{"id":"https://openalex.org/W7172307715","doi":"https://doi.org/10.48550/arxiv.2607.28965","title":"When 5G MIMO Scaling Breaks: Toward 6G Upper-Mid-Band Extreme MIMO","display_name":"When 5G MIMO Scaling Breaks: Toward 6G Upper-Mid-Band Extreme MIMO","publication_year":2026,"publication_date":"2026-07-31","ids":{"openalex":"https://openalex.org/W7172307715","doi":"https://doi.org/10.48550/arxiv.2607.28965"},"language":null,"primary_location":{"id":"doi:10.48550/arxiv.2607.28965","is_oa":true,"landing_page_url":"https://doi.org/10.48550/arxiv.2607.28965","pdf_url":null,"source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":null,"is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"Preprint"},"type":"preprint","indexed_in":["datacite"],"open_access":{"is_oa":true,"oa_status":"green","oa_url":"https://doi.org/10.48550/arxiv.2607.28965","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5081140044","display_name":"Kwang Soon Kim","orcid":"https://orcid.org/0000-0002-5706-174X"},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Kim, Kwang Soon","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5144257356","display_name":"Jeonghun Park","orcid":null},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Park, Jeonghun","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5050737677","display_name":"Byung\u2010Wook Min","orcid":"https://orcid.org/0000-0001-7456-8713"},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Min, Byung-Wook","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5144296367","display_name":"Kwanghoon Lee","orcid":null},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Lee, Kwanghoon","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5064521618","display_name":"Eui Whan Jin","orcid":null},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Jin, Eui Whan","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5079519517","display_name":"Juntaek Han","orcid":"https://orcid.org/0009-0003-5568-5377"},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Han, Juntaek","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5101452459","display_name":"Geonwoo Park","orcid":"https://orcid.org/0000-0003-3712-638X"},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Park, Geonwoo","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5144297418","display_name":"Jun-Seok Ko","orcid":null},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Ko, Jun-Seok","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5016133107","display_name":"Jungho Myung","orcid":"https://orcid.org/0000-0002-7866-5278"},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Myung, Jungho","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5064218464","display_name":"Wooram Shin","orcid":"https://orcid.org/0000-0003-2279-3470"},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Shin, Wooram","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5113928290","display_name":"Young\u2010Jo Ko","orcid":null},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Ko, Young-Jo","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"last","author":{"id":"https://openalex.org/A5144256733","display_name":"Chan-Byoung Chae","orcid":null},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Chae, Chan-Byoung","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]}],"institutions":[],"countries_distinct_count":0,"institutions_distinct_count":0,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":null,"has_fulltext":false,"cited_by_count":0,"citation_normalized_percentile":null,"cited_by_percentile_year":null,"biblio":{"volume":null,"issue":null,"first_page":null,"last_page":null},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11458","display_name":"Advanced Wireless Communication Technologies","score":0.722100019454956,"subfield":{"id":"https://openalex.org/subfields/2208","display_name":"Electrical and Electronic Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T11458","display_name":"Advanced Wireless Communication Technologies","score":0.722100019454956,"subfield":{"id":"https://openalex.org/subfields/2208","display_name":"Electrical and Electronic Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10069","display_name":"Antenna Design and Analysis","score":0.051600001752376556,"subfield":{"id":"https://openalex.org/subfields/2202","display_name":"Aerospace Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10148","display_name":"Advanced MIMO Systems Optimization","score":0.045499999076128006,"subfield":{"id":"https://openalex.org/subfields/2208","display_name":"Electrical and Electronic Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/mimo","display_name":"MIMO","score":0.7389000058174133},{"id":"https://openalex.org/keywords/beamforming","display_name":"Beamforming","score":0.7057999968528748},{"id":"https://openalex.org/keywords/path-loss","display_name":"Path loss","score":0.5102999806404114},{"id":"https://openalex.org/keywords/3g-mimo","display_name":"3G MIMO","score":0.4909000098705292},{"id":"https://openalex.org/keywords/channel","display_name":"Channel (broadcasting)","score":0.4797999858856201},{"id":"https://openalex.org/keywords/transmission","display_name":"Transmission (telecommunications)","score":0.4706000089645386},{"id":"https://openalex.org/keywords/spatial-multiplexing","display_name":"Spatial multiplexing","score":0.41499999165534973},{"id":"https://openalex.org/keywords/channel-state-information","display_name":"Channel state information","score":0.3959999978542328},{"id":"https://openalex.org/keywords/antenna","display_name":"Antenna (radio)","score":0.3822000026702881}],"concepts":[{"id":"https://openalex.org/C207987634","wikidata":"https://www.wikidata.org/wiki/Q176862","display_name":"MIMO","level":3,"score":0.7389000058174133},{"id":"https://openalex.org/C54197355","wikidata":"https://www.wikidata.org/wiki/Q5782992","display_name":"Beamforming","level":2,"score":0.7057999968528748},{"id":"https://openalex.org/C24326235","wikidata":"https://www.wikidata.org/wiki/Q126095","display_name":"Electronic engineering","level":1,"score":0.5929999947547913},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.5684000253677368},{"id":"https://openalex.org/C194273485","wikidata":"https://www.wikidata.org/wiki/Q1478845","display_name":"Path loss","level":3,"score":0.5102999806404114},{"id":"https://openalex.org/C165650700","wikidata":"https://www.wikidata.org/wiki/Q4636347","display_name":"3G MIMO","level":4,"score":0.4909000098705292},{"id":"https://openalex.org/C127162648","wikidata":"https://www.wikidata.org/wiki/Q16858953","display_name":"Channel (broadcasting)","level":2,"score":0.4797999858856201},{"id":"https://openalex.org/C761482","wikidata":"https://www.wikidata.org/wiki/Q118093","display_name":"Transmission (telecommunications)","level":2,"score":0.4706000089645386},{"id":"https://openalex.org/C85884896","wikidata":"https://www.wikidata.org/wiki/Q7574075","display_name":"Spatial multiplexing","level":4,"score":0.41499999165534973},{"id":"https://openalex.org/C148063708","wikidata":"https://www.wikidata.org/wiki/Q5072511","display_name":"Channel state information","level":3,"score":0.3959999978542328},{"id":"https://openalex.org/C21822782","wikidata":"https://www.wikidata.org/wiki/Q131214","display_name":"Antenna (radio)","level":2,"score":0.3822000026702881},{"id":"https://openalex.org/C99844830","wikidata":"https://www.wikidata.org/wiki/Q102441924","display_name":"Scaling","level":2,"score":0.38040000200271606},{"id":"https://openalex.org/C91330434","wikidata":"https://www.wikidata.org/wiki/Q738298","display_name":"Multi-user MIMO","level":4,"score":0.3619000017642975},{"id":"https://openalex.org/C62191587","wikidata":"https://www.wikidata.org/wiki/Q4771249","display_name":"Antenna array","level":3,"score":0.34689998626708984},{"id":"https://openalex.org/C78336883","wikidata":"https://www.wikidata.org/wiki/Q4779385","display_name":"Aperture (computer memory)","level":2,"score":0.33709999918937683},{"id":"https://openalex.org/C160562895","wikidata":"https://www.wikidata.org/wiki/Q7239557","display_name":"Precoding","level":4,"score":0.33379998803138733},{"id":"https://openalex.org/C76155785","wikidata":"https://www.wikidata.org/wiki/Q418","display_name":"Telecommunications","level":1,"score":0.328900009393692},{"id":"https://openalex.org/C19247436","wikidata":"https://www.wikidata.org/wiki/Q192727","display_name":"Physical layer","level":3,"score":0.32519999146461487},{"id":"https://openalex.org/C130946814","wikidata":"https://www.wikidata.org/wiki/Q5988271","display_name":"MIMO-OFDM","level":4,"score":0.29440000653266907},{"id":"https://openalex.org/C555944384","wikidata":"https://www.wikidata.org/wiki/Q249","display_name":"Wireless","level":2,"score":0.2800999879837036},{"id":"https://openalex.org/C127413603","wikidata":"https://www.wikidata.org/wiki/Q11023","display_name":"Engineering","level":0,"score":0.27970001101493835},{"id":"https://openalex.org/C47798520","wikidata":"https://www.wikidata.org/wiki/Q190157","display_name":"Transmitter","level":3,"score":0.2727000117301941},{"id":"https://openalex.org/C2781127089","wikidata":"https://www.wikidata.org/wiki/Q25051821","display_name":"Channel sounding","level":4,"score":0.2709999978542328},{"id":"https://openalex.org/C40409654","wikidata":"https://www.wikidata.org/wiki/Q375889","display_name":"Orthogonal frequency-division multiplexing","level":3,"score":0.2694999873638153},{"id":"https://openalex.org/C79403827","wikidata":"https://www.wikidata.org/wiki/Q3988","display_name":"Real-time computing","level":1,"score":0.2587999999523163},{"id":"https://openalex.org/C68649174","wikidata":"https://www.wikidata.org/wiki/Q1379116","display_name":"Base station","level":2,"score":0.2574000060558319},{"id":"https://openalex.org/C2780056265","wikidata":"https://www.wikidata.org/wiki/Q106239881","display_name":"High dynamic range","level":3,"score":0.2563999891281128},{"id":"https://openalex.org/C74064498","wikidata":"https://www.wikidata.org/wiki/Q3396184","display_name":"Radio frequency","level":2,"score":0.2506999969482422}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.48550/arxiv.2607.28965","is_oa":true,"landing_page_url":"https://doi.org/10.48550/arxiv.2607.28965","pdf_url":null,"source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":null,"is_accepted":false,"is_published":null,"raw_source_name":null,"raw_type":"Preprint"}],"best_oa_location":{"id":"doi:10.48550/arxiv.2607.28965","is_oa":true,"landing_page_url":"https://doi.org/10.48550/arxiv.2607.28965","pdf_url":null,"source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":null,"is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"Preprint"},"sustainable_development_goals":[{"display_name":"Affordable and clean energy","score":0.9083078503608704,"id":"https://metadata.un.org/sdg/7"}],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":0,"referenced_works":[],"related_works":[],"abstract_inverted_index":{"The":[0],"upper-mid":[1],"band,":[2],"particularly":[3],"the":[4,38,49,56,81,117,128,136,185,200],"7-8":[5],"GHz":[6],"range":[7,10],"within":[8,37],"frequency":[9],"3":[11],"(FR3),":[12],"has":[13],"emerged":[14],"as":[15,197,199],"a":[16,107,233],"leading":[17],"spectrum":[18],"candidate":[19],"for":[20,55,110],"wide-area":[21],"sixth-generation":[22],"(6G)":[23],"cellular":[24],"networks.":[25],"Its":[26],"shorter":[27],"wavelength":[28],"enables":[29],"hundreds":[30,90],"of":[31,41,91,119],"antenna":[32,69],"elements":[33],"to":[34,89],"be":[35],"integrated":[36,220],"physical":[39,148],"aperture":[40,51],"an":[42],"existing":[43],"5G":[44,82],"base-station":[45],"panel.":[46],"In":[47,76],"principle,":[48],"resulting":[50],"gain":[52],"can":[53,228],"compensate":[54],"increased":[57],"path":[58],"loss":[59],"and":[60,105,124,127,150,158,165,168,178,192,202,211,225],"enable":[61],"extreme":[62],"MIMO":[63,102],"(E-MIMO)":[64],"with":[65,175],"256":[66],"or":[67,194],"more":[68],"ports":[70,92],"while":[71],"reusing":[72],"current":[73],"cell":[74],"sites.":[75],"practice,":[77],"however,":[78],"simply":[79],"scaling":[80,103,231],"New":[83],"Radio":[84],"(NR)":[85],"architecture":[86],"from":[87],"tens":[88],"encounters":[93],"fundamental":[94],"system-level":[95],"limitations.":[96],"This":[97],"paper":[98],"identifies":[99],"where":[100],"5G-style":[101],"breaks":[104],"develops":[106],"research":[108],"roadmap":[109],"practical":[111],"upper-mid-band":[112],"E-MIMO.":[113],"We":[114,133],"first":[115],"review":[116],"evolution":[118],"FR3":[120],"spectrum,":[121],"its":[122],"propagation":[123],"channel":[125,172,223],"characteristics,":[126],"emerging":[129],"6G":[130,235],"system":[131,182],"requirements.":[132],"then":[134],"organize":[135],"principal":[137],"challenges":[138],"into":[139,232],"four":[140],"coupled":[141],"areas:":[142],"maintaining":[143],"effective":[144],"coverage":[145,186],"across":[146],"all":[147],"channels":[149],"protocol":[151],"states;":[152],"implementing":[153],"wideband,":[154],"energy-efficient":[155],"RF":[156],"devices":[157],"radio":[159],"units;":[160],"developing":[161],"new":[162],"low-power":[163],"array":[164],"beamforming":[166],"architectures;":[167],"acquiring":[169],"sufficiently":[170],"refined":[171],"state":[173],"information":[174],"manageable":[176],"sounding":[177],"feedback":[179],"overhead.":[180],"Representative":[181],"studies":[183],"illustrate":[184],"asymmetry":[187],"between":[188],"user-specific":[189],"data":[190],"transmission":[191],"common":[193],"channel-acquisition":[195],"signals,":[196],"well":[198],"spectral-":[201],"energy-efficiency":[203],"tradeoffs":[204],"among":[205],"fully":[206],"digital,":[207],"hybrid,":[208],"tri-hybrid,":[209],"dynamic-metasurface,":[210],"fluid-antenna":[212],"architectures.":[213],"Finally,":[214],"we":[215],"discuss":[216],"how":[217],"distributed":[218],"apertures,":[219],"sensing,":[221],"AI-assisted":[222],"acquisition,":[224],"environment-aware":[226],"operation":[227],"transform":[229],"fixed-aperture":[230],"deployable":[234],"E-MIMO":[236],"architecture.":[237]},"counts_by_year":[],"updated_date":"2026-08-04T08:18:43.703281","created_date":"2026-08-04T00:00:00"}