Per-survivor AIC Based on Group Decoding for the Space-time Trellis Coded DS-CDMA System

Transcription

1 Per-urvvor AIC Bed on Decodn for te pce-te Tre Coded D-CDA yte JooHyun Y coo of ectrc nneern eou ton Unverty eou, ore oyuny@nucr Je Hon ee coo of ectrc nneern eou ton Unverty eou, ore Abtrct In t pper, we propoe te per-urvvor dptve nterference cnceer PAIC bed on roup decodn for te upn of te pce-te tre coded D-CDA yte Te tre-bed roup decoder TBD obtn te trde-off between perfornce nd copety by decopon te upertre for te entre decoder nto te roup-tree for ubet of uer A te TBD ue te tenttve decon n ec tte trnton to reduce te AI, te error of te tenttve decon cue te error propton to derde everey t perfornce To tte te perfornce derdton, we utze te dptve nterference cnceer un per-urvvor procen wc reduce te netve effect of error propton, nted of te tenttve decon uton reut ow tt te propoed cee better perfornce over te conventon ne uer decoder cee wtout uc ncree of decodn dey nd copety, nd o ceve te perfornce ner tt of te optu uper-tre decoder wt nfcnty ower copety eyword-cda, Adptve Interference Cnceton, Perurvvor Procen, pce-te Tre Code, Decodn I ITRODUCTIO Te pce-te codn tecnue TC, wc provde nfcnt ncree of cpcty n ne uer councton yte, been dopted n te code-dvon utpe-cce CDA yte wt utpe trnt nd receve ntenn to upport te dend on -rte ervce However, n te pce-te coded D-CDA yte, te n of te TC reduced by utpe cce nterference AI ennced fro ut-ntenn trnon In prtcur, wen te ow procen n for te -rte ervce ued or te ner-fr effect n upn trnon occur, te AI ncree even ore to derde everey te perfornce of te yte To tte te perfornce derdton by te AI, te utuer detecton, epecy utuer decodn n te coded yte uc te pce-te coded D-CDA yte, ut be condered []-[3] Te optu utuer decoder ue te uper-tre wt te nuber of tte tt row eponenty wt te nuber of uer Hence, t probtve n prctc peentton nd uboptu utuer detector wt reduced-copety ve been reerced A one of te uboptu utuer decoder, te tre-bed roup decoder TBD reduce te copety by epotn te fct tt te uper-tre for te entre uer cn be decopoed nto te roup-tree for ubet of uer Trde-off between perfornce nd copety ey ceved by dutn te nuber of uer decoded by ec roup-tre In roup decodn, te TBD ette nd cnce te AI wtout decodn dey by un te tenttve decon n ec tte trnton [4],[5] However, wen te tenttve decon of one uer n error, te error propton netvey ffect decodn not ony for tte-trnton of te one net ybo but o for tt of te oter uer n te roup-tre In coneuence te perfornce of te TBD derde everey A n effectve terntve of te tenttve decon n te tre-bed yte, te per-urvvor procen PP been propoed for te reduced copety ubopt cee of te, uc te decon feedbc euence etton nd reduced tte euence etton Te PP nfcnty reduce te netve effect of te error propton In ddton, te per-urvvor ettor octed wt te bet urvvor derved fro dt nforton wt -uty nd zero-dey decon, nd te t of bnd cuton of unnown preter ubtnty fctted wt repect to conventon tecnue nce ny ypotetc dt euence re utneouy condered [6] In t pper, we propoe te per-urvvor dptve nterference cnceer PAIC bed on roup decodn n upn of te pce-te tre coded D-CDA yte We te TBD ente te AI by un te tenttve decon, te PAIC reduce te AI by un te AIC bed on PP Te propoed cee cn prove te perfornce wtout uc ncree of decodn dey nd copety We ornze te ret of te pper foow In ecton II, we preent te pcete coded D-CDA n ode Te PAIC bed on roup decodn deveoped n ecton III oe uton reut re own n ecton IV, nd concuon re drwn n ecton V II PAC-TI CODD D-CDA IA OD Conder D-CDA yte wt utneou uer nd te procen n of F ow te upn of te pce-te coded D-CDA yte wt trnt nd receve ntenn T wor w upported by te Brn ore Proect nd ton Reerc bortory Pror /04/$000 C 004 I

2 b t τ r t y wt te vrnce of 0 / for ec of re nd nry prt In te reur ne-uer recever, te receved n vector depred by te nture euence of te dered uer to e depred n Te depred n of te t uer t te t receve ntenn ven by b r t t τ T y r χ + + η + d d, d d, } + n d d, 3 Fure Upn of te pce-te coded D-CDA yte wt trnt nd receve ntenn Te t dt bt of te t uer b,,,, pcete encoded to codeword,, for trnt ntenn c ybo of te codeword pred by t unue nture euence [,0,,,,,- ] to be trntted wt ybo enery, b /, were b bt enery Te receved bebnd n t te t receve ntenn ven by + n t F 0 r t t τ, nϕ t T ntc were F te ent of fre, t te cnne n, τ rrv te dey fro te t trnt ntenn to te t receve ntenn, ϕt rectnur cp-pue wt unt enery, T ybo durton, T c cp durton, nd n t un noe wt te power pectr denty of 0 Aue tt te cnne between ec pr of trnt nd receve ntenn d Rye fdn to ec oter nd te fdn n of ec cnne contnt over one fre nd vre fro fre to noter Durn ec ybo durton, output pe fro te t cp tced-fter e receved n vector r [r,0, r,,, r,- ] for te t receve ntenn et denote d te d-fted euence for te nture euence of te t uer, [3] For convenence, uppoe tt te rrv te dey ven by τ d Tc for oe nteer d [0, -] Ten te receved n vector r yncronzed wt τ ven by r d + d n d d + d d } + n were n noe vector vn coponent wc re ndependent zero-en cope un rndo vrbe d d were, te cro-correton vue between nd, χ nd η re te dered n nd te nterference-pu-noe wc re ven by η χ nd 4 + d d, + + d d, + d d, } + n, 4b repectvey, nd n n AW wt te vrnce of 0 III PR-URVIVOR AIC BAD O ROUP DCODI F ow te tre tructure for te pce-te tre coded D-CDA yte wt trnt ntenn Aue tt ec uer ue te tre of 4-tte BP pce-te tre code TTC own n F nd te tre-bed roup decoder TBD decode te codn nforton of uer per one roup Ten te roup-tre for te TBD drwn n F b In te roup-tre, tte trnton ny te nuber of uer n te roup occur uccevey durn one ybo te, we t occur once n reur tre Terefore we cn reove te nterference n of te proceed uer, uccevey, n order to tte-trnton bed on per-urvvor procen In ce of two uer n roup uc F b, t te t tte-trnton for te frt uer, ony te depred n of te frt uer ued to copute te brnc etrc Ten, fro tenttve decon for te frt uer, te nterference n reoved to e te depred n of te econd uer wc ued t te t tte-trnton of te econd uer Te ttetrnton of ec te ffect on coputn ony te brnc etrc of tt te After te tte-trnton n te roup re fned, te brnc etrc of two uer re ccuuted to produce te pt etrc nd r decodn procedure contnue on te +t ybo by te Vterb ort [5] /04/$000 C 004 I

3 Tre of 4-tte BP TTC for ec uer decodn of te econd uer, bot te II nd nterference n by te frt uer bed on PP re reoved fro te receved n vector Ten te AIC uppree te redu nterference by te uer n te oter roup nd te TBD fne te roup decodn of tt ybo te Te ont ort for te propoed PAIC nd TBD foruted foow Intzton: uer re dvded nto decodn roup wt uer were,, nd Te t decodn roup wt uer decoded by te TBD, ndvduy, nd te pre TBD decode te uer Wtout o of enerty, ue tt te uer n ec decodn roup re ndeed n order of power Te nt vue of te pt etrc nd eected tte re ven by b -tre of te TBD for uer Fure Tre tructure for te upn of te pce-te tre coded D- CDA yte Γ,0 0 f 0 0,,,0 nd 5 oterwe 0 0 for,, 5b r t y y χ ˆ ε χ ˆ ε ε ε Γ Γ Fure 3 Per-urvvor dptve nterference cnceer PAIC un roup decodn for uer However, f te tenttve decon of te frt uer n error, te wron nterference n reoved to e n error uccevey not ony n te depred n of te econd uer but o n decodn te net ybo of te frt uer To cope wt te error propton, we ntroduce te per-urvvor dptve nterference cnceton bed on te per-urvv procen nted of te pe nterference reov by te tenttve decon F 3 ow te per-urvvor dptve nterference cnceton PAIC cee bed on PP n te TBD for uer In te propoed cee, dfferenty n te conventon TBD, te AIC ued to depred te receve n vector nted of te tced fter For te frt uer, te nter-ybo nterference II bed on PP of te prevou ybo te reoved fro te receved n vector Ten te AIC wt te tp-wet vector tt dptvey coen to nze te uppree te nterference by not ony te econd uer but o te uer n te oter decodn roup nd te depred n vector proceed to te TBD for te frt uer In tep Copute te decodn etrc for te t uer t te t ybo te, 0,,, F For ec uper-tte,,,, + +, + For ec tte, con nto te tte Copute Γ, +, Γ,, +,,,, +,, + +, + 6 were + χ y te brnc etrc nd tnd for te eected vue to nze te pt etrc nd Fnd te per-urvvor tte nd r nγ, +, +,, +, Updte te pt etrc nd tore Γ, +, Γ,, +,, +,, +,,, + + n eory /04/$000 C 004 I

4 tep Reove te nterference n by te t uer fro trou PP for te +t uer Fnd te bet per-urvvor tte rn, +, +,, + + Γ, + Reenerte te n of te t uer bed on PP 9 ˆ χ ˆ ˆ ˆ 0 were ˆ ˆ,, ˆ te codeword wrt te tte trnton,, + nd ˆ te etted cnne n ubtrct te nterference n of te t uer nd e te depred n for te +t uer y d + ˆˆ d r } H w + + χ + were w + te tp-wet vector of te +t uer tep 3 Updte te tp-wet vector of t uer for te net ybo te [],[3] Red te ucden dtnce of te bet per-urvvor brnc fro te eory te error n of te ort e ε + Updte te tp-wet vector by te cope ort, ubect to w H + * w + w + µ ε r 3 Trou te preented ont ort, te propoed cee reove te II nd nterference by te prevou decoded uer n te e decodn roup bed on PP wt reduced error propton, uppree te redu AI by te oter decodn roup trou te AIC, nd updte te tpwet vector of te AIC durn pce-te decodn wtout uc ncree of decodn dey We now conder te copety of te PAIC bed on roup decodn Te optu utuer decoder wt te uper-tre tte were te nuber of nforton bt per ybo Te nuber of tot tte reured by te roup-tree for te TBD tte Te propoed cee te e nuber of tte nd brnce te TBD nce t utze te roup-tre tructure Te eory reureent for te recever depend on te nuber of tte nd wet-tp nd te nuber of eory unt for te uper-tre nd roup-tre decoder re DV nd + D, repectvey, were D V te decon dept of te conventon Vterb decoder [5] Te propoe cee reure ddton + eory unt tn te roup-tre decoder t utze te AIC wt wet tp nd tore te ccuted brnc etrc for PP Aun tt te copron operton coputtony cope te ddton, te nuber of operton reured by te conventon Vterb decoder for ccutn nd eectn te brnc etrc per one tte Γ } Ten, for ec decoded ybo, te nuber of te operton reured by te upertre nd roup-tre decoder re ven by O Γ nd O V Γ, repectvey In te propoed cee, te nuber of te operton reured by PP nd AIC ven by O + + PAIC nd te tot nuber of te operton ven by O Prop + [ + + } OPAIC ] 5 Te propoed cee need ore eory unt tn te TBD evertee te nuber of eory unt nfcnty er tn tt reured by te uper-tre decoder In ddton, te coputton copety of te propoed cee ncree not uc by tt of te TBD te brnc etrc ccuted n decodn re tored nd reued n PP IV IUATIO RUT Te perfornce of te propoed cee evuted n te upn of te pce-te tre coded D-CDA yte wt two trnt ntenn to ec of wc eu trnt power ned Aue tt te recever e perfect etton on te cnne n nd retve rrv te dey of ec uer In uton te nture euence rndoy eected on te fy of te od euence of ent 3 for ec uer nd te fre te nforton dt of 60 bt ncudn pddn bt wc re encoded by te Hon BP pce-te tre code wt 4 tte for two trnt ntenn [] uppoe tt ec cnne between trnt nd receve ntenn d Rye fdn wt f D T f 000, were f D te u Dopper freuency nd T f te fre durton, nd te retve rrv dey of ec uer unfory dtrbuted n [0, 0T c ] Te tep-ze µ of te cope ort for te AIC et to be /04/$000 C 004 I

5 F 3 ow te BR of te pce-te coded D-CDA yte wt nd,, for te ne-uer decoder ne, te roup-tre decoder for uer, te propoed ont per-urvvor AIC nd roup-tre decoder cee for uer PAIC, te optu uper-tre decoder n Rye fdn cnne Te dotted ne of reference curve for ne uer envronent F 3 ow te BR of tt wt te nuber of receve ntenn To decode 4 uer, te uper-tre decoder, roup-tre decoder, nd te propoed cee reure O 664, O 83, nd O Prop 80 operton, repectvey, fro ecton III It own tt te perfornce of te ne uer decoder derde erouy n te utuer envronent wt 4 nd tt of te roup-tre decoder for uer better perfornce tn t but t error foor Te optu uper-tre decoder for 4 uer nd te ont PAIC nd roup-decoder cee for uer nfcnty prove te perfornce wtout error foor However te uper-tre decoder te coputton copety ore tn 3 te uc tt of te roup-tre decoder nd t probtve n prctc ue wt te re nuber of uer nd tte On te contrry te propoed cee obtn te correpondn perfornce proveent wt te ddton copety uc te AIC copute te tp-wet vector over tt of te roup-tre decoder F 3b ow te BR of tt wt te nuber of receve ntenn It own tt te cee wt ve better perfornce tn tt wt In prtcur te perfornce proveent of te propoed cee becoe ore nfcnt It becue te rebty of te perurvvor n PP ncree te ntenn dverty n ncree nd te effect of nterference reducton of te PAIC o ncree V COCUIO In t pper, we propoed te per-urvvor dptve nterference cnceer PAIC bed on roup decodn nd preent te ort for te ont PAIC nd roup-tre decoder cee n te pce-te tre coded D-CDA yte Te propoed cee perfor bot nterference cnceton nd utuer decodn by ubttutn te ucden dtnce of te roup-tre decoder for te error n of te ort trou per-urvvor procen Te perfornce of te propoed cee evuted for te pce-te tre coded D-CDA yte wt two trnt ntenn n Rye fdn cnne It own tt te propoed cee nfcnt perfornce proveent over te conventon ne decoder cee, nd ceve te perfornce ner te ne-uer bound wt nfcnty ower copety tn te optu uper-tre decoder RFRC [] A R Hon nd H, On te teory of pce-te code for P oduton, I Trn Infor Teory, vo 46, no, pp 54-54, r 000 [] J Y nd J H ee, "Interference cnceton for pce-te coded D-CDA yte n Rye fdn cnne wt rrv te dfference," Proc of te I VTC00 prn, pp 44-48, Brn, A, y 00 BR BR ne PAIC b / 0 db 4 ne PAIC b / 0 db b Fure 4 Perfornce of te pce-te tre coded D-CDA yte wt 4 n Rye fdn cnne [3] J Y nd J H ee, "Jont nterference cnceton nd decodn cee for pce-te coded D-CDA yte n utpt fdn cnne," Proc of te I obeco00, pp67-675, Tpe, Twn, ov 7-, 00 [4] A Due-Hen, A fy of utuer decon-feedbc detector for yncronou code-dvon utpe-cce cnne, I Trn Coun, vo 43, no /3/4, pp 4 434, 995 [5] C-Brone nd C Rodruez, "Reduced-copety recever for pce-te coded D-CDA yte, Proc of te I obeco00, pp9-96, Tpe, Twn, ov 7-, 00 [6] R Re, A Poydoro, nd C- Tzou, Per-urvvor procen: ener pproc to n uncertn envronent, I Trn Coun, Vo 43, o /3/4, Feb/r/Apr /04/$000 C 004 I