Energy detection Analysis of Cluster based Cooperative Spectrum Sensing in Cognitive Relay Network

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1 ISSN (Prit) : ISSN (Olie) : Eerg detectio Aalsis of Cluster based Cooerative Sectrum Sesig i Cogitive Rela Network Arab Ro # Suil Patteu # Amla Datta #3 # School of Electroics Egieerig KIIT Uiversit BhubaeswarOrissa Idia 40@kiit.ac.i atteu.suilfet@kiit.ac.i 3 amladatta0@gmail.com Abstract I this stud we aalzed a itra-cluster based cooerative eerg detectio betwee source (S) ad destiatio (D) the etwork model cosistig of oe source oe destiatio ad M umber of clusters betwee the source ad destiatio ad each cluster cosistig of N umber of cogitive relas. We aalzed the erformace of iter-cluster ad itra-cluster cooerative eerg detectio. We derived the detectio robabilit ad false alarm for the imrovemet of eerg detectio of the roosed ew scheme; we also rovided the efficiet umber of relas i each cluster to imrove the erformace of the etwork. For relative comariso we simulated similar situatio like direct (o-cooerative) itercluster ad itra-cluster commuicatio betwee source ad destiatio. Simulatio results show that the roosed itra-cluster based etwork imroves the etwork erformace i comariso to direct ad iter-cluster commuicatio i terms of eerg detectio. Keword - Cooerative Commuicatio Cogitive Rela Eerg Detectio Iter-cluster Itra-cluster. I. INTRODUCTION Due to the fast rogressio of wireless commuicatio egieerig extreme level of cometitio has emerged for sectrum sesig. Though Federal Commuicatio Commissio (FCC) idicates the research regardig the sectrum usage of all licesed sectrums ca be vacat i umerous laces at various times []. Oe of the robable solutio to fix the roblems of the sectrum sesig cogitive radio has bee grated much attetio due to its high sectrum efficiec [ 3]. The cogitive radio sstems make a wa for the secodar users (Ulicesed Users) to easil share the uused licesed sectrum without creatig areciable iterferece at some secified time slot ad some secified geograhical area. Although wheever the Primar User (PU) returs i the oeratio the secodar user (SU) should vacate the sectrum istatl to revet uwated iterferece with the PU. Therefore the icessat sectrum sesig is demaded to observe the resece of the PU. Moreover while the chael suffers from fadig ad shadowig the overall result of the sesig for a cogitive user would be fallig dow. To fix this comlicatio cooerative sectrum sesig is suggested to make use of multiuser diversit i sesig techique [4]. This is ormall carried out i two cosecutive sectios: sesig ad reortig. Sesig describes about each cogitive user which carries out sectrum sesig oe b oe ad reort the etire local sesig exerieces to a receiver ad later it ll take a fial decisio i the absece or the resece of the PU. Most of the earlier work deal with the sceario which sesig exerieces are revealed to the receiver b usig ideal chaels. Though this is urealistic because the chaels i betwee the users ad the receiver are ormall deedet to fadig [5]. I sectrum sesig method eerg detectio is erceived as the most deedable techique whe the revious iformatio of the rimar message sigal is t kow to the secodar user. Ideed the revious iformatio of the PU is alwas ot aticiated. I this article we ll cocetrate o the eerg detectio sesig strateg for roosed cluster based etwork. As metioed i the theor of eerg detectio [6] we ca get the detectio robabilit (P d ) the false alarm robabilit (P f ) which are widel utilized to exlai the caabilit of eerg detectio of a secodar user (Ulicesed) i sectrum sesig. Most of the earlier work cocetrates o sigle rela etwork sigle rela with multile atea or multile rela i a etwork [8-9]. Our mai cotributios i this aer are: a) Itroducig a ew method for cooerative cogitive radio etwork that imroved the eerg detectio based o itra-cluster Cooerative Sectrum Sesig. b) The closed form exressio is derived for the detectio robabilit ad the false alarm for the imrovemet of eerg detectio of the roosed ew method. c) Best-rela selectio o the basis of the maximum received eerg i relas. d) Selectio of otimal umber of relas i each cluster. DOI: 0.87/ijet/07/v9i3/ Vol 9 No 3 Ju-Jul 07

2 ISSN (Prit) : ISSN (Olie) : e) Simulatio results are discussed to comare the erformace of the roosed method with existig methods. The cotet of this aer is arraged i the followig sectios. Sectio II describes the Sstem model for roosed cluster based cooerative commuicatio. The Proosed methodolog is discussed i sectio III. Aaltical Result is reseted i Sectio IV. Sectio V gives the simulatio results ad the coclusio of this aer is draw i Sectio VI. II. SYSTEM MODEL I this stud we cosider a clustered based wireless etwork show i Fig.. It cosist of oe source ad oe destiatio ode deoted b S ad D resectivel i the XY lae. This XY lae is divided ito areas of almost equal size. These areas are created b grouig of radoml geerated cogitive relas (CR) havig sigle trasmittig ad receivig atea. This grou of cogitive relas built a cluster. The distace betwee each cluster to destiatio is calculated ad assumig that the distace betwee ever cluster is almost equal ad it is greater tha the distace betwee the itra-cluster cogitive relas. Let us cosider a M umber of clusters are formed ad each cluster cosists of N umber of cogitive relas (CR) cooerates for sectrum sesig. Let the chaels betwee source (S) ad cogitive relas (CR) are Raleigh faded with AWGN. Basicall our sstem model works i stes as metioed below: A. Iter-Cluster Commuicatio) As the trasmissio distace is larger amog the clusters the source (S) ca rimaril broadcast the message sigal to the relas of the first cluster. The the CRs calculate the eerg ad the rela havig the maximum eerg is selected as best-rela for commuicatio. Suose that the elected best-rela i a cluster wats to sed the message sigal to the elected best-rela of the adjacet cluster the the best-rela of first cluster will act as a source ad the best-rela of secod cluster will act as a destiatio. Fig.. Sstem model for the Cluster based Commuicatio for cooerative rela selectio method B. Itra-Cluster Commuicatio I Itra cluster commuicatio source (S) broadcasts the message sigal or data bits with certai SNR to all CRs of the st cluster. The the relas calculate the eerg ad the relas havig the maximum eerg are selected as best-relas. Here we choose two cogitive relas which have received the maximum eerg. I st ho source (S) trasmit the message sigal to the st best-rela ad i d ho commuicatio d best-rela receives the message sigal from the st best-rela. Now the d best-rela acts as a source ad broadcast to the ext cluster. I this stud we aalze the best-rela selectio i terms of detectio robabilit ad false-alarm to imrove the eerg detectio i cluster based etwork for cooerative rela trasmissio. At st time slot the message sigal (x) from source reaches to all the relas of the st cluster. The received sigal at i th rela is rereseted b [8] h x... () CR i S CR S CR The sectrum sesig for i th CR is rereseted as a biar hothesis i.e. [4] CR i ( t)... H () t h x t H SCR 0....() SCR SCR ( )... Where i= 3 N ad () t is a received message sigal b a cogitive rela (CR) at its sesig CR i chael iut. χ is trasmitted message sigal from source with zero-mea ad S is variace Gaussia DOI: 0.87/ijet/07/v9i3/ Vol 9 No 3 Ju-Jul 07

3 ISSN (Prit) : ISSN (Olie) : Radom variable is the trasmitted ower of the message sigal. Here () t is exressed as the oise with zero-mea ad variace ; hscr is rereseted as the chael coefficiet betwee the source ad cogitive rela. The eerg detector at CR uses biar hothesis determies the resece or absece of Source (S). III. PROPOSED METHODOLOGY I this sectio we discuss about the roosed methodolog of itra-cluster commuicatio show i Fig.. The eerg detectio clusterig cosist of three hases- the broadcastig hase rela selectio hase ad received hase. SCR Fig.. Flowchart for Proosed Itra-Cluster based Commuicatio Network. I the broadcastig hase the source (S) broadcasts the rimar message sigal to the st cluster with certai SNR. I the rela selectio hase the received eerg at each rela of st cluster is calculated ad the relas havig the maximum eerg is selected as best-rela of a cluster which will sed their sesig iformatio to the ext cogitive rela. The received eerg is rereseted as CR i CR i E CR..(3) max( E )......(4) CR i The received eerg of the best-rela is comared with a reselected threshold at the outut of eerg detector. If the eerg is greater tha the reselected threshold the it broadcasts the message sigal to the ext cogitive rela (CR) else it seds a ackowledgemet to the revious cogitive rela (CR). if ; CR broadcast the ext CR E..... (5) if ; Sed a ackoledgemet to revious CR DOI: 0.87/ijet/07/v9i3/ Vol 9 No 3 Ju-Jul 07 3

4 ISSN (Prit) : ISSN (Olie) : I the received hase the message sigal is received from the cogitive rela of the last cluster i the Network. IV. ANALYTICAL MODEL OF DETECTION PROBABILITY The cumulative distributio fuctio (CDF) of a eerg detector ca be writte as [7] F () E =... (6) The robabilit desit fuctio (PDF) ca be obtaied b differetiatig eq. (6) [7] ( ). ( )..... (7) f E f Let [7] f H 0 () ad f H ( ) be the PDF of received message sigal uder H 0 ad H resectivel f ( ) ex( ) 0 H0 f ( ) ex( ) 0 H ( S ) ( S )... (8). (9) Substitutig equatio (8) ad equatio (9) i equatio (7) the PDF of E uder hothesis H 0 ad H ca be rereseted as [7] ( ) ex( ) f ( ) 0 E H 0 ( ) ex( ) ( S ) f ( ) 0 E H Now P d P f ad P m ca be writte as [7] ( S ) Pd f d S.. (0)... () ( ) H... () Pf f d P m ( ) H 0... (3) P.. (4) d DOI: 0.87/ijet/07/v9i3/ Vol 9 No 3 Ju-Jul 07 4

5 ISSN (Prit) : ISSN (Olie) : The detectio robabilit (P d ) of a cogitive rela over Raleigh faded chael ca be writte as [7] PdRa Pd f () d... (5) f Where ( ) is the PDF of SNR over Raleigh fadig. Hece the detectio robabilit (P d ) over Raleigh fadig ca be writte as [7] 3 ( ) ex( ) ex( q ) q dra ex( q )ex( x P erfc q x ) dx x 0 Where q.... (6) It is oticed that P f is ideedet of fadig mechaism. Thus the robabilit of false-alarm (P f ) uder Raleigh faded ca be exressed as [7] Pf Ra Pf. The selected best-rela of a cluster seds their sesig iformatio uder the Raleigh faded sesig chaels to the selected best-rela of the adjacet cluster. Now the revious best-rela acts as a source ad reset act as a destiatio. Thus the message sigal is forwarded from source to destiatio through the clusters i the cooerative cogitive radio etwork. V. SIMULATION RESULTS I this sectio we will discuss the erformace of the roosed sstem usig MATLAB simulatios. A multiho cooerative cluster based etwork with equall saced M umber clusters betwee the source S ad the destiatio D is cosidered. Each cluster is equied with N radoml geerated relas. Throughout the simulatios the S ad the D are located i the XY lae i betwee 3000 meter area. Fig. 3. Eerg Detectio Aalsis for iter-cluster commuicatio at SNR=-0dB Fig. 3. Shows the eerg detectio aalsis of the roosed sstem model i terms of detectio robabilit(p d )ad false-alarm robabilit (P f ) for iter-cluster commuicatio at SNR=-0dB. Here we take M=4 ad M=6 i betwee S ad D to comare with direct commuicatio (S D). We ca see that the detectio robabilit (P d ) icreases whe the umber of the cluster icreases from M=4 to M=6 ad the direct commuicatio from source to destiatio gives the lowest P d. So the eerg detectio erformace ca be raised sigificatl with the icreasig umber of clusters i the cooerative etwork. DOI: 0.87/ijet/07/v9i3/ Vol 9 No 3 Ju-Jul 07 5

6 ISSN (Prit) : ISSN (Olie) : Fig. 4. Eerg Detectio Aalsis for itra-cluster commuicatio at SNR=-0dB Fig. 4. Shows the eerg detectio aalsis of the roosed sstem model i terms of detectio robabilit (P d ) ad false-alarm robabilit (P f ) for itra-cluster commuicatio at SNR=-0dB. Here we take M=4 ad M=6 i betwee S ad D to comare with direct commuicatio (S D). We ca otice that the detectio robabilit (P d ) icreases whe the umber of the cluster icreases from M=4 to M=6 ad the direct commuicatio from source to destiatio gives the lowest P d. Also it gives better erformace i comariso to iter-cluster commuicatio as the commuicatio distace betwee two cogitive relas are less i case of itra-cluster etwork. So the eerg detectio erformace ma be ehaced with the icreasig umber of clusters i the etwork i case of itra-cluster commuicatio tha the iter-cluster commuicatio. Fig. 5. Eerg Detectio Aalsis for M=4 clusters for differet o. of relas (N=0 N=30 N=50) i iter cluster commuicatio. I Fig. 5. We rovide the eerg detectio erformace for differet umber of relas i each cluster like N=0 N=30 N=50 i betwee the Source ad Destiatio i 4 iter-cluster commuicatio. We otice that N=0 gives better erformace tha the N=30 ad N=50. So the otimal umber of cogitive relas i each cluster for 4 iter-cluster commuicatio are 0 which gives the better eerg detectio erformace. DOI: 0.87/ijet/07/v9i3/ Vol 9 No 3 Ju-Jul 07 6

7 ISSN (Prit) : ISSN (Olie) : Fig. 6. Eerg Detectio Aalsis for M=6 clusters for differet o. of relas (N=0 N=30 N=50) i iter cluster commuicatio I Fig. 6. We rovide the eerg detectio erformace for differet umber of relas i each cluster like N=0 N=30 N=50 i betwee the Source ad Destiatio i 6 iter-cluster commuicatio. We otice that N=30 gives better erformace tha the N=0 ad N=50. So the otimal umber of cogitive relas i each cluster for 6 iter-cluster commuicatio are 30 which gives the better eerg detectio erformace. Fig. 7. Eerg Detectio Aalsis for M=4 clusters for differet o. of relas (N=0 N=30 N=50) i itra-cluster commuicatio I Fig. 7 We show the comariso of the eerg detectio erformace for differet umber of relas i each cluster like N=0 N=30 N=50 i betwee the Source ad Destiatio i 4 itra-cluster commuicatio. We ca see that N=30 gives better erformace tha the N=0 ad N=50. So the otimal umber of cogitive relas i each cluster for 4 itra-cluster commuicatio are 30 which gives the better eerg detectio erformace. DOI: 0.87/ijet/07/v9i3/ Vol 9 No 3 Ju-Jul 07 7

8 ISSN (Prit) : ISSN (Olie) : Fig. 8. Eerg Detectio Aalsis for M=6 clusters for differet o. of relas (N=0 N=30 N=50) i itra-cluster commuicatio. I Fig. 8. We give the comariso of the eerg detectio erformace for differet umber of relas i each cluster like N=0 N=30 N=50 i betwee the Source ad Destiatio i 6 itra-cluster commuicatio. We ca see that N=0 gives better erformace tha the N=30 ad N=50. So the otimal umber of cogitive relas i each cluster for 6 itra-cluster commuicatio are 0 which gives the better eerg detectio erformace. From Fig. 5 Fig6 Fig. 7 ad Fig. 8 we ca sa that otimal umber of rela selectio icreases the eerg detectio erformace. Fig. 9. Comarative Eerg Detectio Aalsis i betwee itra-cluster iter-cluster ad direct commuicatio for M=6 clusters ad N=0 cogitive relas. I Fig. 9. We give the comarative eerg detectio aalsis i betwee itra-cluster iter-cluster ad direct commuicatio at SNR=-0dB for M=6 umber of clusters i betwee the source ad destiatio ad each cluster cosist of N=0 umber of relas. Here we ca otice that roosed itra-cluster commuicatio gives a better detectio erformace tha the iter-cluster ad direct commuicatio. VI. CONCLUSION I this article we aalzed the eerg detectio erformace of cluster based cooerative commuicatio etwork for direct commuicatio (o-cooerative) itra-cluster ad iter-cluster commuicatio. We roosed a itra-cluster based etwork for cooerative sectrum sesig based o best-rela selectio comarative results with iter-cluster ad direct commuicatio shows that the roosed itra-cluster based commuicatio imroves the eerg detectio erformace b icreasig the umber of clusters i the etwork. The simulatio results also show that the otimal umber of relas i each cluster which imroves the erformace of the etwork i terms of detectio robabilit ad false-alarm. It has bee show that the all over etwork erformace of the itra-cluster commuicatio etwork is imroved i comariso to the direct commuicatio ad iter-cluster commuicatio etwork. DOI: 0.87/ijet/07/v9i3/ Vol 9 No 3 Ju-Jul 07 8

9 ISSN (Prit) : ISSN (Olie) : REFERENCES [] Z. Q. Bai L. Wag H. X. Zhag ad K. S. Kwak Cluster-based cooerative sectrum sesig for cogitive radio uder badwidth costraits i Proceedigs of the th IEEE Iteratioal Coferece o Commuicatio Sstems November 00. [] J. Zhu Z. Xu F. Wag B. Huag ad B. Zhag Double threshold eerg detectio of cooerative sectrum sesig i cogitive radio i Proceedigs of the 3rd Iteratioal Coferece o Cogitive Radio Orieted Wireless Networks ad Commuicatios (CrowCom '08). 5 Sigaore Ma 008. [3] E. Peh ad Y. C. Liag Otimizatio for cooerative sesig i cogitive radio etworks i Proceedigs of the IEEE Wireless Commuicatios ad Networkig Coferece (WCNC '07).7 3 Kowloo Hog Kog March 007. [4] Shubi Wag Huiqi Liu ad Ku Liu A Imroved Clusterig Cooerative Sectrum Sesig Algorithm Based o Modified Double-Threshold Eerg Detectio ad Its Otimizatio i Cogitive Wireless Sesor Networks Iteratioal Joural of Distributed Sesor Networks Volume 05 Article ID ages. [5] Zhaowei Qu Yag Xu ad Sixig Yi A ovel clusterig-based sectrum sesig i cogitive radio wireless sesor etworks i Cloud Comutig ad Itelliget Sstems (CCIS) 04 IEEE 3rd Iteratioal Coferece o Nov [6] Fa Deg Zeg Fazi ad Refa Li Clusterig-based comressive wide-bad sectrum sesig i cogitive radio etwork i Mobile Ad-hoc ad Sesor Networks 009. MSN 09. 5th Iteratioal Coferece o Dec [7] Kuldee Yadav Abhijit Bhowmick Saja Dhar Ro Sumit Kudu Cooerative Sectrum Sesig based o Damic Clusterig with Imroved Eerg Detector 3rd It'l Cof. o Recet Advaces i Iformatio Techolog I RAIT-06I [8] Arab Ro Suil Patteu Amla Datta Eerg Detectio Aalsis of Hbrid Cooerative Relaig Mode i Cogitive Radio Network. i reseted of the st IEEE Iteratioal coferece o I-SMAC Februar 07. [9] P. Suil Performace Aalsis of Movig Multi-Atea Rela Cooeratio with Hbrid Relaig Scheme i Cooerative Wireless Networks" 06 Iteratioal Coferece o Comutatioal Itelligece ad Networks. [0] Chuhua Su Wei Zhag ad Khaled Be Letaief Cluster-Based Cooerative Sectrum Sesig icogitive Radio Sstems IEEE Commuicatios SocietICC 007 roceedigs. DOI: 0.87/ijet/07/v9i3/ Vol 9 No 3 Ju-Jul 07 9

Performance Analysis of Channel Switching with Various Bandwidths in Cognitive Radio

Performance Analysis of Channel Switching with Various Bandwidths in Cognitive Radio Performace Aalysis of Chael Switchig with Various Badwidths i Cogitive Radio Po-Hao Chag, Keg-Fu Chag, Yu-Che Che, ad Li-Kai Ye Departmet of Electrical Egieerig, Natioal Dog Hwa Uiversity, 1,Sec.2, Da-Hsueh