Optimizing MDS Codes for Caching at the Edge

Size: px
Start display at page:

Download "Optimizing MDS Codes for Caching at the Edge"

Transcription

1 Optimizig Codes for Cachig at the Edge Valerio Bioglio, Frédéric Gabry, Igmar Lad Mathematical ad Algorithmic Scieces Lab Frace esearch Ceter, Huawei Techologies Co Ltd arxiv: v [csit] 8 Sep 05 Abstract I this paper we ivestigate the problem of optimal -ecoded cache placemet at the wireless edge to miimize the backhaul rate i heterogeeous etworks We derive the backhaul rate performace of ay cachig scheme based o file splittig ad ecodig ad we formulate the optimal cachig scheme as a covex optimizatio problem We the thoroughly ivestigate the performace of this optimal scheme for a importat heterogeeous etwork sceario We compare it to several other cachig strategies ad we aalyze the ifluece of the system parameters, such as the popularity ad size of the library files ad the capabilities of the small-cell base statios, o the overall performace of our optimal cachig strategy Our results show that the careful placemet of -ecoded cotet i caches at the wireless edge leads to a sigificat decrease of the load of the etwork backhaul ad hece to a cosiderable performace ehacemet of the etwork I INTODUCTION Cachig cotet at the wireless edge is a promisig techique for future 5G wireless etworks [] Oe of the mai motivatios behid the idea of edge cachig comes from the possibility of sigificatly reducig the backhaul usage ad thus the latecy i cotet retrieval by brigig the cotet closer to the ed users Exploitig the ew capabilities of future multi-tier etworks [], umerous works have recetly ivestigated the potetial beefits of cachig data i desely deployed small-cell base statios ) equipped with storage capabilities [3] I [4] it was show that cachig at the edge ca provide sigificat gais i terms of eergy efficiecy which is cosidered a fudametal metric for future wireless etworks The ivestigatio of cachig from a iformatio-theoretic poit of view is preseted i [5], where cachig metrics are defied ad aalyzed for large etworks I [6] the problem is studied i terms of outage probability Moreover, other embodimets ad advatages of edge cachig have bee discussed i the literature I [7], the idea of usig the mobility of users i the etwork to icrease cachig gais is proposed, while i [8] the authors leverage the possibility of exploitig the storage capabilities of mobile users by cachig cotet directly o the users devices I order to improve the theoretical performace limits of cachig, a ew iterestig perspective stems from usig ideas from codig theory I [9], etwork codig NC) is exploited i a sceario where each user is equipped with a cache For this sceario, the authors show that a etwork codig based cachig scheme decreases the backhaul load i compariso to the usual ucoded schemes However, the extesio of NC to a more complex sceario, where each user ca be served by multiple s, has bee proved to be NP-complete [0] Moreover, the use of NC i a sceario where the iformatio is set via uicast trasmissio does ot give ay advatage Aother promisig related directio is the use of maximumdistace separable ) codes to virtually icrease the storage size i case of overlappig coverage areas I [], cotet is coveyed to distributed helpers usig codes to remedy the limitatios of ucoded delivery i terms of delay Assumig the etwork topology is kow, the cotet placemet strategy is formulated as a covex miimizatio of the overall delay A radom cachig scheme for a cooperative multiple-iput multiple-output MIMO) etwork is combied with ecodig of the cached cotet to icrease the gais resultig from MIMO cooperatio [] Departig from those previous works, i this paper we ivestigate the performace of -ecoded distributed cachig at the s I particular, we cosider a sceario where mobile users ca be served by multiple s I this setup, we derive the oit optimal ecodig ad placemet of the ecoded packets at the s i order to miimize the backhaul rate Our mai cotributios are: We formally defie the problem of cachig -ecoded cotet at the wireless edge for a heterogeeous etwork HetNet) sceario We derive the backhaul rate performace of a cachig scheme based o storig ecoded packets, formulatig the optimal cachig scheme as a covex optimizatio problem We ivestigate the performace of the proposed packet placemet ad delivery scheme for a relevat HetNet sceario Moreover, we compare it to several cachig schemes, aalyzig the beefits of ecodig o the performace of the scheme, as well as the importace of carefully optimizig the placemet of the coded packets Our results show that the use of codes i the placemet of cotet at the wireless edge yields to sigificat offloadig of the etwork backhaul This paper is orgaized as follows I Sectio II, we defie our system model, cachig scheme ad performace measures I Sectio III, we derive the mai theoretical results of the paper I Sectio IV we thoroughly ivestigate the performace of our optimal schemes ad we compare it to other cachig schemes i a heterogeeous etwork sceario Fially, Sectio V cocludes this paper

2 File Library F F F N Core Network MBS MBS M M 3 M 4 M u u u 3 u 4 u 5 u 6 u 7 u 8 u 9 Fig Heterogeeous etwork Fig Istataeous Heterogeeous etwork topology II SYSTEM MODEL I this sectio we describe our system model ad we formally defie cachig schemes for heterogeeous etworks A Network Model We cosider the etwork illustrated i Fig, where U wireless users sed requests to dowload files from a macrocell base statio The macro-cell base statio MBS) has access to a library of N files F = {F,,F N }, each of size B bits Note that the assumptio of equal size files is ustifiable i practice sice files ca be divided ito blocks of the same size We suppose that the users request etire files stored i the library, ie, if k u is the data request for user u, the k u F Each file has a differet probability to be requested by the users I particular, the probability distributio vector of the files is deoted by p = {p,,p N }, referred to as the file popularity, where file F is requested with probability p ad N = p = Moreover N small-cell base statios are deployed i order to serve user requests withi short distace We assume that each has a cache of size M B bits ie, it ca store up to M < N complete files), ad ca sed data to the users through a error-free lik, ie, we assume that cotet is delivered without errors as log as a user is withi the coverage rage We deote by r the coverage rage of the s Each user requestig for files i F is iitially served by the s it ca cotact If the requested file is ot completely preset i the caches, the MBS has to sed the missig data to the user, usig the backhaul coectio The topology of the overall etwork may vary durig time; i particular at each istat t, the coectio etwork ca be described as illustrated i Fig Each user u {,,U} ca be served by d u s depedig o its locatio i the area see Fig 3) I particular, we call γ i the probability for a user to be served by d u = i s This probability depeds o the s deploymet ad o the desity of the users: i Sectio IV we will show how to evaluate this probability i ay sceario B Cachig Schemes A cachig scheme is costituted of two phases, amely the placemet phase ad the delivery phase ) Placemet phase: I this phase, the caches of the s are filled accordig to the placemet strategy This phase typically occurs at a momet with a low amout of file requests, eg at ight ) Delivery phase: I this phase, the users sed requests to the MBS These requests are iitially served by the s coverig their locatios If a user caot collect eough iformatio to recover the file, the MBS has to deliver the missig iformatio through the backhaul Before the placemet phase, each file i the library is split ito fragmets, ie, F = {f ),,f) } for all N I a coded cachig scheme, these fragmets are used to create E ecoded packets {e ),,e) E } We wat to highlight that a fragmet is a ucoded part of a file, while a packet is a ecoded part of a file I the followig, a part of a file ca deote either a fragmet or a ecoded packet I the placemet phase, each receives m parts of file F, where m = [m m N ] is referred to as the cache placemet The placemet problem cosists of fidig the optimal umber of parts m of each file to be stored i the caches i order to miimize the average backhaul rate, which is defied as the average fractio of files that eeds to be dowloaded from the MBS durig the delivery phase

3 Fig 3 Small cells topology 4 3 III PEFOMANCE ANALYSIS OF CACHING SCHEMES I this paper, we propose to store coded packets at the s istead of fragmets or etire files We iitially preset i detail our scheme, ad calculate the average backhaul rate of a coded cachig scheme Afterwards, we prove that, give a placemet scheme m = [m m N ], storig ecoded packets always provides a advatage over storig fragmets i terms of miimizatio of the backhaul rate Fially, we formulate the coded cachig as a optimizatio problem, ad show that fidig a optimal solutio for the problem is tractable A Coded Cachig Scheme Maximum-distace separable codes are codes matchig the sigleto boud I practice, usig a a, b) code it is possible to create a ecoded packets from b iput fragmets, such that ay subset of b ecoded packets is sufficiet to recover the data The most kow example of codes are the eed-solomo S) codes [3] Lately, sub-optimal codes were proposed, like foutai codes [4], where b+ǫ) ecoded packets are eeded for the recovery I the proposed scheme, each receives m differet coded packets for each file F to be stored i its cache, with m = [m m N ] Moreover, the MBS stores m ecoded packets for each file F i order to serve the requests Formally, we propose the followig: ) Placemet phase: The MBS creates E = +N )m ecoded packets usig a E,) code The MBS keeps m ecoded packets, ad seds the other oes so that each stores m uique packets ) Delivery phase: A user requestig file F cotacts d u s, receivig m d u differet ecoded packets If m d u, the user ca recover the file due to the -property of the code Otherwise the MBS seds the remaiig m d u m ecoded packets Sice the MBS kept m ecoded packets, the user does ot receive replicated packets, ad ca decode the file I the followig, we study the performace of the proposed coded scheme i terms of average use of the backhaul lik, ad we compare the results with the ucoded scheme B Performace Aalysis To begi with, we calculate the average backhaul rate of the proposed coded cachig scheme Propositio The average backhaul rate for a ecoded cachig placemet scheme Cm defied by the placemet m = [m m N ] ca be calculated as C m ) = γ i p mi, dm )), ) d= = where S N is the maximum umber of s servig a user Proof: Let u be a user served by d u s If u requests file F, exactly packets have to be collected i order to retrieve F Each stores m packets of the file F, hece the user ca collect d u m differet ecoded packets If d u m the MBS does ot sed ay packet, otherwise d u m packets are set through the backhaul The rate for user u requestig for file F ca cosequetly be calculated as F ) = mi d=, d um ) ) A user has the probability γ d to be served by d s, hece the expected rate for the file F is give by F ) = γ d mi, dm )) Fially, each file has a differet probability to be requested by a user Averagig over the request probability distributio p = [p p N ], The average backhaul rate for the ecoded cachig placemet scheme is give by C m ) = d= = γ d p mi, dm )) I order to evaluate the gai give by the use of codes, we calculate the backhaul rate of a radom cachig scheme, where oly file fragmetatio is exploited I practice, give a placemet m = [m m N ], the MBS seds to each m differet fragmets radomly draw amog the fragmets of file F Propositio The average backhaul rate for a radom cachig placemet scheme C m defied by the placemet m = [m m N ] ca be calculated as Cm) = d= = γ d p m ) d 3) Proof: The proof is similar to the oe proposed for Propositio The mai differece is the calculatio of the

4 rate for a user requestig for a file For the give scheme, if a user u requestig file F is served by d u s, the average backhaul rate is m ) du 4) This is due the fact that i this case the fragmets are ot uique sice they ca be replicated i differet caches Therefore the probability that a sigle fragmet is ot preset i ay of the caches is m /) du The rest of the proof is similar to the oe of Propositio Now we ca prove that, give a cache placemet m = [m m N ], it is preferable i terms of backhaul usage to store coded packets rather tha fragmets Propositio 3 For ay placemet m = [m m N ], it holds that C m ) Cm) 5) Proof: As stated i the proof of Propositio, the differece betwee Equatios ) ad 3) is give by ) ad 4) respectively I order to prove the propositio, we have to prove that 4) is larger tha or equal to ) Sice d ad 0 m /, from Beroulli s iequality ad obviously m m ) d d m, ) d 0 We coclude the proof by oticig that mi, dm ) = mi 0, dm ) m ) d C Optimal Coded Cachig I the followig, we study the placemet problem of ecoded packets as a optimizatio problem, ad show its tractability Based o the average backhaul rate of Propositio, we have the followig result Propositio 4 Fidig the optimal coded placemet scheme Copt) defied by m opt) = [m m N ], which miimizes the average backhaul rate C m ), is a covex optimizatio problem Proof: The placemet problem ca be recast as the followig optimizatio problem: mi m,,m N st d= = m = M = γ d p mi, dm )) 0 m =,,N 6) We recall that the umber of fragmets ca be chose, hece we ca reformulate the optimizatio problem as mi q,,q N st d= = q = M = γ d p mi,dq )) 0 q [,N] where q = m / It ca be easily show that 7) is a covex optimizatio problem, which cocludes the proof IV NUMEICAL ILLUSTATIONS I this sectio we ivestigate the performace of the optimal coded cachig scheme i terms of backhaul rate i a HetNet topology of particular relevace We emphasize that our umerical results ca be further geeralized to ay etwork topology I particular the challegig problem of the optimizatio of the locatios of the small-cell base statios is of cosiderable practical ad theoretical iterest, but outside the scope of this paper A Network Topology I the followig we cosider the etwork depicted i Fig, where the s are deployed accordig to a regular grid with a distace d = 60 meters betwee each The macro-cell base statio coverage area has a radius of D = 500 meters I order to reach ay user i, each has a coverage area of radius r such that d/ r d, which meas that the coverage areas are overlappig as show i the highlighted square i Fig 3 If we deote by A d ad ρ d the total area of where a user ca be served by d s ad its average desity, respectively, the probability γ d that a user is served by d s ca be formally calculated as γ d = ρ da d S i= ρ ia i We ote that for this particular deploymet, the coefficietsa d ca be theoretically approximated usig simple geometrical calculatios I the followig, we cosider the users to be uiformly distributed i, with desity ρ d = ρ = 005 users/m These umbers correspod to 36 small-cell base statios beig deployed, coverig U = 3, 45 mobile users The request probability of the files p = [p p N ] is distributed accordig to a Zipf law of parameter α, ie, p = /α /α, where α represets the skewess of the distributio ad ca takes values i [05;5], see eg [5] 7)

5 Backhaul ate uif) 06 prop) 05 pop) opt) Cache Size M Fig 4 Backhaul rate as a fuctio of the cache size M, with N= 00 files, α = 07 ad r = 60 meters The lies without markers depict the use of codes ecoded packets) i the placemet, while the lie with markers depict ucoded fragmets) placemet B Cachig Strategies I order to evaluate the performace of the optimal coded placemet scheme, we compare the optimal achievable backhaul rate opt) to three other practical placemet schemes, with ad without ecodig of the files: ) most popular placemet C pop) ad Cpop) : each stores the M most popular files Sice etire files are stored for this scheme, we ote that C pop) ad Cpop) are equivalet Hece we call pop) the rate achieved usig this scheme ) uiform placemet C uif) ad Cuif) : the file is divided ito fragmets, which are placed uiformly at radom at each, ie, each stores M/N fragmets of each file I the case that codes are employed, the s store M/N ecoded packets for each file istead of fragmets We call uif) ad uif) the rates achieved usig this scheme with ad without ecodig, respectively 3) proportioal placemet C prop) ad Cprop) : for each file F, fragmets are created, alog with a cogruous umber of ecoded packets The amout of parts m of filef stored at the s is proportioal to its popularity p while satisfyig the size costraits I particular, the umber of parts cached at the is iteratively calculated as i = m i = mi,p i m ) M We call prop) ad prop) the rates achieved usig this scheme with ad without ecodig, respectively C Numerical esults I Fig 4 we depict the backhaul rates as a fuctio of the cache size M To begi with, it ca be oticed that the use of codes gives a advatage i terms of reductio of the backhaul usage, sice placemet always outperforms Backhaul ate uif) prop) pop) opt) Coverage age r Fig 5 Backhaul rate as a fuctio of the coverage radius r, with N= 00 files, α = 07, ad M = 0 files the ucoded placemet for each of the schemes This behavior cofirms the result preseted i Propositio 3 Cosequetly, i the remaider of our aalysis we oly show the rates of cachig schemes Secodly, we observe that, as it ca be expected, the backhaul rates are decreasig whe the storage capacity of the s icreases ad that the optimal cachig scheme outperforms the three other schemes Furthermore, we observe that the differece betwee opt) ad the rate of the other schemes icreases as the cache size icreases Fially, we ca otice that the pop) scheme performs the closest to the optimal scheme for small values of M, gettig worse as M icreases We guess that this scheme is ot able to really take advatage of the ature of future HetNets, ie, of the overlappig betwee coverage areas of the s I Fig 5 we cofirm the previous coecture by represetig the backhaul rates as a fuctio of the coverage radius r of the s We idetify i the figure a strikig behavior for the placemet scheme, as its rate does ot deped o the coverage radius This behavior is due to the fact that the most popular etire files are stored at the s for this scheme: beig served by more s does ot icrease the probability of havig access to ew files sice the same files are stored i Cpop) every cache I cotrast to the Cpop) scheme, the performace of other schemes icreases as the coverage area icreases, ad oticeably the optimal scheme sigificatly outperforms the other schemes as r grows As a umerical illustratio of this fact, we ca imagie the sceario where the N = 00 files are videos of size 00Mbits Whe r = 60, the rate differece betwee opt) This represets a differece of backhaul load of 7Mbits/s if there is demad per secod i the macro cell, which is a cosiderable gai for curret maximal backhaul capacities Fially i Fig 6 we illustrate the backhaul rates as a fuctio of the library size N while the size of the edge caches ad the secod best scheme prop) is 007 remais costat For small library sizes, the Cpop) scheme is outperformed by the other schemes as a spreadig of the library files over the caches is more efficiet tha oly storig a few umber of etire files O the other had, as the library size icreases, the performace of the C pop) scheme becomes

6 Backhaul ate uif) prop) pop) opt) Library Size N Fig 6 Backhaul rate as a fuctio of the library size N, with α = 07, M= 0 files ad r = 60 meters better i compariso to the other schemes The Cpop) scheme, however, is still outperformed by the Cprop) scheme, sice we cosider the overlappig sceario with coverage radius r = 60 meters, which is ufavorable to the Cpop) scheme Moreover, we ca otice that iitially the Cuif) scheme is really close to the optimal oe This is due to the fact that if the library size N is small compared to the cache size M, the optimal scheme is well approximated by the scheme Cuif) that stores the packets uiformly across the files As the library size icreases, this aïve scheme gets worse, sice it does ot take ito accout the popularity of the files O the cotrary, the performace of the Cprop) gets better, eve if the gap with the optimal scheme becomes costat This is due to the fact that this scheme does ot truly exploit the possibility a user has to be served by more tha oe I geeral, the presece of a gap betwee the optimal scheme ad sub-optimal oes highlights the importace of implemetig the optimal cachig placemet scheme to exploit the overlappig coverage regios of the HetNet ad thus to effectively decrease the backhaul load of the overall etwork V CONCLUSIONS We cosidered the problem of optimal -ecoded cotet placemet at the cache-equipped small-cell base statios at the wireless edge i order to miimize the overall backhaul load of the etwork We derived the optimal cachig placemet strategy based o file splittig combied with ecodig, which we formulated as a covex optimizatio problem We the deeply ivestigated the performace of this optimal placemet for a relevat HetNet sceario by comparig it to existig cachig strategies ad by measurig the ifluece of the key parameters, such as the capabilities of the small-cell base statios ad the library statistics Our umerical observatios, which ca be easily geeralized for ay geometric topology, showed that optimizig the placemet of ecoded packets at the wireless edge is of crucial importace, sice it yields a sigificat decrease of the load of the etwork backhaul, ad thus achieves a cosiderable improvemet i terms of delay for cotet delivery to the ed users EFEENCES [] X Wag, M Che, T Taleb, A Ksetii, ad V C M Leug, Cache i the air: Exploitig cotet cachig ad delivery techiques for 5G systems, IEEE Commuicatios Magazie, vol 5, o, pp 3 39, February 04 [] J G Adrews, Seve ways that HetNets are a cellular paradigm shift, IEEE Commuicatios Magazie, vol 5, o 3, pp 36 44, March 03 [3] E Bastug, M Beis, ad M Debbah, Livig o the edge: The role of proactive cachig i 5G wireless etworks, IEEE Commuicatios Magazie, vol 5, o 8, pp 8 89, August 04 [4] B Perabathii, E Bastug, M Koutouris, M Debbah, ad A Cotey, Cachig at the edge: a gree perspective for 5G etworks, i IEEE Iteratioal Coferece o Commuicatios ICC), Lodo, Uited Kigdom, Jue 05 [5] U Niese, D Shah, ad G W Worell, Cachig i wireless etworks, IEEE Trasactios o Iformatio Theory, vol 58, o 0, pp , October 0 [6] E Bastug, M Beis, ad M Debbah, Cache-eabled small cell etworks: Modelig ad tradeoffs, i IEEE Iteratioal Symposium o Wireless Commuicatios Systems ISWCS), Barceloa, Spai, August 04 [7] K Poularakis ad L Tassiulas, Exploitig user mobility for wireless cotet delivery, i IEEE Iteratioal Symposium o Iformatio Theory ISIT), Istabul, Turkey, July 03 [8] N Golrezaei, AG Dimakis, ad A F Molisch, Wireless device-todevice commuicatios with distributed cachig, i IEEE Iteratioal Symposium o Iformatio Theory ISIT), Cambridge, USA, July 0 [9] M A Maddah-Ali ad U Niese, Fudametal limits of cachig, IEEE Trasactios o Iformatio Theory, vol 60, o 5, pp , May 04 [0] K Poularakis, V Sourlas, P Flegkas, ad L Tassiulas, O exploitig etwork codig i cache-capable small-cell etworks, i IEEE Symposium o Computers ad Commuicatios ISCC), Fuchal, Portugal, Jue 04 [] K Shamugam, N Golrezaei, AG Dimakis, A F Molisch, ad G Caire, Femtocachig: Wireless cotet delivery through distributed cachig helpers, IEEE Trasactios o Iformatio Theory, vol 59, o, pp , December 03 [] A Liu ad V Lau, Cache-iduced opportuistic MIMO cooperatio: A ew paradigm for future wireless cotet access etworks, i IEEE Iteratioal Symposium o Iformatio Theory ISIT), Hawaii, USA, July 04 [3] S B Wicker ad V K Bhargava, eed-solomo codes ad their applicatios, Joh Wiley & Sos, 999 [4] D J MacKay, Foutai codes, i IEE Proceedigs-Commuicatios, 005, vol 5, pp [5] L Breslau, P Cao, L Fa, G Phillips, ad S Sheker, Web cachig ad Zipf-like distributios: Evidece ad implicatios, i IEEE Joit Coferece of the Computer ad Commuicatios Societies INFOCOM99), New York, USA, March 999

A New Space-Repetition Code Based on One Bit Feedback Compared to Alamouti Space-Time Code

A New Space-Repetition Code Based on One Bit Feedback Compared to Alamouti Space-Time Code Proceedigs of the 4th WSEAS It. Coferece o Electromagetics, Wireless ad Optical Commuicatios, Veice, Italy, November 0-, 006 107 A New Space-Repetitio Code Based o Oe Bit Feedback Compared to Alamouti

More information

CHAPTER 5 A NEAR-LOSSLESS RUN-LENGTH CODER

CHAPTER 5 A NEAR-LOSSLESS RUN-LENGTH CODER 95 CHAPTER 5 A NEAR-LOSSLESS RUN-LENGTH CODER 5.1 GENERAL Ru-legth codig is a lossless image compressio techique, which produces modest compressio ratios. Oe way of icreasig the compressio ratio of a ru-legth

More information

Application of Improved Genetic Algorithm to Two-side Assembly Line Balancing

Application of Improved Genetic Algorithm to Two-side Assembly Line Balancing 206 3 rd Iteratioal Coferece o Mechaical, Idustrial, ad Maufacturig Egieerig (MIME 206) ISBN: 978--60595-33-7 Applicatio of Improved Geetic Algorithm to Two-side Assembly Lie Balacig Ximi Zhag, Qia Wag,

More information

Joint Power Allocation and Beamforming for Cooperative Networks

Joint Power Allocation and Beamforming for Cooperative Networks It. J. Commuicatios, etwork ad System Scieces,, 4, 447-45 doi:.436/ijcs..4753 Published Olie July (http://www.scirp.org/joural/ijcs) Joit Power Allocatio ad Beamformig for Cooperative etworks Sodes Maadi,,

More information

A SELECTIVE POINTER FORWARDING STRATEGY FOR LOCATION TRACKING IN PERSONAL COMMUNICATION SYSTEMS

A SELECTIVE POINTER FORWARDING STRATEGY FOR LOCATION TRACKING IN PERSONAL COMMUNICATION SYSTEMS A SELETIVE POINTE FOWADING STATEGY FO LOATION TAKING IN PESONAL OUNIATION SYSTES Seo G. hag ad hae Y. Lee Departmet of Idustrial Egieerig, KAIST 373-, Kusug-Dog, Taejo, Korea, 305-70 cylee@heuristic.kaist.ac.kr

More information

The Fundamental Capacity-Delay Tradeoff in Large Mobile Ad Hoc Networks

The Fundamental Capacity-Delay Tradeoff in Large Mobile Ad Hoc Networks The Fudametal Capacity-Delay Tradeoff i Large Mobile Ad Hoc Networks Xiaoju Li ad Ness B. Shroff School of Electrical ad Computer Egieerig, Purdue Uiversity West Lafayette, IN 47907, U.S.A. {lix, shroff}@ec.purdue.edu

More information

Efficient Feedback-Based Scheduling Policies for Chunked Network Codes over Networks with Loss and Delay

Efficient Feedback-Based Scheduling Policies for Chunked Network Codes over Networks with Loss and Delay Efficiet Feedback-Based Schedulig Policies for Chuked Network Codes over Networks with Loss ad Delay Aoosheh Heidarzadeh ad Amir H. Baihashemi Departmet of Systems ad Computer Egieerig, Carleto Uiversity,

More information

ON THE FUNDAMENTAL RELATIONSHIP BETWEEN THE ACHIEVABLE CAPACITY AND DELAY IN MOBILE WIRELESS NETWORKS

ON THE FUNDAMENTAL RELATIONSHIP BETWEEN THE ACHIEVABLE CAPACITY AND DELAY IN MOBILE WIRELESS NETWORKS Chapter ON THE FUNDAMENTAL RELATIONSHIP BETWEEN THE ACHIEVABLE CAPACITY AND DELAY IN MOBILE WIRELESS NETWORKS Xiaoju Li ad Ness B. Shroff School of Electrical ad Computer Egieerig, Purdue Uiversity West

More information

ASample of an XML stream is:

ASample of an XML stream is: 1 Efficiet Multichael i XML Wireless Broadcast Stream Arezoo Khatibi* 1 ad Omid Khatibi 2 1 Faculty of Computer Sciece, Uiversity of Kasha, Kasha, Ira 2 Faculty of Mathematics, Uiversity of Viea,Viea,

More information

x y z HD(x, y) + HD(y, z) HD(x, z)

x y z HD(x, y) + HD(y, z) HD(x, z) Massachusetts Istitute of Techology Departmet of Electrical Egieerig ad Computer Sciece 6.02 Solutios to Chapter 5 Updated: February 16, 2012 Please sed iformatio about errors or omissios to hari; questios

More information

APPLICATION NOTE UNDERSTANDING EFFECTIVE BITS

APPLICATION NOTE UNDERSTANDING EFFECTIVE BITS APPLICATION NOTE AN95091 INTRODUCTION UNDERSTANDING EFFECTIVE BITS Toy Girard, Sigatec, Desig ad Applicatios Egieer Oe criteria ofte used to evaluate a Aalog to Digital Coverter (ADC) or data acquisitio

More information

Permutation Enumeration

Permutation Enumeration RMT 2012 Power Roud Rubric February 18, 2012 Permutatio Eumeratio 1 (a List all permutatios of {1, 2, 3} (b Give a expressio for the umber of permutatios of {1, 2, 3,, } i terms of Compute the umber for

More information

A New Design of Log-Periodic Dipole Array (LPDA) Antenna

A New Design of Log-Periodic Dipole Array (LPDA) Antenna Joural of Commuicatio Egieerig, Vol., No., Ja.-Jue 0 67 A New Desig of Log-Periodic Dipole Array (LPDA) Atea Javad Ghalibafa, Seyed Mohammad Hashemi, ad Seyed Hassa Sedighy Departmet of Electrical Egieerig,

More information

SIDELOBE SUPPRESSION IN OFDM SYSTEMS

SIDELOBE SUPPRESSION IN OFDM SYSTEMS SIDELOBE SUPPRESSION IN OFDM SYSTEMS Iva Cosovic Germa Aerospace Ceter (DLR), Ist. of Commuicatios ad Navigatio Oberpfaffehofe, 82234 Wesslig, Germay iva.cosovic@dlr.de Vijayasarathi Jaardhaam Muich Uiversity

More information

The Institute of Chartered Accountants of Sri Lanka

The Institute of Chartered Accountants of Sri Lanka The Istitute of Chartered Accoutats of Sri Laka Postgraduate Diploma i Busiess ad Fiace Quatitative Techiques for Busiess Hadout 02:Presetatio ad Aalysis of data Presetatio of Data The Stem ad Leaf Display

More information

Sapana P. Dubey. (Department of applied mathematics,piet, Nagpur,India) I. INTRODUCTION

Sapana P. Dubey. (Department of applied mathematics,piet, Nagpur,India) I. INTRODUCTION IOSR Joural of Mathematics (IOSR-JM) www.iosrjourals.org COMPETITION IN COMMUNICATION NETWORK: A GAME WITH PENALTY Sapaa P. Dubey (Departmet of applied mathematics,piet, Nagpur,Idia) ABSTRACT : We are

More information

Using Color Histograms to Recognize People in Real Time Visual Surveillance

Using Color Histograms to Recognize People in Real Time Visual Surveillance Usig Color Histograms to Recogize People i Real Time Visual Surveillace DANIEL WOJTASZEK, ROBERT LAGANIERE S.I.T.E. Uiversity of Ottawa, Ottawa, Otario CANADA daielw@site.uottawa.ca, lagaier@site.uottawa.ca

More information

On the Delay Performance of In-network Aggregation in Lossy Wireless Sensor Networks

On the Delay Performance of In-network Aggregation in Lossy Wireless Sensor Networks O the Delay Performace of I-etwork Aggregatio i Lossy Wireless Sesor Networks Chaghee Joo, Member, IEEE, ad Ness B. Shroff, Fellow, IEEE Abstract I this paper, we study the implicatio of wireless broadcast

More information

General Model :Algorithms in the Real World. Applications. Block Codes

General Model :Algorithms in the Real World. Applications. Block Codes Geeral Model 5-853:Algorithms i the Real World Error Correctig Codes I Overview Hammig Codes Liear Codes 5-853 Page message (m) coder codeword (c) oisy chael decoder codeword (c ) message or error Errors

More information

Information-Theoretic Analysis of an Energy Harvesting Communication System

Information-Theoretic Analysis of an Energy Harvesting Communication System Iformatio-Theoretic Aalysis of a Eergy Harvestig Commuicatio System Omur Ozel Seur Ulukus Departmet of Electrical ad Computer Egieerig Uiversity of Marylad, College Park, MD 074 omur@umd.edu ulukus@umd.edu

More information

INCREASE OF STRAIN GAGE OUTPUT VOLTAGE SIGNALS ACCURACY USING VIRTUAL INSTRUMENT WITH HARMONIC EXCITATION

INCREASE OF STRAIN GAGE OUTPUT VOLTAGE SIGNALS ACCURACY USING VIRTUAL INSTRUMENT WITH HARMONIC EXCITATION XIX IMEKO World Cogress Fudametal ad Applied Metrology September 6, 9, Lisbo, Portugal INCREASE OF STRAIN GAGE OUTPUT VOLTAGE SIGNALS ACCURACY USING VIRTUAL INSTRUMENT WITH HARMONIC EXCITATION Dalibor

More information

Logarithms APPENDIX IV. 265 Appendix

Logarithms APPENDIX IV. 265 Appendix APPENDIX IV Logarithms Sometimes, a umerical expressio may ivolve multiplicatio, divisio or ratioal powers of large umbers. For such calculatios, logarithms are very useful. They help us i makig difficult

More information

Cross-Layer Performance of a Distributed Real-Time MAC Protocol Supporting Variable Bit Rate Multiclass Services in WPANs

Cross-Layer Performance of a Distributed Real-Time MAC Protocol Supporting Variable Bit Rate Multiclass Services in WPANs Cross-Layer Performace of a Distributed Real-Time MAC Protocol Supportig Variable Bit Rate Multiclass Services i WPANs David Tug Chog Wog, Jo W. Ma, ad ee Chaig Chua 3 Istitute for Ifocomm Research, Heg

More information

X-Bar and S-Squared Charts

X-Bar and S-Squared Charts STATGRAPHICS Rev. 7/4/009 X-Bar ad S-Squared Charts Summary The X-Bar ad S-Squared Charts procedure creates cotrol charts for a sigle umeric variable where the data have bee collected i subgroups. It creates

More information

Decode-forward and Compute-forward Coding Schemes for the Two-Way Relay Channel

Decode-forward and Compute-forward Coding Schemes for the Two-Way Relay Channel Decode-forward ad Compute-forward Codig Schemes for the Two-Way Relay Chael Peg Zhog ad Mai Vu Departmet of Electrical ad Computer Egieerig McGill Uiversity Motreal, QC, Caada H3A A7 Emails: peg.zhog@mail.mcgill.ca,

More information

COMPRESSION OF TRANSMULTIPLEXED ACOUSTIC SIGNALS

COMPRESSION OF TRANSMULTIPLEXED ACOUSTIC SIGNALS COMPRESSION OF TRANSMULTIPLEXED ACOUSTIC SIGNALS Mariusz Ziółko, Przemysław Sypka ad Bartosz Ziółko Departmet of Electroics, AGH Uiversity of Sciece ad Techology, al. Mickiewicza 3, 3-59 Kraków, Polad,

More information

Time-Space Opportunistic Routing in Wireless Ad Hoc Networks, Algorithms and Performance

Time-Space Opportunistic Routing in Wireless Ad Hoc Networks, Algorithms and Performance Time-Space Opportuistic Routig i Wireless Ad Hoc Networks, Algorithms ad Performace Fraçois Baccelli, Bartlomiej Blaszczyszy, Paul Muhlethaler To cite this versio: Fraçois Baccelli, Bartlomiej Blaszczyszy,

More information

On Parity based Divide and Conquer Recursive Functions

On Parity based Divide and Conquer Recursive Functions O Parity based Divide ad Coquer Recursive Fuctios Sug-Hyu Cha Abstract The parity based divide ad coquer recursio trees are itroduced where the sizes of the tree do ot grow mootoically as grows. These

More information

Optimal Geolocation Updating for Location Aware Service Provisioning in Wireless Networks

Optimal Geolocation Updating for Location Aware Service Provisioning in Wireless Networks Optimal Geolocatio Updatig for Locatio Aware Service Provisioig i Wireless Networks Siri Tekiay Amer Catovic tekiay@adm.jit.edu axc4466@jit.edu New Jersey Istitute of Techology Uiversity Heights, Newark,

More information

Optimization of Base Station and Maximizing the Lifetime of Wireless Sensor Network

Optimization of Base Station and Maximizing the Lifetime of Wireless Sensor Network Optimizatio of Base Statio ad Maximizig the Lifetime of Wireless Sesor Network P.Parthiba 1, G.Sudararaj 2, K.A.Jagadheesh 3, P.Maiiarasa 4 SS1 Research Scholar, P.S.G College of Techology, Coimbatore,

More information

Analysis of SDR GNSS Using MATLAB

Analysis of SDR GNSS Using MATLAB Iteratioal Joural of Computer Techology ad Electroics Egieerig (IJCTEE) Volume 5, Issue 3, Jue 2015 Aalysis of SDR GNSS Usig MATLAB Abstract This paper explais a software defied radio global avigatio satellite

More information

A New Basic Unit for Cascaded Multilevel Inverters with the Capability of Reducing the Number of Switches

A New Basic Unit for Cascaded Multilevel Inverters with the Capability of Reducing the Number of Switches Joural of Power Electroics, ol, o, pp 67-677, July 67 JPE --6 http://dxdoiorg/6/jpe67 I(Prit: 98-9 / I(Olie: 9-78 A ew Basic Uit for Cascaded Multi Iverters with the Capability of Reducig the umber of

More information

A novel adaptive modulation and coding strategy based on partial feedback for enhanced MBMS network

A novel adaptive modulation and coding strategy based on partial feedback for enhanced MBMS network THE JOURNAL OF CHINA UNIVERSITIES OF POSTS AND TELECOMMUNICATIONS Volume 5, Issue, March 2008 SHENG Yu, PENG Mu-ge, WANG We-bo A ovel adaptive modulatio ad codig strategy based o partial feedback for ehaced

More information

Single Bit DACs in a Nutshell. Part I DAC Basics

Single Bit DACs in a Nutshell. Part I DAC Basics Sigle Bit DACs i a Nutshell Part I DAC Basics By Dave Va Ess, Pricipal Applicatio Egieer, Cypress Semicoductor May embedded applicatios require geeratig aalog outputs uder digital cotrol. It may be a DC

More information

A study on the efficient compression algorithm of the voice/data integrated multiplexer

A study on the efficient compression algorithm of the voice/data integrated multiplexer A study o the efficiet compressio algorithm of the voice/data itegrated multiplexer Gyou-Yo CHO' ad Dog-Ho CHO' * Dept. of Computer Egieerig. KyiigHee Uiv. Kiheugup Yogiku Kyuggido, KOREA 449-71 PHONE

More information

Tier-Aware Resource Allocation in OFDMA Macrocell-Small Cell Networks

Tier-Aware Resource Allocation in OFDMA Macrocell-Small Cell Networks 1 Tier-Aware Resource Allocatio i OFDMA Macrocell-Small Cell Networks Amr Abdelasser, Ekram Hossai, ad Dog I Kim arxiv:145.2v1 [cs.ni] 8 May 214 Abstract We preset a joit sub-chael ad power allocatio framework

More information

Enhancement of the IEEE MAC Protocol for Scalable Data Collection in Dense Sensor Networks

Enhancement of the IEEE MAC Protocol for Scalable Data Collection in Dense Sensor Networks Ehacemet of the IEEE 8.5. MAC Protocol for Scalable Data Collectio i Dese Sesor Networks Kira Yedavalli Departmet of Electrical Egieerig - Systems Uiversity of Souther Califoria Los Ageles, Califoria,

More information

The Throughput and Delay Trade-off of Wireless Ad-hoc Networks

The Throughput and Delay Trade-off of Wireless Ad-hoc Networks The Throughput ad Delay Trade-off of Wireless Ad-hoc Networks. Itroductio I this report, we summarize the papers by Gupta ad Kumar [GK2000], Grossglauser ad Tse [GT2002], Gamal, Mame, Prabhakar, ad hah

More information

Wi-Fi or Femtocell: User Choice and Pricing Strategy of Wireless Service Provider

Wi-Fi or Femtocell: User Choice and Pricing Strategy of Wireless Service Provider Wi-Fi or Femtocell: User Choice ad Pricig Strategy of Wireless Service Provider Yajiao Che, Qia Zhag Departmet of Computer Sciece ad Egieerig Hog Kog Uiversity of Sciece ad Techology Email: {cheyajiao,

More information

Analysis and Optimization Design of Snubber Cricuit for Isolated DC-DC Converters in DC Power Grid

Analysis and Optimization Design of Snubber Cricuit for Isolated DC-DC Converters in DC Power Grid Aalysis ad Optimizatio Desig of Subber Cricuit for Isolated DC-DC Coverters i DC Power Grid Koji Orikawa Nagaoka Uiversity of Techology Nagaoka, Japa orikawa@st.agaokaut.ac.jp Ju-ichi Itoh Nagaoka Uiversity

More information

On the Capacity of k-mpr Wireless Networks

On the Capacity of k-mpr Wireless Networks O the Capacity of -MPR Wireless Networs Mig-Fei Guo, Member, IEEE, Xibig Wag, Member, IEEE, Mi-You Wu, Seior Member, IEEE Abstract The capacity of wireless ad hoc etwors is maily restricted by the umber

More information

Methods to Reduce Arc-Flash Hazards

Methods to Reduce Arc-Flash Hazards Methods to Reduce Arc-Flash Hazards Exercise: Implemetig Istataeous Settigs for a Maiteace Mode Scheme Below is a oe-lie diagram of a substatio with a mai ad two feeders. Because there is virtually o differece

More information

Adaptive Resource Allocation in Multiuser OFDM Systems

Adaptive Resource Allocation in Multiuser OFDM Systems Adaptive Resource Allocatio i Multiuser OFDM Systems Fial Report Multidimesioal Digital Sigal Processig Malik Meherali Saleh The Uiversity of Texas at Austi malikmsaleh@mail.utexas.edu Sprig 005 Abstract

More information

Stochastic Geometry Model for Multi-Channel Fog Radio Access Networks

Stochastic Geometry Model for Multi-Channel Fog Radio Access Networks The 7 Iteratioal Workshop o Spatial Stochastic Models for Wireless Networks SpaSWiN Stochastic Geometry Model for Multi-Chael Fog Radio Access Networks Mostafa Emara *, Hesham ElSawy, Sameh Sorour, Samir

More information

Is Diversity Gain Worth the Pain: Performance Comparison Between Opportunistic Multi-Channel MAC and Single-Channel MAC

Is Diversity Gain Worth the Pain: Performance Comparison Between Opportunistic Multi-Channel MAC and Single-Channel MAC Is Diversity Gai Worth the Pai: Performace Compariso Betwee Opportuistic Multi-Chael MAC ad Sigle-Chael MAC Yag Liu 1, Migya Liu 1 ad Jig Deg 2 1 Departmet of Electrical Egieerig ad Computer Sciece, Uiv.

More information

Broadcast Capacity in Multihop Wireless Networks

Broadcast Capacity in Multihop Wireless Networks Broadcast Capacity i Multihop ireless Networks Alireza Keshavarz- Haddad alireza@rice.edu Viay Ribeiro viay@rice.edu Rudolf Riedi riedi@rice.edu Departmet of Electrical ad Computer Egieerig ad Departmet

More information

Lecture 4: Frequency Reuse Concepts

Lecture 4: Frequency Reuse Concepts EE 499: Wireless & Mobile Commuicatios (8) Lecture 4: Frequecy euse Cocepts Distace betwee Co-Chael Cell Ceters Kowig the relatio betwee,, ad, we ca easily fid distace betwee the ceter poits of two co

More information

Fingerprint Classification Based on Directional Image Constructed Using Wavelet Transform Domains

Fingerprint Classification Based on Directional Image Constructed Using Wavelet Transform Domains 7 Figerprit Classificatio Based o Directioal Image Costructed Usig Wavelet Trasform Domais Musa Mohd Mokji, Syed Abd. Rahma Syed Abu Bakar, Zuwairie Ibrahim 3 Departmet of Microelectroic ad Computer Egieerig

More information

Combined Scheme for Fast PN Code Acquisition

Combined Scheme for Fast PN Code Acquisition 13 th Iteratioal Coferece o AEROSPACE SCIENCES & AVIATION TECHNOLOGY, ASAT- 13, May 6 8, 009, E-Mail: asat@mtc.edu.eg Military Techical College, Kobry Elkobbah, Cairo, Egypt Tel : +(0) 4059 4036138, Fax:

More information

Beam Pattern Scanning (BPS) versus Space-Time Block Coding (STBC) and Space-Time Trellis Coding (STTC)

Beam Pattern Scanning (BPS) versus Space-Time Block Coding (STBC) and Space-Time Trellis Coding (STTC) It. J. Commuicatios, Network ad System Scieces, 2009, 6, 469-479 doi:10.4236/ijcs.2009.26051 Published Olie September 2009 (http://www.scirp.org/joural/ijcs/). 469 Beam Patter Scaig (BPS) versus Space-Time

More information

A New Energy Efficient Data Gathering Approach in Wireless Sensor Networks

A New Energy Efficient Data Gathering Approach in Wireless Sensor Networks Commuicatios ad Network, 0, 4, 6-7 http://dx.doi.org/0.436/c.0.4009 Published Olie February 0 (http://www.scirp.org/joural/c) A New Eergy Efficiet Data Gatherig Approach i Wireless Sesor Networks Jafar

More information

Survey of Low Power Techniques for ROMs

Survey of Low Power Techniques for ROMs Survey of Low Power Techiques for ROMs Edwi de Agel Crystal Semicoductor Corporatio P.O Box 17847 Austi, TX 78744 Earl E. Swartzlader, Jr. Departmet of Electrical ad Computer Egieerig Uiversity of Texas

More information

Measurement-Based Opportunistic Feedback and Scheduling for Wireless Systems

Measurement-Based Opportunistic Feedback and Scheduling for Wireless Systems Measuremet-Based Opportuistic Feedbac ad Schedulig for Wireless Systems Gustavo de Veciaa ad Shailesh Patil Wireless Networig ad Commuicatios Group Dept. of Electrical ad Computer Egieerig The Uiversity

More information

Measurement of Equivalent Input Distortion AN 20

Measurement of Equivalent Input Distortion AN 20 Measuremet of Equivalet Iput Distortio AN 2 Applicatio Note to the R&D SYSTEM Traditioal measuremets of harmoic distortio performed o loudspeakers reveal ot oly the symptoms of the oliearities but also

More information

CS 201: Adversary arguments. This handout presents two lower bounds for selection problems using adversary arguments ëknu73,

CS 201: Adversary arguments. This handout presents two lower bounds for selection problems using adversary arguments ëknu73, CS 01 Schlag Jauary 6, 1999 Witer `99 CS 01: Adversary argumets This hadout presets two lower bouds for selectio problems usig adversary argumets ëku73, HS78, FG76ë. I these proofs a imagiary adversary

More information

CHAPTER 8 JOINT PAPR REDUCTION AND ICI CANCELLATION IN OFDM SYSTEMS

CHAPTER 8 JOINT PAPR REDUCTION AND ICI CANCELLATION IN OFDM SYSTEMS CHAPTER 8 JOIT PAPR REDUCTIO AD ICI CACELLATIO I OFDM SYSTEMS Itercarrier Iterferece (ICI) is aother major issue i implemetig a OFDM system. As discussed i chapter 3, the OFDM subcarriers are arrowbad

More information

Measurements of the Communications Environment in Medium Voltage Power Distribution Lines for Wide-Band Power Line Communications

Measurements of the Communications Environment in Medium Voltage Power Distribution Lines for Wide-Band Power Line Communications Measuremets of the Commuicatios viromet i Medium Voltage Power Distributio Lies for Wide-Bad Power Lie Commuicatios Jae-Jo Lee *,Seug-Ji Choi *,Hui-Myoug Oh *, Wo-Tae Lee *, Kwa-Ho Kim * ad Dae-Youg Lee

More information

Broadcast Throughput Capacity of Wireless Ad Hoc Networks with Multipacket Reception

Broadcast Throughput Capacity of Wireless Ad Hoc Networks with Multipacket Reception Broadcast Throughput Capacity of Wireless Ad Hoc Networks with Multipacket Receptio Zheg Wag, Hamid R. Sadjadpour, J.J. Garcia-Lua-Aceves Departmet of Electrical Egieerig ad Computer Egieerig Uiversity

More information

A D2D-based Protocol for Ultra-Reliable Wireless Communications for Industrial Automation

A D2D-based Protocol for Ultra-Reliable Wireless Communications for Industrial Automation 1 A D2D-based Protocol for Ultra-Reliable Wireless Commuicatios for Idustrial Automatio Liag Liu, Member, IEEE ad Wei Yu, Fellow, IEEE arxiv:1710.01265v3 [cs.it] 15 May 2018 Abstract As a idispesable use

More information

A New Energy Consumption Algorithm with Active Sensor Selection Using GELS in Target Coverage WSN

A New Energy Consumption Algorithm with Active Sensor Selection Using GELS in Target Coverage WSN IJCSI Iteratioal Joural of Computer Sciece Issues, Vol. 10, Issue 4, No 1, July 2013 ISSN (Prit): 1694-0814 ISSN (Olie): 1694-0784 www.ijcsi.org 11 A New Eergy Cosumptio Algorithm with Active Sesor Selectio

More information

Stable Throughput Region of Downlink NOMA Transmissions with Limited CSI

Stable Throughput Region of Downlink NOMA Transmissions with Limited CSI Stable Throughput Regio of Dowlik NOMA Trasmissios with imited CSI Yog Zhou ad Vicet W.S. Wog Departmet of Electrical ad Computer Egieerig The Uiversity of British Columbia, Vacouver, Caada e-mail: {zhou,

More information

International Power, Electronics and Materials Engineering Conference (IPEMEC 2015)

International Power, Electronics and Materials Engineering Conference (IPEMEC 2015) Iteratioal Power, Electroics ad Materials Egieerig Coferece (IPEMEC 205) etwork Mode based o Multi-commuicatio Mechaism Fa Yibi, Liu Zhifeg, Zhag Sheg, Li Yig Departmet of Military Fiace, Military Ecoomy

More information

arxiv: v2 [math.co] 15 Oct 2018

arxiv: v2 [math.co] 15 Oct 2018 THE 21 CARD TRICK AND IT GENERALIZATION DIBYAJYOTI DEB arxiv:1809.04072v2 [math.co] 15 Oct 2018 Abstract. The 21 card trick is well kow. It was recetly show i a episode of the popular YouTube chael Numberphile.

More information

Optimal Arrangement of Buoys Observable by Means of Radar

Optimal Arrangement of Buoys Observable by Means of Radar Optimal Arragemet of Buoys Observable by Meas of Radar TOMASZ PRACZYK Istitute of Naval Weapo ad Computer Sciece Polish Naval Academy Śmidowicza 69, 8-03 Gdyia POLAND t.praczy@amw.gdyia.pl Abstract: -

More information

PHY-MAC dialogue with Multi-Packet Reception

PHY-MAC dialogue with Multi-Packet Reception PHY-AC dialogue with ulti-packet Receptio arc Realp 1 ad Aa I. Pérez-Neira 1 CTTC-Cetre Tecològic de Telecomuicacios de Cataluya Edifici Nexus C/Gra Capità, - 0803-Barceloa (Cataluya-Spai) marc.realp@cttc.es

More information

The Potential of Dynamic Power and Sub-carrier Assignments in Multi-User OFDM-FDMA Cells

The Potential of Dynamic Power and Sub-carrier Assignments in Multi-User OFDM-FDMA Cells The Potetial of Dyamic Power ad Sub-carrier Assigmets i Multi-User OFDM-FDMA Cells Mathias Bohge, James Gross, Adam Wolisz Telecommuicatio Networks Group, TU Berli Eisteiufer 5, 1587 Berli, Germay {bohge

More information

A Framework for Analysis of Connectivity and Performance Bounds in Ad Hoc Networks and Its Application to a Slotted-ALOHA Scenario

A Framework for Analysis of Connectivity and Performance Bounds in Ad Hoc Networks and Its Application to a Slotted-ALOHA Scenario JOURNAL OF COMMUNICATIONS SOFTWARE AND SYSTEMS, VOL., NO., SEPTEMBER 005 35 A Framework for Aalysis of Coectivity ad Performace Bouds i Ad Hoc Networks ad Its Applicatio to a Slotted-ALOHA Sceario Fabrizio

More information

Roberto s Notes on Infinite Series Chapter 1: Series Section 2. Infinite series

Roberto s Notes on Infinite Series Chapter 1: Series Section 2. Infinite series Roberto s Notes o Ifiite Series Chapter : Series Sectio Ifiite series What you eed to ow already: What sequeces are. Basic termiology ad otatio for sequeces. What you ca lear here: What a ifiite series

More information

3. Error Correcting Codes

3. Error Correcting Codes 3. Error Correctig Codes Refereces V. Bhargava, Forward Error Correctio Schemes for Digital Commuicatios, IEEE Commuicatios Magazie, Vol 21 No1 11 19, Jauary 1983 Mischa Schwartz, Iformatio Trasmissio

More information

The Potential of Dynamic Power and Sub-carrier Assignments in Multi-User OFDM-FDMA Cells

The Potential of Dynamic Power and Sub-carrier Assignments in Multi-User OFDM-FDMA Cells The Potetial of Dyamic Power ad Sub-carrier Assigmets i Multi-User OFDM-FDMA Cells Mathias Bohge, James Gross, Adam Wolisz TU Berli Eisteiufer 5, 1587 Berli, Germay {bohge gross wolisz}@tk.tu-berli.de

More information

AC : USING ELLIPTIC INTEGRALS AND FUNCTIONS TO STUDY LARGE-AMPLITUDE OSCILLATIONS OF A PENDULUM

AC : USING ELLIPTIC INTEGRALS AND FUNCTIONS TO STUDY LARGE-AMPLITUDE OSCILLATIONS OF A PENDULUM AC 007-7: USING ELLIPTIC INTEGRALS AND FUNCTIONS TO STUDY LARGE-AMPLITUDE OSCILLATIONS OF A PENDULUM Josue Njock-Libii, Idiaa Uiversity-Purdue Uiversity-Fort Waye Josué Njock Libii is Associate Professor

More information

OPTIMIZED LINK ADAPTATION FOR WIRELESS PACKET COMMUNICATIONS BASED ON DISCRETE-RATE MODULATION AND CODING SCHEMES

OPTIMIZED LINK ADAPTATION FOR WIRELESS PACKET COMMUNICATIONS BASED ON DISCRETE-RATE MODULATION AND CODING SCHEMES OPTIMIZED LIK ADAPTATIO FO WIELE PACKET COMMUICATIO BAED O DICETE-ATE MODULATIO AD CODIG CHEME Jalil eifali Harsii, ad Farshad Lahouti Wireless Multimedia Commuicatios Laboratory chool of Electrical ad

More information

HYBRID ERASURE ERROR PROTOCOLS FOR WIRELESS VIDEO

HYBRID ERASURE ERROR PROTOCOLS FOR WIRELESS VIDEO HYBRID ERASURE ERROR PROTOCOLS FOR WIRELESS VIDEO Shirish S. Karade* ad Hayder Radha Departmet of Electrical & Computer Egieerig / 220 Egieerig Buildig Michiga State Uiversity, East Lasig, MI 48824 USA

More information

lecture notes September 2, Sequential Choice

lecture notes September 2, Sequential Choice 18.310 lecture otes September 2, 2013 Sequetial Choice Lecturer: Michel Goemas 1 A game Cosider the followig game. I have 100 blak cards. I write dow 100 differet umbers o the cards; I ca choose ay umbers

More information

SELEX Elsag. 5/18/2012 R. Pucci SDR 12 WinnComm 1

SELEX Elsag. 5/18/2012 R. Pucci SDR 12 WinnComm 1 SELEX Elsag 5/18/01 R. Pucci SDR 1 WiComm 1 Military BU - SELEX Elsag Possible update of SDR Platforms to COGNITIVE architectures COGNITIVE MANAGER INTERFACE Geolocatio, Voice, Video, etc Applicatio Policy

More information

A Research on Spectrum Allocation Using Optimal Power in Downlink Wireless system

A Research on Spectrum Allocation Using Optimal Power in Downlink Wireless system Iteratioal Research Joural of Egieerig ad Techology (IRJET) e-iss: 2395-0056 Volume: 03 Issue: 04 Apr-206 www.irjet.et p-iss: 2395-0072 A Research o Spectrum Allocatio Usig Optimal Power i Dowli Wireless

More information

4. INTERSYMBOL INTERFERENCE

4. INTERSYMBOL INTERFERENCE DATA COMMUNICATIONS 59 4. INTERSYMBOL INTERFERENCE 4.1 OBJECT The effects of restricted badwidth i basebad data trasmissio will be studied. Measuremets relative to itersymbol iterferece, usig the eye patter

More information

On the Capacity of k-mpr Wireless Networks

On the Capacity of k-mpr Wireless Networks 3878 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 8, NO. 7, JULY 2009 O the Capacity of -MPR Wireless Networs Mig-Fei Guo, Member, IEEE, Xibig Wag, Member, IEEE, Mi-You Wu, Seior Member, IEEE Abstract

More information

PROJECT #2 GENERIC ROBOT SIMULATOR

PROJECT #2 GENERIC ROBOT SIMULATOR Uiversity of Missouri-Columbia Departmet of Electrical ad Computer Egieerig ECE 7330 Itroductio to Mechatroics ad Robotic Visio Fall, 2010 PROJECT #2 GENERIC ROBOT SIMULATOR Luis Alberto Rivera Estrada

More information

Discrete Mathematics and Probability Theory Spring 2014 Anant Sahai Note 12

Discrete Mathematics and Probability Theory Spring 2014 Anant Sahai Note 12 EECS 70 Discrete Mathematics ad Probability Theory Sprig 204 Aat Sahai Note 2 Probability Examples Based o Coutig We will ow look at examples of radom experimets ad their correspodig sample spaces, alog

More information

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

More information

7. Counting Measure. Definitions and Basic Properties

7. Counting Measure. Definitions and Basic Properties Virtual Laboratories > 0. Foudatios > 1 2 3 4 5 6 7 8 9 7. Coutig Measure Defiitios ad Basic Properties Suppose that S is a fiite set. If A S the the cardiality of A is the umber of elemets i A, ad is

More information

Lossless image compression Using Hashing (using collision resolution) Amritpal Singh 1 and Rachna rajpoot 2

Lossless image compression Using Hashing (using collision resolution) Amritpal Singh 1 and Rachna rajpoot 2 Lossless image compressio Usig Hashig (usig collisio resolutio) Amritpal Sigh 1 ad Racha rajpoot 2 1 M.Tech.* CSE Departmet, 2 Departmet of iformatio techology Guru Kashi UiversityTalwadi Sabo, Bathida

More information

Fast Sensor Deployment for Fusion-based Target Detection

Fast Sensor Deployment for Fusion-based Target Detection Fast Sesor Deploymet for Fusio-based Target Detectio Zhaohui Yua*, Rui Ta*, Guoliag Xig*, Cheyag Lu, Yixi Che *Departmet of Computer Sciece, City Uiversity of Hog Kog Departmet of Computer Sciece ad Egieerig,

More information

Test Time Minimization for Hybrid BIST with Test Pattern Broadcasting

Test Time Minimization for Hybrid BIST with Test Pattern Broadcasting Test Time Miimizatio for Hybrid BIST with Test Patter Broadcastig Raimud Ubar, Maksim Jeihhi Departmet of Computer Egieerig Talli Techical Uiversity EE-126 18 Talli, Estoia {raiub, maksim}@pld.ttu.ee Gert

More information

Optimized Opportunistic Multicast Scheduling (OMS) over Wireless Cellular Networks

Optimized Opportunistic Multicast Scheduling (OMS) over Wireless Cellular Networks MITSUBISHI ELECTRIC RESEARCH LABORATORIES http://www.merl.com Optimized Opportuistic Multicast Schedulig OMS) over Wireless Cellular Networks Tze-Pig Low, Ma-O Pu, Y.-W. Peter Hog, C.-C. Jay Kuo TR010-008

More information

Super J-MOS Low Power Loss Superjunction MOSFETs

Super J-MOS Low Power Loss Superjunction MOSFETs Low Power Loss Superjuctio MOSFETs Takahiro Tamura Mutsumi Sawada Takayuki Shimato ABSTRACT Fuji Electric has developed superjuctio MOSFETs with a optimized surface desig that delivers lower switchig.

More information

Unit 5: Estimating with Confidence

Unit 5: Estimating with Confidence Uit 5: Estimatig with Cofidece Sectio 8.2 The Practice of Statistics, 4 th editio For AP* STARNES, YATES, MOORE Uit 5 Estimatig with Cofidece 8.1 8.2 8.3 Cofidece Itervals: The Basics Estimatig a Populatio

More information

Introduction to Wireless Communication Systems ECE 476/ECE 501C/CS 513 Winter 2003

Introduction to Wireless Communication Systems ECE 476/ECE 501C/CS 513 Winter 2003 troductio to Wireless Commuicatio ystems ECE 476/ECE 501C/C 513 Witer 2003 eview for Exam #1 March 4, 2003 Exam Details Must follow seatig chart - Posted 30 miutes before exam. Cheatig will be treated

More information

Network Coding Does Not Change The Multicast Throughput Order of Wireless Ad Hoc Networks

Network Coding Does Not Change The Multicast Throughput Order of Wireless Ad Hoc Networks Network Codig Does Not Chage The Multicast Throughput Order of Wireless Ad Hoc Networks Shirish Karade, Zheg Wag, Hamid R. Sadjadpour, J.J. Garcia-Lua-Aceves Departmet of Electrical Egieerig ad Computer

More information

The Multicast Capacity of Large Multihop Wireless Networks

The Multicast Capacity of Large Multihop Wireless Networks The Multicast Capacity of Large Multihop Wireless Networks Sriivas Shakkottai Dept. of ECE, ad Coordiated Sciece Laboratory Uiversity of Illiois at Urbaa-Champaig sshakkot@uiuc.edu Xi Liu Dept. of Computer

More information

13 Legislative Bargaining

13 Legislative Bargaining 1 Legislative Bargaiig Oe of the most popular legislative models is a model due to Baro & Ferejoh (1989). The model has bee used i applicatios where the role of committees have bee studies, how the legislative

More information

This is an author-deposited version published in : Eprints ID : 15237

This is an author-deposited version published in :   Eprints ID : 15237 Ope Archive TOULOUSE Archive Ouverte (OATAO) OATAO is a ope access repository that collec the work of Toulouse researchers ad makes it freely available over the web where possible. This is a author-deposited

More information

Optimization of Fractional Frequency Reuse in Long Term Evolution Networks

Optimization of Fractional Frequency Reuse in Long Term Evolution Networks 2012 IEEE Wireless Commuicatios ad Networkig Coferece: Mobile ad Wireless Networks Optimizatio of Fractioal Frequecy Reuse i Log Term Evolutio Networks Dimitrios Bilios 1,2, Christos Bouras 1,2, Vasileios

More information

Low Latency Random Access with TTI Bundling in LTE/LTE-A

Low Latency Random Access with TTI Bundling in LTE/LTE-A Low Latecy Radom Access with TTI Budlig i LTE/LTE-A Kaijie Zhou, Navid Nikaei Huawei Techologies Co., Ltd. Chia, zhoukaijie@huawei.com Eurecom, Frace, avid.ikaei@eurecom.fr Abstract To reduce the uplik

More information

OFDMA Based Two-hop Cooperative Relay Network Resources Allocation

OFDMA Based Two-hop Cooperative Relay Network Resources Allocation This full text paper was peer reviewed at the directio of IEEE Commuicatios Society subject matter experts for publicatio i the ICC 008 proceedigs. OFDMA Based Two-hop Cooperative Relay Network Resources

More information

A Distributed Self Spreading Algorithm for Mobile Wireless Sensor Networks

A Distributed Self Spreading Algorithm for Mobile Wireless Sensor Networks A Distributed Self Spreadig Algorithm for Mobile Wireless Sesor Networks jeog Heo ad Pramod K. Varshey Departmet of Electrical Egieerig ad Computer Sciece, Syracuse Uiversity, Syracuse, NY 344,U {heo,varshey}@syr.edu

More information

Hybrid BIST Optimization for Core-based Systems with Test Pattern Broadcasting

Hybrid BIST Optimization for Core-based Systems with Test Pattern Broadcasting Hybrid BIST Optimizatio for Core-based Systems with Test Patter Broadcastig Raimud Ubar, Masim Jeihhi Departmet of Computer Egieerig Talli Techical Uiversity, Estoia {raiub, masim}@pld.ttu.ee Gert Jerva,

More information

Problem of calculating time delay between pulse arrivals

Problem of calculating time delay between pulse arrivals America Joural of Egieerig Research (AJER) 5 America Joural of Egieerig Research (AJER) e-issn: 3-847 p-issn : 3-936 Volume-4, Issue-4, pp-3-4 www.ajer.org Research Paper Problem of calculatig time delay

More information

Circular waveguides. Introduction. Table of Contents

Circular waveguides. Introduction. Table of Contents Itroductio Circular waveguides Waveguides ca be simply described as metal pipes. Depedig o their cross sectio there are rectagular waveguides (described i separate tutorial) ad circular waveguides, which

More information