{"id":"https://openalex.org/W2744778118","doi":"https://doi.org/10.1155/2017/9068272","title":"Keyholes in MIMO-OFDM: Train-to-Wayside Communications in Railway Tunnels","display_name":"Keyholes in MIMO-OFDM: Train-to-Wayside Communications in Railway Tunnels","publication_year":2017,"publication_date":"2017-01-01","ids":{"openalex":"https://openalex.org/W2744778118","doi":"https://doi.org/10.1155/2017/9068272","mag":"2744778118"},"language":"en","primary_location":{"id":"doi:10.1155/2017/9068272","is_oa":true,"landing_page_url":"https://doi.org/10.1155/2017/9068272","pdf_url":"http://downloads.hindawi.com/journals/wcmc/2017/9068272.pdf","source":{"id":"https://openalex.org/S235346","display_name":"Wireless Communications and Mobile Computing","issn_l":"1530-8669","issn":["1530-8669","1530-8677"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320595","host_organization_name":"Wiley","host_organization_lineage":["https://openalex.org/P4310320595"],"host_organization_lineage_names":["Wiley"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Wireless Communications and Mobile Computing","raw_type":"journal-article"},"type":"article","indexed_in":["crossref","doaj"],"open_access":{"is_oa":true,"oa_status":"hybrid","oa_url":"http://downloads.hindawi.com/journals/wcmc/2017/9068272.pdf","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5067063025","display_name":"Juan Moreno","orcid":"https://orcid.org/0000-0002-4626-1535"},"institutions":[{"id":"https://openalex.org/I88060688","display_name":"Universidad Polit\u00e9cnica de Madrid","ror":"https://ror.org/03n6nwv02","country_code":"ES","type":"education","lineage":["https://openalex.org/I88060688"]}],"countries":["ES"],"is_corresponding":true,"raw_author_name":"Juan Moreno Garc\u00eda-Loygorri","raw_affiliation_strings":["Teor\u00eda de la Se\u00f1al y Comunicaciones Department, ETSIS Telecomunicaci\u00f3n, Universidad Polit\u00e9cnica de Madrid (UPM), Campus Sur, Calle Nikola Tesla s/n, 28031 Madrid, Spain"],"raw_orcid":"https://orcid.org/0000-0002-4626-1535","affiliations":[{"raw_affiliation_string":"Teor\u00eda de la Se\u00f1al y Comunicaciones Department, ETSIS Telecomunicaci\u00f3n, Universidad Polit\u00e9cnica de Madrid (UPM), Campus Sur, Calle Nikola Tesla s/n, 28031 Madrid, Spain","institution_ids":["https://openalex.org/I88060688"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5048702183","display_name":"Leandro de Haro Ariet","orcid":"https://orcid.org/0000-0003-3572-1986"},"institutions":[{"id":"https://openalex.org/I88060688","display_name":"Universidad Polit\u00e9cnica de Madrid","ror":"https://ror.org/03n6nwv02","country_code":"ES","type":"education","lineage":["https://openalex.org/I88060688"]}],"countries":["ES"],"is_corresponding":false,"raw_author_name":"Leandro de Haro","raw_affiliation_strings":["ETSI Telecomunicaci\u00f3n, Universidad Polit\u00e9cnica de Madrid (UPM), Ciudad Universitaria, 28040 Madrid, Spain"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"ETSI Telecomunicaci\u00f3n, Universidad Polit\u00e9cnica de Madrid (UPM), Ciudad Universitaria, 28040 Madrid, Spain","institution_ids":["https://openalex.org/I88060688"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5013237489","display_name":"Jos\u00e9 Manuel Riera","orcid":"https://orcid.org/0000-0002-7496-6663"},"institutions":[{"id":"https://openalex.org/I88060688","display_name":"Universidad Polit\u00e9cnica de Madrid","ror":"https://ror.org/03n6nwv02","country_code":"ES","type":"education","lineage":["https://openalex.org/I88060688"]}],"countries":["ES"],"is_corresponding":false,"raw_author_name":"Jos\u00e9 Manuel Riera","raw_affiliation_strings":["ETSI Telecomunicaci\u00f3n, Universidad Polit\u00e9cnica de Madrid (UPM), Ciudad Universitaria, 28040 Madrid, Spain"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"ETSI Telecomunicaci\u00f3n, Universidad Polit\u00e9cnica de Madrid (UPM), Ciudad Universitaria, 28040 Madrid, Spain","institution_ids":["https://openalex.org/I88060688"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5110170627","display_name":"Luis Cu\u00e9llar","orcid":null},"institutions":[{"id":"https://openalex.org/I88060688","display_name":"Universidad Polit\u00e9cnica de Madrid","ror":"https://ror.org/03n6nwv02","country_code":"ES","type":"education","lineage":["https://openalex.org/I88060688"]}],"countries":["ES"],"is_corresponding":false,"raw_author_name":"Luis Cu\u00e9llar","raw_affiliation_strings":["ETSI Telecomunicaci\u00f3n, Universidad Polit\u00e9cnica de Madrid (UPM), Ciudad Universitaria, 28040 Madrid, Spain"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"ETSI Telecomunicaci\u00f3n, Universidad Polit\u00e9cnica de Madrid (UPM), Ciudad Universitaria, 28040 Madrid, Spain","institution_ids":["https://openalex.org/I88060688"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5111386511","display_name":"Carlos Rodr\u00edguez","orcid":null},"institutions":[{"id":"https://openalex.org/I88060688","display_name":"Universidad Polit\u00e9cnica de Madrid","ror":"https://ror.org/03n6nwv02","country_code":"ES","type":"education","lineage":["https://openalex.org/I88060688"]}],"countries":["ES"],"is_corresponding":false,"raw_author_name":"Carlos Rodr\u00edguez","raw_affiliation_strings":["The Engineering Department of Metro de Madrid S.A., Madrid, Spain"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"The Engineering Department of Metro de Madrid S.A., Madrid, Spain","institution_ids":["https://openalex.org/I88060688"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":5,"corresponding_author_ids":["https://openalex.org/A5067063025"],"corresponding_institution_ids":["https://openalex.org/I88060688"],"apc_list":{"value":2300,"currency":"USD","value_usd":2300},"apc_paid":{"value":2300,"currency":"USD","value_usd":2300},"fwci":0.1461,"has_fulltext":true,"cited_by_count":1,"citation_normalized_percentile":{"value":0.51476433,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":90,"max":94},"biblio":{"volume":"2017","issue":null,"first_page":"1","last_page":"7"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10148","display_name":"Advanced MIMO Systems Optimization","score":0.9998999834060669,"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/T10148","display_name":"Advanced MIMO Systems Optimization","score":0.9998999834060669,"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/T12146","display_name":"Power Line Communications and Noise","score":0.9998999834060669,"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/T10936","display_name":"Millimeter-Wave Propagation and Modeling","score":0.9997000098228455,"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/computer-science","display_name":"Computer science","score":0.7113502025604248},{"id":"https://openalex.org/keywords/mimo","display_name":"MIMO","score":0.68104088306427},{"id":"https://openalex.org/keywords/transmitter","display_name":"Transmitter","score":0.6444315910339355},{"id":"https://openalex.org/keywords/algorithm","display_name":"Algorithm","score":0.4905823767185211},{"id":"https://openalex.org/keywords/testbed","display_name":"Testbed","score":0.4687243700027466},{"id":"https://openalex.org/keywords/telecommunications","display_name":"Telecommunications","score":0.4669405519962311},{"id":"https://openalex.org/keywords/telecommunications-link","display_name":"Telecommunications link","score":0.43870487809181213},{"id":"https://openalex.org/keywords/channel","display_name":"Channel (broadcasting)","score":0.3582476079463959},{"id":"https://openalex.org/keywords/computer-network","display_name":"Computer network","score":0.216169536113739}],"concepts":[{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.7113502025604248},{"id":"https://openalex.org/C207987634","wikidata":"https://www.wikidata.org/wiki/Q176862","display_name":"MIMO","level":3,"score":0.68104088306427},{"id":"https://openalex.org/C47798520","wikidata":"https://www.wikidata.org/wiki/Q190157","display_name":"Transmitter","level":3,"score":0.6444315910339355},{"id":"https://openalex.org/C11413529","wikidata":"https://www.wikidata.org/wiki/Q8366","display_name":"Algorithm","level":1,"score":0.4905823767185211},{"id":"https://openalex.org/C31395832","wikidata":"https://www.wikidata.org/wiki/Q1318674","display_name":"Testbed","level":2,"score":0.4687243700027466},{"id":"https://openalex.org/C76155785","wikidata":"https://www.wikidata.org/wiki/Q418","display_name":"Telecommunications","level":1,"score":0.4669405519962311},{"id":"https://openalex.org/C138660444","wikidata":"https://www.wikidata.org/wiki/Q5607897","display_name":"Telecommunications link","level":2,"score":0.43870487809181213},{"id":"https://openalex.org/C127162648","wikidata":"https://www.wikidata.org/wiki/Q16858953","display_name":"Channel (broadcasting)","level":2,"score":0.3582476079463959},{"id":"https://openalex.org/C31258907","wikidata":"https://www.wikidata.org/wiki/Q1301371","display_name":"Computer network","level":1,"score":0.216169536113739}],"mesh":[],"locations_count":2,"locations":[{"id":"doi:10.1155/2017/9068272","is_oa":true,"landing_page_url":"https://doi.org/10.1155/2017/9068272","pdf_url":"http://downloads.hindawi.com/journals/wcmc/2017/9068272.pdf","source":{"id":"https://openalex.org/S235346","display_name":"Wireless Communications and Mobile Computing","issn_l":"1530-8669","issn":["1530-8669","1530-8677"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320595","host_organization_name":"Wiley","host_organization_lineage":["https://openalex.org/P4310320595"],"host_organization_lineage_names":["Wiley"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Wireless Communications and Mobile Computing","raw_type":"journal-article"},{"id":"pmh:oai:doaj.org/article:7bd18999f26441cb9804867365d0b42c","is_oa":true,"landing_page_url":"https://doaj.org/article/7bd18999f26441cb9804867365d0b42c","pdf_url":null,"source":{"id":"https://openalex.org/S4306401280","display_name":"DOAJ (DOAJ: Directory of Open Access Journals)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by-sa","license_id":"https://openalex.org/licenses/cc-by-sa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"Wireless Communications and Mobile Computing, Vol 2017 (2017)","raw_type":"article"}],"best_oa_location":{"id":"doi:10.1155/2017/9068272","is_oa":true,"landing_page_url":"https://doi.org/10.1155/2017/9068272","pdf_url":"http://downloads.hindawi.com/journals/wcmc/2017/9068272.pdf","source":{"id":"https://openalex.org/S235346","display_name":"Wireless Communications and Mobile Computing","issn_l":"1530-8669","issn":["1530-8669","1530-8677"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320595","host_organization_name":"Wiley","host_organization_lineage":["https://openalex.org/P4310320595"],"host_organization_lineage_names":["Wiley"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Wireless Communications and Mobile Computing","raw_type":"journal-article"},"sustainable_development_goals":[],"awards":[{"id":"https://openalex.org/G6123735669","display_name":null,"funder_award_id":"TEC2014-57821-R","funder_id":"https://openalex.org/F4320321837","funder_display_name":"Ministerio de Econom\u00eda y Competitividad"}],"funders":[{"id":"https://openalex.org/F4320321837","display_name":"Ministerio de Econom\u00eda y Competitividad","ror":"https://ror.org/034900433"}],"has_content":{"grobid_xml":true,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W2744778118.pdf","grobid_xml":"https://content.openalex.org/works/W2744778118.grobid-xml"},"referenced_works_count":12,"referenced_works":["https://openalex.org/W2041203084","https://openalex.org/W2079355059","https://openalex.org/W2097872762","https://openalex.org/W2098249016","https://openalex.org/W2100183117","https://openalex.org/W2107004317","https://openalex.org/W2107080958","https://openalex.org/W2116746242","https://openalex.org/W2119332111","https://openalex.org/W2134138008","https://openalex.org/W2155053896","https://openalex.org/W2165943096"],"related_works":["https://openalex.org/W2883256816","https://openalex.org/W2171408034","https://openalex.org/W3003320923","https://openalex.org/W2106140982","https://openalex.org/W2152313554","https://openalex.org/W3048672182","https://openalex.org/W1509300825","https://openalex.org/W2059045613","https://openalex.org/W2502435347","https://openalex.org/W4309910562"],"abstract_inverted_index":{"One":[0],"of":[1,46,54,70,81,114,116,123,153,163,189,202,217],"the":[2,47,52,79,82,112,124,146,154,161,196,215,218],"key":[3],"challenges":[4],"in":[5,61],"railway":[6],"engineering":[7],"is":[8,109,169,221],"how":[9],"to":[10,111],"provide":[11],"passengers":[12],"an":[13,55,71],"efficient,":[14],"secure,":[15],"and":[16,23,27,104,130,171,191],"safe":[17],"service.":[18],"To":[19],"achieve":[20],"this,":[21],"operators":[22],"stakeholders":[24],"demand":[25],"robust":[26],"high-capacity":[28],"train-to-wayside":[29],"broadband":[30],"radio.":[31],"Current":[32],"radio":[33],"technologies":[34],"implement":[35],"MIMO":[36,59,125],"(Multiple-Input":[37],"Multiple-Output)":[38],"technology,":[39],"whose":[40],"use":[41,69,162],"requires":[42],"a":[43,120,141,151,177,199],"good":[44],"characterization":[45],"propagation.":[48],"In":[49],"this":[50],"paper,":[51],"results":[53],"experimental":[56],"campaign":[57,67],"on":[58,173,214],"propagation":[60],"subway":[62],"tunnels":[63],"are":[64,133,137,207],"presented.":[65],"The":[66,135],"makes":[68],"OFDM":[72],"testbed":[73],"at":[74,145,166],"roughly":[75],"600":[76],"MHz,":[77],"allowing":[78],"measurement":[80],"<mml:math":[83],"xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"":[84],"id=\"M1\"><mml:mn":[85],"fontstyle=\"italic\">2</mml:mn><mml:mo>\u00d7</mml:mo><mml:mn":[86],"fontstyle=\"italic\">2</mml:mn></mml:math>":[87],"channel":[88],"transfer":[89],"matrix":[90],"under":[91],"different":[92],"conditions":[93],"regarding":[94],"polarization,":[95],"antenna":[96],"separation,":[97],"tunnel":[98],"cross":[99],"section,":[100],"power":[101],"allocation":[102],"algorithm,":[103],"so":[105,211],"forth.":[106],"Particular":[107],"attention":[108],"paid":[110],"probability":[113,201],"appearance":[115],"keyholes,":[117],"which":[118],"imply":[119],"severe":[121],"degradation":[122],"performance":[126,216],"even":[127],"when":[128],"transmitter":[129],"receiver":[131],"antennas":[132,182],"uncorrelated.":[134],"measurements":[136],"carried":[138],"out":[139],"using":[140],"train":[142],"that":[143,160],"travels":[144],"normal":[147],"operative":[148],"velocities.":[149],"As":[150],"result":[152],"measurements,":[155],"it":[156],"has":[157],"been":[158],"found":[159],"vertical":[164],"polarization":[165],"both":[167],"terminals":[168],"advantageous":[170],"that,":[172],"average":[174],"but":[175],"for":[176],"narrow":[178],"margin,":[179],"\u03bb":[180,184],"-spaced":[181],"outperform":[183],"/2-spaced":[185],"ones":[186],"(90%":[187],"capacities":[188],"7.00":[190],"6.76":[192],"bps/Hz,":[193],"resp.),":[194],"although":[195],"latter":[197],"show":[198],"lower":[200],"keyholes.":[203],"However,":[204],"keyhole":[205],"probabilities":[206],"always":[208],"below":[209],"2%,":[210],"their":[212],"influence":[213],"whole":[219],"system":[220],"limited.":[222]},"counts_by_year":[{"year":2017,"cited_by_count":1}],"updated_date":"2026-05-21T06:26:12.895304","created_date":"2025-10-10T00:00:00"}