{"id":"https://openalex.org/W4281625824","doi":"https://doi.org/10.3390/network2020021","title":"A Computationally Efficient Gradient Algorithm for Downlink Training Sequence Optimization in FDD Massive MIMO Systems","display_name":"A Computationally Efficient Gradient Algorithm for Downlink Training Sequence Optimization in FDD Massive MIMO Systems","publication_year":2022,"publication_date":"2022-06-05","ids":{"openalex":"https://openalex.org/W4281625824","doi":"https://doi.org/10.3390/network2020021"},"language":"en","primary_location":{"id":"doi:10.3390/network2020021","is_oa":true,"landing_page_url":"https://doi.org/10.3390/network2020021","pdf_url":"https://www.mdpi.com/2673-8732/2/2/21/pdf?version=1654605370","source":{"id":"https://openalex.org/S4210214347","display_name":"Network","issn_l":"2673-8732","issn":["2673-8732"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310310987","host_organization_name":"Multidisciplinary Digital Publishing Institute","host_organization_lineage":["https://openalex.org/P4310310987"],"host_organization_lineage_names":["Multidisciplinary Digital Publishing Institute"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Network","raw_type":"journal-article"},"type":"article","indexed_in":["crossref","doaj"],"open_access":{"is_oa":true,"oa_status":"gold","oa_url":"https://www.mdpi.com/2673-8732/2/2/21/pdf?version=1654605370","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5067180435","display_name":"Muntadher Alsabah","orcid":"https://orcid.org/0000-0001-7937-3093"},"institutions":[{"id":"https://openalex.org/I91136226","display_name":"University of Sheffield","ror":"https://ror.org/05krs5044","country_code":"GB","type":"education","lineage":["https://openalex.org/I91136226"]}],"countries":["GB"],"is_corresponding":true,"raw_author_name":"Muntadher Alsabah","raw_affiliation_strings":["Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield S1 4ET, UK"],"raw_orcid":"https://orcid.org/0000-0001-7937-3093","affiliations":[{"raw_affiliation_string":"Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield S1 4ET, UK","institution_ids":["https://openalex.org/I91136226"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5010811055","display_name":"Marwah Abdulrazzaq Naser","orcid":"https://orcid.org/0000-0001-5686-2759"},"institutions":[{"id":"https://openalex.org/I135120706","display_name":"University of Baghdad","ror":"https://ror.org/007f1da21","country_code":"IQ","type":"education","lineage":["https://openalex.org/I135120706"]}],"countries":["IQ"],"is_corresponding":false,"raw_author_name":"Marwah Abdulrazzaq Naser","raw_affiliation_strings":["Continuous Education Center, University of Baghdad, Baghdad 10001, Iraq"],"raw_orcid":"https://orcid.org/0000-0001-5686-2759","affiliations":[{"raw_affiliation_string":"Continuous Education Center, University of Baghdad, Baghdad 10001, Iraq","institution_ids":["https://openalex.org/I135120706"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5020675008","display_name":"Basheera M. Mahmmod","orcid":"https://orcid.org/0000-0002-4121-0843"},"institutions":[{"id":"https://openalex.org/I135120706","display_name":"University of Baghdad","ror":"https://ror.org/007f1da21","country_code":"IQ","type":"education","lineage":["https://openalex.org/I135120706"]}],"countries":["IQ"],"is_corresponding":false,"raw_author_name":"Basheera M. Mahmmod","raw_affiliation_strings":["Department of Computer Engineering, University of Baghdad, Al-Jadriya, Baghdad 10071, Iraq"],"raw_orcid":"https://orcid.org/0000-0002-4121-0843","affiliations":[{"raw_affiliation_string":"Department of Computer Engineering, University of Baghdad, Al-Jadriya, Baghdad 10071, Iraq","institution_ids":["https://openalex.org/I135120706"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5017117569","display_name":"Sadiq H. Abdulhussain","orcid":"https://orcid.org/0000-0002-6439-0082"},"institutions":[{"id":"https://openalex.org/I135120706","display_name":"University of Baghdad","ror":"https://ror.org/007f1da21","country_code":"IQ","type":"education","lineage":["https://openalex.org/I135120706"]}],"countries":["IQ"],"is_corresponding":false,"raw_author_name":"Sadiq H. Abdulhussain","raw_affiliation_strings":["Department of Computer Engineering, University of Baghdad, Al-Jadriya, Baghdad 10071, Iraq"],"raw_orcid":"https://orcid.org/0000-0002-6439-0082","affiliations":[{"raw_affiliation_string":"Department of Computer Engineering, University of Baghdad, Al-Jadriya, Baghdad 10071, Iraq","institution_ids":["https://openalex.org/I135120706"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":2,"corresponding_author_ids":["https://openalex.org/A5067180435"],"corresponding_institution_ids":["https://openalex.org/I91136226"],"apc_list":{"value":1000,"currency":"CHF","value_usd":1082},"apc_paid":{"value":1000,"currency":"CHF","value_usd":1082},"fwci":0.265,"has_fulltext":false,"cited_by_count":4,"citation_normalized_percentile":{"value":0.49991042,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":94,"max":97},"biblio":{"volume":"2","issue":"2","first_page":"329","last_page":"349"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10148","display_name":"Advanced MIMO Systems Optimization","score":1.0,"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":1.0,"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/T12791","display_name":"Full-Duplex Wireless Communications","score":0.9994999766349792,"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/T11392","display_name":"Energy Harvesting in Wireless Networks","score":0.9991000294685364,"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":0.6983925104141235},{"id":"https://openalex.org/keywords/telecommunications-link","display_name":"Telecommunications link","score":0.6891560554504395},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.651765763759613},{"id":"https://openalex.org/keywords/algorithm","display_name":"Algorithm","score":0.614326000213623},{"id":"https://openalex.org/keywords/channel-state-information","display_name":"Channel state information","score":0.5809866786003113},{"id":"https://openalex.org/keywords/computational-complexity-theory","display_name":"Computational complexity theory","score":0.5471901893615723},{"id":"https://openalex.org/keywords/spectral-efficiency","display_name":"Spectral efficiency","score":0.4722684621810913},{"id":"https://openalex.org/keywords/base-station","display_name":"Base station","score":0.4653063416481018},{"id":"https://openalex.org/keywords/wireless","display_name":"Wireless","score":0.4341168701648712},{"id":"https://openalex.org/keywords/rate-of-convergence","display_name":"Rate of convergence","score":0.4169556796550751},{"id":"https://openalex.org/keywords/conjugate-gradient-method","display_name":"Conjugate gradient method","score":0.41157296299934387},{"id":"https://openalex.org/keywords/computer-engineering","display_name":"Computer engineering","score":0.3769332766532898},{"id":"https://openalex.org/keywords/channel","display_name":"Channel (broadcasting)","score":0.3627914786338806},{"id":"https://openalex.org/keywords/telecommunications","display_name":"Telecommunications","score":0.1764054000377655}],"concepts":[{"id":"https://openalex.org/C207987634","wikidata":"https://www.wikidata.org/wiki/Q176862","display_name":"MIMO","level":3,"score":0.6983925104141235},{"id":"https://openalex.org/C138660444","wikidata":"https://www.wikidata.org/wiki/Q5607897","display_name":"Telecommunications link","level":2,"score":0.6891560554504395},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.651765763759613},{"id":"https://openalex.org/C11413529","wikidata":"https://www.wikidata.org/wiki/Q8366","display_name":"Algorithm","level":1,"score":0.614326000213623},{"id":"https://openalex.org/C148063708","wikidata":"https://www.wikidata.org/wiki/Q5072511","display_name":"Channel state information","level":3,"score":0.5809866786003113},{"id":"https://openalex.org/C179799912","wikidata":"https://www.wikidata.org/wiki/Q205084","display_name":"Computational complexity theory","level":2,"score":0.5471901893615723},{"id":"https://openalex.org/C137246740","wikidata":"https://www.wikidata.org/wiki/Q583970","display_name":"Spectral efficiency","level":3,"score":0.4722684621810913},{"id":"https://openalex.org/C68649174","wikidata":"https://www.wikidata.org/wiki/Q1379116","display_name":"Base station","level":2,"score":0.4653063416481018},{"id":"https://openalex.org/C555944384","wikidata":"https://www.wikidata.org/wiki/Q249","display_name":"Wireless","level":2,"score":0.4341168701648712},{"id":"https://openalex.org/C57869625","wikidata":"https://www.wikidata.org/wiki/Q1783502","display_name":"Rate of convergence","level":3,"score":0.4169556796550751},{"id":"https://openalex.org/C81184566","wikidata":"https://www.wikidata.org/wiki/Q1191895","display_name":"Conjugate gradient method","level":2,"score":0.41157296299934387},{"id":"https://openalex.org/C113775141","wikidata":"https://www.wikidata.org/wiki/Q428691","display_name":"Computer engineering","level":1,"score":0.3769332766532898},{"id":"https://openalex.org/C127162648","wikidata":"https://www.wikidata.org/wiki/Q16858953","display_name":"Channel (broadcasting)","level":2,"score":0.3627914786338806},{"id":"https://openalex.org/C76155785","wikidata":"https://www.wikidata.org/wiki/Q418","display_name":"Telecommunications","level":1,"score":0.1764054000377655}],"mesh":[],"locations_count":3,"locations":[{"id":"doi:10.3390/network2020021","is_oa":true,"landing_page_url":"https://doi.org/10.3390/network2020021","pdf_url":"https://www.mdpi.com/2673-8732/2/2/21/pdf?version=1654605370","source":{"id":"https://openalex.org/S4210214347","display_name":"Network","issn_l":"2673-8732","issn":["2673-8732"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310310987","host_organization_name":"Multidisciplinary Digital Publishing Institute","host_organization_lineage":["https://openalex.org/P4310310987"],"host_organization_lineage_names":["Multidisciplinary Digital Publishing Institute"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Network","raw_type":"journal-article"},{"id":"pmh:oai:doaj.org/article:c8f9f0295c4545e8bd28a07ad130f3a0","is_oa":false,"landing_page_url":"https://doaj.org/article/c8f9f0295c4545e8bd28a07ad130f3a0","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":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"Network, Vol 2, Iss 2, Pp 329-349 (2022)","raw_type":"article"},{"id":"pmh:oai:mdpi.com:/2673-8732/2/2/21/","is_oa":true,"landing_page_url":"https://dx.doi.org/10.3390/network2020021","pdf_url":null,"source":{"id":"https://openalex.org/S4306400947","display_name":"MDPI (MDPI AG)","issn_l":null,"issn":null,"is_oa":true,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I4210097602","host_organization_name":"Multidisciplinary Digital Publishing Institute (Switzerland)","host_organization_lineage":["https://openalex.org/I4210097602"],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"Network; Volume 2; Issue 2; Pages: 329-349","raw_type":"Text"}],"best_oa_location":{"id":"doi:10.3390/network2020021","is_oa":true,"landing_page_url":"https://doi.org/10.3390/network2020021","pdf_url":"https://www.mdpi.com/2673-8732/2/2/21/pdf?version=1654605370","source":{"id":"https://openalex.org/S4210214347","display_name":"Network","issn_l":"2673-8732","issn":["2673-8732"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310310987","host_organization_name":"Multidisciplinary Digital Publishing Institute","host_organization_lineage":["https://openalex.org/P4310310987"],"host_organization_lineage_names":["Multidisciplinary Digital Publishing Institute"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Network","raw_type":"journal-article"},"sustainable_development_goals":[{"id":"https://metadata.un.org/sdg/7","score":0.9100000262260437,"display_name":"Affordable and clean energy"}],"awards":[],"funders":[],"has_content":{"grobid_xml":false,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W4281625824.pdf"},"referenced_works_count":55,"referenced_works":["https://openalex.org/W615589970","https://openalex.org/W1489793438","https://openalex.org/W1531510426","https://openalex.org/W1583608886","https://openalex.org/W1884691811","https://openalex.org/W2015301486","https://openalex.org/W2032023051","https://openalex.org/W2035750833","https://openalex.org/W2036030019","https://openalex.org/W2059335839","https://openalex.org/W2069732313","https://openalex.org/W2076159682","https://openalex.org/W2076457767","https://openalex.org/W2084304524","https://openalex.org/W2107062901","https://openalex.org/W2108256297","https://openalex.org/W2111136894","https://openalex.org/W2113157322","https://openalex.org/W2128513990","https://openalex.org/W2130793677","https://openalex.org/W2147601077","https://openalex.org/W2152137214","https://openalex.org/W2259391824","https://openalex.org/W2272774410","https://openalex.org/W2519766179","https://openalex.org/W2540675799","https://openalex.org/W2605149632","https://openalex.org/W2621216226","https://openalex.org/W2625300002","https://openalex.org/W2792133228","https://openalex.org/W2921038745","https://openalex.org/W2963532871","https://openalex.org/W2964079960","https://openalex.org/W3012505043","https://openalex.org/W3033931948","https://openalex.org/W3034099365","https://openalex.org/W3090858036","https://openalex.org/W3101962249","https://openalex.org/W3103200723","https://openalex.org/W3106776568","https://openalex.org/W3112476779","https://openalex.org/W3135335762","https://openalex.org/W3138211747","https://openalex.org/W3144312728","https://openalex.org/W3152550128","https://openalex.org/W3180655257","https://openalex.org/W3186872294","https://openalex.org/W3190464085","https://openalex.org/W3197571222","https://openalex.org/W3204993703","https://openalex.org/W3211304744","https://openalex.org/W3211536314","https://openalex.org/W4200580283","https://openalex.org/W4205293427","https://openalex.org/W4206498489"],"related_works":["https://openalex.org/W2548963335","https://openalex.org/W2159941915","https://openalex.org/W1995129237","https://openalex.org/W4388081250","https://openalex.org/W2909457694","https://openalex.org/W1761601995","https://openalex.org/W2904599916","https://openalex.org/W4313028534","https://openalex.org/W2601693592","https://openalex.org/W2101989320"],"abstract_inverted_index":{"Future":[0],"wireless":[1,41],"networks":[2],"will":[3],"require":[4],"advance":[5],"physical-layer":[6],"techniques":[7],"to":[8,31,46,51,104,115,152,167,223,230],"meet":[9],"the":[10,36,47,57,147,154,164,181,185,190,197,205,210,231],"requirements":[11],"of":[12,14,35,49,189],"Internet":[13],"Everything":[15],"(IoE)":[16],"applications":[17],"and":[18,60,124,129,184],"massive":[19,26],"communication":[20],"systems.":[21],"To":[22,132,178],"this":[23,117,134,179],"end,":[24,180],"a":[25,53,84,138,169,217,224],"MIMO":[27],"(m-MIMO)":[28],"system":[29,90],"is":[30,44,103],"date":[32,105],"considered":[33],"one":[34],"key":[37],"technologies":[38],"for":[39,71,173],"future":[40],"networks.":[42],"This":[43],"due":[45],"capability":[48],"m-MIMO":[50,89,176],"bring":[52],"significant":[54],"improvement":[55],"in":[56,83,150,228],"spectral":[58],"efficiency":[59],"energy":[61],"efficiency.":[62],"However,":[63],"designing":[64],"an":[65,174],"efficient":[66,140],"downlink":[67],"(DL)":[68],"training":[69,156,192,207],"sequence":[70,157],"fast":[72,170],"channel":[73,100],"state":[74],"information":[75],"(CSI)":[76],"estimation,":[77],"i.e.,":[78,97],"with":[79,196],"limited":[80],"coherence":[81],"time,":[82],"frequency":[85],"division":[86],"duplex":[87],"(FDD)":[88],"when":[91],"users":[92],"exhibit":[93,120],"different":[94],"correlation":[95],"patterns,":[96],"span":[98],"distinct":[99],"covariance":[101],"matrices,":[102],"very":[106],"challenging.":[107],"Although":[108],"advanced":[109],"iterative":[110,199,233],"algorithms":[111],"have":[112],"been":[113],"developed":[114],"address":[116],"challenge,":[118,135],"they":[119],"slow":[121],"convergence":[122,165,226],"speed":[123],"thus":[125],"deliver":[126],"high":[127],"latency":[128],"computational":[130,186,220],"complexity.":[131],"overcome":[133],"we":[136],"propose":[137],"computationally":[139],"conjugate":[141],"gradient-descent":[142],"(CGD)":[143],"algorithm":[144],"based":[145],"on":[146],"Riemannian":[148],"manifold":[149],"order":[151],"optimize":[153],"DL":[155],"at":[158],"base":[159],"station":[160],"(BS),":[161],"while":[162,215],"improving":[163],"rate":[166,183,213,227],"provide":[168],"CSI":[171],"estimation":[172],"FDD":[175],"system.":[177],"sum":[182,212],"complexity":[187,221],"performances":[188],"proposed":[191,206],"solution":[193,208],"are":[194],"compared":[195],"state-of-the-art":[198,232],"algorithms.":[200,234],"The":[201],"results":[202],"show":[203],"that":[204],"maximizes":[209],"achievable":[211],"performance,":[214],"delivering":[216],"lower":[218],"overall":[219],"owing":[222],"faster":[225],"comparison":[229]},"counts_by_year":[{"year":2026,"cited_by_count":1},{"year":2024,"cited_by_count":3}],"updated_date":"2026-05-22T06:13:13.366637","created_date":"2022-06-13T00:00:00"}
