WO2005076758A2

WO2005076758A2 - A method and system for transmitting and receiving data streams

Info

Publication number: WO2005076758A2
Application number: PCT/KR2005/000391
Authority: WO
Inventors: Bong Hoe Kim; Dong Youn Seo; Joon Kui Ahn; Hak Seong Kim; Seung Hwan Won; Dong Wook Roh
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2004-02-11
Filing date: 2005-02-11
Publication date: 2005-08-25
Anticipated expiration: 2006-08-11
Also published as: US20100185777A1; WO2005076758A3; ATE532275T1; EP1719265A2; US8059771B2; EP1719265B1

Abstract

A method and system for transmitting and receiving data using a plurality of antennas are disclosed. The method of transmitting includes the steps of receiving at a transmitter (50) feedback information from a receiving end (55), wherein said feedback information includes channel quality information (CQI), antenna weight values, and antenna group selection information. The transmitter (50)comprises a switch unit (51) to group the plurality of transmitting antennas into a plurality of antenna groups according to the group selection information included in the feedback information. The data streams (52) are transmitted based on the weight values included in the feedback information to a receiving end (55) through the plurality of antenna groups, wherein each data stream is modulated and coded according to the channel quality information (CQI) in order to obtaimn a maximum data throughput.

Description

AMETHODA )SYSTEMFORTKANSMLTΠNGANDREX3I^

DATAS?ΓREAIVIS

TechnkalFieki The present invention relates to a transmission system and more particulady, to a method of

transmitting andreceiving data streams using aplurality of antennas. A ioiighthepresent invention is suitable for

a wide scope of applications, it is particularly suitable for grouping a plurality of antennas into sub-groups of

antennas based on an antenna cαn±anation having a maximum data Ihroughput and transmitting such

information. Moreover, it is suitable for taismitting a plurality of data streams based on weight values for each

antenna The related arts do not show such features of applying waght values to 1ιarκmitti^

groiiping antenna rambinatiαnstodetenh^

Background Art

?hatransmissiondiveϊsity(Tx diversity) schαne, asingledata stream is transmittedusing at least

aid can acquire effider^ymdecxxing, called divositygaiα

As another aspect of diversityschemei aφa mul lexingme^hDdhasbeαiproposed. lithe

antennas respectively, lhareceivingend, atleasttwo antennas are introduced, and each anramaieceives at least

two signals sJmutoneously.?IhaEfore, the received sigpalsmusitberecove^sφaratelywiftiadetedion

transmitted independently so diffirentmodulatiαnor coding scheme is applicable to each signal

In the existing diveϊsity schemes, data streams are transmitted viaafixed set of antennas without

regard to apotenl y more efficient and effective antennacαmbination As aresuft, tiansmissionmay suffer

meffiάaxyaώdekysduetourKlerutilizatim^

resources couldbe wasted Therefore, the amount of daktiHisn±ted suffers.

For example, in a system having four antennas in ataismitting aid wWch are sdtotiansmit data

stream 1 from antennas 1 and2arκldatastream2fiomantennas3 arκ!4,otherantennaconfigurationisnot

considered If antennas 1 arκ!2havestκ^sigpdstrenglhα3m^^ and4,yetdatastream 1 does

not?havemuchdaktotransmitwh^

much data to transmit, result^

Another disadvantage of the existing diva^scheme is fliataitenr signal støigths are not

ccΩsaderedpriortotøisnώiingdakllTO^ In other wcatk, (Mais transmitted through an antenna

i^ardessoffl eliar iiissimi^ofthatantennaAsaresd

could occur. Jhac tion,ftιeamoιιπtofdalatørιsrώttedsuffiϊs.

Fαrexan le_>mas}5tanlravingtwoanta

strong while antama2 has weak signal størgth. By tansnittir^adafe stream 1hraughbotl arώamas,tlιe

transmission in aniama2wouldsuSer and cαnstcfeedineffiάαit

Disclosure of Invention

Accordingly, the present invention is directed to a [title] to substantially obviates one or more problans due to limitations aiddisadvantages of fl erelated art

An object of the present invention is to provide a method of transmitting and receiving data

streams havingwdght values appliedtothe data streams and selectingagroupofanla nasprovidingamaximum

datathroughput

Another object of the present invention is to provide a method of transmitting and receiving data

streams by having wdght values applied thereto.

streams by selectingagtoup of antamasprovidingamaHmumdata irou^put

Additional advantages, objects, and features of the invention will be set forth in part in Ihe

descφtion which follows and in part will become apparent to those having ordinary skill in the art upon

examination of the following or may be learned fiom practice of the invention The objectives and other

advantages of fee invention may be realized and attained by the structure particuWyrx)iπted out in fiiewrittai

description and claims hereof as well as the appaided drawings.

To achieve these objects and other advantages and in accxadancewilhthepurposeoftheinva tiQn,

as embodied and broadly described liadn, a method for transmitting data streams using a pk

include the step of recaving feedback information fiom a recaving aid, whae the feedback information includes

group selection information and weight values for the plurality of antennas. The method further includes the step

of grouping the plurality of antennas into a plurality of antenna groups based on group selection information

which is included in the feedback information. Furthamore, 1he method includes the step of transmitting to a

recaving end aplurality of data streams through the plurality of antenna groups, respectively, based on the weight

values.

Si another aspect of the present invention, ametiiod for receiving data streams using aplurality of antennas include estimating a channel status for each antenna Theme&odfuriherincludesthestep of calculating

a wdght value and a Signal-to-?Bιterferenceplus-Noise ? atio (SINR) for each antenna using the estimated

channel status and calculating a data throughput ffr each combination of antennas using me S

further includes the step of selecting a combination of antennas which provides the maximum data throughput

fiom a plurality of antenna combinations. The method further includes the step of transmitting feedback

informationto a transmitting aid in which the feedback information includes Ihe calculated wdght value for each

antenna and the select combination of antennas. Moreover, the method includes the step of recaving aplurality

of data streams fiom the transmitting aid, fiomwhichmeplura of dak streams to

of antennas based on the wdght value for each channel are transmitted It is to be understood mat bo the foregoing gaiaal description and the following detailed

descriptionofmepresaτlinventimareexenpl^

ofmeinvaition as claimed

Brief Description o Drawings The accompanying drawings, which are included to provide a further undastanding of the

invaition and are incorporated in and constitute a part of this application, illustrate embodime ts) of the invention

and togsthawithlhe description savetoe lainlheprin leoftheinvαition. In the drawing; FIG. 1 illustrates aD^ITDscfaαneha\ά]gfoιιrtiHτsmissim antennas; FIG.2 illustrates aTxAA scheme havingtwo transmission antamas; and FIG. 3 illustrates a IXTxAA scheme having four transmission antamas and two receiving

antennas.

FIG.4illustrates a!>5T?TD scheme havingafeature of selecting antamaccmbinations. FIG.5illuslιatesaI TxAAschemehavingafeattιreof seledingantania combinations.

FIG.6 illustrates a flowchart showing aprocess of selecting aπteimaconmiriationsmthe receiving

end

Best Mode for Carrying Out the Invention

Reference will now be made in detail to the preferred embodimaits of file present invention,

examples of which are illustrated in the accompanying drawings. Wherever possible;, the same reference

nuπteswiflbeusedftroughoutthedra^

As apart of divasity transmission scheme, Space Time Transmit Divasity (STTD) andmodes 1

and2 of Transmit Antenna Array (TxAA) are widely used The STTD scheme is anopailoφ technique using

two antamas to exploit diversity. More specifically, fiie STTD anploys space-time coding to achieve diversity.

Furthermore, the STTD schane is applicable to all of the downlink physical channel except Synchronization

Channel (SCH) of Wideband Code Division Multiple Access (WCDMA). Because STTD scheme does not

require feedback signal, dekys caused by feedback transmission does not affect transmission in the STTD

scheme The operation ofSl ID is lurtha- explained using the following Table 1.

[Tablel]

In Table l,trepresenistimeandt+Trepresenfst^ The

space-time coded symbols, as indicatedin Table 1, are transmitted tliroughtrananission antennas l a^

symbolis transmitted vkindependentcbanneLAssumingtofhecn^ same, the following equations inEquatiαn 1 describes how the signals arerecaved at the recaving aid

r_l = r(t) = h_l$_l-h₂s₂ +ι r₂ = r(t+ 7)= h_ls₂ + h₂s_l +n₂ β, Λ Here,rιandr₂represaιtreceivedsignalsateachantenna,and ^{1 _0Cιe} ₅ "^2_α2e ^p^gg^

channels between therec ving antennas and each ofthe transmitting antennas 1 and! Furthermore, n_\ and«₂

represent noise in the receiving end lithis diversity sdie e, pilot sigpals areusedto estimate each channel status. Furthermore, by

ccmbiningrecdved signals, asinEquatic 2, the tiHismittedsyrnbolcanbe estimated For exarrφle^

estimai ^TibolhasaneffedofMaximumM

[Equation 2] s_x = Afø + i%r₂ = («? + )s_λ + / + h₂n₂ §₂ = h^*r₂ - h₂r^* = fø² + cξ)s_λ + ^*n₂ - h₂n_λ

In Equation 2, .πepresaits adecoded symbol at fiierecavmg end, arxl/z represents channel.

Furihamore, rrepresents arecdved signal, ^represents amplitude, jrepresaits symbol transmitted fiom the

transmisamaι4and«represaτfsccmplexroisem Since thae are two recaving antamas,

two equations arepresaιtedaccoιdinglymEquatiαn2. Forimprovedandeffidenttransmissiσn,fow

for Multi-foMιιMOut(!vmϊO). This isp^

scheme. In this schanet, for examples, there are four transmit antennastotwo receiving antennas are available. In the SHD scheme;, file transmitted dakis divided into two sub-groups and each sub-group is

transmittedby STTD operation More specifically, two data streams are space ime cxxMby the STTD encocter,

and transmitted as space-time coded symto

g upedinsub-groupsoftwo.FIG.1 ilksliatesfiiisσperatimin detail

Code Set (MCS) control 13 is available to control moduMcm and codingratetoeach set of dak streams llbased

on Channel QuaKtyMormation(CQO feedback, footherworcls, eadimodulationandcodingratecanbe

indepεndenflychangεdbasedmlheCQIfeedb^ llaandllbarepassed

fiτroughrespectiveSTlDencode3sl2aandl2b li^

Furthermore, four antennas 14a ltransmitthecc eddakstreams.

?fa ad&tiσn, the rec vή^ aκl of fiie sys^

btorecdve the ti isrmtted signal andperfc-^

Asadosedlo technique employing feedback CQ1, TxAA schane also uses two antamas to

exploit the divasity. FIG.2 illustrates the operation in detail In therecdvirigaidoftheTxAAsdian^adetector

21 estinatescharmelstateusingpMsigm

Signal-1x Ihterfeιaιce-plu&-NoiseRatio (SINK). Additionally, the estimated channel status infoimationis usedby

a wdght gaιaata 22toga aateawdght value for each channeL The genaated wdght values, wi and w≥, are

transrattedtothelransinittingendtobeφpliedtoftie dak stream

T3ιe wdght values are appliedtothe dak streams thai Iransmittedtolherecdving antennas.

Assumingtherearetworecdvir^aπtennas,forexampleifiιerecd

canbe expressed in thefollowing equation. {Equation 3]

Mquatim3,srepresentsasyrnlxitiH]sr^^

wd^ tSjΛii-ferφies ittransmissio clMmelSjand Z_! andn₂representtheAdditiveWhiteGaussianNoise

(AWGN).

Infiie receiving end, file original dak needs to be extracted To acccmplishlhis, dak symbol

following equation. [Equation 4] s= (M +w₂ ^₂ )* r\ +fø k _l +w₂ h₂₂ )* r

?hEquaticm4,iτ tesa3tsade(xxMsymbolatfiιerecdv^ and^

r esai1herecdvedsignalateachrecd\ ngaπtama,andwι andwyepresentwdghtvalues.

Before wdght values canbe fed backtoihe transmission end, ftiereceiving end gaiastes wdght

values. Anraampleofacqiiiringawdgl value :^^

dga vectocortespond igtothem^^ Thefollowing

equation is an exampleofdetemώHngawdght value.

[Equation 5] Rw = Λw

IhEquation5,Ris a∞varianeematrix, wisawdghtvector, andλrepresenfs amaximum value of the covariancematrix.

IntheTxAAsdιemeitwomodescanbefound;rιamely,mode 1 arxlmcde 2. T?he difference

between thetwo modes liesinamefliod of acquiring awdghtvα±r. More spec^cafiy, inmode 1, awdght

vector is expressedin 1 bit, whilemode2 expresses awdght vector in4bits. Model oftheTxAAschemeαnploysaclosedloφteclm^

mode 1, 1 Htphaseirfonuatimislransrmttedtoti

information Simode 2, 4bits aretiHismittedtofiierecdving aid during eachtime slot, of which 1 bithasphase

informationand3 bits have ampfitudeinfoimation. kmoc ,pilotsyr]±»ls^chareort^^

antennas on aDedicatedPhysical Control Charmel (DPCCH). Inmode 2, file same dedicatedpilot symbols are

transmitted through two antennas intheDPCCH.

T?he recaving end estimates each charmel corresponding to each aπtama for eachtime stotuang

ismaximized Therecdvingadtransmitspliaseandanφ?!^^

value.

As explained above, inmode2, feedback infor atim comprises phase information as well as

Teaesfrial Ractio Access Ne^cdc(Ul AN), uses the following list (Table l)toanalyze heιecdved

information. Inotha-worfs,ftιetiH srdtfingaιd∞nuse4wdght\^ltιes 1 bit feedback

infoιmatior],byusingaccflsteMαnro ∞meώ^

infoιmation,Table2cmbeusedTbati^tl etransm^ V foraw ght

value of afirst antenna, andinteφrefsthereceivedfeedback^ Table2wbichshowstiιe mappingbetweenphase adjustment, ^%andreceivedfeεdbackinfoιmatim

[Table2]

Asexplainedabove^fl ewdgjhtvalueofthefir^ ^ .Thewaght wι is the calculatedby avaagingtherecdvedphases overtwo consecutive slots. Algorithmically, vt^is calculated as follows.

[Equation 6]

∑ ^{CO S}(Λ ) ^ ^BJ^E C ^ 3* Vt , z'=tt — 1 2-=M 1 .7

Inmode 1 atfiamebαϊlar,1heaveragfagopa^αnissK^ymocMedl^nrec timofthe feedback cαmmandforslotOofafiame, the average is calculatedbasedαnthe command for slot 13 ofthe previous frame andthe command for slot 0 of the current frame. In o1hawords,fiame information fiom slot 14 is notusedlhereason for this istocσmeupwifiilhe average* value basedm(0,7r)and(7i/2,-7[72). The average can beacquiredfiiroughthefoπowingequatiQa [Equation 7[ costøπ + eosfa') , M Mll + ti)

^W2 = + J-

Ih?Equation7, ^φ°represaτtsphase adjustment firm fiamej-1, slot 13, and ^{Φ l3} representsphase

a stmaτtfiomfiamej,slotO.

For the first fiame of transmission, the recaving aid determines the feedback commands ina

normal way and send fhemtoUTRAN. Before the fiιstfeεdbad£corι andisrecdved,fiιeU?ERANslτalluse ( 1+7) fi e initial wdght, ² .lEtavingrecavedfhefeedbackcon^

to the following equation

[Equation 8]

COS(JΓ /2) + COS( ₎) .sin(fl 2) + sin(^₀) w₂ -

InEquationδ, )iEpresaolsp?hasea( ustinentfiOmslotOof1hefiistfiame.

Like mode l,mode2offlιe TxAA schaiieemployδaclcδedlo techraquetoachieve diversity.

In this closed loφmocte,thae s lόpαssible combination

recaving aid selecte aid transmits theFSMaccordingtoT^^

rønsteMonroktiαnisd∞eatftierecdvingaidandm

UTRAN.

[Table3]

[Table4]

Ihfhe first bit, since allftie information canbe cxm±aned,amaximum value canbe selected fiom

foundin order of 8 >4>2 combinations. w Byusingthephase and w ^it information, wdght vector =h ^wJ canbe determined See

Equation 9.

[Equation 9]

lha 15 slot configuration, 4bit feedback information gets transmittedthrough four slots. As arestύt,

anpfitudeftedbackinfoimatimmthe last fiiree slots arenot transmitted In such cases, flieprevious ai litude

infom onistransmitted

Since fiiere is no feedback intbrmatiαninfiie first fianeoftransmission, phase information listed in

Table 5 canbe used At the same tme,fiιe1ransmissionpower fiom two antennas aedvided equally inhalf fiom

flie total transmissiQnpower.

[Table5]

Ihtoansmitting dakusing aplurality of antamas, as inthe?DSlTD schane;, fourtransmit antennas

ranbeintroducedtofiie TxAA sdieme for ?MMO. Mafoiraitenm scheme, or aDouble-Trananit Aπtaina

Array (D-TxAA), fiie transmitted dak is divided into two sub-groups and each sub-group is transmittedby the

TxAAopaation.

FIG.3 illustrates aDTxAA scheme for fiie (4, 2) antenna configuration. More specifically, there

are four transmitting antennas to two recaving antamas. As showrιinthefigureifiιetransnitaπlamas32a-32d

are grouped into two sub-groups. Theuppa two transmit a tamas 32a and32b transmit (kkstreaml and the

Iowa- two transmit antamas 32c and32d transmit dak stream 2. Aαmtrofier otshowninthe drawing applies

wdghtvaluesrecdvedrnfeedbad nfonnati^

In the receiving end35, detectors 34a ard 34b mtherecdving end 35 estimate channel status usir^ pilot signals. The channel status information is usedby fiie w glit generator 36tocalculatewd^ t values for each

wdght values are appliedto ead transmissionanlamaof eachsub-gtoiω.

Afterthe wdghtvakes are appliedto each sub-group, each sub-group transmits the dak streams to

fi erecavinga nrmTherecavedsignalscan

made that there are two recaving antennas.

[Equation 10]

In this equation, wj-w are wdght values for each sub-group, Λ_m is charmel cceffident fiom the

m-th transmit aπte nato then-flireceive antama, si and^ are symbols, and«ι ax z₂ are AWGN vectors.

Since si and sχ are transmitted to each recaving antama, the dak can be recovered after filtaing

out the channel information and wdght value fiom the combined signals. Furthamore, more reliable dak

re∞verycaibeactøevedthrou^aiinteriaen^ as expressed in Equation

11, if an interference elemait acquired throiighdakrecoveryprocess o£j[ canbe eliminated, reliabilityαfø canbe

increased

In this equation, wι→v₄ are wdght values for each sub-group, 7?^ is charmel ∞effide t from the

m-thtransmitaπtenrmto1he] fi rec^ andr₂arerecdved signals.

The wdght values, fed back to the transmitting aid, is an agεnvector corresponding to the

agenvalue derived fixrnifiiecharmelmatrix.

[Equation 12]

[Equation 13]

In Equation 12 and Equation 13,

, ^Λi2 ' ^Λ3 are covanance

matrices of ha and h , ^² ' ^⁴ represent the maximum values of the covariance matrices, and ¹² ' ^{2 2}* ³ arethedgavectorscαnesporxlingtomaximumdgaivarue^

Η e above described method is an example of one of the methods that can be used to acquire

wd^valιιes.Difeeπtmefiιodsmaybeusedtoobtainwd^ιtvalues.

In the above example;, two receiving antennas are provided However, the D-TxAA scheme can

be extended for a configuration having more antamas. For example, the D-TxAAsdiane can be exta d for the

(4, 4) antenrmcαnfiguratioo.

As explained above^ dakrates for sub-groups canbe independαilly controlled Si other words, the

dak rates for

Accordingly, if the channel status is gxxl, transmission canbe achieved by usingliigh order modulation, which is

similar to Quadrature Amplitue Modulation (QAM), or by inαeasing the code rate. On the contrary, if the channel status is bad, transmission can be achieved by using a low order modulation, which is similar to

transmits as feedback the channel status infomiationtofiielransmisaon l

Anothaaιιbcxfcaτtoffiιe present invaώmrelates to maximizirig dak throughput InFlG.4, a

SwitchUnit41 matiHisrm1tingerd40andanAnta^ areadded

tothe(4^)antamaconfiguraticmfiτm FIG.1. fiiFIG.4, the recaving end 45 estimates channel status uangpflot signals. The status of estimated

channels are used to calculate fiie SINR for channels of each antama combination. For instance, the SINR o£ not

only (1,2X3,4) antenna combination calculated, other combinations such as (13X2,4) and (1,4X23) are calculated

as well Based on fiie SINR, fiie dak throughputs of antenna combinations are calculated Then the antenna

cornbinaticmhavingthemaxttiiimdakthro selected

From the recaving end, fi e selected antenna combination is fed back, along with the CQ1, to the

transmission aid 40. Based on this feedback information, the Switch Unit 41 applies the selected antama

αmibinaticα The dakstreams are thai transmitted FIG 5isanexaπ leofT TxAAschemewhereacapadtytoseled

madeavailabletoasjstemcOmprising 5,aSvwtchI 51 ina

transmission a d 50 and an Antenna Combination Selector 53marerøvingerd55aeaddedtothe(4_;2) antama

configuration ofFIG.3.

In FIG.5, detectors 59a and 59b in the receiving end 55 estimate channel status using pilot signals.

The estimated ctø el status information is used by the wdght gaierator 56 to cdcudate wdght values for each

combination of antamas as well as for each antenna Furthamαte;, fiie SINR for channels of each antama

combination ae calculated by using the estimated channel status information. For instance;, the SINRoξ not only (1,2X3,4) antenna combination calculated, other combinations such as (13X2,4) and (1,4X23) are calculated as

well The SINR of each antama can also be calculated by using the estimated charmel status information For

example, the SINR of not only of (1,2X3,4) antama combination calculated, fiie SINR of each antenna (e.g,

aitenna 1 , antenna 2, etc.) may also be calculated ?Based on the SINR of each antama combination, the dak

throughputs of each antama combination are calculated fiom which the antenna combination liaving the

maxhnumdaktiiroiigbputis selected

The selected antenmcαnbination is fed back, along with the wdght values and fiie CQI, to the

transmitting end 50. ?Based on this feedback information, the Switch Unit 51 applies the selected antenna

combination Furthermore, the wdght values are applied to each aitenr oflhesub-groiEps. The dak streams are

thmtransmiltedtotherecdvir^aιd55vkselectedanten

and I TxAA divasity. Wifii numerous antama combinations available, the antama combination having a

maximum dakfiiroughput is selected

In FIG. 6, diarmel status is estimated using pilot signals (S41). Based on the estimated chamel

status information, the SINR for channels of each antama combination are calculated (S42). Furthemiore,

available dak Ihrou^ut for each anten combiriati

completed, the antenna combination having the maximum dak throughput is selected (S44). The selected

antenna combination having fiie maximum dak throughput is compared to fiie antama combination of the

curπa ifaim combination (S45). If the selected antama cα binationhasalarga" dak throughput, the selected

antama combination is fed back to the transmitting aid (S46). If the dak throughput amount of the selected

antenna combinationis same or less than that of fiie current antenna cαnΛinatiαri, Ihenno feedbackis transmitted

In such cases, the transmitting aid transmits fiie dakbased on the cuαent antama corrminatiσn. The foregoingprocessof selecting antama cxm±ώιationisnotlimitedtoaD^TTDand?DTx^

sdieme, but can be applied to other transmission schemes. Moreover, fiie combination of antennas is not limited

to above described combinations, but canuse ofiier combinations. Furthamore, a number of antennas in sub-

groups could increase wiftiincreasemnLmibaoftransmissiQn antamas. Before transmission of feedback takes place with respect to fiie selected antama cαnbinafion, the

dak fiiroughputs of the selected antenna combination and the curta t antenna combination shoidd be ccmφared

If the amount of dak fiirougbput of fiie selected antama combination is similar, same, or even lower than the

current (or initial) antenna combination, feedbad need rrøtkkeplace. The reason for fiiis is to

everytimeachar^ chamelsktuscrøiβ.Therefor^

(or initial) antama combination when there is substantial difference in dak throughput and at initial system

cfownlink cαitrol signal which rm^

B will be apparaώ to those skilled in fie art that various modffications aid variations can be made

in the present invention without departing fiom file spirit or scope of the inventions. Thus, it is intended that fiie

present invaitioncovas fliemodifications aid variations of this invaώmr )vided they ccmewiftim the scqpeof

the appaided claims and their equivalaifs.

Claims

HATISCLAIMEDIS:

1. Amefliodfortiansnittingdakstreamsusingapluralityofanta^ receiving feedbadcinf m onfiomarecdviiigaid, thefeedba infonnationiiTcludirigaπtamagroup

selecti∞infoirriatimaidwdgjitval^ grouping theplurafityofailamasintoaplural^^

infoimationi ludedinthefeeclbackinformation; and transmitting to arecdvirig a d, apkratityof dak stre

respectively, basedonthewdghtvalues.

2. ThemefiiodofcIaiml,whereintiiefeedback^

information(CQl) for each antenna

3. Themefiιedofclaiml,wherdneachdakstreamism

4. Amefiιcxiforrecdvingdakstreamsusirιgaplura ofaτtenrιas^ estimating adiannel status for each antama; calculating a wdght value for each combination of antamas using the estimated channel

status; calculating a Signal-tehδ tejfeenc&plus-Noise Ratio (SINR) for each combination of

antamas usingflie estimated charmel status; calculatingadaklhroughput for each combinationof antamas using the SINR seledingaαmibinationofantennasprovidirigthemaxinii^ fiomaplurality

ofantamaccmbinations; transmitting feedback information to a transmitting end, the feedback infoirnation including

the calculated wdght value for each antenna and the selected ccmibination of antamas; and recaving a plurality of dak streams fiom the transmitting aid, whadn the tian^

teansmits thepkralityof dak streams through the selected cornbinaticmofantennas, based onfiiewagtt value for

eachcha el

The me&odofclaim4,wherdnesιtimating charmel status furtherincludesijsirigpto signals.

6. Tlie method of claim 4, whaein the feedback information further includes channel quality

infcmιatim(COJ^foreacharιtenna

7. The method of claim 4, wherein the estimated diannel status is used to

values.

8. Theme&edofclaim4,wheremfiιeestima^

9. Amefliedfortransmittingdakstreamsusin^

thestepsof recaving, fiomarecdvingend, feedback information includiiigwdghtvalues forfiie

antenrιasmcludedintheantennagroιrps;and transmitting, to therecaving aid, apkralityof dak streams through aplurality ofpreκlefined

antama groups, respectively, based onfiie wdght values, eachpredefined antama groups comprising at least one

ofthepruralityof antennas.

10. Tlτemethodofclam9,wherem1hefeedbackin^^

irfαrmation(CQ]) for each antenna

11. Tlιeme{hodofclaim9,wherdneachdakstreamism

12. Amefiιod:forrecdvingda stι nsusinga

least one aiterina, themethod comprisirig the steps of estimating a channel status for each antama; calculating awdght value for each antenπausingthe estimated channel status; transmitting feedback information to a transmitting end, the feedback information including

fiιecalculafedwdgjιtvalueforeachantenrιa;and receiving a plurality of dak streams fiom fiie transmitting aid, vvte inflie transmitting aid

transmits fiie plurality of ak streams through apkralityof pre-defined antama groups, respectively, based cm fiie

wdght values, eachpreκ?fefmedanfcnragroιιpsc^^

13. Themethodofclaim 12,v ιereJnestimatitιgcharmelstatusfύ^^

14. The method of claim 12, wherein the feedback infonnation further includes chamel quality

information (CQI) for each antenna

15. The method of claim 12, wherein fiie estimated diarmelinfoimatiQn is used to calculate the

wdgjht values.

16. Ame&odfortiarHτώtirιgdakεtreamsusinga receiving feedback informatimfiomarec vn

groi selecticminformation; grouping thepluralityof antamas intoapluralityof antama groirps based on the group

selectimMoiiriationincludedinfhe feedbackinfbrmatiσn; and transmitting, to therecdving end, aplurality of the dak streams Ihroughthepluralityof antenna

groups, respectively.

17. Themeflxxlofclaml6,vvhadnfitefeeά ackinfom

information (CQT) for eadi antama

18. Themeflιodofclaiml6,eaώdaks(reamismodulatedandαDdedbasedonflιeC

19. Amefi odforrecdvingdakstreansusirigapluralityofante^ estimating a channel status for each antenna; calculating a Signal-to-Iπterferaiceplus-Noise Ratio (SINR) for each antama using the

estimated channel status; c^culatir]gadaktiτrougj utforeach selectingacombinatimofantennaspro from aplurality

ofaπtOTraαm±rinatiσns; transmitting feedback information to a tra smitting aid, fiie feedback information indicating

the selected combination of antamas; and recaving a pluratity of dak strcarrø fhm

transmits thepluralityof dak streams throughthe selected combination of antennas.

20. Themethodofclaim 19,\\4ιerdnestimatmgcharmelstalusfu^^

21. T?he method of claim 19, whadn the estimated channel information is used to calculate fiie

SINR

22. Ηιemethodofclaim45,wherøinflιefeedbackiΛ

charmel qua information(CQl) for eachantama

23. A transmitting system, comprising: a plurality of antennas for recaving feedback information from a recaving end, including

antama group selection information and tiansmittitig, to a recaving aid, a pluratity of dak strear though the

pfuralityof antenna groups, respectively, and a switch unit for grouping the plurality of antamas into a pbrafityofantamagourps based on

24. The system of claim 23, wherein fi e feedback information further includes charmel quality

information(CQl)foreadιaτterma

25. The system of claim 23, whadn the feedback information further includes wdght values for

thepluralityof antennas.

26. The systan of claim 23, whβein fiie dak streams are transmitted to the receiving aid, based

on wdght values.

27. Arecdving systan, comprising: adeteefor for detectingachamelstatus for each antenna; a wdght gεnaator for calculating a wdght value for each antenna using the detected channel

status; an antenna combination selector for calculating a Signal-to-Ihterfererice-pIu&Noise Ratio

(SINR) using the detected channel status, calciitøfirig a clak throughput for e haπte ^

SINR, selecting a combination of aitennas providing the nmimum<to

combinations, and transmitting feedback information to a transmitting end, the feedback information including

thecalculatedwaghtvalue for eadiantermaand fi e selected combination of antema^ and a plurality of antennas for receiving a plurality of dak streams fiom fi e transmitting aid,

whadnthetiansrmtfing endtran^

basedonlhewdghtvalueforeachaπtama

28. Thesystanofc?lam27,wherdndetecting1te

29. The system of claim 27, wherein the feedba infom αnfiirtha include dιannelqua

information (CQ1) for each channel

30. The syste of claim 27, whadn flie detected channel status is used to calculate flie wdght

values.

31. Thesystanofclaim27,wherdnflιedetectedch^

32. A transmittingsyst^ comprising: a plurality of aitamas for recaving feedback information ficm a receiving aid, includ

aitenna group selection information and transmitting, to arecaving aid, aplurality of dak streams through fiie

pkralityof antenna groups, respectively, and a switch unit for grouping the plurality of antamas into aplurality ofantama groups based on

33. The systan of claim 32, whaein the feedback infotmatim fiιrtherirκiudes channel qi ty

information (CQ1) for each antenna

34. Arecaving system, comprising: adetectorforddectingacharmelsiktusforeadiaritenna; an antama combination selector for calculating a Signal-tehϊπtafeaice^lus-Noise Ratio

SINR, sdecting a combination of antamas providing the maximum dak fiiroughput fiom aplurality of antama

combinations^ and transmitting feedback infoimatim to a transmitting βι4 flie fe

theselec ccmbiiationofantennasjand a plurality of antamas for recaving a plurality of dak streams fiom the transmitting end,

whadn flie transmitting end transmits fiiepluralityofdak streams through the selected combination of antennas.

35. The system ofclamH further α iprising a wdght generator for calculating a w gh value

fiom each antennausirigthe detected channel status.

36. The systan of claim 35, wherein the feedback informatimfurfiιaincιι les wdght values for

each aitenna

37. Thesystemofclam35,wherømtiιedetected(marmelstat^

for each antama

38. The systan of claim 34, wherein detecting the channel statusforeachantenr fikhaincludes

usingpilotsignals.

39. The siystem of claim 34, whaein flie feedbadc infomiation &rflierinciudes charmel quality

information (CQQ for each channel

40. Thesystem of claim34, wherein fliedetectedcharmel^at isusedtoc^cuktelheSBSlR