{"id":"https://openalex.org/W4210339785","doi":"https://doi.org/10.1109/globecom46510.2021.9685790","title":"Optimal Discrete Beamforming for Intelligent Reflecting Surface","display_name":"Optimal Discrete Beamforming for Intelligent Reflecting Surface","publication_year":2021,"publication_date":"2021-12-01","ids":{"openalex":"https://openalex.org/W4210339785","doi":"https://doi.org/10.1109/globecom46510.2021.9685790"},"language":"en","primary_location":{"id":"doi:10.1109/globecom46510.2021.9685790","is_oa":false,"landing_page_url":"https://doi.org/10.1109/globecom46510.2021.9685790","pdf_url":null,"source":{"id":"https://openalex.org/S4363607714","display_name":"2021 IEEE Global Communications Conference (GLOBECOM)","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":"conference"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"2021 IEEE Global Communications Conference (GLOBECOM)","raw_type":"proceedings-article"},"type":"conference-paper","indexed_in":["crossref"],"open_access":{"is_oa":false,"oa_status":"closed","oa_url":null,"any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5085839084","display_name":"Yaowen Zhang","orcid":null},"institutions":[{"id":"https://openalex.org/I4210116924","display_name":"Chinese University of Hong Kong, Shenzhen","ror":"https://ror.org/02d5ks197","country_code":"CN","type":"education","lineage":["https://openalex.org/I177725633","https://openalex.org/I180726961","https://openalex.org/I4210116924"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Yaowen Zhang","raw_affiliation_strings":["School of Science and Engineering, The Chinese University of Hong Kong,Shenzhen,China","School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"School of Science and Engineering, The Chinese University of Hong Kong,Shenzhen,China","institution_ids":["https://openalex.org/I4210116924"]},{"raw_affiliation_string":"School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, China","institution_ids":["https://openalex.org/I4210116924"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5041857749","display_name":"Shuyi Ren","orcid":null},"institutions":[{"id":"https://openalex.org/I4210116924","display_name":"Chinese University of Hong Kong, Shenzhen","ror":"https://ror.org/02d5ks197","country_code":"CN","type":"education","lineage":["https://openalex.org/I177725633","https://openalex.org/I180726961","https://openalex.org/I4210116924"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Shuyi Ren","raw_affiliation_strings":["School of Science and Engineering, The Chinese University of Hong Kong,Shenzhen,China","School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"School of Science and Engineering, The Chinese University of Hong Kong,Shenzhen,China","institution_ids":["https://openalex.org/I4210116924"]},{"raw_affiliation_string":"School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, China","institution_ids":["https://openalex.org/I4210116924"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5022905256","display_name":"Kaiming Shen","orcid":"https://orcid.org/0000-0003-0680-7975"},"institutions":[{"id":"https://openalex.org/I4210116924","display_name":"Chinese University of Hong Kong, Shenzhen","ror":"https://ror.org/02d5ks197","country_code":"CN","type":"education","lineage":["https://openalex.org/I177725633","https://openalex.org/I180726961","https://openalex.org/I4210116924"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Kaiming Shen","raw_affiliation_strings":["School of Science and Engineering, The Chinese University of Hong Kong,Shenzhen,China","School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"School of Science and Engineering, The Chinese University of Hong Kong,Shenzhen,China","institution_ids":["https://openalex.org/I4210116924"]},{"raw_affiliation_string":"School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, China","institution_ids":["https://openalex.org/I4210116924"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5101766226","display_name":"Zhi\u2010Quan Luo","orcid":"https://orcid.org/0000-0003-3995-914X"},"institutions":[{"id":"https://openalex.org/I4210099586","display_name":"Shenzhen Research Institute of Big Data","ror":"https://ror.org/00z1gwf89","country_code":"CN","type":"education","lineage":["https://openalex.org/I4210099586"]},{"id":"https://openalex.org/I4210116924","display_name":"Chinese University of Hong Kong, Shenzhen","ror":"https://ror.org/02d5ks197","country_code":"CN","type":"education","lineage":["https://openalex.org/I177725633","https://openalex.org/I180726961","https://openalex.org/I4210116924"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Zhi-Quan Luo","raw_affiliation_strings":["School of Science and Engineering, The Chinese University of Hong Kong,Shenzhen,China","School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, China","Shenzhen Research Institute of Big Data, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"School of Science and Engineering, The Chinese University of Hong Kong,Shenzhen,China","institution_ids":["https://openalex.org/I4210116924"]},{"raw_affiliation_string":"School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, China","institution_ids":["https://openalex.org/I4210116924"]},{"raw_affiliation_string":"Shenzhen Research Institute of Big Data, China","institution_ids":["https://openalex.org/I4210099586"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":2,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":1.221,"has_fulltext":false,"cited_by_count":5,"citation_normalized_percentile":{"value":0.78686909,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":90,"max":96},"biblio":{"volume":null,"issue":null,"first_page":"1","last_page":"6"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11458","display_name":"Advanced Wireless Communication Technologies","score":0.9998000264167786,"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":0.9998000264167786,"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/T11192","display_name":"Underwater Vehicles and Communication Systems","score":0.9775000214576721,"subfield":{"id":"https://openalex.org/subfields/2212","display_name":"Ocean 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/T12989","display_name":"Ocular Disorders and Treatments","score":0.9502000212669373,"subfield":{"id":"https://openalex.org/subfields/1311","display_name":"Genetics"},"field":{"id":"https://openalex.org/fields/13","display_name":"Biochemistry, Genetics and Molecular Biology"},"domain":{"id":"https://openalex.org/domains/1","display_name":"Life Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/beamforming","display_name":"Beamforming","score":0.657477855682373},{"id":"https://openalex.org/keywords/constraint","display_name":"Constraint (computer-aided design)","score":0.5325815677642822},{"id":"https://openalex.org/keywords/mathematical-optimization","display_name":"Mathematical optimization","score":0.5291168093681335},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.5207797884941101},{"id":"https://openalex.org/keywords/channel-state-information","display_name":"Channel state information","score":0.5175787210464478},{"id":"https://openalex.org/keywords/channel","display_name":"Channel (broadcasting)","score":0.4929070472717285},{"id":"https://openalex.org/keywords/algorithm","display_name":"Algorithm","score":0.49072229862213135},{"id":"https://openalex.org/keywords/greedy-algorithm","display_name":"Greedy algorithm","score":0.4906240999698639},{"id":"https://openalex.org/keywords/surface","display_name":"Surface (topology)","score":0.4577327072620392},{"id":"https://openalex.org/keywords/approximation-algorithm","display_name":"Approximation algorithm","score":0.45560967922210693},{"id":"https://openalex.org/keywords/binary-number","display_name":"Binary number","score":0.45370644330978394},{"id":"https://openalex.org/keywords/time-complexity","display_name":"Time complexity","score":0.43960872292518616},{"id":"https://openalex.org/keywords/polynomial","display_name":"Polynomial","score":0.41679874062538147},{"id":"https://openalex.org/keywords/set","display_name":"Set (abstract data type)","score":0.4151558578014374},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.34356364607810974},{"id":"https://openalex.org/keywords/wireless","display_name":"Wireless","score":0.16062775254249573},{"id":"https://openalex.org/keywords/telecommunications","display_name":"Telecommunications","score":0.1269325315952301},{"id":"https://openalex.org/keywords/mathematical-analysis","display_name":"Mathematical analysis","score":0.09471133351325989},{"id":"https://openalex.org/keywords/geometry","display_name":"Geometry","score":0.08313870429992676}],"concepts":[{"id":"https://openalex.org/C54197355","wikidata":"https://www.wikidata.org/wiki/Q5782992","display_name":"Beamforming","level":2,"score":0.657477855682373},{"id":"https://openalex.org/C2776036281","wikidata":"https://www.wikidata.org/wiki/Q48769818","display_name":"Constraint (computer-aided design)","level":2,"score":0.5325815677642822},{"id":"https://openalex.org/C126255220","wikidata":"https://www.wikidata.org/wiki/Q141495","display_name":"Mathematical optimization","level":1,"score":0.5291168093681335},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.5207797884941101},{"id":"https://openalex.org/C148063708","wikidata":"https://www.wikidata.org/wiki/Q5072511","display_name":"Channel state information","level":3,"score":0.5175787210464478},{"id":"https://openalex.org/C127162648","wikidata":"https://www.wikidata.org/wiki/Q16858953","display_name":"Channel (broadcasting)","level":2,"score":0.4929070472717285},{"id":"https://openalex.org/C11413529","wikidata":"https://www.wikidata.org/wiki/Q8366","display_name":"Algorithm","level":1,"score":0.49072229862213135},{"id":"https://openalex.org/C51823790","wikidata":"https://www.wikidata.org/wiki/Q504353","display_name":"Greedy algorithm","level":2,"score":0.4906240999698639},{"id":"https://openalex.org/C2776799497","wikidata":"https://www.wikidata.org/wiki/Q484298","display_name":"Surface (topology)","level":2,"score":0.4577327072620392},{"id":"https://openalex.org/C148764684","wikidata":"https://www.wikidata.org/wiki/Q621751","display_name":"Approximation algorithm","level":2,"score":0.45560967922210693},{"id":"https://openalex.org/C48372109","wikidata":"https://www.wikidata.org/wiki/Q3913","display_name":"Binary number","level":2,"score":0.45370644330978394},{"id":"https://openalex.org/C311688","wikidata":"https://www.wikidata.org/wiki/Q2393193","display_name":"Time complexity","level":2,"score":0.43960872292518616},{"id":"https://openalex.org/C90119067","wikidata":"https://www.wikidata.org/wiki/Q43260","display_name":"Polynomial","level":2,"score":0.41679874062538147},{"id":"https://openalex.org/C177264268","wikidata":"https://www.wikidata.org/wiki/Q1514741","display_name":"Set (abstract data type)","level":2,"score":0.4151558578014374},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.34356364607810974},{"id":"https://openalex.org/C555944384","wikidata":"https://www.wikidata.org/wiki/Q249","display_name":"Wireless","level":2,"score":0.16062775254249573},{"id":"https://openalex.org/C76155785","wikidata":"https://www.wikidata.org/wiki/Q418","display_name":"Telecommunications","level":1,"score":0.1269325315952301},{"id":"https://openalex.org/C134306372","wikidata":"https://www.wikidata.org/wiki/Q7754","display_name":"Mathematical analysis","level":1,"score":0.09471133351325989},{"id":"https://openalex.org/C2524010","wikidata":"https://www.wikidata.org/wiki/Q8087","display_name":"Geometry","level":1,"score":0.08313870429992676},{"id":"https://openalex.org/C199360897","wikidata":"https://www.wikidata.org/wiki/Q9143","display_name":"Programming language","level":1,"score":0.0},{"id":"https://openalex.org/C94375191","wikidata":"https://www.wikidata.org/wiki/Q11205","display_name":"Arithmetic","level":1,"score":0.0}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1109/globecom46510.2021.9685790","is_oa":false,"landing_page_url":"https://doi.org/10.1109/globecom46510.2021.9685790","pdf_url":null,"source":{"id":"https://openalex.org/S4363607714","display_name":"2021 IEEE Global Communications Conference (GLOBECOM)","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":"conference"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"2021 IEEE Global Communications Conference (GLOBECOM)","raw_type":"proceedings-article"}],"best_oa_location":null,"sustainable_development_goals":[],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":22,"referenced_works":["https://openalex.org/W1996215314","https://openalex.org/W2143406968","https://openalex.org/W2950077417","https://openalex.org/W2971912794","https://openalex.org/W2985466239","https://openalex.org/W2990747873","https://openalex.org/W2995554704","https://openalex.org/W3009902505","https://openalex.org/W3010695123","https://openalex.org/W3012004564","https://openalex.org/W3013719647","https://openalex.org/W3017150380","https://openalex.org/W3032095193","https://openalex.org/W3034533409","https://openalex.org/W3034980365","https://openalex.org/W3039402952","https://openalex.org/W3098797675","https://openalex.org/W3113871758","https://openalex.org/W3120117232","https://openalex.org/W3130026012","https://openalex.org/W4236826464","https://openalex.org/W6774773516"],"related_works":["https://openalex.org/W2088352174","https://openalex.org/W3084132786","https://openalex.org/W4327661444","https://openalex.org/W2034991012","https://openalex.org/W3204684126","https://openalex.org/W3117290964","https://openalex.org/W1594413663","https://openalex.org/W2962917430","https://openalex.org/W2028468530","https://openalex.org/W189401716"],"abstract_inverted_index":{"This":[0],"work":[1],"pursues":[2],"an":[3,132],"optimal":[4],"strategy":[5],"of":[6,27,62,108,126,143,162,170],"designing":[7],"passive":[8],"beamformer":[9],"for":[10,30],"intelligent":[11],"reflecting":[12],"surface":[13],"(IRS)":[14],"in":[15,51,69,96,103,155,167],"order":[16],"to":[17,48,86,92],"maximize":[18],"the":[19,25,41,55,59,63,80,89,93,97,104,106,144,152,163,168],"overall":[20],"channel":[21,171],"strength.":[22],"In":[23,115],"particular,":[24],"choice":[26],"phase":[28],"shift":[29],"each":[31],"reflective":[32],"element":[33],"is":[34,46,85,124,139],"restricted":[35],"to$K":[36],"\\geq":[37],"2$discrete":[38],"values.":[39],"Although":[40],"resulting":[42],"discrete":[43],"beamforming":[44,75],"problem":[45,76],"believed":[47],"be":[49,67,113],"NP-hard":[50],"some":[52],"prior":[53],"works,":[54],"paper":[56],"shows":[57],"that":[58,123],"global":[60,145],"optimum":[61,146],"binary":[64],"case":[65],"with$K=2$can":[66],"achieved":[68],"linear":[70,120],"time.":[71],"For":[72],"a":[73,119,128,159],"general$K$-ary":[74],"with$K":[77],">":[78],"2$,":[79],"state-of-the-art":[81],"polynomial":[82],"time":[83,121],"algorithm":[84,122,166],"greedily":[87],"project":[88],"relaxed":[90],"solution":[91,130],"closest":[94],"point":[95],"constraint":[98],"set.":[99],"However,":[100],"as":[101],"shown":[102],"paper,":[105],"performance":[107,138],"this":[109],"greedy":[110],"method":[111,154],"cannot":[112],"guaranteed.":[114],"contrast,":[116],"we":[117,157],"propose":[118],"capable":[125],"reaching":[127],"near-optimal":[129],"with":[131],"approximation":[133,165],"ratio":[134],"of$(1+\\cos(\\pi/K))/2$,":[135],"i.e.,":[136],"its":[137],"at":[140],"least":[141],"75%":[142],"for$K\\geq":[147],"3$.":[148],"Furthermore,":[149],"inspired":[150],"by":[151],"RFocus":[153],"[1],":[156],"develop":[158],"statistic":[160],"implementation":[161],"above":[164],"absence":[169],"state":[172],"information":[173],"(CSI).":[174]},"counts_by_year":[{"year":2025,"cited_by_count":2},{"year":2024,"cited_by_count":2},{"year":2023,"cited_by_count":1}],"updated_date":"2026-07-29T14:22:42.915294","created_date":"2025-10-10T00:00:00"}