Commun. Workshops (ICC Workshops), pp.1-6, May 2018. 10.1109\/ICCW.2018.8403508","DOI":"10.1109\/ICCW.2018.8403508"},{"key":"27","doi-asserted-by":"publisher","unstructured":"[27] D. Verenzuela, E. Bj\u00f6rnson, and L. Sanguinetti, \u201cSpectral and energy efficiency of superimposed pilots in uplink massive MIMO,\u201d IEEE Trans. Wireless Commun., vol.17, no.11, pp.7099-7115, Nov. 2018. 10.1109\/twc.2018.2860939","DOI":"10.1109\/TWC.2018.2860939"},{"key":"28","doi-asserted-by":"publisher","unstructured":"[28] W. Zeng, Y. He, B. Li, and S. Wang, \u201cPilot assignment for cell free massive MIMO systems using a weighted graphic framework,\u201d IEEE Trans. Veh. Technol., vol.70, no.6, pp.6190-6194, June 2021. 10.1109\/tvt.2021.3076440","DOI":"10.1109\/TVT.2021.3076440"},{"key":"29","doi-asserted-by":"publisher","unstructured":"[29] S. Buzzi, C. D&apos;Andrea, M. Fresia, Y.-P. Zhang, and S. Feng, \u201cPilot assignment in cell-free massive MIMO based on the Hungarian algorithm,\u201d IEEE Wireless Commun. Lett., vol.10, no.1, pp.34-37, Jan. 2021. 10.1109\/LWC.2020.3020003","DOI":"10.1109\/LWC.2020.3020003"},{"key":"30","doi-asserted-by":"publisher","unstructured":"[30] E. Nayebi, A. Ashikhmin, T.L. Marzetta, H. Yang, and B.D. Rao, \u201cPrecoding and power optimization in cell-free massive mimo systems,\u201d IEEE Trans. Wireless Commun., vol.16, no.7, pp.4445-4459, July 2017. 10.1109\/TWC.2017.2698449","DOI":"10.1109\/TWC.2017.2698449"},{"key":"31","doi-asserted-by":"crossref","unstructured":"[31] M. Bashar, K. Cumanan, A.G. Burr, M. Debbah, and H.Q. Ngo, \u201cEnhanced max-min SINR for uplink cell-free massive MIMO systems,\u201d Proc. IEEE ICC, May 2018. 10.1109\/icc.2018.8422577","DOI":"10.1109\/ICC.2018.8422577"},{"key":"32","doi-asserted-by":"publisher","unstructured":"[32] T.H. Nguyen, T.K. Nguyen, H.D. Han, and V.D. Nguyen, \u201cOptimal power control and load balancing for uplink cell-free multi-user massive MIMO,\u201d IEEE Access, vol.6, pp.14462-14473, Feb. 2018. 10.1109\/access.2018.2797874","DOI":"10.1109\/ACCESS.2018.2797874"},{"key":"33","doi-asserted-by":"crossref","unstructured":"[33] Y. Zhang, H. Cao, M. Zhou, and L. Yang, \u201cPower optimization for energy efficiency in cell-free massive MIMO with ZF receiver,\u201d Proc. IEEE ICACT, pp.366-371, Feb. 2019. 10.23919\/icact.2019.8702035","DOI":"10.23919\/ICACT.2019.8702035"},{"key":"34","doi-asserted-by":"publisher","unstructured":"[34] S. Buzzi and C. D&apos;Andrea, \u201cCell-free massive MIMO: User-centric approach,\u201d IEEE Commun. Lett., vol.6, no.6, pp.706-709, 2017. 10.1109\/lwc.2017.2734893","DOI":"10.1109\/LWC.2017.2734893"},{"key":"35","doi-asserted-by":"crossref","unstructured":"[35] E. Bj\u00f6rnson and L. Sanguinetti, \u201cA new look at cell-free massive MIMO: Making it practical with dynamic cooperation,\u201d Proc. IEEE PIMRC 2019, Sept. 2019. 10.1109\/pimrc.2019.8904101","DOI":"10.1109\/PIMRC.2019.8904101"},{"key":"36","unstructured":"[36] F.R. Palou, G. Femenias, A.G. Armada, and A. P\u00e9rez-Neira, \u201cClustered cell-free massive MIMO,\u201d Proc. IEEE Globecom Workshops (GC Wkshps 2018), 2018. 10.1109\/glocomw.2018.8644255"},{"key":"37","doi-asserted-by":"crossref","unstructured":"[37] R. Van Rompaey and M. Moonen, \u201cScalable and distributed MMSE algorithms for uplink receive combining in cell free massive MIMO systems,\u201d IEEE ICASSP 2021, June 2021. 10.1109\/icassp39728.2021.9414456","DOI":"10.1109\/ICASSP39728.2021.9414456"},{"key":"38","doi-asserted-by":"crossref","unstructured":"[38] R. Takahashi, H. Mastuo, and F. Adachi, \u201cJoint multilayered user clustering and scheduling for 5G advanced ultra-dense RAN,\u201d Proc. IEEE VTC fall 2020, Dec. 2020. 10.1109\/vtc2020-fall49728.2020.9348724","DOI":"10.1109\/VTC2020-Fall49728.2020.9348724"},{"key":"39","doi-asserted-by":"crossref","unstructured":"[39] C.F. Mendoza, S. Schwarz, and M. Rupp, \u201cCluster formation in scalable cell-free massive MIMO networks,\u201d Proc. WiMob2020, Oct. 2020. 10.1109\/wimob50308.2020.9253391","DOI":"10.1109\/WiMob50308.2020.9253391"},{"key":"40","doi-asserted-by":"crossref","unstructured":"[40] S. Mosleh, H. Almosa, E. Perrins, and L. Liu, \u201cDownlink resource allocation in cell-free massive MIMO systems,\u201d Proc. ICNC, pp.883-887, 2019. 10.1109\/iccnc.2019.8685542","DOI":"10.1109\/ICCNC.2019.8685542"},{"key":"41","doi-asserted-by":"publisher","unstructured":"[41] H.A. Ammar, R. Adve, S. Shahbazpanahi, G. Boudreau, and K.V. Srinivas, \u201cDownlink resource allocation in multiuser cell-free MIMO networks with user-centric clustering,\u201d IEEE Trans. Wireless Commun., vol.21, no.3, pp.1482-1497, Aug. 2021. 10.1109\/twc.2021.3104456","DOI":"10.1109\/TWC.2021.3104456"},{"key":"42","unstructured":"[42] 3GPP TS38.211, \u201cNR; Physical channels and modulation,\u201d Sept. 2021."},{"key":"43","unstructured":"[43] 3GPP RP-213598, \u201cNR MIMO evolution for downlink and uplink,\u201d Dec. 2021."},{"key":"44","doi-asserted-by":"publisher","unstructured":"[44] S. Chen, J. Zhang, E. Bj\u00f6rnson, J. Zhang, and B. Ai, \u201cStructured massive access for scalable cell-free massive MIMO systems,\u201d IEEE J. Sel. Areas Commun., vol.39, no.4, pp.1086-1100, Aug. 2020. 10.1109\/JSAC.2020.3018836","DOI":"10.1109\/JSAC.2020.3018836"},{"key":"45","doi-asserted-by":"publisher","unstructured":"[45] C.M. Yetis, E. Bj\u00f6rnson, and P. Giselsson, \u201cJoint analog beam selection and digital beamforming in millimeter wave cell-free massive MIMO systems,\u201d IEEE Open J. Commun., vol.2, pp.1647-1662, July 2021. 10.1109\/OJCOMS.2021.3094823","DOI":"10.1109\/OJCOMS.2021.3094823"},{"key":"46","doi-asserted-by":"crossref","unstructured":"[46] A.A. Avidh, Y. Sambo, S. Ansari, and M.A. Imran, \u201cHybrid beamforming with fixed phase shifters for uplink cell-free millimetre-wave massive MIMO systems,\u201d Proc. EuCNC 2021, June 2021. 10.1109\/eucnc\/6gsummit51104.2021.9482579","DOI":"10.1109\/EuCNC\/6GSummit51104.2021.9482579"},{"key":"47","doi-asserted-by":"publisher","unstructured":"[47] L. Bonati, M. Polese, S. D&apos;Oro, S. Basagni, and T. Melodia, \u201cOpen, programmable, and virtualized 5G networks: State-of-the-art and the road ahead,\u201d Computer Networks, vol.182, 107516, Dec. 2020. 10.1016\/j.comnet.2020.107516","DOI":"10.1016\/j.comnet.2020.107516"},{"key":"48","doi-asserted-by":"publisher","unstructured":"[48] D. Wang, C. Zhang, Y. Du, J. Zhao, M. Jiang, and X. You, \u201cImplementation of a cloud-based cell-free distributed massive MIMO system,\u201d IEEE Commun. Mag., vol.58, no.8, pp.61-67, Aug. 2020. 10.1109\/mcom.001.2000106","DOI":"10.1109\/MCOM.001.2000106"},{"key":"49","doi-asserted-by":"crossref","unstructured":"[49] J.S. Vardakas, K. Ramantas, E. Datsika, M. Payaro, S. Pollin, E. Vinogradov, M. Varvarigos, P. Kokkinos, R. Gonzalez-Sanchez, J.J.V. Olmos, I. Chochliouros, P. Chanclou, P. Samarati, A. Flizikowski, M.A. Rahman, and C. Verikoukis, \u201cTowards machine-learning-based 5G and beyond intelligent networks: The MARSAL project vision,\u201d Proc. IEEE MeditCom, Sept. 2021. 10.1109\/meditcom49071.2021.9647671","DOI":"10.1109\/MeditCom49071.2021.9647671"},{"key":"50","doi-asserted-by":"crossref","unstructured":"[50] K. Yamazaki, T. Ohseki, Y. Amano, H. Shinbo, T. Murakami, and Y. Kishi, \u201cProposal for a user-centric RAN architecture towards beyond 5G,\u201d Proc. ITU Kaleidoscope 2021, Dec. 2021. 10.23919\/ituk53220.2021.9690496","DOI":"10.23919\/ITUK53220.2021.9690496"},{"key":"51","unstructured":"[51] W. Roh and A. Paulraj, \u201cMIMO channel capacity for the distributed antenna,\u201d Proc. IEEE VTC-fall 2002, Sept. 2002. 10.1109\/vetecf.2002.1040690"},{"key":"52","doi-asserted-by":"publisher","unstructured":"[52] T. Okuyama, S. Suyama, J. Mashino, and Y. Okumura, \u201c5G distributed massive MIMO with ultra-high density antenna deployment in low SHF bands,\u201d IEICE Trans. Commun., vol.E100-B, no.10, pp.1921-1927, Oct. 2017. 10.1587\/transcom.2017ebp3040","DOI":"10.1587\/transcom.2017EBP3040"},{"key":"53","doi-asserted-by":"crossref","unstructured":"[53] T. Okuyama, S. Suyama, J. Mashino, Y. Okumura, K. Shiizaki, C. Akiyama, M. Tsutsui, H. Seki, and M. Minowa, \u201cAntenna deployment of 5G ultra high-density distributed massive MIMO by low-SHF-band indoor and outdoor experiments,\u201d Proc. IEEE VTC Fall 2017, Sept. 2017. 10.1109\/vtcfall.2017.8288005","DOI":"10.1109\/VTCFall.2017.8288005"},{"key":"54","doi-asserted-by":"crossref","unstructured":"[54] T. Choi, P. Luo, A. Ramesh, and A.F. Molisch, \u201cCo-located vs distributed vs semi-distributed MIMO: Measurement-based evaluation,\u201d Proc. 54th Asilomar Conf. Signals, Syst. Comput., Nov.2020. 10.1109\/ieeeconf51394.2020.9443568","DOI":"10.1109\/IEEECONF51394.2020.9443568"},{"key":"55","doi-asserted-by":"crossref","unstructured":"[55] Z. Chen and E. Bj\u00f6rnson, \u201cCan we rely on channel hardening in cell-free massive MIMO?,\u201d Proc. IEEE GC Wkshps. 2017, Dec. 2017. 10.1109\/glocomw.2017.8269162","DOI":"10.1109\/GLOCOMW.2017.8269162"},{"key":"56","doi-asserted-by":"crossref","unstructured":"[56] M. Ito, I. Kanno, T. Ohseki, K. Yamazaki, Y. Kishi, T. Choi, and A.F. Molisch, \u201cEffect of antenna distribution on spectral and energy efficiency of cell-free massive MIMO,\u201d Proc. IEEE VTC-fall 2021, Sept. 2021.","DOI":"10.1109\/VTC2021-Fall52928.2021.9625300"},{"key":"57","unstructured":"[57] CPRI Interface Specification, v. 6.0, Aug. 2013."},{"key":"58","doi-asserted-by":"crossref","unstructured":"[58] M. Bashar, K. Cumanan, A.G. Burr, H.Q. Ngo, and M. Debbah, \u201cCell-free massive MIMO with limited backhaul,\u201d Proc. IEEE ICC2018, 2018. 10.1109\/icc.2018.8422865","DOI":"10.1109\/ICC.2018.8422865"},{"key":"59","doi-asserted-by":"crossref","unstructured":"[59] P. Parida, H.S. Dhillon, and A.F. Molisch, \u201cDownlink performance analysis of cell-free massive MIMO with finite fronthaul capacity,\u201d Proc. IEEE VTC-fall 2018, Sept. 2018. 10.1109\/VTCFall.2018.8690797","DOI":"10.1109\/VTCFall.2018.8690797"},{"key":"60","doi-asserted-by":"crossref","unstructured":"[60] X. Hu, C. Zhong, X. Chen, W. Xu, and Z. Zhang, \u201cRate analysis and ADC bits allocation for cell-free massive MIMO systems with low-resolution ADCs,\u201d Proc. IEEE GLOBECOM 2018, Dec. 2018. 10.1109\/glocom.2018.8647412","DOI":"10.1109\/GLOCOM.2018.8647412"},{"key":"61","doi-asserted-by":"publisher","unstructured":"[61] G. Femenias and F. Riera-Palou, \u201cFronthaul-constrained cell-free massive MIMO with low resolution ADCs,\u201d IEEE Access, vol.8, pp.116195-116215, 2020. 10.1109\/ACCESS.2020.3004499","DOI":"10.1109\/ACCESS.2020.3004499"},{"key":"62","doi-asserted-by":"publisher","unstructured":"[62] K. Ando, H. Iimori, T. Takahashi, K. Ishibashi, and G.T.F. De Abreu, \u201cUplink signal detection for scalable cell-free massive MIMO systems with robustness to rate-limited fronthaul,\u201d IEEE Access, vol.9, pp.102770-102782, July 2021. 10.1109\/access.2021.3098638","DOI":"10.1109\/ACCESS.2021.3098638"},{"key":"63","doi-asserted-by":"crossref","unstructured":"[63] M. Bashar, K. Cumanan, A.G. Burr, H.Q. Ngo, E.G. Larsson, and P. Xiao, \u201cOn the energy efficiency of limited-backhaul cell-free massive MIMO,\u201d Proc. ICC 2019, 2019. 10.1109\/icc.2019.8761134","DOI":"10.1109\/ICC.2019.8761134"},{"key":"64","doi-asserted-by":"publisher","unstructured":"[64] D. Novak, R.B. Waterhouse, A. Nirmalathas, C. Lim, P.A. Gamage, T.R. Clark, M.L. Dennis, and J.A. Nanzer, \u201cRadio-over-fiber technologies for emerging wireless systems,\u201d IEEE J. Quantum Electron., vol.52, no.1, pp.1-11, Jan. 2016. 10.1109\/jqe.2015.2504107","DOI":"10.1109\/JQE.2015.2504107"},{"key":"65","doi-asserted-by":"crossref","unstructured":"[65] P. Perry, C. Browning, B. Scotney, A. Delmade, S. McClean, L. Barry, A. Peters, and P. Morrow, \u201cComparison of analogue and digital fronthaul for 5G MIMO signals,\u201d Proc. IEEE ICC 2020, June 2020. 10.1109\/icc40277.2020.9148787","DOI":"10.1109\/ICC40277.2020.9148787"},{"key":"66","doi-asserted-by":"publisher","unstructured":"[66] S. Ishimura, B.G. Kim, K. Tanaka, K. Nishimura, H. Kim, Y.C. Chung, and M. Suzuki, \u201cBroadband IF-over-fiber transmission with parallel IM\/PM transmitter overcoming dispersion-induced RF power fading for high-capacity mobile fronthaul links,\u201d IEEE Photon. J., vol.10, no.1, Feb. 2018. 10.1109\/JPHOT.2017.2787722","DOI":"10.1109\/JPHOT.2017.2787722"},{"key":"67","doi-asserted-by":"publisher","unstructured":"[67] S. Ishimura, A. Bekkali, K. Tanaka, K. Nishimura, and M. Suzuki, \u201c1.032-Tb\/s CPRI-equivalent rate IF-over-fiber transmission using a parallel IM\/PM transmitter for high-capacity mobile fronthaul links,\u201d IEEE\/OSA J. Lightw. Technol., vol.36, no.8, pp.1478-1484, April 2018. 10.1109\/jlt.2017.2787151","DOI":"10.1109\/JLT.2017.2787151"},{"key":"68","doi-asserted-by":"publisher","unstructured":"[68] J. Kim, M. Sung, S.H. Cho, Y.J. Won, B.C. Lim, S.K. Pyun, J.K. Lee, and J.H. Lee, \u201cMIMO-supporting radio-over-fiber system and its application in mmWave-based indoor 5G mobile network,\u201d J. Lightwave Technol., vol.38, no.1, pp.101-111, Jan. 2020. 10.1109\/jlt.2019.2931318","DOI":"10.1109\/JLT.2019.2931318"},{"key":"69","doi-asserted-by":"publisher","unstructured":"[69] H.Y. Kao, S. Ishimura, K. Tanaka, K. Nishimura, and R. Inohara, \u201cEnd-to-end demonstration of fiber-wireless fronthaul networks using a hybrid multi-IF-over-fiber and radio-over-fiber system,\u201d IEEE Photon. J., vol.13, no.4, Aug. 2021. 10.1109\/jphot.2021.3106706","DOI":"10.1109\/JPHOT.2021.3106706"},{"key":"70","unstructured":"[70] KDDI Research Inc., \u201cWorld first successful demonstration of wireless network deployment methodology for Beyond 5G,\u201d Oct. 2021 (Press Release). https:\/\/www.kddi-research.jp\/english\/newsrelease\/2021\/100701.html"},{"key":"71","unstructured":"[71] Ericsson, \u201cRadio Stripes: Re-thinking mobile networks,\u201d Feb. 2019 (Press Release). https:\/\/www.ericsson.com\/en\/blog\/2019\/2\/radio-stripes"},{"key":"72","doi-asserted-by":"crossref","unstructured":"[72] Z.H. Shaik, E. Bj\u00f6rnson, and E.G. Larsson, \u201cCell-free massive MIMO with radio stripes and sequential uplink processing,\u201d Proc. IEEE ICC Workshops, June 2020. 10.1109\/iccworkshops49005.2020.9145164","DOI":"10.1109\/ICCWorkshops49005.2020.9145164"},{"key":"73","doi-asserted-by":"publisher","unstructured":"[73] D. Hu, L. He, and X. Wang, \u201cSemi-blind pilot decontamination for massive MIMO systems,\u201d IEEE Trans. Wireless Commun., vol.15, no.1, pp.525-536, Jan. 2016. 10.1109\/twc.2015.2475745","DOI":"10.1109\/TWC.2015.2475745"},{"key":"74","doi-asserted-by":"publisher","unstructured":"[74] X. Zhu, L. Dai, Z. Wang, and X. Wang, \u201cWeighted-graph-coloring-based pilot decontamination for multicell massive MIMO systems,\u201d IEEE Trans. Veh. Technol., vol.66, no.3, pp.2829-2834, March 2017. 10.1109\/tvt.2016.2572203","DOI":"10.1109\/TVT.2016.2572203"},{"key":"75","doi-asserted-by":"crossref","unstructured":"[75] F. G\u00f6ttsch, N. Osawa, T. Ohseki, K. Yamazaki, and G. Caire, \u201cThe impact of subspace-based pilot decontamination in user-centric scalable cell-free wireless networks,\u201d Proc. IEEE SPAWC, Oct. 2021. 10.1109\/spawc51858.2021.9593169","DOI":"10.1109\/SPAWC51858.2021.9593169"},{"key":"76","doi-asserted-by":"crossref","unstructured":"[76] G. Interdonato, P. Frenger, and E.G. Larsson, \u201cScalability aspects of cell-free massive MIMO,\u201d Proc. ICC 2019, May 2019. 10.1109\/icc.2019.8761828","DOI":"10.1109\/ICC.2019.8761828"},{"key":"77","doi-asserted-by":"publisher","unstructured":"[77] E. Bj\u00f6rnson and L. Sanguinetti, \u201cScalable cell-free massive MIMO systems,\u201d IEEE Trans. Commun., vol.68, no.7, pp.4247-4261, 2020. 10.1109\/tcomm.2020.2987311","DOI":"10.1109\/TCOMM.2020.2987311"},{"key":"78","doi-asserted-by":"crossref","unstructured":"[78] C. D&apos;Andrea and E.G. Larsson, \u201cUser association in scalable cell-free massive MIMO systems,\u201d Proc. 54th Asilomar Conf. Signals, Syst. Comput., Nov. 2020. 10.1109\/ieeeconf51394.2020.9443536","DOI":"10.1109\/IEEECONF51394.2020.9443536"},{"key":"79","unstructured":"[79] M. Ito, I. Kanno, K. Yamazaki, K. Ando, S. Fukue, H. Iimori, and K. Ishibashi, \u201cPerformance evaluation of scalable cell-free massive MIMO systems with multiple CPUs subject to backhaul capacity limitation,\u201d IEICE Technical Report, RCS, Oct. 2021 (in Japanese)."},{"key":"80","doi-asserted-by":"publisher","unstructured":"[80] T. Zhou, K. Xu, X. Xia, W. Xie, and J. Xu, \u201cAchievable rate optimization for aerial intelligent reflecting surface-aided cell-free massive MIMO system,\u201d IEEE Access, vol.9, pp.3828-3837, 2021. 10.1109\/access.2020.3047450","DOI":"10.1109\/ACCESS.2020.3047450"},{"key":"81","doi-asserted-by":"publisher","unstructured":"[81] Y. Al-Eryani, M. Akrout, and E. Hossain, \u201cMultiple access in cell-free networks: Outage performance dynamic clustering and deep reinforcement learning-based design,\u201d IEEE J. Sel. Areas Commun., vol.39, no.4, pp.1028-1042, April 2021. 10.1109\/JSAC.2020.3018825","DOI":"10.1109\/JSAC.2020.3018825"}],"container-title":["IEICE Transactions on Communications"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.jstage.jst.go.jp\/article\/transcom\/E105.B\/10\/E105.B_2021MEI0001\/_pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,1,10]],"date-time":"2024-01-10T15:00:38Z","timestamp":1704898838000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.jstage.jst.go.jp\/article\/transcom\/E105.B\/10\/E105.B_2021MEI0001\/_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,10,1]]},"references-count":81,"journal-issue":{"issue":"10","published-print":{"date-parts":[[2022]]}},"URL":"https:\/\/doi.org\/10.1587\/transcom.2021mei0001","relation":{},"ISSN":["0916-8516","1745-1345"],"issn-type":[{"value":"0916-8516","type":"print"},{"value":"1745-1345","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,10,1]]},"article-number":"2021MEI0001"}}