Scheduling Algorithm with Delay-limited for VoIP in LTE

Size: px
Start display at page:

Download "Scheduling Algorithm with Delay-limited for VoIP in LTE"

Transcription

1 Proceedigs of APSIPA Aual Summit ad Coferece December 15 Schedulig Algorithm with Delay-limited for VoIP i LTE Jua Che #, Weguo Yag #, Suixiag Gao #, Lei Zhou * # School of Mathematical Scieces, Uiversity of Chiese Academy of Scieces, Beijig, Chia Chejua1@mails.ucas.ac.c yagwg@ucas.ac.c sxgao@ucas.ac.c * Huawei Techologies Co. LTD. Beijig, Chia kevi.zhoulei@huawei.com Abstract The log term evolutio (LTE) is a breakthrough techology with respect to the previous geeratio of cellular etworks, as it is based o a all-ip architecture that aims at supportig several high quality services, such as video streamig, voice-over-iteret-protocol (VoIP) ad everythig related to the widebad Iteret access. I the recet years, VOIP service is becomig more ad more popular ad importat, while the tight delay requiremets ad the scarcity of radio resources problem remai the mai challeges for it. To solve these problems, we costruct a mathematical model ad desig a ovel algorithm for the schedulig problem of VOIP. Limitig the delay, our algorithm solve the scarcity of radio resources problem by miimizig the total umber of radio resources scheduled durig a certai period of time, which ca esure the quality-ofexperiece (QOE) of user equipmet (UE) ad high resource utilizatio rate. Moreover, the maximum delay of a UE with a certai average trasmittig rate is determied theoretically. Fially, we give simulatio results of our schedulig algorithm ad the compariso with the modified largest weighted delay first (M- LWDF) ad the expoetial/proportioal fair (EXP/PF) algorithms, by which we demostrate the effectiveess of our algorithm o delay ad resource utilizatio. Idex Terms delay-limited, radio resource, schedulig, VoIP, LTE I. INTRODUCTION The LTE system, which is desiged based o the orthogoal frequecy divisio multiplexig (OFDM) to provide services icludig real-time multimedia services i the IP-based PS domai, represets a very promisig aswer to the ever risig badwidth demad of mobile applicatios ad eables diverse mobile multimedia service provisio. The cotiuous rise of real-time multimedia services (such as voice ad video service) over the Iteret, ad the eed for ubiquitous access to them, are drivig the evolutio of cellular etworks. Such services usually exhibit a large variety of quality-of-service (QoS) requiremets, such as trasmissio rate, delay, ad packet-droppig ratio, which are difficult to satisfy i a wireless eviromet due to the limit of radio resources, the variability of the chael coditio, ad resource cotetio amog multiple UEs. Although the latest mobile broadbad techologies, icludig 3GPP techologies based o LTE ad LTE-advaced stadards, offer much higher capacities with peak rates up to 34 Mb/s over a MHz chael [1, ], the successful implemetatio of multimedia services i the PS domai is still a challege whe loss sesitive real-time multimedia service characteristics are take ito accout, especially i the wireless eviromet with fadig ad delay. Despite the icreasig demad for packet-data based commuicatio, the voice commuicatio will always play a importat role i wireless etworks. I the existig CDMA ad WCDMA based cellular systems, the voice service is provided separately i the circuit switchig (CS) domai. O the other had, LTE is desiged to provide all services icludig the voice service i the IP-based PS domai. QoS provisio for VoIP traffic i the PS domai is difficult because the VoIP service is sesitive to packet delay ad loss. Nevertheless, UEs expect higher voice service quality i LTE tha i CS domai based voice services i the existig cellular systems. Therefore, it is pivotal to satisfy the QoS requiremets of VoIP-based voice services i LTE. I geeral, the most importat objective of a multimedia service is the satisfactio of the ed UEs, i.e., their QoE. This is strictly related to the system s ability to provide for the applicatio flows a suitable QoS [3], geerally defied i terms of etwork delivery capacity ad resource availability (i.e. there should be limited packet loss ratios ad delays). The delay requiremets are tight i the multimedia services. As a example, i real-time multimedia services, ed-to-ed delay costraits i cotet delivery have to match the requiremets related to the huma perceptio of iteractivity. I wireless commuicatio the problem of lost packets attracted much attetio. Fortuately, with the itroductio of H-ARQ i LTE, the packet loss rate over the air iterface has bee greatly reduced (this has already bee proved usig 3GPP system simulatios). Besides, the problem of radio-resource scarcity has bee a importat issue. So, supportig VoIP i LTE ecouters the followig problems [4]: (1) The tight delay requiremet combied with the frequet arrival of small VoIP packets () The scarcity of radio resources alog with cotrol chael restrictios i LTE. Resource schedulig plays a key role i both cotrollig delay ad savig resources i LTE. Thus, desigig effective schedulig methods to meet the striget delay requiremets of VoIP ad solve the radio-resource scarcity problem i LTE is very urget. We cosider the dowlik of VoIP i this paper as there is far more dowlik traffic i the system tha uplik traffic, which causes the eed for dowlik optimizatio to be more urget. I this paper, our mai cotributios are as follows: APSIPA ASC 15

2 Proceedigs of APSIPA Aual Summit ad Coferece December 15 (1) A stochastic mathematical model is established with hard packet-delivery deadlie costraits. The model is proposed by limitig the delay withi a certai deadlie to meet the striget delay requiremets of VoIP. It also miimizes the total umber of radio resources used i a give period to solve the problem of radio-resource scarcity. () We desig a effective delay-limited (DL) algorithm by forecastig ad estimatig the future wireless chael coditios based o the kow actual chael coditios. Moreover, give a certai average trasmittig rate, we determie the maximum delay of a UE theoretically. (3) We simulate the DL schedulig algorithms, i compariso with M-LWDF ad EXP/PF algorithms. O this basis, we aalyse the effects of DL algorithm. The results demostrate that the DL algorithm has a beeficial effect o delay ad resource utilizatio. The remaider of this paper is orgaized as follows. Sectio II outlies other work related to schedulig i the VoIP service. Sectio III describes the dowlik resource allocatio i LTE, stated as a specific optimizatio problem, ad gives the mathematical model for the problem. Sectio IV presets the DL algorithm for VoIP service i LTE, ad determies theoretically the maximum delay of the UE with a certai average trasmissio rate. Sectio V gives the simulatio results obtaied usig the DL algorithm ad compares DL algorithm with M-LWDF ad EXP/PF algorithms. The fial part gives a summarizatio. II. RELATED WORK I the LTE system, resource schedulig for VOIP services is very importat ad challegig because of the cotiuous icrease i the demad for voice services ad the difficulty i satisfyig delay ad packet-droppig ratio requiremets. May algorithms for VoIP i LTE systems have bee desiged [5 1]. To date, the schedulig methods used for VoIP i LTE systems ca be divided ito three types: persistet schedulig, semipersistet schedulig, ad dyamic schedulig. A. Persistet Schedulig Persistet schedulig [5, 6] has bee proposed to reduce sigallig overheads i VoIP services. The idea behid persistet schedulig is to pre-allocate a sequece of frequecytime resources with a fixed MCS to a VoIP UE at the begiig of a specified period. This allocatio remais valid util the UE receives aother allocatio due to a chage i chael quality or the expiratio of a timer. A big disadvatage of such a scheme is the lack of flexibility i the time domai which may result i a problematic differece betwee allocated ad required resources. To reduce wastage whe a VoIP call does ot make full use of its allocated resources, two paired VoIP UEs ca share resources dyamically. Persistet schedulig always divides ad allocates the resources to specific groups of UEs, omittig the fadig i the commuicatio chael. This blid strategy is either effective or fair. B. Semi-persistet Schedulig Semi-persistet schedulig [7, 8] is a algorithm which ca reduce sigallig overheads ad icrease system capacity. I a semi-persistet schedulig algorithm, oly whe the UE equipmet creates a ew voice, ca it apply for resources ad it always occupies the same resource block (RB) i each ms. As VoIP is characterized by small size ad frequet ad regular arrival of data packets, the semi-persistet schedulig algorithm reduces the radio resources occupied by a large umber of schedulig sigals. However, as the UE requests i the semipersistet schedulig method are o a first-come first-served basis, this relatively fair schedulig scheme ca lead to takig up too may available radio resources caused by retrasmittig data associated with UEs with poor chael quality, thus reducig the overall radio resource utilizatio. C. Dyamic schedulig Dyamic schedulig is a geeral schedulig method. I radio resource schedulig for each basic RB uit, the scheduler allocates resources based o the resource request by the UE equipmet. Applicatio of this schedulig method to VOIP services i LTE causes a icreased cosumptio of radio resources. Typical dyamic schedulig algorithms iclude the pollig schedulig algorithm, the maximum carrier to iterferece ratio (MAX C/I) schedulig algorithm [9, 1], ad the proportioal fair (PF) schedulig algorithm [11]. I additio, scholars have proposed improved algorithms for maximum weight delay priority ad other ehaced algorithms, which, to some extet, ehace the performace of the dyamic schedulig. Recetly, a very thorough discussio of the related work i this field has bee reported i [1], ad EXP ad LOG rules have bee preseted as the most promisig approaches for dowlik schedulig i LTE systems with delay-sesitive applicatios. However, for VOIP i LTE, these improved dyamic schedulig algorithms have a limited scope to optimizatio busiess. I particular, the dyamic schedulig algorithms caot meet the striget delay requiremets of VoIP. Both the time ad frequecy domais ca be optimized usig dyamic algorithms, leadig to probably ideal schemes for the UE. I fact, the desig of a efficiet packet scheduler for a wireless system is a difficult task that typically ivolves a large umber of coflictig requiremets. These must be aalysed ad weighed-up before a balaced solutio ca be implemeted [13]. O the oe had, the scheduler must be efficiet i utilizig the available radio resources as the wireless spectrum is the most precious resource i the wireless commuicatio system. O the other had, services should be fairly scheduled so as to guaratee a certai level of service for UEs with bad chael coditios. Amog the various fairess criteria, proportioal fairess (PF) schedulig is widely cosidered as a good solutio because it provides a attractive trade-off betwee the maximum average throughput ad UE fairess. It does this by exploitig the temporal diversity ad gametheoretic equilibrium i a multi UE eviromet [14]. A typical PF scheduler oly cosiders the performace of a average system throughput ad fairess. Such a PF scheduler usually does ot cosider other QoS performace metrics, e.g. packetdroppig probability ad packet delay. The average delay APSIPA ASC 15

3 Proceedigs of APSIPA Aual Summit ad Coferece December 15 performace i multi UE OFDM was studied i [15]. However, the delay problem has ot bee effectively solved. Some schedulig strategies, such as M-LWDF [16] ad EXP/PF [17] algorithms which are ot origially desiged for OFDMA systems, guaratee the delay requiremets. The M-LWDF ad EXP/P algorithms have bee applied to LTE based o the assumptio that a strictly positive probability of discardig packets [18] is acceptable. Ad they have bee demostrated that they guaratee good throughput, little delay ad a acceptable level of fairess. However, ulike i other systems, i LTE, good throughput is ot equal to savig resources. As the tight delay requiremet ad savig resource are ot guarateed at the same time i most of the curret algorithms, we costruct a mathematical model ad desig a algorithm to meet the tight delay requiremet ad solve the problem of radioresource scarcity at the same time. This is the mai cotributio of this paper. III. PROBLEM STATEMENT AND MATHEMATICAL MODEL A. Dowlik Resource Allocatio i LTE I LTE [19 1], access to the radio spectrum is based o OFDM. The air iterface has bee desiged to use OFDM for the dowlik, i.e., from the evolved ode B (enb) to UEs. Radio resources are apportioed ito the time/frequecy domai. I the time domai, they are distributed every trasmissio time iterval (TTI), each oe lastig 1 ms. Furthermore, each TTI is composed of two time slots of.5 ms, correspodig to 7 OFDM symbols i the default cofiguratio with a short cyclic prefix. Te cosecutive TTIs form a LTE frame which lasts 1 ms. I the frequecy domai, the total badwidth is istead divided ito18 khz sub-chaels, each with 1 cosecutive ad equally-spaced OFDM sub-carriers. A time/frequecy radio resource, spaig over oe time slot of.5 ms i the time domai ad over oe sub-chael i the frequecy domai, is called a resource block (RB) ad correspods to the smallest radio resource uit that ca be assiged to a UE for data trasmissio. Note that as the sub-chael dimesio is fixed, the umber of sub-chaels varies accordig to the differet system badwidth cofiguratio. Portios of the spectrum should be distributed every TTI amog the UEs. Packet schedulers work i the time ad frequecy domai with a coarseess of oe TTI or oe RB, respectively. The fastest schedulig is required to be doe withi 1 ms accordig to the symbol legth of RB. At the base statio, i.e. the enb, the packet scheduler distributes radio resources amog UEs. The schedulig decisios are strictly related to the chael quality experieced by UEs. The dowlik resource schedulig, a resource allocatio process, refers to the system determiig whe ad what resources are available for the UE to trasfer data. The whole process ca be divided ito the followig sequece of operatios that are repeated: (1) The enb prepares the list of RBs which ca be scheduled i the curret TTI ad the seds it to the UEs. () Each UE decodes the referece sigals ad reports the chael quality to the enb which helps to estimate the quality of the dowlik chael. (3) The enb allocates resources usig a schedulig strategy depedig o whether the dowlik chael quality is good or bad. (4) The enb trasmits data i the dowlik chael accordig to the allocatio results. The UEs receive the data ad determie whether to sed a retrasmissio request idicatio. (5) The enb trasmits the ew or retrasmissio data. Now assume that whe a ew schedulig time tis reached, the first ad secod operatios ca be completed. I other words, the chael quality is kow at t. The mai problem is the third operatio. That is, desigig a effective schedulig strategy to allocate resources (which is the mai purpose of this paper). As we ca calculate chael trasmissio rate accordig to the chael coditio, we use trasmissio rate istead of chael coditio i the followig. B. Problem Restatemet To make the problem easier to solve, the followig assumptios are set out: (1)Each data packet ca be trasmitted after beig separated ito may parts. ()Each data packet ca be trasmitted successfully oe time. I other words, there are o trasmissio errors i the system. The lost packet is iserted ito the frot of the queue ad retrasmitted whe a trasmissio error happes. This will cause o problem for our algorithm. VoIP is characterized by the small size, frequet trasmissio, ad regular arrival of data packets. Based o these characteristics, we give aother assumptio (3) The time iterval of producig packet is already idetified ad kow, deoted by t (ms). For Iteret telephoy, a delay of 1 ms is cosidered as the limit for a good perceived quality, while the delay has to be less tha 3 ms for satisfactory quality []. I Ref. [3], for example, a delay of ms is cosidered for video iteractive applicatios. So, to meet the tight delay requiremets of VoIP i the LTE system, we limit the delay of each packet with a certai deadlie which is less ms accordig to the delay requiremets of each UE. The problem of radio-resource scarcity has bee a importat issue the wireless commuicatio facig. I LTE, the radio resource is divided ito some RBs i frequecy domai ad time domai. Moreover, each RB ca be oly used by oe UE. Therefore, to save radio resource for other service, we miimize the total umber of radio resources used i a certai period of time. Based o the assumptios, the problem ca be described strictly. There are N UEs which cotiue to produce data packets, ad R available RBs at each TTI to be allocated to UEs to trasmit packets. The time iterval of producig data packets for each UE is t. The rate that oe RB trasmits packets ad the size of the data packets are all radom. Each RB ca oly trasmit data packets for oe UE. The delay limit of UE is DL ms. Now, we eed to desig a method to schedule R APSIPA ASC 15

4 Proceedigs of APSIPA Aual Summit ad Coferece December 15 available RBs for N UEs i time T, ad the resources will be scheduled oce each TTI. Moreover, the method eeds to meet the followig three coditios: (1) The total umber of RBs used i T is as little as possible. () Each data packet of UE must be trasmitted successfully withi DL ms. programmig problems are NP-hard. Thus, we caot solve our problem i polyomial time. Cosequetly, we propose to use a heuristic algorithm to tackle this problem. IV. ALGORITHM AND ANALYSIS A. Delay-limited (DL) Schedulig Algorithm I part A, we trasform the radom problem to the determiistic problem by some assumptios. However those assumptios do ot always comply with the actual situatio. For example, i actual situatios, the rate after the scheduled time, ad the sizes of data packets are radom ad ot kow precisely. So to solve this problem, we have to desig a algorithm which ca be used i actual settigs. I this part, we will desig a olie algorithm which esures that every packet of user ca be trasmitted successfully withi DL ms at a high resource utilizatio rate. From Sectio III.C, we kow that the proposed optimizatio problem is a large-scale 1 iteger liear radom programmig problem, which are NP-hard. Thus, we caot precisely solve the problem i polyomial time. Cosequetly, we propose to use a heuristic algorithm to tackle this problem. I this sectio, we desig a algorithm which esures that every packet of UE ca be trasmitted successfully withi DL at a high resource utilizatio rate. The mai idea of the algorithm is to first forecast UE s average trasmittig rate i the ext TTI usig the kow trasmittig rates ad the choose some data packets of UEs whose chael coditios are very good to be trasmitted together. I order to itroduce our algorithm more clearly, we explai the mea of some symbols appear i the algorithm i TABLE I followig. C. Mathematical Model We formulate the mathematical model of the above optimizatio problem as follows: Symbol explaatio: N: Total umber of UEs R: Total umber of available RBs at each time T: Total time DL : Delay limit of UE. x,i,t,r : The proportio of the ith packet accoutig at RB whe the ith data packet produced by UE is trasmitted at time t by the rth RB y,t,r : If the rth RB trasmits UE s data packets at time tit equals to 1, else it equals to v,t,r : The rate of the rth RB trasmittig UE s data packet at time t c,i : The size of the ith data packet produced by UE Mathematical modeli N T R Mi y ( v), t, r 1t 1 r 1 Such that N y 1,t, r 1, ( i 1) t DL R t ( i 1) t r 1 t, r (1) x x,i,t, r,i,t, r v,t,r c,i,, i () TABLE I EXPLANATION OF THE SYMBOLS USED IN ALGORITHM 1 y,t, r,, t, r (3) Symbols i x,i,t, r [,1] y,t,r {,1} v(, r, t ) (4) Where v {v,t,r } ad c {c,i } are radom variables ad v,t 1,,..., N i 1,,... t,1,,..., T r 1,,..., R. The goal is to miimize the total umber of RGBs used i time T usig a objective fuctio depedig o the radom variable v. Eq. (1) esures that each RB ca oly trasmit data packets for oe UE. Eq. () idicates that the size of UE s data trasmitted i the time iterval (i 1) t,(i 1) t DL i 1,,...,t r v schedulig time is t The average rate of v, t with respect to time t. It will be updated usig the formula v U b must ot be less tha the size of the ith data packet of UE. This esures that each data packet for UE must be trasmitted withi DL ms. As v ad c are radom variables, Eq. () is, i essece, a radom costrait. Eq. (3) idicates that the data trasmitted by oe RB must be less tha the largest amout of data that the RB ca trasmit. The model has RNT T t variables ad RT N 1 T t RNT costraits. Obviously, this is a 1 large-scale iteger liear radom programmig problem. Geerally speakig, iteger liear Meaig The trasmissio rate of the rth RB trasmittig the data packet of UE at time t(kow oly after the schedulig time t 1 ) The average rate of UE with respect to RB at time t, calculated usig v v(, r, t ) R oly whe the s The size of data of UE m The size of a ew data packet produced by UE, it ca be updated whe the schedulig time reaches the time whe a ew packet is produced The curret maximum delay of data packets ot trasmitted to UE The umber of RBs that UE eeds i the ext t m The total umber of RBs that will be scheduled i the ext k 4 av (1 a)v,t,where a is a adjustable costat The set of UEs that eed RBs t APSIPA ASC 15

5 Proceedigs of APSIPA Aual Summit ad Coferece December 15 m e tv The umber of RBs that will be scheduled at each time i the ext t The time iterval for schedulig resources i the ext The ext schedulig time Note: Except, other symbols i Table I are related with the schedulig time ad they are updated as the schedulig. tt v(, r, t) The algorithm icludes the followig steps: Step1. Forecast each UE s average rate i the ext time whe a ew data packet is produced. for UE =1 to N do Calculate v, v(, r, t) R t Update v av (1 a) v, ed for r t t t at the Where a is a adjustable costat, ad its value is i the iterval [, 1]. What a s specific value is does ot affect the algorithm. The optimal value of a ca be got with statistics o a large amout of data. Step. Judge ad choose the UEs that eed some RBs i the ext t. for UE = 1 to N do Update if v b the Put Update b b s or k ( DL t 1)* t ito U k else Update k k t ed if ed for Where the UEs whose average trasmissio rate is less tha the amout of data or delay time is close to delay limit are chose to get RBs i the ext. Step3. Estimate the umber of RBs that eeds to be scheduled i the ext t accordig to the average rate, ad fid the umber ext t. for UE U t m e of RBs that will be scheduled at each TTI of the do Calculate m b v ed for Calculate m m if m 1, t else m 1 ed if U m the m e, t t e, tv m tv 1 Where the umber the ext t is the sum of umber of RBs eeded by UEs that m of RBs that eeds to be scheduled i delay of UE s data packet ad UE s average trasmissio rate v is as follows: are chose i step. The let it be assiged to each TTI of the ext t averagely to get the umber. Step4. With the largest rate method, assig me RBs to those UEs chose i Step at each TTI of the ext t. for i = 1 to m e if U the do Fid out the biggest rate Where the largest rate method is to assig oe RB to the UE who eeds RBs ad has biggest trasmit rate with the RB. Based o the four steps above, we propose Delay-limited (DL) schedulig algorithm as followig: B. Algorithm Aalysis v max The core idea of the DL algorithm above is delay limitig. Actually, we ca prove that limitig is implemeted i the DL algorithm usig the followig theorem. Theorem: Let the size of all the data packets be.the, if the DL algorithm is feasible, the relatio betwee the biggest (1) If v s, the maximum delay of the UE is less tha or equal to t m e from V { v(, r, t) U, r 1,..., R}, deote the UE correspodig to v max by max ad the RB b r max Schedule the r max th RB to the UE max Update b b v v( max, rmax, t), if m v max max max max, m 1 max 3 b max, t max Update ed if if m ed if ed if ed for m max max ad DL k 1 t the get out UE max the from U Algorithm1: Delay-limited (DL) schedulig algorithm: Iitializatio: Let U. s = size of the first data packet produced by UE. Let v v,, b s, {1,...,N} t k, for time = to T do Call Step 1 if t is the time of a ew data packet beig produced, the Call Step Call Step 3 ed if if is the time of ew data packet beig produced or, the Call Step 4 ed if tt t tv ed for t s t tt APSIPA ASC 15

6 Proceedigs of APSIPA Aual Summit ad Coferece December 15 We simulate the DL schedulig algorithm usig real data from the Huawei Compay. The data cosist of the trasmissio rates of some UEs with 16 RBs available i 1 ms. Accordig to the actual situatio, we set t ms, ad the same size s 4 bit for all packets. We also set the same delay limit for all UEs DL 14 ms. I order to successfully simulate the situatio, we let the data packets be produced i the first 86 ms, ad o data packets are allowed to be produced i the fial 14 ms. As a result, the total umber of data packets beig produced by each UE is 44. Based o the above assumptios, we make the followig simulatios: () If v s ad v s t DL, the maximum delay of the UE is less tha or equal to v s t (3) If v s ad v s t DL, the maximum delay of the UE is less tha or equal to DL. Proof: For a arbitrary UE, let its arbitrary data packet be produced at time t. Let the average trasmissio rate of the UE be v ad the size of each data packets be s. Ad let the data 3 ot trasmitted of the previous data packet be bs, thus v bs. D. Schedulig Results of DL Algorithm For compariso purposes, we solve mathematical model I i Sectio III.C usig CPLEX software whose result is close to the optimal solutio ad simulate the DL algorithms with the followig three differet cases: Case1.1: T = 1 N = 19 R = 16 Case1.: T = 1 N = 19 R = 3 Case1.3: T = 1 N = 1 R = 16. The results are show i Table II. So (1)If v s, accordig to the DL algorithm, each data packet ca be scheduled i a RB withi t after it is produced. Moreover, despite bs icrease after each t ms, i all 3 time v bs, so bs / 3v v s. Thus, each data packet ca be trasmitted successfully withi t after it is produced, that is, the maximum delay is t. () If v s ad v s t DL for a particular data TABLE II TOTAL NUMBER OF RBS USED OF TWO METHODS packet whose productio time is t, the accordig to the DL algorithm, the latest iterval it ca be scheduled i is t v s 1 t, t v s t. For v s, it ca be scheduled Case1.1 Case1. Case1.3 completely, so the data packet ca be scheduled successfully withi v s t after it was produced, ad the maximum delay is v s t Total umber of RBs scheduled DL algorithm CPLEX method As show i Table II, the total umber of RBs scheduled by DL algorithm is oly about 3% larger tha usig solvig the mathematic model directly. This idicates that the forecastig ad estimatio of the chael coditios are feasible ad reasoable. Also, the DL algorithm takes the smallest amout of time to ru, which shows that the DL algorithm is both feasible ad effective. So, combiig together the feasibility, effectiveess, ad actual situatio cosidered, the DL algorithm is reasoable. I order to better uderstad the schedulig results of the DL algorithm, we simulate the DL algorithm usig the data of Case 1.. I Table III, we show explicitly the umber of RBs used by each UE, the average delay ad maximum delay of each UE with a certai average trasmissio rate.. (3) If v s ad v s t DL, accordig to the DL algorithm, the data packet produced at time t will be scheduled at the latest i [t DL t t DL ], so the maximum delay is DL. V. SIMULATION AND RESULT The key performace idicators of the algorithm give i this paper are the delay of each UE ad the extet of savig radio resource. So, i this sectio, we aalyse ad evaluate the performace of the DL schedulig algorithm by simulatio results. TABLEIII SCHEDULING RESULT FOR 19 UES USING THE DL ALDORITHM Average trasmissio rate (bit) Number of RBs used UE Average delay (ms) Max. delay (ms) UE APSIPA ASC 15

7 Proceedigs of APSIPA Aual Summit ad Coferece December 15 Average trasmissio rate (bit) Number of RBs used Average delay (ms) Max. delay (ms) As ca be see from Table III, the umber of RBs scheduled for the UEs decreases with icreasig average trasmissio rate. This is i lie with the actual situatio i which a UE with good chael coditios eeds fewer resources to trasmit the same amout of data. Besides, Table III also shows that the maximum delay for each UE is far less tha 14 ms, which proves that the DL algorithm ca guaratee the delay limit. Moreover, Table III shows that the average delay of each UE is less tha 14/ ms, which demostrates that the DL algorithm has a good effect o delay. E. Effect of the DL Algorithm o Delay As the delay is oe of the key issues of the VOIP services i LTE, we aalyse the effect of delay of the DL algorithm i the ext subsectio. From Table III, we kow that the average delay for each UE is less tha 14/ ms, which meas that the DL algorithm has a good effect o delay. Next, we ivestigate the stability of the delay resultig from the DL algorithm. First, we cosider the distributio of the data packets with differet delays for each UE (see Fig. 1). For the sake of coveiece, the delay is divided ito the followig three rages: Rage 1: the delay is less tha the average delay mius ms Rage : the delay is withi ms of the average delay Rage 3: the delay is larger tha the average delay plus ms delay is i the rage 1 delay is i the rage delay is i the rage 3 umber of packes UE Fig.1. The distributio of packets for each UE accordig to their delay with respect to the average delay. As ca be see from Fig. 1, the delays of most data packets fall i Rage. I other words, the delays of most data packets are close to the average delay, which idicates that data packets with larger delays are relatively rare. I fact, further calculatios show that the ratio of the umber of late data packets to the total umber is less tha. for all UEs. Besides, Fig. 1 also shows that the delays of the data packets for each UE are stable. Next we cosider the distributio of the maximum delay i the etire system, as show i Fig.. maximum delay of packets trasmitted successfully schedulig time Fig..The maximum delay of the packets trasmitted completely at each time slot APSIPA ASC 15

8 Proceedigs of APSIPA Aual Summit ad Coferece December 15 Fig. shows the maximum delay of the packets that were trasmitted completely at schedulig time t i the etire time domai. From the figure, we see that the maximum delay is maily cocetrated i the rage 8 ms i the time domai. This is a good idicatio that the delay i the system as a whole is small ad stable. F. Effect o Resource Utilizatio of the DL Algorithm As stated i the itroductio, the scarcity of radio resources is oe of the major problems the VOIP services ecouter i schedulig resources. So, usig a few resources ad havig a high resource utilizatio rate must be achieved for a good schedulig algorithm. Next, we will show the effect of the DL algorithm o resource utilizatio. From Table II, we kow that the total umber of RBs scheduled usig the DL algorithm is oly about 3% more tha TABLE IV the optimal solutio, which idicates that the DL algorithm has a good effect o savig resources. Next we cosider the resource utilizatio rate. Let CA TD be the total size of all data packets of UE, ad let be the total size of data that the RBs assiged to UE ca trasmit. We defie resource utilizatio rate RU TD CA RESOURCE UTILIZATION RATE OF EACH UE RU of UE with the formula I the simulatios above, * TD T DL t s = 1 14 * 4 = 17,6. The, accordig to the data i Table III, we ca get the RU rate for each UE. The results are show i Table IV. UE RU UE RU As Table IV shows, the RUs of all the UEs are almost larger tha.9, meaig that whe a RB is scheduled to oe UE, it is fully utilized. Thus, the waste of resources is very little. The results therefore show that the DL algorithm has a high resource utilizatio. Next, we demostrate that the DL algorithm ot oly esures a high resource utilizatio, but also has good uiformity across the etire time domai ad stability at ay particular time. umber of RBs scheduled umber of RBs scheduled schedulig time (a) R= schedulig time (b) R=1 Fig.3. The umber of RBs scheduled at each TTI. Fig. 3 shows the umber of RBs scheduled at time t whe the total umber (R) of RBs available at each TTI is equal to 3 ad 1. From the figure, we ca see that the umber of RBs scheduled is uiformly distributed over the etire time domai. I additio, comparig Fig. 3(a) with 3(b), we ca see that the umbers of RBs scheduled at each TTI i these two figures are almost the same. I other words, the umber of RBs scheduled almost remais costat with the additio of available RBs. This idicates that the schedulig of the DL algorithm is stable i the etire system, ad this also icreases the likelihood of more UEs joiig the system. G. Compare the DL Algrithm with M-LWDF ad EXP/PF Algrithms I the last three parts of this sectio, we aalyse ad evaluate the performace of the DL schedulig algorithm. I order to APSIPA ASC 15

9 Proceedigs of APSIPA Aual Summit ad Coferece December 15 show the performace of the DL schedulig algorithm, we compare it with M-LWDF ad EXP/PF algorithms have bee proved to be better schedulig algorithms for VOIP i LTE ad have a good effect o delay. We simulate the DL, M-LWDF ad EXP/PF algorithms i the followig three differet cases: Case.1: T = 1 N = 19 R = 3 Case.: T = 1 N = 8 R = 3 Case.3: T = 1 N = 8 R = 5. The results are show i Table V. TABLE V SCHEDULING RESULT OF THREE ALGORITHMS The umber of RB scheduled i T Case.1 DL algorithm M-LWDF algorithm EXP/PF algorithm Case Case As ca be see from Table V, the umber of RBs scheduled usig DL algorithm is far less tha usig M-LWDF ad EXP/PF algorithms. Moreover, whe the total time (T) ad total umber (N) of UEs do t vary while the umber(r) of available RBs icreases, the umber of RBs scheduled by DL algorithm has o sigificat chage, but the umbers of RBs scheduled by M-LWDF ad EXP/PF algorithms substatially icrease. This demostrates that the DL algorithm does effectively esure that the umber of RBs used is as little as possible. As is kow, savig resources ot oly requires the umber of RBs used to be as little as possible, but also eeds full use of each RB. I order to aalyse the extet of usig each RB, we show the RU of each UE usig DL, M-LWDF ad EXP/PF algorithms with the result of Case. i Figure 4. As show i Fig. 4, the RU of each UE usig DL algorithm is larger tha.9, which is almost equal to the maximum RU of all UEs usig LWDF ad EXP/PF algorithms. This demostrates that our DL algorithm makes full use of each RB, which is better tha the other two algorithms. As the above aalysis shows, the DL algorithm ca ot oly make the umber of scheduled RBs to be very little, but also esure each RB to be used fully. 1.9 the resource utilizatio rate of each UE DL.1 M-LWDF EXP DF the 8 UEs Fig. 4.The RU of each UE usig DL, M-LWDF ad EXP/PF algorithms 8 7 the average delay of each UE DL M-LWDF EXP DF the 8 UEs Fig. 5. The average delay of each UE usig DL, M-LWDF ad EXP/PF algorithms I Part A, we aalyse the effect o delay of DL algorithm through compariso with M-LWDF ad EXP/PF algorithms. We aalyse the fairess by showig average delay of each UE usig DL, M-LWDF ad EXP/PF algorithms i Fig APSIPA ASC 15

10 Proceedigs of APSIPA Aual Summit ad Coferece December 15 As ca be see from Fig. 5, whe cosidered as a whole, the average delay of each UE usig DL algorithm is ot bigger tha usig M-LWDF ad EXP/PF algorithms. Moreover, we ca see that the gap of the average delay i differet UEs usig DL algorithm is less tha usig M-LWDF ad EXP/PF algorithms, showig that the DL algorithm has a better fairess for all UEs o delay. By these facts, we ca see that the DL algorithm has a good effect o fairess. VI. CONCLUSIONS I this paper, we costruct a mathematical model ad propose a efficiet VoIP packet schedulig algorithm for VoIP i LTE. The cores of our model ad algorithm are to meet the striget delay requiremets of VOIP by limitig the delay with a certai deadlie ad to solve the problem of scarcity of radio resources by miimizig the total umber of radio resources scheduled i a certai period of time. As a result of applyig our algorithm, we are able to esure a high QOE for every UE ad a high resource utilizatio rate. By coductig the simulatios for our algorithm ad comparig it with M- LWDF ad EXP/PF algorithms, we foud that our algorithm has a good effect o both delay ad resource utilizatio. ACKNOWLEDGMENT This work is supported by the Natioal 973 Pla project uder Grat No. 11CB769, the Natioal 863 Pla project uder Grat No.11AA1A1, the NSF of Chia (113311, ), the "Strategic Priority Research Program" of the Chiese Academy of Scieces (XDA613), ad Huawei Techology Co. Ltd. REFERENCES [1] 3G Americas, HSPA to LTE Advaced: 3GPP Broad bad Evolutio to IMT Advaced, RYSAVY Research Rep. Sept. 9. [] S. Ahmadi, A Overview of Next-Geeratio Mobile WiMAX Techology, IEEE Commu. Mag. Vol. 47, o. 6, Jue 9, pp [3] S. Khirma ad P. Herikse, Relatioship betwee quality-of-service ad quality-of-experiece for public iteret service, i Proc. Passive ad Active Measuremet PAM, Fort Collis, CO, Mar.. [4] Bag Wag et al, Performace of VoIP o HSDPA, IEEE VTC, Vol.4: , May 5. [5] 3GPP TSG RAN WG1 Meetig #47, R1-6375, Discussio o cotrol sigallig for persistet schedulig of VoIP, Riga, Latvia, November 6 1, 6. [6] 3GPP TSG RAN WG1 Meetig #47bis, R1-798, Persistet Schedulig i E-UTRA, Sorreto, Italy, Jauary 15 19, 7. [7] Dajie Jiag, Haimig Wag, EsaMalkamaki. Priciple ad Performace of Semi-persistet Schedulig for VoIP i LTE System, i Iteratioal Coferece o Wireless Commuicatios, Networkig ad Mobile Computig, 7. [8] Jihua Liu, Chujig Hu, Zhagchao Ma, Semi-Persistet Schedulig for VoIP Service i the LTE-Advaced Relayig Networks IEEE ICCCAS, 1. [9] Ericsso, N.S, Adaptive modulatio ad schedulig of IP traffic over fadig chaels, VTC 1999-Fall. IEEE VTS 5th, 1999(): [1] Lag T J, Williams E A, Crossley W A. Average ad Maximum Revisit Time Trade Studies For Satellite Costellatio Usig a Multiobjective Geetic Algorithm [J]. JOURNAL of Astroautical Scieces, 1, 49<3>: [11] Kia Chug Beh, Armour, S. ad Doufexi, A. Joit Time-Frequecy Domai Proportioal Fair Scheduler with HARQ for 3GPP LTE systems. Vehicular Techology Coferece, 8.VTC 8-Fall. IEEE 68th, 8: 1-5. [1] Bilal Sadiq, Seug Ju Baek, Member. Delay-Optimal Opportuistic Schedulig ad Approximatios: The Log Rule. IEEE: 13. [13] I. F. Akyildiz, D. A. Levie, ad I. Joe, A slotted CDMA protocol with BER schedulig for wireless multimedia etworks, IEEE/ACM Tras. Netw., vol. 7, o., pp , Apr [14] F. Kelly, Chargig ad rate cotrol for elastic traffic, Eur. Tras. Telecommu, vol. 8, o. 1, pp , Ja [15] H. Kim ad Y. Ha, A proportioal fair schedulig for multicarrier trasmissio systems, IEEE Commu. Lett, vol. 9, o. 3, pp. 1 1 Mar. 5. [16] M. Adrews, K. Kumara, K. Ramaa, A. Stolyar, P. Whitig, ad R. Vijayakumar, Providig quality of service over a shared wireless lik, IEEE Commu. Mag., vol. 39, o., pp , Feb. 1. [17] H. Ramli, R. Basukala, K. Sadrasegara, ad R. Patachaiaad, Performace of well-kow packet schedulig algorithms i the dowlik 3GPP LTE system, i Proc. of IEEE Malaysia Iteratioal Cof. o Comm., MICC, Kuala Lumpur,Malaysia, 9, pp [18] F Capozzi, G Piro, La Grieco, G boggia, P Camarda, Dowlik packet schedulig i lte cellular etworks: Key Desig Issues ad A survey, IEEE Commu. Surv. Tutorials, 1. [19] 3GPP, Techical Specificatios Group Radio Access Network -Physical chael ad Modulatio (release 8), 3GPP TS [] Giuseppe Piro, Luigi Grieco, Gearo Boggia, etc. Two-level dowlik schedulig for real-time multimedia services i LTE etworks. IEEE Tras. o Multimedia, vol.13, o.5, Oct. 11. [1] Davider Sigh, Preeti Sigh, Radio Resource Schedulig i 3GPP LTE: A Review IJETT, 13. [] S. Na ad S. Yoo, Allowable propagatio delay for VoIP calls of acceptable quality, i Proc. 1st It. Workshop Advaced Iteret Services ad Applicatios, Spriger-Vorlage, Lodo, U.K.,, pp [3] G.-M. Su, Z. Ha, M. Wu, ad K. Liu, Joit uplik ad dowlik optimizatio for real-time multiuser video streamig over WLANs, IEEE J. Sel. Topics Sigal Process, vol. 1, o., pp. 8 94, Aug APSIPA ASC 15

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

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

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

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

Selective Periodic Component Carrier Assignment Technique in LTE and LTE-A Systems

Selective Periodic Component Carrier Assignment Technique in LTE and LTE-A Systems Selective Periodic Compoet Carrier Assigmet Techique i LTE ad LTE-A Systems Husu S. Narma ad Mohammed Atiquzzama School of Computer Sciece, Uiversity of Oklahoma, Norma, OK 73019 Email: {husu, atiq}@ou.edu

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

Radar emitter recognition method based on AdaBoost and decision tree Tang Xiaojing1, a, Chen Weigao1 and Zhu Weigang1 1

Radar emitter recognition method based on AdaBoost and decision tree Tang Xiaojing1, a, Chen Weigao1 and Zhu Weigang1 1 Advaces i Egieerig Research, volume 8 d Iteratioal Coferece o Automatio, Mechaical Cotrol ad Computatioal Egieerig (AMCCE 7) Radar emitter recogitio method based o AdaBoost ad decisio tree Tag Xiaojig,

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

LETTER A Novel Adaptive Channel Estimation Scheme for DS-CDMA

LETTER A Novel Adaptive Channel Estimation Scheme for DS-CDMA 1274 LETTER A Novel Adaptive Chael Estimatio Scheme for DS-CDMA Che HE a), Member ad Xiao-xiag LI, Nomember SUMMARY This paper proposes a adaptive chael estimatio scheme, which uses differet movig average

More information

Spread Spectrum Signal for Digital Communications

Spread Spectrum Signal for Digital Communications Wireless Iformatio Trasmissio System Lab. Spread Spectrum Sigal for Digital Commuicatios Istitute of Commuicatios Egieerig Natioal Su Yat-se Uiversity Spread Spectrum Commuicatios Defiitio: The trasmitted

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

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

Design of FPGA Based SPWM Single Phase Inverter

Design of FPGA Based SPWM Single Phase Inverter Proceedigs of MUCEET2009 Malaysia Techical Uiversities Coferece o Egieerig ad Techology Jue 20-22, 2009, MS Garde,Kuata, Pahag, Malaysia MUCEET2009 Desig of FPGA Based SPWM Sigle Phase Iverter Afarulrazi

More information

Subcarriers and Bits Allocation in Multiuser Orthogonal Frequency Division Multiplexing System

Subcarriers and Bits Allocation in Multiuser Orthogonal Frequency Division Multiplexing System Sesors & Trasducers, Vol. 168, Issue 4, April 014, pp. 10-15 Sesors & Trasducers 014 by IFSA Publishig, S. L. http://www.sesorsportal.com Subcarriers ad Bits Allocatio i Multiuser Orthogoal Frequecy Divisio

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

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

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

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

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

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

ECONOMIC LOT SCHEDULING

ECONOMIC LOT SCHEDULING ECONOMIC LOT SCHEDULING JS, FFS ad ELS Job Shop (JS) - Each ob ca be differet from others - Make to order, low volume - Each ob has its ow sequece Fleible Flow Shop (FFS) - Limited umber of product types

More information

Data Acquisition System for Electric Vehicle s Driving Motor Test Bench Based on VC++ *

Data Acquisition System for Electric Vehicle s Driving Motor Test Bench Based on VC++ * Available olie at www.sciecedirect.com Physics Procedia 33 (0 ) 75 73 0 Iteratioal Coferece o Medical Physics ad Biomedical Egieerig Data Acquisitio System for Electric Vehicle s Drivig Motor Test Bech

More information

ROBUST RADIO RESOURCE ALLOCATION IN LTE NETWORKS BY CHANNEL AND RELAY ASSIGNMENT

ROBUST RADIO RESOURCE ALLOCATION IN LTE NETWORKS BY CHANNEL AND RELAY ASSIGNMENT Joural of Egieerig Sciece ad Techology Vol. 12, No. 7 (2017) 1845-1854 School of Egieerig, Taylor s Uiversity ROBUST RADIO RESOURCE ALLOCATION IN LTE NETWORKS BY CHANNEL AND RELAY ASSIGNMENT R. SANTHAKUMAR*,

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

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

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

NEXT GENERATION WIRELESS LAN SYSTEM DESIGN 1. Chutima Prommak, Joseph Kabara, David Tipper, Chalermpol Charnsripinyo

NEXT GENERATION WIRELESS LAN SYSTEM DESIGN 1. Chutima Prommak, Joseph Kabara, David Tipper, Chalermpol Charnsripinyo NEXT GENERATION WIRELESS LAN SYSTEM DESIGN Chutima Prommak, Joseph Kabara, David Tipper, Chalermpol Charsripiyo Departmet of Iformatio Sciece & Telecommuicatios 35 N. Bellefield ave., Uiversity of Pittsburgh,

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

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

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

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

ISSN (Print) Research Article. *Corresponding author Oleksandr V. Lemeshko

ISSN (Print) Research Article. *Corresponding author Oleksandr V. Lemeshko Scholars Joural of Egieerig ad Techology (SJET) Sch. J. Eg. Tech., 06; 4(4):69-74 Scholars Academic ad Scietific Publisher (A Iteratioal Publisher for Academic ad Scietific Resources) www.sasublisher.com

More information

Intermediate Information Structures

Intermediate Information Structures Modified from Maria s lectures CPSC 335 Itermediate Iformatio Structures LECTURE 11 Compressio ad Huffma Codig Jo Roke Computer Sciece Uiversity of Calgary Caada Lecture Overview Codes ad Optimal Codes

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

A Radio Resource Allocation Algorithm for QoS Provision in PMP-based Systems

A Radio Resource Allocation Algorithm for QoS Provision in PMP-based Systems 530 OURAL OF COMMUICATIOS, VOL. 5, O. 7, ULY 00 A Radio Resource Allocatio Algorithm for QoS Provisio i PMP-based Systems Pig Wag Broadbad Wireless commuicatios ad Multimedia laboratory, Key Laboratory

More information

Comparison of Frequency Offset Estimation Methods for OFDM Burst Transmission in the Selective Fading Channels

Comparison of Frequency Offset Estimation Methods for OFDM Burst Transmission in the Selective Fading Channels Compariso of Frequecy Offset Estimatio Methods for OFDM Burst Trasmissio i the Selective Fadig Chaels Zbigiew Długaszewski Istitute of Electroics ad Telecommuicatios Pozań Uiversity of Techology 60-965

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

Mixed Contiguous and Aggregated Spectrum Allocation Algorithm for CR based TD-LTE System

Mixed Contiguous and Aggregated Spectrum Allocation Algorithm for CR based TD-LTE System Commuicatios ad etwork, 2013, 5, 298-302 http://dx.doi.org/10.4236/c.2013.532055 Published Olie September 2013 (http://www.scirp.org/oural/c) ixed Cotiguous ad Aggregated Spectrum Allocatio Algorithm for

More information

Design of FPGA- Based SPWM Single Phase Full-Bridge Inverter

Design of FPGA- Based SPWM Single Phase Full-Bridge Inverter Desig of FPGA- Based SPWM Sigle Phase Full-Bridge Iverter Afarulrazi Abu Bakar 1, *,Md Zarafi Ahmad 1 ad Farrah Salwai Abdullah 1 1 Faculty of Electrical ad Electroic Egieerig, UTHM *Email:afarul@uthm.edu.my

More information

HOW BAD RECEIVER COORDINATES CAN AFFECT GPS TIMING

HOW BAD RECEIVER COORDINATES CAN AFFECT GPS TIMING HOW BAD RECEIVER COORDINATES CAN AFFECT GPS TIMING H. Chadsey U.S. Naval Observatory Washigto, D.C. 2392 Abstract May sources of error are possible whe GPS is used for time comparisos. Some of these mo

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

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

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

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

Resource Allocation in Downlink MIMO-OFDMA with Proportional Fairness

Resource Allocation in Downlink MIMO-OFDMA with Proportional Fairness 8 JOURAL OF COUICATIOS VOL. 4 O. FERUARY 009 Resource Allocatio i Dowli IO-OFDA with Proportioal Fairess i Da ad Chi Chug o Departmet of Electrical ad Computer Egieerig atioal Uiversity of Sigapore Email:{dabi

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

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

Cancellation of Multiuser Interference due to Carrier Frequency Offsets in Uplink OFDMA

Cancellation of Multiuser Interference due to Carrier Frequency Offsets in Uplink OFDMA Cacellatio of Multiuser Iterferece due to Carrier Frequecy Offsets i Upli OFDMA S. Maohar, V. Tiiya, D. Sreedhar, ad A. Chocaligam Departmet of ECE, Idia Istitute of Sciece, Bagalore 56001, INDIA Abstract

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

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

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

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

Joint Resource Allocation Scheme for Device-To-Device Communication under a Cellular Network

Joint Resource Allocation Scheme for Device-To-Device Communication under a Cellular Network BULGARIAN ACAEMY OF SCIENCES CYBERNETICS AN INFORMATION TECHNOLOGIES Volume 15, No 6 Special Issue o Logistics, Iformatics ad Service Sciece Sofia 015 Prit ISSN: 1311-970; Olie ISSN: 1314-4081 OI: 10.1515/cait-015-0070

More information

A Reduced Complexity Channel Estimation for OFDM Systems with Precoding and Transmit Diversity in Mobile Wireless Channels Hlaing Minn, Dong In Kim an

A Reduced Complexity Channel Estimation for OFDM Systems with Precoding and Transmit Diversity in Mobile Wireless Channels Hlaing Minn, Dong In Kim an A Reduced Complexity Chael Estimatio for OFDM Systems with Precodig ad Trasmit Diversity i Mobile Wireless Chaels Hlaig Mi, Dog I Kim ad Vijay K. Bhargava Departmet of Electrical ad Computer 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

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

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

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

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

Message Scheduling for the FlexRay Protocol: The Dynamic Segment

Message Scheduling for the FlexRay Protocol: The Dynamic Segment IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 1 Message Schedulig for the FlexRay Protocol: The Dyamic Segmet Ece Gura Schmidt, Member, IEEE, Klaus Schmidt Abstract The FlexRay commuicatio protocol is expected

More information

ECE 333: Introduction to Communication Networks Fall Lecture 4: Physical layer II

ECE 333: Introduction to Communication Networks Fall Lecture 4: Physical layer II ECE 333: Itroductio to Commuicatio Networks Fall 22 Lecture : Physical layer II Impairmets - distortio, oise Fudametal limits Examples Notes: his lecture cotiues the discussio of the physical layer. Recall,

More information

Novel pseudo random number generation using variant logic framework

Novel pseudo random number generation using variant logic framework Edith Cowa Uiversity Research Olie Iteratioal Cyber Resiliece coferece Cofereces, Symposia ad Campus Evets 011 Novel pseudo radom umber geeratio usig variat logic framework Jeffrey Zheg Yua Uiversity,

More information

A NEW DISCRETE HARTLEY TRANSFORM PRECODING BASED INTERLEAVED-OFDMA UPLINK SYSTEM WITH REDUCED PAPR FOR 4G CELLULAR NETWORKS

A NEW DISCRETE HARTLEY TRANSFORM PRECODING BASED INTERLEAVED-OFDMA UPLINK SYSTEM WITH REDUCED PAPR FOR 4G CELLULAR NETWORKS Joural of Egieerig Sciece ad Techology Vol. 6, No. 6 (211) 685-694 School of Egieerig, Taylor s Uiversity A NEW DISCRETE HARTLEY TRANSFORM PRECODING BASED INTERLEAVED-OFDMA UPLINK SYSTEM WITH REDUCED PAPR

More information

Evaluation of turbulent parameters based on angle-of-arrival fluctuation Yang LI 1,Chao GAO 2, Yi-Ming LI 2, Gang YANG 2 & Xiao-Feng LI 2

Evaluation of turbulent parameters based on angle-of-arrival fluctuation Yang LI 1,Chao GAO 2, Yi-Ming LI 2, Gang YANG 2 & Xiao-Feng LI 2 Iteratioal Coferece o Iformatio Techology ad Maagemet Iovatio (ICITMI 15) Evaluatio of turbulet parameters based o agle-of-arrival fluctuatio Yag LI 1,Chao GAO, Yi-Mig LI, Gag YANG & Xiao-Feg LI 1 Accoutig

More information

Ch 9 Sequences, Series, and Probability

Ch 9 Sequences, Series, and Probability Ch 9 Sequeces, Series, ad Probability Have you ever bee to a casio ad played blackjack? It is the oly game i the casio that you ca wi based o the Law of large umbers. I the early 1990s a group of math

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

Throughput/Delay Analysis of Spectrally Phase- Encoded Optical CDMA over WDM Networks

Throughput/Delay Analysis of Spectrally Phase- Encoded Optical CDMA over WDM Networks Throughput/Delay Aalysis of pectrally Phase- Ecoded Optical over etwors K. Putsri *,. ittichivapa * ad H.M.H.halaby ** * Kig Mogut s Istitute of Techology Ladrabag Departmet of Telecommuicatios Egieerig,

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

Subscriber Pulse Metering (SPM) Detection

Subscriber Pulse Metering (SPM) Detection Subscriber Pulse Meterig () Detectio Versatile telephoe call-charge ad security fuctios for PBX, Payphoe ad Pair-Gai applicatios - employig CML s family of 12kHz ad 16kHz ICs INNOVATIONS INV/Telecom//1

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

Joint Rate Control and Scheduling for Real-Time Wireless Networks

Joint Rate Control and Scheduling for Real-Time Wireless Networks Joit Rate Cotrol ad Schedulig for Real-Time Wireless Networks Shuai Zuo, I-Hog Hou, Tie Liu, Aathram Swami, ad Prithwish Basu Abstract This paper studies wireless etworks with multiple real-time flows

More information

Implementation of Fuzzy Multiple Objective Decision Making Algorithm in a Heterogeneous Mobile Environment

Implementation of Fuzzy Multiple Objective Decision Making Algorithm in a Heterogeneous Mobile Environment Implemetatio of Fuzzy Multiple Objective Decisio Makig Algorithm i a Heterogeeous Mobile Eviromet P.M.L. ha, Y.F. Hu, R.E. Sheriff, Departmet of Electroics ad Telecommuicatios Departmet of yberetics, Iteret

More information

Broadcasting in Multichannel Cognitive Radio Ad Hoc Networks

Broadcasting in Multichannel Cognitive Radio Ad Hoc Networks 2013 IEEE Wireless Commuicatios ad Networkig Coferece (WCNC): MAC Broadcastig i Multichael Cogitive Radio Ad Hoc Networks Zaw Htike Departmet of Computer Egieerig Kyug Hee Uiversity 1 Seocheo,Giheug, Yogi,

More information

ACCEPTED FOR PUBLICATION AT THE EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING 1

ACCEPTED FOR PUBLICATION AT THE EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING 1 ACCEPTED FOR PUBLICATIO AT TE EURASIP JOURAL O WIRELESS COMMUICATIOS AD ETWORKIG 1 A Approach to Optimum Joit Beamformig Desig i a MIMO-OFDM Multiuser System Atoio Pascual-Iserte, Aa I. Pérez-eira, ad

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

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

Importance Analysis of Urban Rail Transit Network Station Based on Passenger

Importance Analysis of Urban Rail Transit Network Station Based on Passenger Joural of Itelliget Learig Systems ad Applicatios, 201, 5, 22-26 Published Olie November 201 (http://www.scirp.org/joural/jilsa) http://dx.doi.org/10.426/jilsa.201.54027 Importace Aalysis of Urba Rail

More information

Distributed Resource Management in Multi-hop Cognitive Radio Networks for Delay Sensitive Transmission

Distributed Resource Management in Multi-hop Cognitive Radio Networks for Delay Sensitive Transmission 1 Distributed Resource Maagemet i Multi-hop Cogitive Radio Networs for Delay Sesitive Trasmissio Hsie-Po Shiag ad Mihaela va der Schaar Departmet of Electrical Egieerig (EE), Uiversity of Califoria Los

More information

Compound Controller for DC Motor Servo System Based on Inner-Loop Extended State Observer

Compound Controller for DC Motor Servo System Based on Inner-Loop Extended State Observer BULGARIAN ACADEMY OF SCIENCES CYBERNETICS AND INFORMATION TECHNOLOGIES Volume 6, No 5 Special Issue o Applicatio of Advaced Computig ad Simulatio i Iformatio Systems Sofia 06 Prit ISSN: 3-970; Olie ISSN:

More information

Minimum Normalized Transmit Rate Based Fair Scheduling Algorithm in Orthogonal Frequency Division Multiplexing (OFDM)

Minimum Normalized Transmit Rate Based Fair Scheduling Algorithm in Orthogonal Frequency Division Multiplexing (OFDM) Iteratioal Joural of Electroic Egieerig Research ISSN 097-640 Volue 1 Nuber 4 (009) pp. 337 344 Research Idia Publicatios http://www.ripublicatio.co/ijeer.ht Miiu Noralized Trasit Rate Based Fair Schedulig

More information

The Firing Dispersion of Bullet Test Sample Analysis

The Firing Dispersion of Bullet Test Sample Analysis Iteratioal Joural of Materials, Mechaics ad Maufacturig, Vol., No., Ma 5 The Firig Dispersio of Bullet Test Sample Aalsis Youliag Xu, Jubi Zhag, Li Ma, ad Yoghai Sha Udisputed, this approach does reduce

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

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

Adaptive Channel Estimation Techniques for MIMO OFDM Systems

Adaptive Channel Estimation Techniques for MIMO OFDM Systems (IJACSA) Iteratioal Joural of Advaced Computer Sciece ad Applicatios, Adaptive Chael Estimatio Techiques for MIMO OFDM Systems Md. Masud Raa Dept. of Electroics ad Radio Egieerig Kyug ee Uiversity South

More information

Delta- Sigma Modulator with Signal Dependant Feedback Gain

Delta- Sigma Modulator with Signal Dependant Feedback Gain Delta- Sigma Modulator with Sigal Depedat Feedback Gai K.Diwakar #1 ad V.Vioth Kumar *2 # Departmet of Electroics ad Commuicatio Egieerig * Departmet of Electroics ad Istrumetatio Egieerig Vel Tech Uiversity,Cheai,

More information

Performance Evaluation of Scheduling in IEEE Based Wireless Mesh Networks

Performance Evaluation of Scheduling in IEEE Based Wireless Mesh Networks Performace Evaluatio of Schedulig i IEEE 802.6 Based Wireless Mesh Networks Bo Ha, Fug Po Tso, Lidog Li ad Weijia Jia Departmet of Computer Sciece, City Uiversity of Hog Kog 83 Tat Chee Aveue, Kowloo,

More information

TO DETERMINE THE NUMERICAL APERTURE OF A GIVEN OPTICAL FIBER. 2. Sunil Kumar 3. Varun Sharma 4. Jaswinder Singh

TO DETERMINE THE NUMERICAL APERTURE OF A GIVEN OPTICAL FIBER. 2. Sunil Kumar 3. Varun Sharma 4. Jaswinder Singh TO DETERMINE THE NUMERICAL APERTURE OF A GIVEN OPTICAL FIBER Submitted to: Mr. Rohit Verma Submitted By:. Rajesh Kumar. Suil Kumar 3. Varu Sharma 4. Jaswider Sigh INDRODUCTION TO AN OPTICAL FIBER Optical

More information

High Speed Area Efficient Modulo 2 1

High Speed Area Efficient Modulo 2 1 High Speed Area Efficiet Modulo 2 1 1-Soali Sigh (PG Scholar VLSI, RKDF Ist Bhopal M.P) 2- Mr. Maish Trivedi (HOD EC Departmet, RKDF Ist Bhopal M.P) Adder Abstract Modular adder is oe of the key compoets

More information

Density Slicing Reference Manual

Density Slicing Reference Manual Desity Slicig Referece Maual Improvisio, Viscout Cetre II, Uiversity of Warwick Sciece Park, Millbur Hill Road, Covetry. CV4 7HS Tel: 0044 (0) 24 7669 2229 Fax: 0044 (0) 24 7669 0091 e-mail: admi@improvisio.com

More information

WSN Node Localization Regularization Algorithm Based on Quasi Optimal Criterion Parameter Selection

WSN Node Localization Regularization Algorithm Based on Quasi Optimal Criterion Parameter Selection Sesors & rasducers Vol. 23 Special Issue July 203 pp. 94-98 Sesors & rasducers 203 by IFSA http://www.sesorsportal.com WSN Node Localizatio Regularizatio Algorithm Based o Quasi Optimal Criterio Parameter

More information

A SIMPLE METHOD OF GOAL DIRECTED LOSSY SYNTHESIS AND NETWORK OPTIMIZATION

A SIMPLE METHOD OF GOAL DIRECTED LOSSY SYNTHESIS AND NETWORK OPTIMIZATION 49 A SIMPL MOD OF GOAL DIRCD LOSSY SYNSIS AND NWORK OPIMIZAION K. ájek a),. Michal b), J. Sedláek b), M. Steibauer b) a) Uiversity of Defece, Kouicova 65,63 00 ro,czech Republic, b) ro Uiversity of echology,

More information

AkinwaJe, A.T., IbharaJu, F.T. and Arogundade, 0.1'. Department of Computer Sciences University of Agriculture, Abeokuta, Nigeria

AkinwaJe, A.T., IbharaJu, F.T. and Arogundade, 0.1'. Department of Computer Sciences University of Agriculture, Abeokuta, Nigeria COMPARATIVE ANALYSIS OF ARTIFICIAL NEURAL NETWORK'S BACK PROPAGATION ALGORITHM TO STATISTICAL LEAST SQURE METHOD IN SECURITY PREDICTION USING NIGERIAN STOCK EXCHANGE MARKET AkiwaJe, A.T., IbharaJu, F.T.

More information

Learning with handoff cost constraint for network selection in heterogeneous wireless networks

Learning with handoff cost constraint for network selection in heterogeneous wireless networks WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commu. Mob. Comput. 16; 16:441 458 Published olie 16 October 14 i Wiley Olie Library (wileyolielibrary.com). DOI: 1.1/wcm.55 RESEARCH ARTICLE Learig

More information

Outline. Motivation. Analog Functional Testing in Mixed-Signal Systems. Motivation and Background. Built-In Self-Test Architecture

Outline. Motivation. Analog Functional Testing in Mixed-Signal Systems. Motivation and Background. Built-In Self-Test Architecture Aalog Fuctioal Testig i Mixed-Sigal s Jie Qi Dept. of Electrical & Computer Egieerig Aubur Uiversity Co-Advisors: Charles Stroud ad Foster Dai Outlie Motivatio ad Backgroud Built-I Self-Test Architecture

More information

WAVE-BASED TRANSIENT ANALYSIS USING BLOCK NEWTON-JACOBI

WAVE-BASED TRANSIENT ANALYSIS USING BLOCK NEWTON-JACOBI WAVE-BASED TRANSIENT ANALYSIS USING BLOCK NEWTON-JACOBI Muhammad Kabir McGill Uiversity Departmet of Electrical ad Computer Egieerig Motreal, QC H3A 2A7 Email: muhammad.kabir@mail.mcgill.ca Carlos Christofferse

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

Evaluation of High-speed Train Communication Handover Models Based on DEA

Evaluation of High-speed Train Communication Handover Models Based on DEA Evaluatio of High-speed rai Commuicatio Hadover Models Based o DEA Yuzhe Zhou State Key Laboratory of Rail raffic Cotrol ad Safety Beiig Jiaotog Uiversity Beiig 100044 P.R. Chia 12120198@btu.edu.c Bo Ai

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

Adaptive Load Balance and Handoff Management Strategy for Adaptive Antenna Array Wireless Networks

Adaptive Load Balance and Handoff Management Strategy for Adaptive Antenna Array Wireless Networks Adaptive Load Balace ad Hadoff Maagemet Strategy for Adaptive Atea Array Wireless Networs Jog-Shi Che 1 We-Chi Chiag 2 Neg-Chug Wag 3 Yug-Fa Huag 4 124 Graduate Istitute of Networig ad Commuicatio Egieerig

More information

High-Order CCII-Based Mixed-Mode Universal Filter

High-Order CCII-Based Mixed-Mode Universal Filter High-Order CCII-Based Mixed-Mode Uiversal Filter Che-Nog Lee Departmet of Computer ad Commuicatio Egieerig, Taipei Chegshih Uiversity of Sciece ad Techology, Taipei, Taiwa, R. O. C. Abstract This paper

More information