Optimal Multi Antenna Spectrum Sensing Technique For Cognitive Radio

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1 L C T R O I C R A R C A R T I C L Opal Mul Annna pcru nng Tchnqu For Cognv Rao Dlp Bapala Dparn o lcronc an Councaon ngnrng GITAM Unvry Vahapana Ahra rah Ina lp@ga.u lp@gal.co ABTRACT I onln: 39- I prn: 39-5 : In h papr w conr h prary ur con probl n cognv rao y by ung ul annna a h cognv rao rcvr. An opal quar law cobnr ul annna ba pcru nng chnqu propo ung h ulapr pcru aon ho. Th ulapr pcru aon ho prouc ngl pcru a wh nu pcral laag an varanc ung an orhonoral aly o apr h Dcr rola lpan qunc D. An nrgy cor whch pl bu ha a poor proranc a a low gnal o no rao R. ywor: Cognv rao pcru nngul apr pcru aon ho ul annna pcru nng.ror. I. ITRODUCTIO Rao pcru rr o h xng naural u ha u n rn wrl councaon y an rvc: obl x all-ba an low-powr vc councaon y ulra wban nor c.[].du o ncra n wrl chnolog hr a probl o pcru cary.cognv rao CR a nw wrl councaon chnology ha agn a pcru ynacally o h conary ur whn h prary ur ar no ung lcn pcru. Thr ar rn yp o pcru nng chnqu ar hr l Mach lr nrgy cor cycloaonary ul apr ho.mach lr []an cycloaonary ar cla a hgh oranc pcru nng chnqu bu hy rqur vry prary ur ran gnal. whch rqur prary ur noraon. Th avanag n h cycloaonary con [3] whch rqur cyclc rqunc o h prary ur an alo a long nng. larly h praccal plnaon o nrgy cor ay bu gv vry poor proranc a low gnal o no rao R. II. IMORTAC OF MTOD FOR ACTRUM IG I COGITIV RADIO TOR Mulapr pcru aon ho wa propo n 98 by Thoon []. u an opal ban o ban pa lr nown a apr or wnow. Th orhonoral apr ar call Dcr rola lpan qunc D [6]. prouc a ngl pcru a wh nu pcral laag an goo varanc. Th pcru aon n an approxaon o h opal a; h axu llhoo ML On avanag or copar o ML h ac ha ha lowr copuaon coplxy. nc h r vlopn o n 98 h avanc ho ha bn wly u n any applcaon. In aon o h powr pcru aon n gnal procng an councaon applcaon u n nurocnc gophyc an onar. III. T IMORTAC OF UAG OF MULTI ATA BA CTRUM IG I CR YTM In orr o prov h paal vry clacal wrl councaon u ul annna a ranr Tx or rcvr Rx or boh. uch vry provn ncra h y aa ra IJRA Volu Iu a g 63

2 an capacy. Th raon bhn h ha a h anc bwn annna chon proprly hr wll b a hgh probably o rcvng npnn ang hrough h rn annna [9]. Thror h ang c wll b ga. IV. RGY DTCTOR Th probably o con n a h probably ha h CR cor c corrcly h prnc o h R gnal. Thror h yp o probably rla o h whch rprn h R gnal plu no whr ha r { D / } r rprn h probably.i clar p h ngraon ovr ro h hrhol o nny. nc h au a Gauan rbuon; can b n nally a ollow[5] [ p / Q VAR[ ] whr an Var ar h an an varanc o h gvn rbuon rpcvly. Th r Q h coplnary cuulav rbuon uncon Q 3 Th probably o al alar n a h probably ha h CR cor c by a h prnc o h R gnal.thror h yp o probably rla o h whch rprn h no only. r { D / } In h ca clar ha h ovr nny[5] h ngraon ro h hrhol o [ p / Q VAR[ ] whr an Var ar h an an varanc o h gvn rbuon rpcvly. 5 V. MULTI TAR CTRUM TIMATIO MTOD o o h avanag o ul apr aon ho ar. an nrgy ba pcru nng chnqu. a wban pcru nng chnqu 3. o no n any pror noraon abou h R gnal.. non cohrn nor paral cohrn.. n o now h no varanc o conrol h hrhol. 5. nz h pcral laag ou h ban an prov h varanc o a. A gnral procur or ul apr pcru aon con o our p. Fr choo a banwh prouc C = whr h apl z or aon an h banwh noralz by h apl ra. Th choc o parar C a ra-o bwn pcral roluon an varanc. Typcally 3 C 6 an w u = C aa apr o pror h aon or h raon ha wll b gvn blow. con copu h aa apr.. lpan qunc. Dno h h aa apr n vcor or by w. I can b calcula by h ollowng gn quaon 6 whr h j h nry o Toplz arx n by n w j j j j Th gn valu rang bwn an uny an ar organz n an cnng orr uch ha.... Th r [ ] o h ar ona clo o uny whra h r ar nglgbl. Morovr h apr o lowr orr hav uch rongr nrgyconcnraon capably han hr hgh-orr counrpar uggng ha uc o u h r apr or pcral aon. Thr h corrponng gnpcra ar n by Fourr ranor o h apr.. wnow aa qunc rulng n Y n w n x n j n a a uncon o rquncy r wn gn h nh nry o w. Gvn a n apl-z conran h nrgy rbuon o ach gnpcru all bwn h banwh ro o + u o IJRA Volu Iu a g 6

3 nrgy-concnraon propry o lpan qunc Fnally w cobn h gn pcra o or a ngl pcru a Y 9 whr h wghng acor /... u o accoun or h rlav poranc o h gn pcru o concrn. Th rcv R gnal a h CR rcvr apl o gnra a n cr apl r x ; M whr no h annna nubr an h nx Th cr apl ar o ulpl wh rn apr v Tapr ar D. h Th aoca gn valu o h apr. Th prouc appl o a Fourr ranor o copu h nrgy concnra n h banwh - cnr a rquncy. Th hal banwh prouc. Th oal nubr o gnra apr. Th bnary hypoh or CR pcru nng h h a h l an ung h annna branch gvn by : x : x l w l l l w l whr l=.l- OFDM bloc nx an x l w l an l no h CR rcv no a h branch an R ran apl. Th ran R gnal or by h zro an AG w l a h oupu ro h rn annna branch whch ar npnn an wh ncal varanc. For orhonoral apr u n h hr wll b rn gn pcru prouc ro ach annna n a [6] j v x l Y whr ar h noralz rquncy bn. Th powr pcru a gvn by [] Y M Th nrgy cor whn h apl ar an a unor pacng gv h powr pcru ny aon[7] j x l 3 A Dcon ac or h an Th con ac ovr L ung n h or h annna a j L v x l l 3 Th con ac ovr L ung n or h h annna a L j x l l B Man an Varanc o an ung ngl Annna For ngl annna -ba pcru nng an accorng o h cnral l hor h nubr o apl L larg h con ac aypocally norally rbu wh an[8] [ L ] L an varanc VAR LC VAR LC 6. c 5 7 Th con ac or h nrgy Dcor aypocally norally rbu wh an[9] 8 IJRA Volu Iu a g 65

4 an varanc VAR L VAR L 9 C Dcon an Fal Alar probabl For a norally rbu con ac h probabl o con an al alar ar n a / / Q VAR / / / Q VAR / Th probably o con n a / / Q VAR / Th r rbuon uncon Q h coplnary cuulav Q an rprn h chon hrhol. Thu h rn probabl o ung ngl annna can b rn a [8] Q L LC Q L 5 LC Q L LC 3 6 Th nubr o apl rqur by ung ngl annna L L L can b wrn a[8] a b L 7 whr a an b ar a b LC LC Q Q an ML LC ML D Man an Varanc o an ung M Annna Th con ac or quar law cobnng ung M annna or boh chnqu an rpcvly a ollow [] an LC LC M L v x l l M L x l l j j 8. 9 Th con ac ung quar law cobnng a u o ncal an npnn norally rbu M annna con ac. Thu h an o h ung M LC LC ML ML annna [3] can b na 3 an h varanc MLC VAR 3 LC MLC For h h an o h con ac ung quar law cobnng hrough M annna can b n a 3 VI. IMULATIO RULT In our y ach no o h cognv rao CR nwor u 6-FFT wh aplng rquncy Mz.Th prary ur R ranr u 6- IFFT wh ybol uraon T=.5μ an ran Q gnal wh noralz qual o wh ach ubcarrr. Th ul annna chnqu -LC -LC. In chnqu h u hal- an wh prouc = an h nubr o apr =5.In g.an g conr h AG channl wh R=--B an OFDM bloc. L= u n nng an h nubr o apl u L= X =6 =8 whch approxaly corrpon o 6 μ. IJRA Volu Iu a g 66

5 nubr o aplb probably o con p probably o con p.9 -LC M= -LC M= an CR-B. Thn h nal con clar o h CR no RFRC [] FCC "pcru olcy Ta Forc" FCC T Doc o 3-35 ov probably o al alar p Fg.. robably o con V probably o al alar ung an wh M= Annna a h Rcvr LC M= -LC M= [] I. F. Aylz. Y. L M. C. Vuran an. Mohany "x gnraon/ ynac pcru acc/cognv rao wrl nwor: a urvy" Copur wor vol. 5 pp [3] Y. Zng Y. C. Lang A. T. oang an R.Zhang "A rvw on pcru nng or cognv rao: challng an oluon URAI Journal on Avanc n gnal rocng vol [] D. J. Thoon "pcru aon an haronc analy rocng o h I vol. 7 pp gnal o no rao R B Fg.. gnal o no rao R V probably o con or M= Annna a h Rcvr. 7 [5] F.F Dagha M.-. Aloun an M.. on On h nrgy con o unnown gnal ovr ang channl" roc. o I In. Con. Coun. ICC 3 Anchorag UA pp May LC M= -LC M= [6] D. lpan "rola phroal wav uncon Fourr analy an uncrany. V- Th cr ca" Bll y Tchncal Journal vol. 57 pp gnal o no rao R B Fg. 3. gnal o o rao R V ubr o apl B or M= Annna a h Rcvr. VII. COCLUDIG RMAR r w conr h con o prary ur by ang an cor. Mulpl annna M= u a h rcvr. Ung ul annna n -LC gv or provn n proranc copar o ha or -LC an alo ho rqur l nubr o apl o c h prary ur copar o h. Th OR rul coopraon u o coopra h gnra bnary con ro h nvual CR no a a [7] D. B. rcval an A. T. aln pcral analy or phycal applcaon: ulapr an convnonal unvara chnqu: Cabrg Unv r 993. [8] O. A. Algha M. Z. Ah an M. A. Abu- Rgh "robabl o Dcon an Fal Alar n Mul apr Ba pcru nng or Cognv Rao y n AG" roc. o I Inl. Con. on Co. y ICC ngapor. [9] Q. Zh C. huguang an A.. ay "Opal Lnar Coopraon or pcru nng n Cognv Rao wor lc Topc n gnal rocng I Journal o vol. pp.8-8 hr IJRA Volu Iu a g 67