WCDMA BASICS

Nguyn l mng RANTng quan 3G.Kin trc mng CDMA.Nguyn l v tuyn WCDMA.

Nguyn l mng RANTng quan 3G.Qu trnh pht trin ln 3GCc chun 3GBng tn s dng trong 3GCc dch v ca 3GKin trc mng CDMA.Nguyn l v tuyn WCDMA.

Tng quan 3G

Tng quan 3G3G Evolution3G(IMT-2000) l tiu chun m cc dch v tho mn nhng yu cu ca ITU : nng cao dung lng, tng thch vi h thng 2G, h tr Multimedia, dch v d liu gi tc cao... c thng mi ha vo khong nm 2000.Chia lm 2 nhm tiu chun :3GPP - da vo WCDMA3GPP2 - da vo CDMA2000Cc cng ngh truy nhp s dng trong 3G:WCDMACDMA2000TD-SCDMATrong TD-SCDMA c pht trin bi Trung Quc.

Tng quan 3GPh tn s 3G

Tng quan 3GBng tn chnh: 2GHz1920 ~ 1980MHz / 2110 ~ 2170MHz. Viettel ang s dng bng B trong bng tn 3G.Cc bng tn ph:1900Mhz: 1850 ~ 1910 MHz / 1930 MHz ~ 1990 MHz (USA).1800Mhz: 1710 ~ 1785MHz / 1805 ~ 1880MHz (Japan)900Mhz: 890 ~ 915MHz / 935 ~ 960MHz (Australia)S tn s v tuyn (UARFCN) = tn s trung tm x 5. i vi bng tn chnh tn s nh sau:UL: 9612 ~ 9888.DL: 10562 ~ 10838.3 tn s chnh (DL) ca mng 3G VT l: f1: 10663, f2: 10638, f3: 10688. (1935MHz-1950MHz/2125MHz-2140MHz)

Tng quan 3GDch v 3G

Nguyn l mng RANTng quan 3G.Kin trc mng CDMA.Kin trc ca h thng WCDMACc giao din chnhCc phin bn WCDMANguyn l v tuyn WCDMA.

Kin trc mng WCDMA v qu trnh pht trinCng ngh mng li 3GCDMA WCDMACN: based on MAP and GPRSRTT: WCDMA - FDD/TDD TD-SCDMACN: based on MAP RTT: TD-SCDMA cdma2000CN: based on ANSI 41 and MIPRTT: cdma2000

Kin trc mng WCDMA v qu trnh pht trin

Kin trc mng WCDMA v qu trnh pht trin

Kin trc mng WCDMA v qu trnh pht trinPhase 2+(Release 97) GPRS 171.2kbpsPhase 1GSM 9.6kbpsRelease 99UMTS 2MbpsRelease 99EDGE 473.2kbpsRelease 8LTE >300MbpsRelease 6HSUPA 5.76MbpsRelease 5HSDPA 14.4MbpsRelease 7/8HSPA+ 28.8Mbps/ 42MbpsRelease 9/10LTE Advanced

Nguyn l mng RANTng quan 3G.Kin trc mng CDMA.Nguyn l v tuyn WCDMA.Cng ngh a truy nhp v song cngQu trnh iu ch xy ra trong WCDMASource codingChannel coding/interleavingSpreading and StramblingModulationRadio chanel

Nguyn l v tuyn CDMACng ngh a truy nhp:a truy nhp phn chia theo tn s FDMA.a truy nhp phn chia theo thi gian TDMA.a truy nhp phn chia theo m CDMA.

Nguyn l v tuyn CDMAa truy nhp phn chia theo tn s FDMA

Nguyn l v tuyn CDMAa truy nhp phn chia theo thi gian TDMA

My phtMy thuspread spectrumNguyn l v tuyn CDMAa truy nhp phn chia theo m CDMA

Nguyn l v tuyn CDMAK thut truyn song cng:Song cng phn chia theo tn s FDD.Song cng phn chia theo thi gian TDD.

Nguyn l v tuyn CDMA

Nguyn l v tuyn CDMA- Chun m ha H.324 c dng cho VP.WCDMA Source Coding

B m ha AMR (a tc thch ng): dng cho thoi, tc AMR c th thay i ty thuc vo iu kin v tuyn. Tc bit ca AMR c th c iu khin bi RAN ph thuc vo ti v QoS ca cc dch v thoi.

Nguyn l v tuyn CDMA

Nguyn l v tuyn CDMAM ha khi-CRC: dng pht hin li.M ha knh WCDMA:Tng kh nng chng nhiu ca tn hin khi truyn ngoi mi trng v tuyn.S dng 2 loi m ha knh:Convolutional Code (1/2,1/3): dng cho thoi v VP.Turbo Code (1/3): dng cho d liu tc cao.Ghp xen: hn ch kh nng li bit lin tc.

Nguyn l v tuyn CDMA

Nguyn l v tuyn CDMATnh tng quan: o lng s ging nhau gia 2 tn hiu nh phn.

Nguyn l v tuyn CDMAS dng m trc giao

Nguyn l v tuyn CDMAS dng m trc giao

Nguyn l v tuyn CDMA

Nguyn l v tuyn CDMA li x l:PG=10log(chip rate/bit rate) li x l khc nhau i vi cc dch v khc nhau. Nu tc bit ln th li x l s nh hn. UE cn nhiu cng sut cho dch v ny vng ph ca dch v s nh hn.

Nguyn l v tuyn CDMAK thut tri ph: bao gm 2 bcTri ph: chuyn nh dng ca tn hiu t symbol sang chip, v lm tng bng thng ca tn hiu ln 3.84Mcps (tc chip). Cc m tri ph trc giao vi nhau (Correlation = 0) nn khng nh hng ln nhau (l tng).Xo trn: phn bit cc b thu pht vi nhau, khng lm thay i bng thng tn hiu.

Nguyn l v tuyn CDMAM tri ph CDMAM OVSF (m h s tri ph bin thin trc giao) c s dng.

Nguyn l v tuyn CDMASF = chip rate / symbol rate.D liu tc cao cn m tri ph c SF nh.D liu tc thp cn m tri ph c SF ln.

Nguyn l v tuyn CDMAChc nng ca m tri ph:i vi Downlink, m tri ph dng phn bit cc knh vt l khc nhau trong 1 cell.i vi Uplink, m tri ph dng phn bit cc knh vt l khc nhau ca 1 User.Chc nng ca m Scrambling:i vi Downlink, m tri ph dng phn bit cc Cell khc nhau trong cng 1 tn s.i vi Downlink, m tri ph dng phn bit User khc nhau trong cng 1 tn s.

Nguyn l v tuyn CDMAM Scrambling:S dng chui Gold.C 224 m xo trn ng ln c s dng xo trn tn hiu ng ln. Cc code ng ln c gn bi RNCi vi ng DL s dng 512 m xo trn c s (PSC)

Nguyn l v tuyn CDMANhm PSC512 PSC s c phn thnh 64 nhm, mi nhm gm 8 PSC gip ng b cell nhanh hn trong qu trnh Cell Seach.Mi cell ch c cp ch mt PSC.

Nguyn l v tuyn CDMACode Multiplexing DL

Nguyn l v tuyn CDMACode Multiplexing UL

Nguyn l v tuyn CDMA

Nguyn l v tuyn CDMATng quan iu ch

Nguyn l v tuyn CDMABPSK

Nguyn l v tuyn CDMAQPSK

Nguyn l v tuyn CDMACc kiu iu ch trong WCDMA ng xung: QPSK v QAM.

ng ln: BPSK

Nguyn l v tuyn CDMA

Nguyn l v tuyn CDMAFading

Nguyn l v tuyn CDMAFading:Fading chm: do che khut.Fading nhanh: do a ng.

Nguyn l v tuyn CDMAK thut phn tp: c s dng kt hp cc tn hiu khng tng quan thu c.Gim nh hng ca fadingCi thin tin cy thng tin lin lcGia tng vng ph v dung lngCc k thut phn tpPhn tp thi gian: Channel coding, interleaving.Phn tp tn s: nhy tn.Phn tp khng gian.Phn tp cc.

Nguyn l v tuyn CDMANguyn l ca b thu RAKE

Tng ktTng quan 3G: cc chun, bng tn, dch vKin trc mng 3G, cc giao din, phin bnNguyn l v tuyn WCDMAa truy nhp, song cng.Source codingChannel coding/interleavingSpreadingModulationRadio channel

Chn thnh cm n cc anh ch lng nghe!

***- Th h u tin l mng thng tin di ng tng t trong khong thi gian t gia thp nin 1970 n gia nm 1980. Cc bc t ph quan trng nht trong giai on ny l cc khi nim v mng t bo a ra bi cc phng th nghim Bell LABs vo nhng nm 1970, so vi cc h thng thng tin di ng c. H thng mng di ng t bo da trn cc t bo thc hin ti s dng tn s v do kh nng tng cng nng lc h thng.- Cc v d in hnh ca cc h thng thng tin di ng th h u tin l h thng AMPS, TACS nng cao ca M, h thng NMT v NTT. H thng AMPS (Advanced Mobile Phone System) s dng bng tn 800 MHz ca h thng truyn dn di ng tng t v n c ng dng rng ri Bc M, Nam M v mt s nc Thi Bnh Dng. H thng TACS (Total Access Communication System) s dng bng tn 900 MHz. H thng ny c ng dng rng ri Anh, Nht Bn v mt s nc chu .- Tnh nng chnh ca h thng thng tin di ng u tin l s dng cng ngh ti s dng tn s, thng qua iu ch tng t cho cc tn hiu thoi v cung cp mt knh thu bao tng t 30Khz/25Khz khc nhau.- Tuy nhin, chng cn c cc khuyt im sau:+ Hiu nng s dng ph tn thp.+ Cc kim dch v b gii hn.+ Khng c dch v d liu tc d cao.+ Bo mt km v d b nghe trm.+ Gi thit b cao.- gii quyt nhng khuyt im k thut c bn ca cc h thng tng t, cc cng ngh thng tin di ng s c ra i v cc h thng thng tin di ng th h hai c th hin bi GSM v i din ca IS-95 ra i vo gia nm 1980. Cc v d in hnh ca cc h thng thng tin di ng t bo th h hai l DAMPS ca M, IS-95 v h thng GSM chu u.- H thng GSM (Global System for Mobile Communications) c ngun gc t chu u. c thit k nh l tiu chun TDMA cho thng tin di ng s t bo, n h tr tc d liu 64 kbps v c th kt ni vi ISDN. N s dng bng tn 900 MHz trong khi h thng DCS1800 s dng bng tn 1800 MHz. H thng GSM s dng cc ch FDD v TDMA v mi sng mang h tr tm knh vi bng thng tn hiu l 200 kHz.- DAMPS (Digital Advanced Mobile Phone System) cn c gi l IS-54 (North America Digital Cellular System). S dng bng tn 800 MHz, n l chun ra i trc ca hai chun di ng s Bc M v quy nh c th vic s dng phng thc TDMA.- Chun IS-95 l mt chun di ng s khc ca Bc M. S dng bng tn 800 MHz hoc 1900 MHz, n quy nh c th vic s dng cc ch CDMA v tr thnh s la chn u tin trong s cc cng ngh ca cc mng PCS (Personal Communication System) ca M.- H thng thng tin di ng 2G tp trung vo vic truyn cc dch v thoi v d liu tc thp, th h thng thng tin di ng 2,5 G xut hin vo nm 1996 nhm vo vic truyn cc dch v tc d liu trung bnh. Cc h thng ny bao gm GPRS v IS-95B.- Cc h thng CDMA c dung lng rt ln n tng ng hoc thm ch gp hai mi ln so vi cc h thng tng t. Nhng cng ngh CDMA bng hp trng thnh ti thi im mun hn so vi cng ngh GSM, ng dng ca chng n nay cho nhng nc chm trin khai GSM v hin nay ch c ng dng thng mi quy m ln l Bc M, Hn Quc v Trung Quc. Cc dch v chnh ca thng tin di ng hin vn cn cc dch v thoi v cc dch v d liu tc thp.- Vi s pht trin ca cc mng, d liu v truyn thng a phng tin cng chng kin s pht trin nhanh chng; v vy, mc tiu ca thng tin di ng 3G l thc hin truyn thng a phng tin bng rng.

*Cc h thng thng tin di ng 3G l loi h thng c th cung cp nhiu loi dch v a phng tin cht lng cao v c th cung cp vng ph lin tc ton cu v roaming ton cu. Chng l tng thch vi cc mng c nh v c th thc hin bt k loi thng tin lin lc bt c lc no v bt c ni u vi thit b u cui cm tay. a ra vo nm 1985 bi ITU (International Telecommunication Union), h thng thng tin di ng 3G c gi l FPLMTS (Future Public Land Mobile Telecommunication System) v sau ny c i tn l IMT-2000 (International Mobile Telecommunication-2000). Cc h thng ln bao gm WCDMA, CDMA2000 v UWC-136. Ngy 05 thng mi mt nm 1999, Hi ngh ln th 18 ca ITU-R TG8 / 1 thng qua khuyn ngh chi tit k thut cc giao din v tuyn ca IMT-2000 v cng ngh TD-SCDMA ca Trung Quc a ra c kt hp vo cc phn chi tit k thut ca IMT-2000 CDMA TDD. iu ny cho thy cng vic ca cc TG8 / 1 xy dng cc thng s k thut ca giao din v tuyn trong cc h thng thng tin di ng 3G c bn i vo mt kt thc; s pht trin v ng dng ca cc h thng thng tin di ng 3G s a vo mt giai on mi v rt cn thit.

*- ITU phn b 230 MHz tn s cho cc h thng thng tin di ng 3G IMT-2000: 1885 ~ 2025MHz ng ln v 2110 ~ 2200 MHz ng xung. Trong , cc di tn s 1980 MHz ~ 2010 MHz (uplink) v ca 2170 MHz ~ 2200 MHz (downlink) c s dng cho cc dch v v tinh di ng. Nh vy bng tn uplink v downlink l khng i xng, vic s dng ch FDD tn s kp hoc n tn s ch TDD c th c xem xt. K hoch ny c thng qua WRC92 v bng tn mi b sung c ph duyt trn c s ca WRC-92 ti hi ngh WRC2000 trong nm 2000: 806 MHz ~ 960 MHz, 1710 MHz ~ 1885 MHz v 2500 MHz ~ 2690 MHz. *-H thng WCDMA s dng ph tn s sau y (cc bng tn khc ngoi quy nh ca 3GPP cng c th c s dng): Uplink 1920 MHz ~ 1980 MHz v downlink 2110 MHz ~ 2170 MHz. Mi tn s sng mang c rng 5M v khong cch song cng l 190 MHz. Ti M, cc ph tn s c s dng l 1850 MHz ~ 1910 MHz trong ng ln n 1930 MHz ~ 1990 MHz ng xung v khong cch song cng l 80 MHz. *- Tng thch vi nhiu cc dch v v cc ng dng ca 2G, h thng 3G c mt nn tng dch v m tch hp cung cp mt tng lai rng cho cc dch v 3G khc nhau.- Cc dch v 3G c k tha t cc dch v 2G. Trong mt kin trc mi, kh nng dch v mi c to ra, v nhiu loi dch v khc ang c sn. Cc c tnh dch v bin i rt nhiu; do , mi dch v c tnh nng khc nhau. Ni c mt s tnh nng nh sau:Tng thch ngc vi tt c cc dch v ca GSM.Cc dch v thi gian thc (m thoi) chng hn nh dch v thoi thng thng c cc yu cu QoS.Khi nim v dch v a phng tin (trc tuyn, tng tc, nn) c gii thiu.

**WCDMA RAN FundamentalConfidential Information of Huawei. No Spreading Without Permission N-*- c trnh by r bi t chc 3GPP chun chu u, cc mng li tin trin trn c s GSM / GPRS v do c th tng thch vi cc mng GSM/GPRS hin ti. C th c da trn cng ngh TDM, ATM v IP pht trin hng ti kin trc mng IP. Da trn cng ngh ATM, UTRAN x l mt cch ging nhau i vi cc dch v thoi v d liu gi.- H thng CDMA2000 l mt chun 3G a ra trn c s cc chun IS-95. Cng vic chun ho hin ang c thc hin bi 3GPP2. Min chuyn mch (CS) c chuyn th t mng 2G CDMA IS95, min chuyn mch gi (PS) l mt mng gi da trn cng ngh Mobile IP. Mng truy nhp v tuyn (RAN) l da trn nn tng chuyn mch ATM, n cung cp cc giao din thch ng vi nhiu lp.- Chun TD-SCDMA c a ra bi Chinese Wireless Telecommunication Standard (CWTS) Group v by gi n c sp nhp vo cc chi tit k thut lin quan n WCDMA TDD ca 3GPP. Cc mng li pht trintrn c s GSM/GPRS. Giao din v tuyn s dng ch TD-SCDMA. WCDMA bao gm RAN (Radio Access Network) v CN (Core Network). RAN c s dng x l tt c cc chc nng lin quan n v tuyn, trong khi CN c s dng x l tt c cc cuc gi thoi v cc kt ni d liu trong h thng UMTS, v thc hin cc chc nng bn ngoi mng chuyn mch v nh tuyn.V lgic, CN c chia lm min CS (Circuit Switched) v min PS (Packet Switched). UTRAN, CN v UE (User Equipment) vi nhau to thnh ton b h thng UMTS.Mt RNS gm c mt RNC v mt hoc nhiu Node B. Giao din Iu c s dng gia RNC v CN trong khi cc giao din Iub c s dng gia RNC v Node B. Trong UTRAN, cc RNC kt ni vi nhau thng qua giao din Iur. Giao din Iur c th kt ni RNCs thng qua cc kt ni trc tip gia chng hoc kt ni chng thng qua mt mng truyn dn. RNC c s dng cp pht v kim sot cc ngun ti nguyn v tuyn ca cc node B c kt ni n n. Tuy nhin, Node B phc v chuyn i d liu gia giao din Iub v giao din Uu, v ng thi, n cng tham gia vo mt phn ca qun l ti nguyn v tuyn.

**Cc cu trc tng th ca mng WCDMA c nh ngha trong 3GPP TS 23,002. Hin ti, c cc phin bn sau: R99, R4, R5,R6..3GPP bt u xy dng chi tit k thut 3G vo cui nm 1998 v u nm 1999. Theo k hoch, phin bn R99 s c hon thnh vo cui nm 1999, nhng trong thc t n khng hon thnh cho n thng Ba nm 2000. bo m quyn li u t ca cc nh khai thc, min CS ca phin bn R99 v c bn khng thay i, do h tr vic chuyn i sun s ca GSM/GPRS/3G. Sau khi phin bn R99, phin bn khng cn t tn theo nm. ng thi, cc chc nng ca R2000 c thc hin bi hai phase sau: R4 v R5. Trong mng R4, MSC l min CS ca CN c chia thnh MSC Server v cc MGW, ng thi, mt SGW c thm vo, v HLR c th c thay th bng HSS (khng r rng trong c t k thut).Trong mng R5, VOIP end-to-end c h tr v mng li s dng mt cch phong ph cc phn t chc nng mi thay i th tc cuc gi gc. Vi IMS (IP Multimedia Subsystem), mng c th s dng HSS thay v HLR. Trong mng R5, HSDPA (High Speed Downlink Packet Access) cng c h tr, n c th h tr dch v d liu tc cao.Trong mng R6, cc HSUPA c h tr c th cung cp dch v tc UL ln n 5.76Mbps. V MBMS (Multimedia Broadcast Multicast Service) cng c h tr.Phin bn R7, HSPA+ c gii thiu vi phng php iu ch cao hn v s dng anten Mimo. Max DL: 28Mbps/42Mbps, Max UL: 11Mbps.Phin bn R8, WCDMA LTE c gii thiu. OFDMA thay th cho CDMA. Max DL: >300Mbps, Max UL: 100Mbps.

**** Trong phng php ny rng bng tn cp pht cho h thng B Mhz c chia thnh n bng tn con, mi bng tn con c n nh cho mi knh ring c rng bng tn l B/n Mhz. Hay ni cch khc phng thc a truy nhp ny mi knh c cp pht mt tn s c nh tn s phi phn chia v quy hoch trn ton th gii. Cc h thng tng t l v d in hnh s dng phng php a truy nhp ny. u im: khng cn ng b, tr thp do khng cn x l tn hiu nhiu. Phng php ny c nhc im l hiu sut s dng tn s thp, kh nng bo mt km. *-TDMA c ngha l bng thng ca mt sng mang c chia thnh nhiu knh phn chia theo thi gian (hay gi l khe thi gian). Mi ngi s dng chim mt khe thi gian v vic truyn/nhn nhn cc tn hiu bn trong cc khe thi gian c quy nh. Do , n c gi a truy cp phn chia theo thi gian. Hnh thc a truy nhp ny c s dng trong c hai h thng di ng l h thng t bo s v GSM.-So vi FDMA, TDMA cho php tit kim tn s v thit b thu pht hn. TDMA thng kt hp vi FDMA nng cao dung lng h thng.-Nhc im ca TDMA l i hi ng b tt, thit b phc tp hn, tr truyn ln hn so vi TDMA.

*CDMA l mt phng thc a truy nhp c thc hin bi iu ch tri ph. Khng ging nh FDMA v TDMA, c hai u ring bit cc thng tin ngi dng v thi gian v tn s, CDMA c th truyn ti cc thng tin ca nhiu ngi dng trn mt knh cng mt lc. iu quan trng l mi thng tin trc khi truyn phi c iu ch bng cch iu ch tri ph khc nhau n cc tn hiu bng rng, sau tt c cc tn hiu s c trn ln v gi. Cc tn hiu hn hp s c gii iu ch bng cch gii iu ch tri ph khc nhau cc b nhn khc nhau. Bi v tt c cc m tri ph l trc giao, ch c thng tin c c gii iu ch tri ph bng cng m gii tri ph mi c th c c phc hi trong tn hiu hn hp. CDMA c nhiu u im hn so vi cc phng php a truy nhp FDMA v TDMA nh: dung lng cao hn, kh nng chng nhiu v fading tt hn, bo mt tt hn, quy hoch mng d hn Tuy nhin CDMA cng khng trnh khi nhc im: ng b phc tp hn (ngoi ng b v thi gian cn phi ng b m), phn cng cng phc tp hn

- Trong h thng thng tin di ng 3G, WCDMA v CDMA2000 s dng k thut song cng theo tn s (FDD), TD-SCDMA s dng k thut song cng theo thi gian (FDD)* Source Coding c th gia tng hiu qu truyn. Channel coding c th gip truyn ng tin cy hn. Spreading c th gia tng kh nng chng nhiu. Thng qua iu ch, cc tn hiu s c truyn trong cc tn hiu v tuyn t cc tn hiu s. Bit, Symbol, Chip: Bit: d liu sau khi m ha ngun. Symbol: d liu sau khi m ha knh v ghp xen. Chip: d liu sau khi tri ph.*AMR c th tng thch vi cc ht hng thng tin di ng hin ti (GSM, IS-95, PDC), v vy n d dng thit k cc u cui a mode.CccodecAMRcung cpkh nngthch ng vic chm ha n vi cciu kinknh v tuyn.Ch m ha mnh mnhtc chntrongiu kin sng v tuyn ti.Ccch mnguncung cp tc ngun cao nhtc chntrongiu kinsng v tuyntt.Trongsut qu trnh thng tinAMR,b nhno cht lng lin k v tuyn v phi tr b truyn hoc l kt qu o kim hoc l ch codec hin ti, b truyn s s dng trong frame tip theo. S ic thc hincng nhanhcng tttheo ditt hnqu trnh tin trincacht lngknh. Chun m ha H.324 c dng cho VP gm: H.263 thut ton nn Video. G.723 thut ton nn Thoi. H.223/H.245 Multiplexing v giao thc iu khin. **Channel coding: Block Coding, Channel coding, interleaving. c s dng chng nhiu v fading. Block coding dng pht hin li. Channel coding: Convolutional code v Turbo Code. Convolutional code c s dng chng nhiu. K thut ny s chn cc bit d tha vo trong thng tin ban u. Khi mt code b nhiu, cc bit d tha c th c s dng phc hi tn hiu ban u. M Turbo c xem l rt hiu qu bi v chng c th thc hin gn vi gii hn l thuyt theo nh l Shannon. Hiu qu ca n l tt nht i vi d liu tc cao, nhng hiu qu thp i vi dch v tc thp. i vi d liu tc cao, Turbo coding hiu qu hn nhiu so vi Convolutional coding.Channel coding hot ng tt i vi cc li ngu nhin, nhng n kh d b n li, l in hnh trong h thng di ng. c bit l s di chuyn nhanh ca UE trong h thng CDMA c th gy ra li bit lin tip nu Power control khng nhanh qun l nhiu. Hu ht cc m hnh m ha thc hin tt trn d liu li ngu nhin hn l trn d liu li khi. Vn ny c th d dng c gii quyt bi interleaving, l cc li bit tri ph trong mt thi gian di. Vi interleaving th khng c 2 bit k cn c truyn gn nhau, v d liu li c ngu nhin ha.Chu k interleaving cng ln th d liu c ngu nhin tt hn nhng s tng delay.

***-Bng cch tri ph, mi symbol c nhn vi tt c cc chip trong chui trc giao c giao cho ngi dng. Chui kt qu c x l v sau c truyn qua cc knh vt l cng vi cc symbol khc. Cc sn phm trong nhng biu tng ngi dng v m truyn l mt chui cc ch s phi c truyn i 4 ln tc ca tn hiu nh phn ban u c m ha.

*-B nhn gii tri ph cc chip bng cch s dng cng mt m c s dng trong my pht. Ch rng trong iu kin khng c nhiu, nhng symbol hoc ch s l hon ton hi phc m khng c li no. Trong thc t, knh khng phi l hon ton khng nhiu, nhng h thng CDMA s dng k thut Forward Error Correction chng li cc tc ng ca ting n v tng cng hiu sut ca h thng. -Khi code sai c s dng cho gii tri ph, kt qu tng quan a ra mt gi tr trung bnh bng khng. y l mt minh chng r rng v li th ca tnh cht trc dao ca cc code. Cho d code sai c s dng bi ngi dng ch hoc cc ngi dng khc , kt qu tng quan lun l zero bi v tnh cht trc giao ca m.*-H thng thng tin v tuyn truyn thng truyn d liu bng cch s dng bng thng ti thiu cn thit thc hin n nh l mt tn hiu bng hp. H thng CDMA kt hp d liu u vo ca chng vi mt chui tri ph nhanh v truyn tn hiu bng rng. Chui tri ph l c lp c pht ra b nhn v c trn vi cc tn hiu bng rng n phc hi d liu ban u. Gii tri ph cho php tng ch ng k t l thun vi bng thng ca tn hiu tri ph. S tng ch ny c th c s dng tng hiu nng h thng v phm vi, hoc cho php nhiu ngi dng m ho, hoc c hai. Mt chui bit s c gi qua mt lin kt v tuyn yu cu mt bng thng nht nh c truyn v nhn thnh cng.

*-i vi dch v ph bin, tc bit ca cc cuc gi thoi l 12.2kbps, tc bit ca VP l 64kbps, v cc gi dch v tc bit cao l 384kbps (R99). Sau khi tri ph, tc chip ca tt c cc dch v khc nhau tr thnh 3.84Mcps.

*-Tri ph c ngha l tng bng thng ca tn hiu ngoi bng thng thng cn thit thch ng vi thng tin. Qu trnh tri ph trong UTRAN bao gm hai hot ng ring bit: m ha knh v xo trn.-Hot ng u tin l m ha knh, bin i mi biu tng d liu vo trong mt s chip, do tng bng thng ca tn hiu. S lng chip cho mi d liu biu tng c gi l h s tri ph (SF). M ha knh l m trc giao, c ngha l trong mi trng l tng chng khng nh hng ln nhau.-Hot ng th hai l hot ng xo trn. Xo trn c s dng trn tri ph, v vy n khng thay i bng thng tn hiu nhng ch lm cho cc tn hiu t cc ngun khc nhau tch ri nhau. Khi tc chip t c trong m ha knh bi cc m m ha knh, tc chip khng b nh hng bi cc xo trn.

*- M tri ph c to ra t bit 1. M tri ph c nh ngha di dng Cch,SF,k; trong : ch: vit tt ca Channelization Code, SF: h s tri ph, k: th t ca m 0