DS-CDMA Cellular Systems Performance with Base Station Assignment, Power Control Error, and Beamforming over Multipath Fading

Transcription

1 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 DS-CDMA Ceuar Syses Perforae wh Base Sao Assge Power Coro Error ad Beaforg over Mupah Fadg Mohaad Dosaraa Moghada Hadreza Bahsh ad Ghoareza Dadashzadeh Depare of Eera Egeerg sa Azad Uversy Qazv Brah Qazv ra _doghada@au.a.r Depare of Eera Egeerg Shahed Uversy ehra ra ahsh@shahed.a.r gdadashzadeh@shahed.a.r Asra he erferee reduo apay of aea arrays ase sao assge ad he power oro agorhs have ee osdered separaey as eas o rease he apay wreess ouao ewors. hs paper we propose ase sao assge ehod ased o zg he raser power BSA-MP ehue a dre seuee-ode dvso upe aess DS-CDMA reever he presee of freuey-seeve Rayegh fadg ad power oro error PCE. hs reever osss of osraed eas ea suared CMS agorh ahed fer MF ad axa rao og MRC hree sages. Aso we prese swhed-ea SB ehue he frs sage of he RAKE reever for ehag sga o erferee pus ose rao SNR DS-CDMA euar syses. he suao resus dae ha BSA-MP ehue a sgfay prove he ewor error rae BER oparso wh he oveoa ase. Fay we dsuss o hree paraeers of he PCE uer of resovae pahs ad hae propagao odos pah-oss expoe ad shadowg ad her effes o apay of he syse va soe opuer suaos. KEYWORDS Adapve eaforg ase sao assge DS-CDMA power oro error ahed fer axa rao og. NRODUCON Syses uzg ode-dvso upe aess CDMA are urrey eg depoyed aroud he oury ad aroud he word respose o he ever reasg dead for euar/persoa ouaos serves. Exesve researh has ee pushed o he perforae aayss of CDMA syses. Fadg s aog he aor faors affeg he perforae of suh syses. Fadg s geeray haraerzed aordg o s effe over a geographa area. arge-sae fadg osss of pah oss ad shadowg he aer er referrg o fuuaos he reeved sga ea power. arge-sae fadg s affeed y proe erra oours ewee he raser ad reever. Sa-sae fadg s he oo referee o he rapd hages sga apude ad phase over a sa spaa separao. hs wor he oed effe of arge- ad sa-sae fadg are osdered. he sa-sae fadg s assued o e govered y he Rayegh dsruo Rayegh fadg [] []. Besdes fadg CDMA syses are susepe o he ear-far proe. s we ow ha order o fuy expo he poea advaage of CDMA syses power oro s reured o ouera he effes of he ear-far proe. he CDMA syse apay s axzed f eah DO : 0.5/

2 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 oe raser power eve s oroed so ha s sga arrves a he ase sao BS wh he u reured sga o erferee pus ose rao SNR []-[7]. However whe appyg power oro prae he perforae s resred y a uer of aos ad herefore perfe power oro ao e aheved. he ssue of he effe of power oro errors o CDMA syses has reeved a grea dea of aeo over he as few years []-[4]. Aordgy hs paper we osder he effe of power oro error PCE o dre-seuee DS-CDMA euar syses. Aso dversy s oe effeve ehue for ehag he SNR for wreess ewors. Dversy expos he rado aure of rado propagao y fdg depede or a eas hghy uorreaed sga pahs for ouao. f oe rado pah udergoes a deep fade aoher depede pah ay have a srog sga. By havg ore ha oe pah o see fro he SNR a he reever a e proved. he dversy shee a e dvded o hree ehods: he spae dversy; he e dversy; 3 he freuey dversy. hese shees he sae forao s frs reeved or rased a dffere oaos or e sos/freuey ads. Afer ha hese sgas are oed o rease he reeved SNR. he aea array s a exape of he spae dversy whh uses a eaforer o rease he SNR for a paruar dreo [8]-[0]. hs wor we use osraed eas ea suared CMS agorh ad swhed-ea SB ehue for he spae dversy. o prove he perforae of euar syses ase sao assge BSA ehue a e used. he ase sao assge a uer of ase saos are poea reevers of a oe raser. Here he oeve s o deere he assge of users o ase saos whh zes he aoaed oe powers []-[4]. spe ode ad upe-e syses he user s oeed o he eares ase sao. hs way s o opa euar syses uder he shadowg ad upah fadg haes ad a rease he syse BER. hs paper we prese ase sao assge ehod ased o zg he raser power BSA-MP for dereasg he BER a es [5]-[7]. he goa of hs paper s o exed he wors [5]-[9] y osderg o upe-e syse BSA-MP ehue ad PCE. [5]-[7] we proposed he BSA-MP ehue DS-CDMA syses upah fadg haes whou osderg he PCE. Aso [8] ad [9] a RAKE reever sge-e syse was proposed he presee of freuey-seeve Rayegh fadg hae ad he oveoa BSA was osdered. hs wor he perforae aayss of DS-CDMA syse freuey-seeve Rayegh fadg hae has ee suded. f he deay spread a upah hae s arger ha a frao of a syo he deayed opoes w ause er-syo erferee S. Adapve reever eaforg shees have ee wdey used o redue oh o-hae erferee CC ad S ad o derease he error rae BER y adusg he ea paer suh ha he effeve SNR a he oupu of he eaforer s opay reased [0]. hs paper a RAKE reever DS-CDMA syse s aayzed hree sages aordg o Fgure [8]. he frs sage hs reever uses CMS adapve eaforg agorh o fd opu aea weghs assug perfe esao of he hae paraeers dreo deay ad power for he desred user. he desred user resovae pahs dreos are fed o he eaforer o redue he er-pah erferee P fro oher dreos. Aso he RAKE reever uses oveoa deoduao he seod sage ad oveoa axa rao og MRC he hrd sage o redue upe aess erferee MA ad he oher erferees. Redug he MA ad CC w furher derease he syse BER. he orgazao of he reader of hs paper s as foows. he syse ode s gve Seo. he RAKE reever sruure s desred Seo 3. Seo 4 we propose he BSA-MP ehue. Seo 5 we prese he SB ehue. Fay suao resus ad ousos are gve Seo 6 ad Seo 7 respevey. 86

3 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 Fgure. Bo dagra of a hree-sage RAKE reever DS-CDMA syse [8]. SYSEM MODE hs paper we fous o he up ouao pahs a DS-CDMA euar syse. he hae s odeed as a freuey seeve hae wh Rayegh dsruo ad ogora dsrued shadowg. ay we osder pahs for eah ha opay oed hrough a RAKE reever aordg o Fg.. Aso we assue ha here are M ave ase saos he ewor wh K users oeed o h ase sao. A eah ase sao a aea array of S sesors ad N weghs s epoyed where S = N o reeve sgas fro a users. Aso for spy we assue a syhroous DS-CDMA shee ad BPSK oduao order o spfy he aayss of proposed ehue. Addoay hs paper we assue a sow fadg hae he hae rado paraeers do o hage sgfay durg he erva. Hee he reeved sga he ase sao ad sesor s fro a users a e wre as [] [8] [] r s = Pλ Γ x y α = exp π sd sθ / λ where P = E / represes he reeved sga power of a users wh e he presee of perfe power oro where E ad are he eergy per ad perod for a users respevey. he varae λ s PCE for user e user whh s assued o foow a og-ora dsruo ad hus a e wre as λ = 0 where υ s a υ /0 σ υ for a users [4]. Aso ; Gaussa rado varae wh ea 0 ad varae s he pseudo ose PN hps of user wh a hp perod of s he forao seuee of user wh a perod of = G where G s proessg ga; s he h pah e deay for user ; θ s he dreo of arrva DoA he h pah for user ; α s he opex Gaussa fadg hae oeffe fro he h pah of user ; λ s sga waveegh; d s he dsae ewee he aea eees ha for avod he spaa aasg shoud e defed as d = 0.5λ ; s a addve whe Gaussa ose AWGN proess wh a wo-sded power spera desy PSD of N 0 /. Aso for Γ x y s defed as oveoa BSA ehue 87

4 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 Fgure. he dsae ewee wo pars of oe rasers ad ase sao reevers [] Γ ξ { 0 } /0 α x y = d x y Θ α d x y 0 ξ /0 ; S ; S where are he dsae ewee user ad BS ad BS respevey see Fgure ; Aso he varae Θ defed he se of he eares BSs o user ; ξ s a rado varae odeg he shadowg ewee user ad α s pah-oss expoe; d x y ad d x y BS ; S BS s he se of users ha oeed o BS ad oeed o BS [4]. BS o S o s he se of users ha o Aso shoud e eoed ha he rased power of user e o BS he ase of he PPC s gve y ξ x y /0 0 P p = d α 3 Aordgy he reeved sga he ase sao sesor s for user s gve y [8] = Pλ α exp π sd sθ λ r s / s = where where s he erferee for user sesor s ad a e show o e s s M K = Pλ Γ x y = exp α = = 5 π sd sθ / λ K s he uer of users e ad M s he uer of ase saos/es. 3. RAKE RECEVER PERFORMANCE ANAYSS he RAKE reever sruure he DS-CDMA syse s show Fgure. he reeved sga s spaay proessed y a eaforg ru wh CMS agorh oe for eah resovae pah eaforers. he resua sga s he passed o o a se of parae 4 88

5 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 ahed fers MFs o a fger-y-fger ass. Aso he oupu sgas fro he ahed fers are oed aordg o he oveoa MRC prpe ad he are fed o he deso ru of he desred user. 3.. Cosraed MS Agorh s we ow ha a array of N weghs has N degree of freedo for adapve eaforg [8] []. hs eas ha wh a array of N weghs oe a geeraes N paer us ad a ea axu desred dreos. Fro E. 5 s ear ha he M uer of users s K u = K ad he uer of erferee sgas s K u. o u a = of hese erferee sgas; oe woud have o have K u weghs whh s o praa. So we fous oy o he pahs of he desred user. hus he u uer of he aea array weghs s where ypay vares fro o 6 [8]. hs paper we use he CMS adapve eaforg agorh. hs agorh s a grade ased agorh o ze he oa proessor oupu power ased o he oo dreo osra. he adapve agorh s desged o adap effey agreee wh he evroe ad ae o peraey preserve he desred freuey respose he oo dreo whe zg he oupu power of he array. he oed for of he osra s aed osra for arrowad eaforg [0] []. hs for osder a arrowad eaforer where he arrowad sga fro eah eee of sar aea are uped y he opex wegh auaed y usg arrowad adapve eaforg agorh ad he sued o produe he oupu of he array. he defo of he opex weghs of hs eaforer he h erao for user he h pah s as foows [] [3]. [ ] = w w w 0... N w 6 Aordgy he oupu of he array he h erao he h pah for user where [ ] r 0 r r N y H w r s gve y = 7 r =.... he expeed oupu power of he array he h erao s gve y where. r. E y * H H = w r r w = E y y E = w H R w r r E s deoed he expeao ad R r r s he orreao arx of he reeved veor A rea-e CMS agorh for deerg he opa wegh veor for user pah s [] [3]: w w H = w µ g w a θ = 8 he h 9 where 89

6 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 θ = exp sθ... exp N s ] [ d d θ a 0 deoes spaa respose of he array for user he h pah. Aso E. 9 w s he ew wegh opued a he h erao for user he h pah. Aso he varae saar µ deoes a posve saar grade sep sze ha oros he overgee haraers of he agorh ha s how fas ad how ose he esaed weghs approah he opa weghs ad g H surfae R w r r w w deoes a uased esae of he grade of he power whh s he expeed oupu power of he array wh respe o w afer he h erao. he agorh s osraed eause he wegh veor H θ = sasfes he osra a eah erao ha s w a agorh as foows []. where θ. Rewre he CMS g a w = β w µ w N β θ a θ H he grade of w R wh respe o g r r w H a = N w s gve y = R H w R w w * r r r r w = w 3 ad s opuao usg hs expresso reures owedge of R r r whh oray s o avaae prae. For a sadard MS agorh a esae of he grade a eah erao s ade y repag sa eadg o r r R y s ose sape r H r avaae a e = r y * g w 4 he CMS s a fas overgee agorh. However s drasay sesve o he sah he dreo of arrva. Meawhe he weghs esaed y he sadard agorh are sesve o he sga power reurg a ower sep sze he presee of a srog sga for he agorh o overge whh ur regardg he derease of s-aduse error he overgee e s reased [] [4]. shoud e eoed ha for he aea arrays wegh veor he CMS agorh ad for g µ w overge afer a few erao s approxaey eua o he uer of eaforer weghs.e. = N [4]. Aordgy he oupu sga fro he h eaforer =... a e wre as [8] y where = P α ~ λ 5 s a zero ea Gaussa ose of varae ~ σ ad he P s defed as 90

7 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 9 g P ~ α θ λ = = 6 ad he MA s defed as M K g y x P α θ λ Γ = = = = 7 where θ g s he agude respose of he h eaforer for user oward he DoA θ. 3.. Mahed Fer Sage Usg eaforg he frs sage w redue he P for he desred user ad he MA fro he oher users whose sgas arrve a dffere ages fro he desred user sga ou-ea erferee. Now he seod sage of he RAKE reever he oupu sga fro he h eaforer s drey passes o o a fer ahed o he desred user s sgaure seuee. he h ahed fer oupu orrespodg o he h s [8]: P z ~ = α λ 8 where d ~ ~ = 9 d = 0 ad d = f we assue ha he pahs deays fro a users are ess ha he syo durao < for a users sgas o a pahs he h P ad MA a he oupu of he h ahed fer are expressed as R g P ~ α θ λ = = ad

8 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 K M = Pλ Γ x y g θ α R = = = where he auoorreao fuo R s [] [8]: 3 R = d 4 f a users deays are upes of he hp perod he where he auoorreao fuo G G R = G = 0= 0 R 5 R s: R = he ase of a axa-egh seuee -seuee ad for 0 we have []: d 6 R = / G / G ; ; Maxa Rao Cog Sage Dversy og has ee osdered as a effe way o oa upah fadg eause he oed SNR s reased opared wh he SNR of eah dversy rah. he opu oer s he MRC whose SNR s he su of he SNR s of eah dvdua dversy rah [] [5]. Afer he fger-ahed fer he fgers sgas are oed aordg o he MRC prpe he hrd sage of he RAKE reever. hs paper we use he oveoa MRC ha he sga of user he h pah s oed usg upyg y he opex ougae ofα. he SNR oupu of he RAKE reever for user [5] odoed oα s gve as [8] where SNR SNR = SNR α α 8 = Pα e α = 9 E ~ E E βυ s he SNR oupu of he RAKE reever pah for user ad β = 0 / 0. 9

9 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 O he oher had E[ λ ] for a users a e wre as [6] E β συ / [ λ ] e = 30 Now usg Es. 9- ad 30 we a e rewre he SNR E. 9 as foows [7] [8]. where η = M K SNR βυ α e α = 3 β σ / 0.5 η e υ E / N x y α g θ R = = = α Γ = g θ R 0 3 Γ ad α = E α. Aso E. 3 x y = E Γ x y order o perfor he BER we assue Gaussa approxao for he proay desy fuo of erferee pus ose. he odoa BER for a BPSK oduao s [] [8]: where α α BER = Q SNR 33 x = exp u / Q du π x HE BSA-MP ECHNQUE he syse apay gh e proved f he users are aowed o swh o aerave ase saos espeay whe here are ogesed areas he ewor. Ovousy whe up perforae s of oer he swhg shoud happe ased o he oa erferees see y he ase saos [4]. So far we have osdered he power oro proe for a uer of raser-reever pars wh fxed assges whh a e used up or dow oe ouao syses. a up searo where ase saos are eupped wh aea arrays he proe of o power oro ad eaforg as we as ase sao assge auray arses []. hs paper we odfy he BSA-MP ehue upah fadg hae o suppor ase sao assge as we. he odfed ehue a e suarzed as foows [5]-[7]. ay y he oveoa BSA ehue eah oe oes o s ase sao aordg o E.. Esae he wegh veor for a users wh he CMS agorh usg E.. 93

10 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 Fgure eas eah ase sao wh he SB ehue Fgure 4. See of ea for wo users wo pahs wh he SB ehue 3 Cauae he rased power of a users usg E Fay Kr = Ku / M users ha her rased power s hgher ha he oher users o e rasferred o oher ase saos aordg o he foowg euao where he fuo x reurs he eger poro of a uer x. where Γ x y Θ = d Θ d α ξ { d x y 0 } /0 ξ /0 α x y 0 α ξ { d x y 0 } /0 α x y 0 ξ /0 ; S ; S ; S BS BS S BS s he se of users ha are e u o oeed o BS [4]. shoud e eoed ha he ehue for users ha are prese he order of es he BER a e effevey redued. 5. HE SWCHED-BEAM ECHNQUE Oe spe aerave o he fuy adapve aea s he swhed-ea arheure whh he es ea s hose fro a uer of fxed seered eas. Swhed-ea syses are ehoogay he spes ad a e peeed y usg a uer of fxed depede or dreoa aeas [9]. We s he odos of he SB ehue for hs paper as foows [30]. Aordg o Fgure 3 eas overage age s o s 0. hus eah ase sao has 36 eas. o 35 o 30 ad overap ewee oseuve eas Aordg o Fgure 4 eah user a e use oe ea for s eah pah o ouae wh a ase sao a ay e. 94

11 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 Fgure 5. oao po of ase saos ad users four es 6 Fgure 6. a Foa feeda geeraor for FSR poyoa g D D D = for sxsage shf regser Expadg he oa ery 03 o ary for [] 6. SMUAON RESUS We osder M = 4 ase saos for a four-e CDMA syse o a grd ad sze as Fgure 5. We assue a ufor ear array of S o-dreoa aeas eah ase sao wh aea spag d = λ /. Aso we assue he pu daa rae = 9.6 Kps ; he uer of aea weghs N = 3 ; freuey-seeve fadg hae wh = resovae propagao pahs; varae of he opex Gaussa fadg hae oeffe σ α = 4dB ; pah-oss opoe α = 4 ; varae of he og-ora shadow fadg σ ξ = 8dB ; resouo R = ; a vaue for wegh veors he CMS agorh w 0 = 0. aso s assued ha he dsruo of users a es s ufor. hs paper we use -seuee geeraor wh proessg ga G = 64 ased o ear feeda shf regser FSR ru usg he Foa feeda approah []. hs sruure s show Fgure 6 a. Aso aordg o [] we use he seuee geeraed y he poyoa orrespodg o he ery he oa represeao of geeraor poyoa ORGP= [03]* for a sx-sage shf regser. Fgure 6 shows expadg he oa ery 03 o ary g D = D D. for. he he FSR poyoa s 6 Fgure 7 shows he average BER versus he sga o ose rao SNR for dffere reevers oe wo ad hree-sage reevers K = 3 ave users ad a og-oray dsrued PCE u whσ υ = 4dB. shoud e eoed ha hs suao K = 8 users a e rasferred o r 95

12 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 oher ase saos wh he BSA-MP ehue. s ear ha MF oy reever oe-sage reever ad he ase of he oveoa BSA ehue we s have he error foor a hgh SNR. Usg CMS ad MRC reever wo-sage RAKE reever or CMS MF ad MRC reever he hree-sage RAKE reever as Fgure has a eer perforae ha usg MF oy. Aso we oserve ha usg he BSA-MP ehue CMS MF ad MRC reever he average BER s ower ha he oveoa BSA ehue. For exape a a SNR of 0dB he average BER s for he hree-sage RAKE reever wh he oveoa BSA Fgure 7. Average BER of a users versus he SNR for σ υ = 4dB ad K = 3 u Fgure 8. Average BER of a users versus he SNR for dffere vaues of ehue whe for he BSA-MP ehue he average BER s Aso a e see ha he average BER he CMS agorh s hgher ha he SB ehue. addo we oserve ha usg he BSA-MP ehue SB MF ad MRC reever he average BER s ower ha oher ases. For exape a a SNR of db he average BER usg he BSA-MP ehue s for SB ehue whe he average BER for CMS agorh s Aso s ear ha he MA s o reoved oay ad he perforae s s worse ha he sge user per e oud. Resus for he average BER versus he SNR for CMS MF ad MRC reever ad K u = 3 ave users ad dffere vaues of σ υ are provded Fgure 8. hs fgure sar o Fgure 7 we oserve ha he average BER for he BSA-MP ehue s σ υ 96

13 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 ower ha he oveoa BSA ehue. Aso a e see ha he average BER for σ = 0dB υ perfe power oro s ower ha he oher ases [5]. For exape a a SNR of 0dBad for he BSA-MP ehue he average BER s forσ = 0dB whe for σ υ = db adσ υ = 8dB he average BER are ad 0.0 respevey. Fgure 9 shows he average BER versus he uer of ave users K for dffere reevers as Fgure 7 ad forsnr = 0dB adσ υ = 4dB. A a BER of 0.0 CMS MF ad MRC reever wh he BSA-MP ehue suppor K = 36 users whe for he oveoa BSA u u υ Fgure 9. Average BER versus K u for σ υ = 4dB ad SNR = 0dB Fgure 0. Average BER of a users versus K u for dffere vaues of σ υ ehue suppor Ku = users. addo he fgure shows ha he average BER he CMS agorh s hgher ha he SB ehue. For exape A a BER of ad for he BSA-MP ehue SB MF ad MRC reever suppor Ku = 40 users whe CMS MF ad MRC reever suppor K u = 8 users respevey. Aso a e see ha he hree-sage RAKE reever a aheve ower BER ha he oher reevers. shoud e eoed ha 97

14 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 reasg he uer of ave users K u w rease he uer of users ha a e rasferred o oher ase saos K he BSA-MP ehue. r Fgure 0 preses he average BER versus he uer of ave users as Fgure 8 for SNR = 0dB ad dffere vaues of σ. Sar o Fgure 8 we oserve ha he average BER υ for σ = 0 υ db s ower haσ υ = 48dB. For exape a a BER of 0.0 ad for he BSA- MP ehue he hree-sage RAKE reever whσ υ = 0dBsuppor Ku = 44 users whe for σ υ = 48dB suppor Ku = ad 30 users respevey. Aordgy hs ase wh σ υ fro o 8 db he syse apay degrades fro 9% o 3% opared o he ase of perfe power oro. Fgure. fuee of pah-oss expoe o average BER σ υ = 4 db SNR = 0dB Fgure. fuee of varae of shadowg o average BER σ υ = 4dB SNR = 0dB Oher resus dspayed Fgures ad show he fuee of hae propagao odos pah-oss expoe ad varae of shadowg σ o he average BER for he α CMS MF ad MRC reever ad he BSA-MP ehue. hs suaos we assue SNR = 0dB adσ = 4dB. Fgure we a oserve ha as expeed a rease he υ ξ 98

15 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 pah-oss expoe eas a derease he MA eve ad herefore a provee syse perforae. For exape a a BER of 0.0 apay s respevey 6 36 users for 3 ad 5. Fgure s see ha f σ reases fro 6 o 8 db he uer of ave users ξ dereases y approxaey 55% for a reured average BER of whereas f reases fro 4 o 6 db he apay dereases y approxaey 3%. Fay Fgure 3 shows urves of he average BER versus he uer of ave users forσ υ = 4dB SNR = 0dB ad dffere vaues of he uer of propagao pahs. a e see ha for BER=0.003 he uer of users aowed he syse reases fro 8 o 35 whe vares fro o 4. α = σ ξ Fgure 3. Average BER for dffere vaues of he uer of propagao pahs σ υ = 4dB SNR = 0dB 7. CONCUSONS hs paper we suded he RAKE reever perforae of upe-e DS-CDMA syse wh he spae dversy proessg Rayegh freuey-seeve hae ode power oro error ad ase sao assge. hs reever osss of hree sages. he frs sage wh he CMS agorh he desred users sga a arrary pah s passed ad he P s redued oher pahs eah RAKE fger. Aso hs sage he MA fro oher users s redued. hus he MF a e used for he MA reduo eah RAKE fger he seod sage. Aso he hrd sage he oupu sgas fro he ahed fers are oed aordg o he oveoa MRC prpe ad he are fed o he deso ru for he desred user. Aordgy we proposed BSA-MP ehue o redue he CC ad he MA DS-CDMA euar syses. has ee show ha y usg aea arrays a he ase saos he proposed ehue w derease he average BER of he syse o suppor a sgfay arger uer of users. has aso ee oserved ha he average BER hree-sage RAKE reever s ess ha he oe- ad wo-sage RAKE reevers. O he oher had has ee show ha he average BER he SB ehue s ower ha he CMS agorh. Aso our suaos show ha he varaos power eve due o PCE have a derea effe o syse perforae. 99

16 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 ACKNOWEDGEMEN hs researh was suppored y he sa Azad Uversy Qazv Brah Qazv ra. REFERENCES [] R.. Peerso R. E. Zeer ad D. E. Borh Spread-Speru Couaos. Pree-Ha 995. [] W. Ye ad A. M. Haovh Perforae of euar CDMA wh e se aea array Rayegh fadg ad power oro error EEE rasaos o Couaos vo. 48 o. 7 pp Juy 000. [3] A. Arardo ad D. Sea O he aaya evauao of osed-oop power-oro error sass DS-CDMA euar syses EEE rasaos o Vehuar ehoogy vo. 49 o. 6 pp Nov [4]. Carraso ad G. Feeas Reverse perforae of a DS-CDMA syse wh oh fas ad sow power oroed users EEE rasaos o Wreess Couaos vo. 7 o. 4 pp Apr [5]. Qa ad Z. Ga Varae zao sohas power oro CDMA syse EEE rasaos o Wreess Couaos vo. 5 o. pp Ja [6] M. Raa H. Kovo ad. Haro Adapve osed-oop power oro agorhs for CDMA euar ouao syses EEE rasaos o Vehuar ehoogy vo. 53 o. 6 pp Nov [7] J. Wag ad A. Yu Ope-oop power oro error euar CDMA overay syses EEE Joura o Seeed Areas Couaos vo. 9 o. 7 pp Juy 00. [8] J.. Wag Adsso oro wh dsrued o dversy ad power oro for wreess ewors EEE rasaos o Vehuar ehoogy vo. 58 o. pp Ja [9] K. Kuaa J. MDoough B. Rauh D. Kaow P. N. Garer ad W. Beaforg wh a axu egeropy rero EEE rasaos o Audo Speeh ad aguage Proessg vo. 7 o. 5 pp Juy 009. [0] J. Chag. assuas ad F. Rashd-Farroh Jo raser reever dversy for effe spae dvso uaess EEE rasaos o Wreess Couaos vo. o. pp. 6-7 Ja. 00. [] F. Rashd-Farroh. assuas ad K. J. Ray-u Jo opa power oro ad eaforg wreess ewors usg aea arrays EEE rasaos o Couaos vo. 46 o. 0 pp O [] R. D. Yaes ad C. Huag egraed power oro ad ase sao assge EEE rasaos o Vehuar ehoogy vo. 44 o. 3 pp Aug [3] S. V. Hay A agorh for oed e-se seeo ad power oro o axze euar spread speru apay EEE Joura o Seeed Areas Couaos vo. 3 o. 7 pp Sep [4] M. Mahoud ad E. S. Sousa Jo power oro ase sao assge ad seorzao for CDMA euar syses Pro. 000 EEE Vehuar ehoogy Coferee Boso MA vo. pp Sep [5] M. Dosaraa-Moghada H. Bahsh ad G. Dadashzadeh erferee aagee for DS-CDMA reever hrough ase sao assge upah fadg haes Pro. 00 EEE eraoa Coferee o Wreess Couaos Neworg ad forao Seury Beg Cha pp Jue 00. [6] M. Dosaraa-Moghada H. Bahsh ad G. Dadashzadeh Jo osraed MS agorh ad ase sao assge for DS-CDMA reever upah fadg haes Aeped for 00

17 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 puao he EEE Wreess Couaos Neworg ad Moe Copug Chegdu Cha Sep [7] M. Dosaraa-Moghada H. Bahsh ad G. Dadashzadeh erferee aagee for DS-CDMA syses hrough osed-oop power oro ase sao assge ad eaforg Joura of Wreess Sesor Newor vo. o. 6 pp Jue 00. [8] N. A. Mohaed ad J. G. Duha A ow-opexy oed aea array ad erferee aeao DS-CDMA reever upah fadg haes EEE Joura o Seeed Areas Couaos vo. 0 o. pp Fe. 00. [9] N. A. Mohaed ad J. G. Duha Adapve eaforg for DS-CDMA usg ougae grade agorh a upah fadg hae Pro. 999 EEE Eergg ehooges Syp. Daas X pp Apr [0] F. Rashd-Farroh K. J. Ray-u ad. assuas ras eaforg ad power oro for euar syses EEE Joura o Seeed Areas Couaos vo. 6 o. 8 pp O [] J. va ad. Kwo-Yeug Dga Beaforg Wreess Couaos. Areh-House 996. [] S. Xyu. Xaohua ad Z. Jaag Rous adapve eaforg ased o axu ehood esao eraoa Coferee o Mrowave ad Meer Wave ehoogy vo. 3 pp Apr [3] M. Z. Shar ad. S. Durra Narrowad eaforg agorh for sar aeas eraoa Bhura Coferee o Apped Sees & ehoogy pp Ja [4] S. Hay Adapve fer heory. 3 h ed. New Jersey: Pree Ha 996. [5] N. Kog ad. B. Mse Average SNR of a geerazed dversy seeo og shee EEE Couaos eers vo. 3 o. 3 pp Mar [6] J. M. Roero-Jerez C. eez-aao ad A. Daz-Esrea Effe of power oro perfeos o he reverse of euar CDMA ewors uder upah fadg EEE rasaos o Vehuar ehoogy vo. 53 o. pp. 6-7 Ja [7] J. C. er ad. S. Rappapor Sar Aeas for Wreess Couaos S -95 ad hrd Geerao CDMA Appaos. Pree-Ha 999. [8] M. Dosaraa-Moghada H. Bahsh G. Dadashzadeh ad M. Godarzvad-Cheg Jo ase sao assge power oro error ad adapve eaforg for DS-CDMA euar syses upah fadg haes Aeped for puao EEE Goa Moe Cogress Shagha Cha O [9] B. Ae ad M. Beah O he aayss of swhed-ea aeas for he W-CDMA dow EEE rasaos o Vehuar ehoogy vo. 53 o. 3 pp May 004. [30] M. Dosaraa-Moghada H. Bahsh ad G. Dadashzadeh Jo erazed power oro ad e seorg for erferee aagee CDMA euar syses a D ura evroe Joura of Wreess Sesor Newor vo. o. 8 pp Aug. 00. Auhors Mohaad Dosaraa Moghada was or ehra ra o May He reeved he B.S. degree eera egeerg fro sa Azad Uversy Qazv Brah Qazv ra ad he M.S. degree ouao egeerg fro Ferdows Uversy Mashad ra 00 ad 005 respevey. He s urrey worg oward he Ph.D degree he Depare of Eera Egeerg sa Azad Uversy See & Researh Brah ehra ra. Hs researh eress ude power oro wreess ouaos array ad sasa sga proessg sar aeas ad adapve ferg. 0

18 eraoa Joura of Copuer Newors & Couaos JCNC Vo.3 No. Jauary 0 Hadreza Bahsh was or ehra ra o Apr He reeved he B.S. degree eera egeerg fro ehra Uversy ra 99 he M.S. ad Ph.D. degree Eera Egeerg fro ara Modarres Uversy ra 995 ad 00 respevey. Se 00 he has ee as a Asssa Professor of Eera Egeerg a Shahed Uversy ehra ra. Hs researh eress ude wreess ouaos uuser deeo ad sar aeas. Ghoareza Dadashzadeh was or Ura ra 964. He reeved he B.S. degree ouao egeerg fro Shraz Uversy Shraz ra 99 ad M.S. ad Ph.D. degree ouao egeerg fro ara Modarres Uversy MU ehra ra 996 ad 00 respevey. Fro 998 o 003 he has wored as head researher of Sar Aea for Moe Couao Syses SAMCS ad WAN 80. proe rado ouaos group of ra eeo Researh Ceer RC. Fro 004 o 008 he was dea of Couaos ehoogy sue C RC. He s urrey as Asssae Professor he Depare of Eera Egeerg a Shahed Uversy ehra ra. He s a eer of EEE sue of Eeros forao ad Couao Egeers ECE of Japa ad raa Assoao of Eera ad Eeros Egeers AEEE of ra. He hoored reeved he frs degree of aoa researher 007 fro ra s sry of C. Hs researh eress ude aea desg ad sar aeas. 0