Designers of fifth-generation (5G) wireless networks

Size: px
Start display at page:

Download "Designers of fifth-generation (5G) wireless networks"

Transcription

1 Enling Nonorthogonl Multiple Access in the Sprse Code Domin istockphoto.com/vertigo3d TOWARD 5G WIRELESS INTERFACE TECHNOLOGY Fn Wei, Wen Chen, Yongpeng Wu, Jun Li, nd Yun Luo Designers of fifth-genertion (5G) wireless networks re focusing on enling highly relile low-ltency communictions tht support high dt rte nd llow mssive connectivity. Nonorthogonl multiple ccess (NOMA), n essentil enling technology tilored to ccommodte wide rnge of communiction requirements, shows potentil s tool for helping 5G networks to fulfill these promised cpilities. By coordinting connections for mssive numers of devices within the sme resource lock on power domin, frequency domin, or code domin, NOMA is superior to conventionl orthogonl multiple ccess in terms of network connectivity, system throughputs, nd other chrcteristics. Sprse code multiple ccess (SCMA) is kind of multicrrier code-domin NOMA nd hs een studied extensively. The chllenge in designing high-qulity SCMA system is crfting fesile encoding nd decoding schemes to meet the desired requirements. In this rticle, we descrie re - cent progress in designing multidimensionl codeooks, prcticl low-complexity decoder, nd grnt-free multiple ccess for SCMA systems. Our prticulr focus is on showing how the designs of the multidimensionl constelltion nd fctor grphs (FGs) hve formed the foundtion of SCMA codeooks. In ddition, we review vrious lowcomplexity SCMA decoders with specil emphsis on Digitl Oject Identifier 1.119/MVT Dte of puliction: 1 Octoer 218 sphere decoding. Also, we introduce SCMA grnt-free trnsmission sed on the frmework of elief propgtion (BP) nd discuss the prolem of collision resolution. Bckground New fetures for the next genertion of wireless networks hve emerged from the 3rd Genertion Prtnership Project. These fetures include enhnced moile rodnd (embb), mssive mchine-type communictions (mmtc), nd ultrrelile low-ltency communiction (URLLC). The im of embb is to permit high dt rte for wireless networks ecuse the typicl 5G trnsmission rte will e 1 G/s, with the pek rte fster thn 1 G/s, which is roughly ten or 1 times fster thn tht of the fourthgenertion networks. Besides enling these speeds, mmtc should ccommodte mssive connectivity y llowing networks to connect millions of devices within single squre kilometer, cpcity fr greter thn tht permitted y tody s conventionl networks. Menwhile, URLLC should reduce end-to-end dely to mtter of milliseconds, therey supporting such communiction cpilities s rel-time moile control nd vehicle-to-vehicle pplictions nd communictions. Conventionl orthogonl multiple ccess, such s timedivision multiple ccess, code-division multiple ccess, nd orthogonl frequency-division multiple ccess (OFDMA), ssigns the orthogonl resource to ech user exclusively. However, s mssive numers of devices re /18 218ieee IEEE vehiculr technology mgzine decemer 218

2 connected t the sme time, ville time frequency resources quickly ecome scrce. With mssive connectivity, the inefficiency of giving every user exclusive ccess to such limited resources ecomes pprent. Moreover, chnnel codes, s they hve evolved, hve pushed conventionl point-to-point trnsmission nerly to the Shnnon limits. Thus, it is essentil to explore network communiction using next-genertion wireless interfce technologies tht tke full dvntge of the spectrl efficiency, offer more throughputs, nd ccommodte more connected users. To this end, NOMA, which llows multiple users to trnsmit simultneously within the shred resources, represents promising frontier for study. Developers hve proposed vrious NOMA techniques sed on differing principles. These include power-domin NOMA, low-density signtures (LDSs), SCMA, nd pttern-division multiple ccess. While the techniques hve different rtionles, they shre n underlying gol: tht multiple users should e le to trnsmit simultneously in ech orthogonl time frequency resource. Here, we comprehensively review recent progress on SCMA [1], code-domin NOMA. The focus is on designing codes to mke SCMA especilly relile. Also, prcticl lowcomplexity decoder for the multiuser system needs to e developed to ccommodte mssive connectivity demnds. To enle the low-ltency communiction, grntfree multiple ccess my e the preferred lterntive to conventionl request grnt multiple ccess. Thus, it is interesting to consider SCMA comined with grnt-free trnsmission. We specificlly look t the low-complexity grnt-free receiver design nd the collision resolution prolem within the contention-sed trnsmission. Function Nodes Vrile Nodes Rdio Chnnels UE 1 Chnnel Decoder 1 UE 2 Chnnel Decoder 2 Active Users Detection nd Chnnel Estimtion... UE J Chnnel Decoder J SCMA Decoder SCMA In this section, we provide rief introduction to SCMA. Figure 1 depicts the lock digrm for the uplink SCMA system. In the encoder, coded its re modulted to the multidimensionl sprse codewords consisting of the high-dimensionl lttice points. As n exmple, Figure 2 illustrtes the four-dimensionl sprse codewords with two nonzero entries. The nonzero entries cn e modulted to OFDMA sucrriers or the multiple-input, multipleoutput (MIMO) ntenns. Note tht choosing the positions of nonzero entries cn e viewed s comi ntionl prolem. Therefore, t most, ` N K j users cn e ccommodted, where K is the totl numer of sucrriers nd N denotes the numer of nonzero entries. To enle the sprse structure of codewords, the numer of nonzero entries should stisfy N % K. This reduces the likelihood tht users will experience collisions in single sucrrier nd further simplifies decoding. For the four-dimensionl codewords in Figure 2, the mximum numer of users is six, wheres, due to the sprsity of codewords, the numer of possile collisions mong users is reduced to three per sucrrier. Illustrtion of SCMA Codeword x k Codeook x k * * * 1 c 1 x 1 UE 1 Chnnel Encoder 1 SCMA Encoder 1 UE 2 2 c 2 x 2 Chnnel Encoder 2 SCMA Encoder 2... J c J x UE J Chnnel Encoder J SCMA Encoder J J Figure 1 A lock digrm of SCMA systems. decemer 218 IEEE vehiculr technology mgzine 19

3 Codeook 1 Codeook 2 Codeook 3 Codeook 4 Codeook 5 Codeook Sucrrier 1 Sucrrier 2 Sucrrier 3 Sucrrier 4 Figure 2 A four-dimensionl SCMA codeook structure. The SCMA codeook construction cn e formult - ed s suoptiml multiple-stge optimiztion prolem. Initilly, mother constelltion sed on high-dimensionl lttice points ws constructed. Therefter, lttice rottion for the mother constelltion ws further pplied to optimize the product distnce of the constelltion nd induce the dependency nd power vritions mong the lttice dimensions. The susequent design of the codeook ddresses the needs of distinct users y introducing the constelltion function opertors, including complex conjugtes, phse rottions, nd dimensionl permuttions for the lttice constelltions. Those opertors only render the distinct codewords for the users while leving the minimum Eucliden distnce of the constelltions unchnged. After receiving the superimposed codewords, the decoder performs chnnel estimtion nd dt decoding sed on pilots s well s dt signls. The ctive user identifiction is lso necessry if grnt-free trnsmission is considered. The sprse structure of SCMA codewords cn e represented y n FG s in low-density prity check (LDPC) codes. This structure enles the decoder to employ the messge-pssing lgorithm (MPA) for the itertive decoding of the dt. SCMA Encoder Design nd the Performnce Limits Anlysis As code-domin NOMA, SCMA requires, on verge, less energy for signl constelltion ecuse of the shping gin of multidimensionl codewords. Thus, the codeook design helps the SCMA system to perform etter. In this section, we review the literture out SCMA codeook design nd provide insights regrding performnce limits of the SCMA system. SCMA Codeook Design As multicrrier NOMA, the codeooks of SCMA re essentilly multidimensionl constelltion points. SCMA, s originlly plnned, presented systemtic construction method for codeook design where the high-dimensionl constelltion points were generted sed on squre-qudrture mplitude modultion (QAM). Str- QAM hs emerged s n lterntive pproch offering etter it-error-rte (BER) performnce in the fding chnnels. It lso outperforms the squre-qam in pekpower-limited systems. Consequently, reserchers rought forwrd str-qam-sed codeook design for SCMA [2]. By optimizing the coordintes of the signl points in different rings of the str-qam, the str-qam-sed SCMA enjoys lrger minimum Eucliden distnce compred with LDS nd the codeooks in [1]. To leverge the rtio of pek-to-verge power s well s the spectrum efficiency, sphericl codes hve een dpted s nother pproch for the high-dimensionl codeook design of SCMA [3]. Vrious good sphericl codes hve een constructed through inry codes, shells of lttices, permuttions of vectors or computer serching, nd y other mens. The optiml sphericl codes with low dimensions were shown to hve lrge coding gins. An SCMA codeook with good performnce cn e otined y conctenting those low-dimensionl sphericl codes. Aprt from the mother constelltion design, the FG is nother importnt feture in elevting the performnce of the SCMA system. A properly designed FG my expnd system cpcity, reduce the interference of ech sucrrier, nd reduce decoding complexity for the receiver. In [4], the cpcity of uplink SCMA is derived when the covrince mtrix of the codewords is digonl. The FG 2 IEEE vehiculr technology mgzine decemer 218

4 design is formulted s n integer progrming optimiztion prolem with the oject function eing the sum rte of the system. Ech link etween the vrile node nd function node in the FG is determined y mximizing the individul user rte in one sucrrier itertively. In Figure 3, the throughputs of different FG construction nd power-lloction schemes re compred. This shows tht, through the optimiztion of FGs, some users my occupy one sucrrier exclusively nd experience no interference from other users. In other words, the irregulr SCMA ws shown to hve etter system performnce. Performnce Limits of the SCMA System A system sed on multidimensionl SCMA codewords cn e viewed s equivlent to n MIMO system. In ddition, the MPA receiver my reduce or even eliminte the multiuser interference in ech sucrrier. Thus, the SCMA system cn e treted s kind of single-user MIMO system. With the known results of MIMO, the process of deriving the lower ound of symol error rte for SCMA is strightforwrd [5]. Furthermore, n inspection of the pir-wised proility of MIMO SCMA with lrge-scle fding chnnel shows tht the diversity order of SCMA is minly due to two fctors: the numer of received ntenns nd the signl-spce diversity of the SCMA multidimensionl codewords [6]. In ddition, evidence shows tht lrge-scle fding only ffects the coding gin of the system. SCMA Decoder Design The invention of turo codes hs inspired developers to pply the turo principle in the design of communiction systems. The turo principle hs lso led developers to implement soft informtion etween the SCMA decoder nd the forwrd error correction decoder. This technique lowers the coded BER of SCMA [7]. However, improved BER performnce increses decoding complexity for the receiver. This is why low-complexity decoder is especilly essentil for SCMA. As the LDPC codes, SCMA cn e represented y the FG. Thus, it is nturl to use the BP or MPA for the SCMA decoder. Due to the sprsity of the codewords, MPA hs resonle decoding complexity for the low nd middle modultion order systems. However, when the numer of users is incresing or the modultion order is high (e.g., the 32- or 64-ry SCMA), decoding ecomes prohiitively complex. As such, stisfctory low-complexity decoders for SCMA re needed. One such decoder is sed on prtil mrginliztion [8], n ide grounded in the oservtion tht the convergence rte of messge pssing for different users my e different. Prtil mrginliztion demonstrtes tht it is etter to nlyze the trnsmit symols for users with fster convergence rtes efore the lgorithm termintion. Those symols cn e sutrcted from the To enle the low-ltency communiction, grnt-free multiple ccess my e the preferred lterntive to conventionl request grnt multiple ccess. received signls. For the remining users, messge pssing will only e involved in the susequent itertions. Theoreticlly, the complexity of prtil mrginliztion is exponentil, nd the performnce is highly dependent on which portion of users re chosen to e judged first. While most work in this re focuses on simplifying decoding on the receiver side, proper constelltion design cn lso stremline computing demnds [9]. The ide is shown in Figure 4. For the multidimensionl SCMA codewords with modultion order M, one cn project tht to the constelltion with m 1 M points. Evidently, this will cuse some overlps on the point leling. Nevertheless, the decoder is le to distinguish points from one nother s long s the overlp points re sepr - ted on the other dimensions (e.g., points 1 nd 1 overlp on dimension 1 ut re seprted on dimension 2). Since m 1 M, the decoding complexity is reduced from M dc to m dc, where dc is the numer of collision users in ech sucrrier. Reserchers working on improving MPA re concentrting on updting the function nodes. In ech itertion, the MPA decoder seeks the point tht is most likely to e trnsmitted. However, the scheme requires n exhustive serch through ll possile comintions of trnsmitted signls, mking it inefficient. As n lterntive Throughput (/s/hz) Trnsmit Power (dbm) Proposed Codeook nd Proposed Power Rndom Codeook nd Equl Power Rndom Codeook nd Proposed Power Proposed Codeook nd Equl Power Figure 3 Throughput comprisons for different codeook nd power lloction schemes. decemer 218 IEEE vehiculr technology mgzine 21

5 The SCMA codeook construction cn e formulted s suoptiml multiple-stge optimiztion prolem. pproch, the decoder cn lso proceed in more efficient wy y considering only the signl points ner the received signls. The ide is essentilly the sme s tht of sphere decoder. For the SCMA, the decoder seeks cndidte list first y list-sphere decoding (LSD). Next, MPA cn e operted within the cndidte list, thus simplifying decoding [1], [11]. The size of the cndidte set cn e tuned to lnce the decoding complexity nd the performnce. Essentilly, sphere decoder cn e viewed s kind of depth-first tree serch lgorithm. Figure 5 shows n exmple of serching tree with L = 5 levels. The serch process strts from the root node nd proceeds to the lef nodes. All solid lines correspond to the survivl pths during the serch, while the dotted lines correspond to the eliminted pths. The decoding complexity depends on the numer of visited nodes on the inry tree during the serch process. Thus, y voiding the unnecessry visits to nodes, simpler serch is possile if some rnches of the tree re pruned properly. SCMA is kind of multisucrrier NOMA. As such, insted of crrying out sphere decoding on different sucrriers independently, the messges re exchnged from different sucrriers so tht some rnches my e pruned in dvnce on the lower serch Y Y 2 X 1 X Sucrrier 1 Sucrrier 2 Figure 4 A low numer of projections for four-ry SCMA. Figure 5 A sphere decoder depth-first tree serch. Level 1 Level 2 Level 3 Level 4 Level 5 levels. More specificlly, when point is reported to e excluded in the list y one sucrrier, the other sucrriers cn circumvent the route to this point y pruning the unnecessry rnches of the serching tree. Figure 6() shows the numer of visited nodes with node pruning (NP-LSD-MPA) versus the conventionl methods (LSD-MPA). Figure 6() demonstrtes tht node pruning results in improved BER performnce. In fct, n LSD error occurs when the ctul trnsmit point is not contined within the cndidte list. Hence, if the redundncy nodes re pruned within the list, the ctul trnsmit point would likely enter the finl list nd, thus, improve the performnce. A sphere decoder for SCMA lso hs the dvntge of eing pplicle to the low numer of projection codewords proposed in [9] (see [11] for detiled discussion). SCMA with Grnt-Free Trnsmission Another chllenge for the dvnced multiple-ccess technique developers is to ddress the issue of user scheduling. In long-term evolution networks, user scheduling is relized through the request-grnt procedure, where ctive users periodiclly send scheduling requests to the se sttion (BS) nd wit for the grnts s well s resource ssignments. However, the hndshkes etween the BS nd the ctive users my result in considerle delys. Menwhile, the dynmic signling degrdes the spectrl efficiency of the network. Thus, contention-sed grnt-free trnsmission is dvocted in the future 5G network. Insted of the hndshkes, ctive users contend the shred resources nd trnsmit directly to the BS. However, two prolems rise in grnt-free multiple ccess: user identifiction nd collision resolution. Identifiction of Active Users for Grnt-Free SCMA For typicl 5G scenrios, such s those involving mmtc, the numer of users connected to the network is presumed to e huge. While millions of devices re connected to the network, only few users re communicting t the sme time. Thus, the tsk of identifying ctive users is generlly frmed s kind of compressed sensing prolem. With the understnding tht inctive users re sending no dt symols nd hve no chnnel responses, the chnnels from ll users cn e viewed s sprse vector with nonzero entries representing ctive users. Therefore, ctive users cn e recognized y detecting support of the sprse vector. In [12], three lgorithms re proposed tht use pilot signls only to estimte the sprse chnnel vectors. Generlly, chnnel estimtes sed on dt re more ccurte thn those sed only on pilot signls. Further, user ctivity informtion is contined not only in the received pilot signls ut lso the dt signls. Thus, one proposed receiver would, y exploiting oth pilot nd 22 IEEE vehiculr technology mgzine decemer 218

6 dt signls, perform joint user identifiction, chnnel estimtion, nd dt decoding [13]. For the prolem of estimting hyrid continuous (chnnel coefficients) nd discrete (dt symols) vriles, direct mximum likelihood detection is unrelistic ecuse it is so complex. Thus, low-complexity itertive decoder sed on the FG of SCMA is necessry. The FG representtion of SCMA with estimtion of hyrid vriles is formulted in Figure 7(). The representtion shows three loops: one for estimting chnnels, one for detecting dt, nd one for detecting user ctivity. In the dt-detection loop, the term p( xk ck ) denotes the mpping function of SCMA encoder k, which mps the coded its to the SCMA codewords. The function node ftn corresponds to the likelihood function on the tth time slot, sucrrier n. For the chnnel-estimtion loop, the tpped-dely chnnel model with length L is considered. The function z nk, corresponds to the Fourier trnsformtion of chnnel responses from the lg domin to the frequency domin. To fcilitte the detection of sprse signls, the two-lyer hierrchy chnnel model is used for modeling ech chnnel tp hkl. On the first lyer, the chnnel is ssumed to follow the Gussin distriution with vrince m kl. On the second lyer, the vrince is further modeled s gmm distriution C ( mkl, ) with noninformtive priori prmeter of, for instnce, = 1-7 nd = 1-7. Such formultion of chnnel responses leds to the Student s t distriution when integrting out the vriles m kl. The Student s t distriution exhiits hevy tils nd thus fvors sprse solutions for the prolem of identifying ctive users. Essentilly, sphere decoder cn e viewed s kind of depth-first tree serch lgorithm. With the formultion of FG, the messge pssing for dt symols my e clculted sed on BP. However, the direct BP updting is cumersome for the hyrid continuous nd discrete vrile models. The ide for rendering trctle computtion is to pproximte the virtul vriles, defined s the production of discrete dt symols nd chnnel coefficients, into some continuous distriutions for the ske of low-complexity computtion; see Figure 7() for illustrtions. To ensure the ccurcy of pproximtion, the true distriution of vriles is projected into Gussin distriution for ech user individully with the minimized Kullck Leiler (KL) divergence. This coincides with the ide of expecttion propgtion (EP) messge pssing. With Gussin distriuted messges, BP updting is now trctle y some simpler computtion. Figure 8, which demonstrtes the performnce of receiver sed on EP messge pssing, exmines mchinetype communictions where 256 coded its re contined in ech pcket. The user identifiction comprison y the joint nd pilot-ided-only detector is shown in Figure 8(). The ctivity for ech user is determined y the power of the estimted chnnels since inctive users experience the equivlent of zero chnnel coefficients. Clerly, y exploring the pilot nd dt symols concurrently, the joint detector cn chieve much lower error-detection rte. Figure 8() Averge Numer of Visited Nodes LSD-MPA, E /N = 12 db LSD-MPA, E /N = 18 db NP-LSD-MPA, E /N = 12 db NP-LSD-MPA, E /N = 18 db LSD-LNP, E /N = 12 db LSD-LNP, E /N = 18 db BER Turo SCMA (16 Points) Mx-log-MPA NP-LSD-MPA, T mx = 14 LSD-MPA, T mx = 14 LNP LSD-LNP, T mx = 35 PM-MPA, Rs = 4, m = Level of the Serch Tree () E /N (db) () Figure 6 An evlution of () the verge numer of nodes visited in ech level of the serching tree for the 15% overloded 16-ry SCMA system nd () the BER performnce of the 15% overloded 16-ry SCMA system. LSD-MPA corresponds to the list sphere decoder. NP-LSD-MPA denotes the LSD with node pruning, nd LNP is the low numer of projected SCMA codewords. The conventionl mx-log- MPA is used s performnce enchmrk. PM-MPA denotes the decoder sed on prtil mrginliztion [8]. decemer 218 IEEE vehiculr technology mgzine 23

7 compres the BER performnce for different decoding lgorithms. The pilot-ided MPA (P-MPA) lgorithm, which relies on pilots only for chnnel estimtion nd user detection, hs the worst performnce. Other joint messge-pssing receivers, such s BP-MF nd BP-GA, re less effective due to their inccurte pproximtion for the true proility. Becuse the proility estimte stems from minimized KL divergence, the performnce gp etween the BP-GA-EP receiver [13] nd receiver (Genie) with exct chnnel stte informtion nd user ctivity is only roughly 1 db. User Activity Detection Loop Chnnel Estimtion Loop p (λ 1,1 ) λ 1,1 q 1,1 h 1,1 Dt Detection Loop x t,1 p(x t,1 c t,1) p(c t,1 ) p (λ 1,l ) λ 1,l q 1,l h 1,l ϕ 1,k(1) α 1,k(1) f t,1 x t,2 p(x t,2 c t,2) p(c t,2 ) p (λ 1,L ) λ 1,L q 1,L h 1,L ϕ 1,k(dc) α 1,k(dc) f t,n x t,k p(x t,k c t,k ) p(c t,k ) p (λ K,1 ) λ K,1 q K,1 h K,1 ϕ N,k(1) α N,k(1) f t,n x t,k 1 p(x t,k 1 c t,k 1 ) p(c t,k 1 ) p (λ K,l ) λ K,l q K,l h K,l ϕ N,k(dc) α N,k(dc) x t,k p(x t,k c t,k ) p( c t,k ) p (λ K,L ) λ K,L q K,L h K,L Function Nodes Vrile Nodes () X n1 u n1 n1 I nk ftn ( nk ) f tn I xnk ftn (X nk ) X n2 f tn I ftn unk (u nk ) u nk I unk ftn (u nk ) ndc I xnk ftn (X nk ) X ndc u ndc u nk = nk X nk () (c) Figure 7 The FG representtion of () the SCMA with hyrid vriles estimtion nd () nd (c) the messge pssing within function node n. () The digrm shows the messge pssing with direct BP. (c) The digrm shows the messge pssing with EP pproximtion, i.e., the extrinsic messges for virtul vrile u, which is the production of chnnel h nd dt x, re pproximted with Gussin distriutions with the minimized KL divergence. 24 IEEE vehiculr technology mgzine decemer 218

8 Collision Resolution for Grnt-Free SCMA The rdio resources for grnt-free trnsmission re defined in [12]. The sic rdio resource, which is referred to s contention trnsmission unit (CTU), is defined s the comintion of time dt, frequency dt, SCMA codeook dt, nd pilot dt. The user equipment (UE) is (possily) mpped to CTUs vi the mpping rule CTUindex = UEID mod NCTU, where NCTU denotes the numer of CTUs. In mmtc, the numer of UEs would lwys exceed the numer of ville CTUs. As consequence, multiple UEs cn e mpped to the sme CTU for dt trnsmission. A collision hppens when two or more ctive UEs trnsmit concurrently within the sme CTU. To resolve the UE collision prolems, the conventionl pproch conducts retrnsmission y the rndom ckoff mechnism. However, if the sttic mpping rule is used, constnt collisions my hppen when ursty trffic occurs even when the rndom ck-off is used. Further, some CTUs my e llocted with more UEs due to the numer of UEs exceeding tht of CTUs. To circumvent the prior descried issues, n UE-to-CTU mpping rule sed on cknowledgment (ACK) feedck is proposed [14]. The ide is to use the conventionl sttic mpping rule in the first round of hndshking etween BSs nd UEs. Next, n ACK list contining the detection nd decoding results for ll UEs is fed ck from the BSs to receivers. For ech UE, two its re ssigned to indicte the sttus: (, ) for no dt received, (1, 1) for dt successfully decoded, nd (, 1) for retrnsmission needed. Figure 9 is n illustrtion of the mpping rule sed on ACK feedck. Figure 1 depicts detiled grnt-free trnsmission procedure with mpping rule sed on ACK feedck. Trnsmission dely is ssumed to e three time slots, nd MAPi denotes the mpping rule generted in the ith time slot. To strt with, MAP1 in the first time slot is set sed on conventionl sttic mpping rule. Afterwrds, with the receipt of ACK from the BS, n dptive MAP4 is determined y UEs. Specificlly, for UE j, if the code is 1, indicting tht UE j needs to retrnsmit, n exclusive CTU is immeditely ssigned gin. The BS counts the numer of CTUs ssocited with only one UE, i.e., Nsingle nd set CTUindex = j mod Nsingle. If the code is not 1, n exclusive CTU is unnecessry. The BS now counts the numer of CTUs ssocited with multiple UEs, i.e., Nmulti nd set CTUindex = j mod Nmulti + Nsingle. The susequent slots cn e hndled in similr mnner. Theoreticl nlysis of methods sed on ACK feedck shows tht the collision proility would lwys e less thn tht of conventionl sttic mpping rules. Conclusions nd Future Chllenges This rticle reviewed the stte of the rt for SCMA technologies. We specificlly considered techniques using code-domin NOMA, SCMA, s promising for wireless interfces of the future. We showed how BER Error Detection Rte Pilot (N p = 7) Pilot (N p = 11) Joint (N p = 7) Joint (N p = 11) E /N (db) E /N (db) proper mother constelltion design s well s the dynmic FG construction cn led to n improved SCMA codeook design. This rticle lso descried issues relted to low-complexity decoders ccommodting multiuser decoding for SCMA. The ide is sed on sphere decoding, which voids exhustive serching during the MPA. To meet the URLLC requirement, SCMA systems dopt grnt-free trnsmission methods. We introduced receiver tht performs joint chnnel estimtion, dt decoding, nd the detection of ctive users sed on EP messge pssing. Finlly, UE-to-CTU mpping rule sed on ACK feedck, solution to the user-collision prolem. () () Genie BP-GA-EP BP-MF BP-GA P-MPA Figure 8 An evlution of () the error-detection rte y joint nd pilot-only methods nd () the BER performnce of the four-ry SCMA system. BP-GA-EP denotes the hyrid BP nd EP messge pssing with Gussin pproximtion. BP-MF represents the hyrid BP nd men-field pproximtion. BP-GA is the BP Gussin pproximtion using the centrl limit theorem. decemer 218 IEEE vehiculr technology mgzine 25

9 Collision CTU1 CTU2 CTU3 CTU4 CTU5 CTU8 CTU9 CTU UE ID : Unsuccessfully Decoded No Trnsmission Successfully Decoded UE14 ACK: Proposed Mpping Rule CTU1 CTU2 CTU3 CTU4 CTU5 CTU8 CTU9 CTU UE ID : 14 UE ID : UE ID : 6 15 UE ID : 7 16 UE ID : 8 16 Figure 9 The mpping rule sed on ACK feedck. MAP1 ACK1 MAP4 ACKi 6 MAPi 3 UEs T1 T7 Ti Dt ACK Dt ACK Dt BS T4 T1 MAP1 ACK1 MAP4 MAP4 ACK7 MAP1 MAPi 3 ACKi MAPi+3 Ti+3 Figure 1 The procedure of the grnt-free trnsmission with the ACK feedcksed method. Issues relted to SCMA tht require further investigtion include the following: The decoding of SCMA relies on the loopy BP lgorithm. However, conventionl BP exhiits poor convergence ehvior on the loopy FGs. The convergence rte is slow, nd lgorithms occsionlly chieved locl optiml points. BP rules re the consequence of minimizing the constrined Bethe free energy, which is no longer convex when FG contins loops. To overcome this poor convergence, convex Bethe free energy needs to e constructed for loopy FG. Furthermore, when comined with other 5G techniques, such s mssive MIMO, the design of the SCMA decoder should lso e recst. The decoding complexity would typiclly grow exponentilly with the numer of ntenns. Thus, there is n emerging need to develop low-complexity receiver for mssive MIMO SCMA. Since multiple users shre the sme re - source element in NOMA, the user piring 26 IEEE vehiculr technology mgzine decemer 218

10 serves s nother interest prolem. For power-domin NOMA, with fixed power lloction, the sum rte cn e enlrged y selecting users with distinctive chnnel conditions. On the other hnd, it is etter to pir the users with similr chnnel conditions in cognitive rdio-inspired NOMA [15]. Unlike power-domin NOMA tht trnsmits on single resource element, the sitution for SCMA is rther complex when the user pring is performed on multiple crriers. Artificil intelligence (AI) comined with 5G is nother reserch trend. AI cn e used to solve prolems tht re intrctle in clssicl communiction system. For instnce, comintoril optimiztion is typiclly the NP-hrd prolem nd is frequently encountered in SCMA, such s in issues relted to codeook ssignment, user selection, nd resource lloction. Alterntive solutions to those prolems might e found y AI using mchine-lerning-sed methods. The SCMA system cn lso e formulted s n utoencoder, where the end-to-end communiction cn e joint-optimized through the construction of deep neurl networks. The utoencoder is trined through the BER or lock error rte nd cn ccommodte vrious chnnel conditions s well s system prmeters. The performnce of SCMA would likely improve with the much lower computtionl complexity. Acknowledgments This work ws supported y the Ntionl Nturl Science Foundtion of Chin under grnts nd , the Science nd Technology Commission of Shnghi Municiplity Project under grnts 16JC1429 nd , the Nturl Science Foundtion of Gungxi Province under grnt 215GXNSFDA13937, nd the Ntionl Science nd Technology Mjor Project under grnts 217ZX312-5 nd 218ZX Author Informtion Fn Wei (weifn89@sjtu.edu.cn) is currently pursuing his Ph.D. degree in informtion nd communiction engineering t the Shnghi Institute for Advnced Communiction nd Dt Science, Deprtment of Electronic Engineering, Shnghi Jio Tong University, Chin. His reserch interests include wireless communiction with focus on nonorthogonl multiple ccess. Wen Chen (wenchen@sjtu.edu.cn) is professor t the Shnghi Institute for Advnced Communiction nd Dt Science, Deprtment of Electronic Engineering, Shnghi Jio Tong University, Chin. His interests include multiple ccess, coded coopertion, nd green heterogeneous networks. Yongpeng Wu (yongpeng.wu@sjtu.edu. cn) is n ssocite professor t the Shnghi Institute for Advnced Communiction nd Dt Science, Deprtment of Electronic Engineering, Shnghi Jio Tong University, Chin. His reserch in terests include mssive multiple-input, multiple-output (MIMO) systems; mssive MIMO systems; nd physicl-lyer security. Jun Li (jun.li@njust.edu.cn) is professor t the School of Electronic nd Opticl Engineering, Nnjing University of Science nd Technology, Chin. His reserch interests include network informtion theory, ultrdense wireless networks, nd moile edge computing. Yun Luo (yunluo@sjtu.edu.cn) is professor in the Computer Science nd Engineering Deprtment, Shnghi Jio Tong Uni versity, Chin. His reserch interests include informtion theory, communiction coding theory, nd computer security. References [1] H. Nikopour nd H. Bligh, Sprse code multiple ccess, in Proc. IEEE 24th Int. Symp. Personl Indoor nd Moile Rdio Communictions (PIMRC), pp , 213. [2] L. Yu, X. Lei, P. Fn, nd D. Chen, An optimized design of SCMA codeook sed on str-qam signling constelltions, in Proc. Int. Conf. Wireless Communictions nd Signl Processing (WCSP), pp. 1 5, Oct [3] J. Bo, Z. M, M. A. Mhmdu, Z. Zhu, nd D. Chen, Sphericl codes for SCMA codeook, in Proc. IEEE 83rd Vehiculr Technology Conf. (VTC Spring), My 216, pp [4] Z. Li, W. Chen, F. Wei, F. Wng, X. Xu, nd Y. Chen, Joint codeook ssignment nd power lloction for SCMA sed on cpcity with Gussin input, in Proc. IEEE Int. Conf. Communictions in Chin (ICCC), Chengdu, Chin, July 216, pp [5] D. Ci, P. Fn, nd P. T. Mthiopoulos, A tight lower ound for the symol error performnce of the uplink sprse code multiple ccess, IEEE Wireless Commun. Lett., vol. 6, no. 2, pp , Apr [6] J. Bo, Z. M, M. Xio, Z. Ding, nd Z. Zhu, Performnce nlysis of uplink SCMA with receiver diversity nd rndomly deployed users, IEEE Trns. Veh. Technol., vol. 67, no. 3, pp , Mr [7] Y. Wu, S. Zhng, nd Y. Chen, Itertive multiuser receiver in sprse code multiple ccess systems, in Proc. IEEE Int. Conf. Communictions (ICC), London, 215, pp [8] H. Mu, Z. M, M. Alhji, P. Fn, nd D. Chen, A fixed low complexity messge pss lgorithm detector for up-link SCMA system, IEEE Wireless Commun. Lett., vol. 4, no. 6, pp , Dec [9] A. Byesteh, H. Nikopour, M. Therzdeh, H. Bligh, nd J. M, Low complexity techniques for SCMA detection, in Proc. IEEE Gloecom Workshops, Dec. 215, pp [1] F. Wei nd W. Chen, A low complexity SCMA decoder sed on list sphere decoding, in Proc. IEEE Glol Commun., Wshington, D.C., Dec [11] F. Wei nd W. Chen, Low complexity itertive receiver design for sprse code multiple ccess, IEEE Trns. Commun., vol. 65, no. 2, pp , Fe [12] A. Byesteh, E. Yi, H. Nikopour, nd H. Bligh, Blind detection of SCMA for uplink grnt-free multiple-ccess, in Proc. Int. Symp. Wireless Wireless Communiction Systems, Aug. 214, pp [13] F. Wei, W. Chen, Y. Wu, J. M, nd T. A. Tsiftsis, Messge-pssing receiver design for joint chnnel estimtion nd dt decoding in uplink grnt-free SCMA systems, IEEE Trns. Wireless Commun., to e pulished. [14] J. Shen, W. Chen, F. Wei, nd Y. Wu, ACK feedck sed UE-to-CTU mpping rule for SCMA uplink grnt-free trnsmission, in Proc. Int. Conf. Wireless Communictions nd Signl Processing (WCSP), Nnjing, Chin, Oct. 217, pp [15] Z. Ding, P. Fn, nd H. V. Poor, Impct of user piring on 5G nonorthogonl multiple-ccess downlink trnsmissions, IEEE Trns. Veh. Technol., vol. 65, no. 8, pp , Aug decemer 218 IEEE vehiculr technology mgzine 27

Multi-beam antennas in a broadband wireless access system

Multi-beam antennas in a broadband wireless access system Multi-em ntenns in rodnd wireless ccess system Ulrik Engström, Mrtin Johnsson, nders Derneryd nd jörn Johnnisson ntenn Reserch Center Ericsson Reserch Ericsson SE-4 84 Mölndl Sweden E-mil: ulrik.engstrom@ericsson.com,

More information

INSTITUTE OF AERONAUTICAL ENGINEERING (Autonomous) Dundigal, Hyderabad

INSTITUTE OF AERONAUTICAL ENGINEERING (Autonomous) Dundigal, Hyderabad Hll Ticket No Question Pper Code: AEC009 INSTITUTE OF AERONAUTICAL ENGINEERING (Autonomous) Dundigl, Hyderd - 500 043 MODEL QUESTION PAPER Four Yer B.Tech V Semester End Exmintions, Novemer - 2018 Regultions:

More information

Solutions to exercise 1 in ETS052 Computer Communication

Solutions to exercise 1 in ETS052 Computer Communication Solutions to exercise in TS52 Computer Communiction 23 Septemer, 23 If it occupies millisecond = 3 seconds, then second is occupied y 3 = 3 its = kps. kps If it occupies 2 microseconds = 2 6 seconds, then

More information

Interference Cancellation Method without Feedback Amount for Three Users Interference Channel

Interference Cancellation Method without Feedback Amount for Three Users Interference Channel Open Access Librry Journl 07, Volume, e57 ISSN Online: -97 ISSN Print: -9705 Interference Cncelltion Method without Feedbc Amount for Three Users Interference Chnnel Xini Tin, otin Zhng, Wenie Ji School

More information

Network-coded Cooperation for Multi-unicast with Non-Ideal Source-Relay Channels

Network-coded Cooperation for Multi-unicast with Non-Ideal Source-Relay Channels This full text pper ws peer reviewed t the direction of IEEE Communictions Society suject mtter experts for puliction in the IEEE ICC 2010 proceedings Network-coded Coopertion for Multi-unicst with Non-Idel

More information

METHOD OF LOCATION USING SIGNALS OF UNKNOWN ORIGIN. Inventor: Brian L. Baskin

METHOD OF LOCATION USING SIGNALS OF UNKNOWN ORIGIN. Inventor: Brian L. Baskin METHOD OF LOCATION USING SIGNALS OF UNKNOWN ORIGIN Inventor: Brin L. Bskin 1 ABSTRACT The present invention encompsses method of loction comprising: using plurlity of signl trnsceivers to receive one or

More information

To provide data transmission in indoor

To provide data transmission in indoor Hittite Journl of Science nd Engineering, 2018, 5 (1) 25-29 ISSN NUMBER: 2148-4171 DOI: 10.17350/HJSE19030000074 A New Demodultor For Inverse Pulse Position Modultion Technique Mehmet Sönmez Osmniye Korkut

More information

Dataflow Language Model. DataFlow Models. Applications of Dataflow. Dataflow Languages. Kahn process networks. A Kahn Process (1)

Dataflow Language Model. DataFlow Models. Applications of Dataflow. Dataflow Languages. Kahn process networks. A Kahn Process (1) The slides contin revisited mterils from: Peter Mrwedel, TU Dortmund Lothr Thiele, ETH Zurich Frnk Vhid, University of liforni, Riverside Dtflow Lnguge Model Drsticlly different wy of looking t computtion:

More information

On the Description of Communications Between Software Components with UML

On the Description of Communications Between Software Components with UML On the Description of Communictions Between Softwre Components with UML Zhiwei An Dennis Peters Fculty of Engineering nd Applied Science Memoril University of Newfoundlnd St. John s NL A1B 3X5 zhiwei@engr.mun.c

More information

ABB STOTZ-KONTAKT. ABB i-bus EIB Current Module SM/S Intelligent Installation Systems. User Manual SM/S In = 16 A AC Un = 230 V AC

ABB STOTZ-KONTAKT. ABB i-bus EIB Current Module SM/S Intelligent Installation Systems. User Manual SM/S In = 16 A AC Un = 230 V AC User Mnul ntelligent nstlltion Systems A B 1 2 3 4 5 6 7 8 30 ma 30 ma n = AC Un = 230 V AC 30 ma 9 10 11 12 C ABB STOTZ-KONTAKT Appliction Softwre Current Vlue Threshold/1 Contents Pge 1 Device Chrcteristics...

More information

CHAPTER 3 AMPLIFIER DESIGN TECHNIQUES

CHAPTER 3 AMPLIFIER DESIGN TECHNIQUES CHAPTER 3 AMPLIFIER DEIGN TECHNIQUE 3.0 Introduction olid-stte microwve mplifiers ply n importnt role in communiction where it hs different pplictions, including low noise, high gin, nd high power mplifiers.

More information

Geometric quantities for polar curves

Geometric quantities for polar curves Roerto s Notes on Integrl Clculus Chpter 5: Bsic pplictions of integrtion Section 10 Geometric quntities for polr curves Wht you need to know lredy: How to use integrls to compute res nd lengths of regions

More information

Design of UHF Fractal Antenna for Localized Near-Field RFID Application

Design of UHF Fractal Antenna for Localized Near-Field RFID Application 1 Design of UHF Frctl Antenn for Loclized Ner-Field RFID Appliction Yonghui To, Erfu Yng, Yxin Dong, nd Gng Wng, Memer, IEEE Astrct In this pper, frctl structure is proposed for loclized ner-field UHF

More information

Genetic Representations for Evolutionary Minimization of Network Coding Resources

Genetic Representations for Evolutionary Minimization of Network Coding Resources Genetic Representtions for Evolutionry Minimiztion of Network Coding Resources Minkyu Kim 1, Vrun Aggrwl 2, Un-My O Reilly 2, Muriel Médrd 1, nd Wonsik Kim 1 1 Lortory for Informtion nd Decision Systems

More information

Travel Prediction-based Data Forwarding for Sparse Vehicular Networks. Technical Report

Travel Prediction-based Data Forwarding for Sparse Vehicular Networks. Technical Report Trvel Prediction-sed Dt Forwrding for Sprse Vehiculr Networks Technicl Report Deprtment of Computer Science nd Engineering University of Minnesot 4-192 Keller Hll 200 Union Street SE Minnepolis, MN 55455-0159

More information

Study on SLT calibration method of 2-port waveguide DUT

Study on SLT calibration method of 2-port waveguide DUT Interntionl Conference on Advnced Electronic cience nd Technology (AET 206) tudy on LT clibrtion method of 2-port wveguide DUT Wenqing Luo, Anyong Hu, Ki Liu nd Xi Chen chool of Electronics nd Informtion

More information

Throughput of Wireless Relay Networks with Interference Processing

Throughput of Wireless Relay Networks with Interference Processing NCC 2009, Jnury 16-18, IIT Guwhti 170 Throughput of Wireless Rely Networks with Interference Processing M. Bm, rikrishn Bhshym nd Andrew Thngrj, eprtment of Electricl Engineering, Indin Institute of Technology,

More information

Information-Coupled Turbo Codes for LTE Systems

Information-Coupled Turbo Codes for LTE Systems Informtion-Coupled Turbo Codes for LTE Systems Lei Yng, Yixun Xie, Xiowei Wu, Jinhong Yun, Xingqing Cheng nd Lei Wn rxiv:709.06774v [cs.it] 20 Sep 207 Abstrct We propose new clss of informtion-coupled

More information

Experiment 3: Non-Ideal Operational Amplifiers

Experiment 3: Non-Ideal Operational Amplifiers Experiment 3: Non-Idel Opertionl Amplifiers Fll 2009 Equivlent Circuits The bsic ssumptions for n idel opertionl mplifier re n infinite differentil gin ( d ), n infinite input resistnce (R i ), zero output

More information

MAXIMUM FLOWS IN FUZZY NETWORKS WITH FUNNEL-SHAPED NODES

MAXIMUM FLOWS IN FUZZY NETWORKS WITH FUNNEL-SHAPED NODES MAXIMUM FLOWS IN FUZZY NETWORKS WITH FUNNEL-SHAPED NODES Romn V. Tyshchuk Informtion Systems Deprtment, AMI corportion, Donetsk, Ukrine E-mil: rt_science@hotmil.com 1 INTRODUCTION During the considertion

More information

CHAPTER 2 LITERATURE STUDY

CHAPTER 2 LITERATURE STUDY CHAPTER LITERATURE STUDY. Introduction Multipliction involves two bsic opertions: the genertion of the prtil products nd their ccumultion. Therefore, there re two possible wys to speed up the multipliction:

More information

Kirchhoff s Rules. Kirchhoff s Laws. Kirchhoff s Rules. Kirchhoff s Laws. Practice. Understanding SPH4UW. Kirchhoff s Voltage Rule (KVR):

Kirchhoff s Rules. Kirchhoff s Laws. Kirchhoff s Rules. Kirchhoff s Laws. Practice. Understanding SPH4UW. Kirchhoff s Voltage Rule (KVR): SPH4UW Kirchhoff s ules Kirchhoff s oltge ule (K): Sum of voltge drops round loop is zero. Kirchhoff s Lws Kirchhoff s Current ule (KC): Current going in equls current coming out. Kirchhoff s ules etween

More information

Energy Harvesting Two-Way Channels With Decoding and Processing Costs

Energy Harvesting Two-Way Channels With Decoding and Processing Costs IEEE TRANSACTIONS ON GREEN COMMUNICATIONS AND NETWORKING, VOL., NO., MARCH 07 3 Energy Hrvesting Two-Wy Chnnels With Decoding nd Processing Costs Ahmed Arf, Student Member, IEEE, Abdulrhmn Bknin, Student

More information

Experiment 3: Non-Ideal Operational Amplifiers

Experiment 3: Non-Ideal Operational Amplifiers Experiment 3: Non-Idel Opertionl Amplifiers 9/11/06 Equivlent Circuits The bsic ssumptions for n idel opertionl mplifier re n infinite differentil gin ( d ), n infinite input resistnce (R i ), zero output

More information

THE explosive traffic demand is challenging current cellular. MmWave Massive MIMO Based Wireless Backhaul for 5G Ultra-Dense Network

THE explosive traffic demand is challenging current cellular. MmWave Massive MIMO Based Wireless Backhaul for 5G Ultra-Dense Network MmWve Mssive MIMO Bsed Wireless Bchul for 5G Ultr-Dense Networ Zhen Go, Linglong Di, De Mi, Zhocheng Wng, Muhmmd Ali Imrn, nd Muhmmd Zeeshn Shir rxiv:508.03940v3 [cs.it] 27 Nov 205 Abstrct Ultr-dense networ

More information

Algorithms for Memory Hierarchies Lecture 14

Algorithms for Memory Hierarchies Lecture 14 Algorithms for emory Hierrchies Lecture 4 Lecturer: Nodri Sitchinv Scribe: ichel Hmnn Prllelism nd Cche Obliviousness The combintion of prllelism nd cche obliviousness is n ongoing topic of reserch, in

More information

A Slot-Asynchronous MAC Protocol Design for Blind Rendezvous in Cognitive Radio Networks

A Slot-Asynchronous MAC Protocol Design for Blind Rendezvous in Cognitive Radio Networks Globecom 04 - Wireless Networking Symposium A Slot-Asynchronous MAC Protocol Design for Blind Rendezvous in Cognitive Rdio Networks Xingy Liu nd Jing Xie Deprtment of Electricl nd Computer Engineering

More information

LATEST CALIBRATION OF GLONASS P-CODE TIME RECEIVERS

LATEST CALIBRATION OF GLONASS P-CODE TIME RECEIVERS LATEST CALIBRATION OF GLONASS P-CODE TIME RECEIVERS A. Fos 1, J. Nwroci 2, nd W. Lewndowsi 3 1 Spce Reserch Centre of Polish Acdemy of Sciences, ul. Brtyc 18A, 00-716 Wrsw, Polnd; E-mil: fos@c.ww.pl; Tel.:

More information

Mixed CMOS PTL Adders

Mixed CMOS PTL Adders Anis do XXVI Congresso d SBC WCOMPA l I Workshop de Computção e Aplicções 14 20 de julho de 2006 Cmpo Grnde, MS Mixed CMOS PTL Adders Déor Mott, Reginldo d N. Tvres Engenhri em Sistems Digitis Universidde

More information

& Y Connected resistors, Light emitting diode.

& Y Connected resistors, Light emitting diode. & Y Connected resistors, Light emitting diode. Experiment # 02 Ojectives: To get some hndson experience with the physicl instruments. To investigte the equivlent resistors, nd Y connected resistors, nd

More information

Soft-decision Viterbi Decoding with Diversity Combining. T.Sakai, K.Kobayashi, S.Kubota, M.Morikura, S.Kato

Soft-decision Viterbi Decoding with Diversity Combining. T.Sakai, K.Kobayashi, S.Kubota, M.Morikura, S.Kato Softdecision Viterbi Decoding with Diversity Combining T.Ski, K.Kobyshi, S.Kubot, M.Morikur, S.Kto NTT Rdio Communiction Systems Lbortories 2356 Tke, Yokosukshi, Kngw, 2383 Jpn ABSTRACT Diversity combining

More information

Adaptive Network Coding for Wireless Access Networks

Adaptive Network Coding for Wireless Access Networks Adptive Network Coding for Wireless Access Networks Tun Trn School of Electricl Engineering nd Computer Science Oregon Stte University, Corvllis, Oregon 9733 Emil: trntu@eecs.orst.edu Thinh Nguyen School

More information

Sequential Logic (2) Synchronous vs Asynchronous Sequential Circuit. Clock Signal. Synchronous Sequential Circuits. FSM Overview 9/10/12

Sequential Logic (2) Synchronous vs Asynchronous Sequential Circuit. Clock Signal. Synchronous Sequential Circuits. FSM Overview 9/10/12 9//2 Sequentil (2) ENGG5 st Semester, 22 Dr. Hden So Deprtment of Electricl nd Electronic Engineering http://www.eee.hku.hk/~engg5 Snchronous vs Asnchronous Sequentil Circuit This Course snchronous Sequentil

More information

A New Algorithm to Compute Alternate Paths in Reliable OSPF (ROSPF)

A New Algorithm to Compute Alternate Paths in Reliable OSPF (ROSPF) A New Algorithm to Compute Alternte Pths in Relile OSPF (ROSPF) Jin Pu *, Eric Mnning, Gholmli C. Shoj, Annd Srinivsn ** PANDA Group, Computer Science Deprtment University of Victori Victori, BC, Cnd Astrct

More information

Chapter 2 Literature Review

Chapter 2 Literature Review Chpter 2 Literture Review 2.1 ADDER TOPOLOGIES Mny different dder rchitectures hve een proposed for inry ddition since 1950 s to improve vrious spects of speed, re nd power. Ripple Crry Adder hve the simplest

More information

Analysis of Coding-aware MAC Protocols based on Reverse Direction Protocol for IEEE based Wireless Networks using Network Coding*

Analysis of Coding-aware MAC Protocols based on Reverse Direction Protocol for IEEE based Wireless Networks using Network Coding* Anlysis of oding-wre MA Protocols sed on Reverse irection Protocol for IEEE 8.-sed Wireless Networks using Network oding* Rul Plcios, Htegereil Kssye Hile, Jesus Alonso-Zrte nd Frizio Grnelli {plciostrujillo,

More information

Proceedings of Meetings on Acoustics

Proceedings of Meetings on Acoustics Proceedings of Meetings on Acoustics Volume 19, 2013 http://cousticlsociety.org/ ICA 2013 Montrel Montrel, Cnd 2-7 June 2013 Signl Processing in Acoustics Session 4SP: Sensor Arry Bemforming nd Its Applictions

More information

Efficient and Resilient Key Discovery based on Pseudo-Random Key Pre-Deployment

Efficient and Resilient Key Discovery based on Pseudo-Random Key Pre-Deployment Efficient nd Resilient Key Discovery sed on Pseudo-Rndom Key Pre-Deployment p. 1 Efficient nd Resilient Key Discovery sed on Pseudo-Rndom Key Pre-Deployment Roerto Di Pietro, Luigi V. Mncini, nd Alessndro

More information

ISSCC 2006 / SESSION 21 / ADVANCED CLOCKING, LOGIC AND SIGNALING TECHNIQUES / 21.5

ISSCC 2006 / SESSION 21 / ADVANCED CLOCKING, LOGIC AND SIGNALING TECHNIQUES / 21.5 21.5 A 1.1GHz Chrge-Recovery Logic Visvesh Sthe, Jung-Ying Chueh, Mrios Ppefthymiou University of Michign, Ann Aror, MI Boost Logic is chrge-recovery circuit fmily cple of operting t GHz-clss frequencies

More information

University of Bristol - Explore Bristol Research. Peer reviewed version. Link to published version (if available): /iet-com.2017.

University of Bristol - Explore Bristol Research. Peer reviewed version. Link to published version (if available): /iet-com.2017. Ameen, A. S., Berrki, D., Doufexi, A., & Nix, A. R. (2018). LTE-Advnced network inter-cell interference nlysis nd mitigtion using 3D nlogue emforming. IET Communictions, 12(13), 1563-1572. DOI: 10.1049/ietcom.2017.0765

More information

Signaling-Embedded Preamble Design for Flexible Optical Transport Networks

Signaling-Embedded Preamble Design for Flexible Optical Transport Networks Signling-Embedded Premble Design for Flexible Opticl Trnsport Networks Linglong Di nd Zhocheng Wng Tsinghu Ntionl Lbortory for Informtion Science nd Technology, Deprtment of Electronic Engineering, Tsinghu

More information

2016 2Q Wireless Communication Engineering. #10 Spread Spectrum & Code Division Multiple Access (CDMA)

2016 2Q Wireless Communication Engineering. #10 Spread Spectrum & Code Division Multiple Access (CDMA) 16 Q Wireless Communiction Engineering #1 Spred Spectrum & Code Division Multiple Access (CDMA Kei Skguchi skguchi@mobile.ee. July 9, 16 Course Schedule ( Dte ext Contents #7 July 15 4.6 Error correction

More information

10.4 AREAS AND LENGTHS IN POLAR COORDINATES

10.4 AREAS AND LENGTHS IN POLAR COORDINATES 65 CHAPTER PARAMETRIC EQUATINS AND PLAR CRDINATES.4 AREAS AND LENGTHS IN PLAR CRDINATES In this section we develop the formul for the re of region whose oundry is given y polr eqution. We need to use the

More information

EXIT CHARTS FOR TURBO RECEIVERS IN MIMO SYSTEMS

EXIT CHARTS FOR TURBO RECEIVERS IN MIMO SYSTEMS EXIT CHATS FO TUBO ECEIVES IN MIMO SYSTEMS Césr Hermosill Universidd Técnic Federico Snt Mrí Vlpríso, Chile hermosil@inrs-telecomuquebecc Leszek Szczeciński Institut Ntionl de l echerche Scientifique-EMT

More information

CSI-SF: Estimating Wireless Channel State Using CSI Sampling & Fusion

CSI-SF: Estimating Wireless Channel State Using CSI Sampling & Fusion CSI-SF: Estimting Wireless Chnnel Stte Using CSI Smpling & Fusion Riccrdo Crepldi, Jeongkeun Lee, Rul Etkin, Sung-Ju Lee, Robin Krvets University of Illinois t Urbn-Chmpign Hewlett-Pckrd Lbortories Emil:{rcrepl,rhk}@illinoisedu,

More information

Design and implementation of a high-speed bit-serial SFQ adder based on the binary decision diagram

Design and implementation of a high-speed bit-serial SFQ adder based on the binary decision diagram INSTITUTE OFPHYSICS PUBLISHING Supercond. Sci. Technol. 16 (23) 1497 152 SUPERCONDUCTORSCIENCE AND TECHNOLOGY PII: S953-248(3)67111-3 Design nd implementtion of high-speed it-seril SFQ dder sed on the

More information

High-speed Simulation of the GPRS Link Layer

High-speed Simulation of the GPRS Link Layer 989 High-speed Simultion of the GPRS Link Lyer J Gozlvez nd J Dunlop Deprtment of Electronic nd Electricl Engineering, University of Strthclyde 204 George St, Glsgow G-lXW, Scotlnd Tel: +44 4 548 206,

More information

Y9.ET1.3 Implementation of Secure Energy Management against Cyber/physical Attacks for FREEDM System

Y9.ET1.3 Implementation of Secure Energy Management against Cyber/physical Attacks for FREEDM System Y9.ET1.3 Implementtion of Secure Energy ngement ginst Cyber/physicl Attcks for FREED System Project Leder: Fculty: Students: Dr. Bruce cillin Dr. o-yuen Chow Jie Dun 1. Project Gols Develop resilient cyber-physicl

More information

RT-Link: A Time-Synchronized Link Protocol for Energy Constrained Multi-hop Wireless Networks

RT-Link: A Time-Synchronized Link Protocol for Energy Constrained Multi-hop Wireless Networks RT-Link: A Time-Synchronized Link Protocol for Energy Constrined Multi-hop Wireless Networks Anthony Rowe, Rhul Mnghrm, Rj Rjkumr Electricl nd Computer Engineering Deprtment, Crnegie Mellon University,

More information

Area-Time Efficient Digit-Serial-Serial Two s Complement Multiplier

Area-Time Efficient Digit-Serial-Serial Two s Complement Multiplier Are-Time Efficient Digit-Seril-Seril Two s Complement Multiplier Essm Elsyed nd Htem M. El-Boghddi Computer Engineering Deprtment, Ciro University, Egypt Astrct - Multipliction is n importnt primitive

More information

AN ANALYSIS ON SYNTHETIC APERTURE RADAR DATA AND ENHANCEMENT OF RECONSTRUCTED IMAGES

AN ANALYSIS ON SYNTHETIC APERTURE RADAR DATA AND ENHANCEMENT OF RECONSTRUCTED IMAGES AN ANALYSIS ON SYNTHETIC APERTURE RADAR DATA AND ENHANCEMENT OF RECONSTRUCTED IMAGES Cihn Erş e-mil: ers@eh.itu.edu.tr Istnul Technicl University, Fculty of Electricl nd Electronics Engineering, Deprtment

More information

Topology Design in Time-Evolving Delay-Tolerant Networks with Unreliable Links

Topology Design in Time-Evolving Delay-Tolerant Networks with Unreliable Links Topology Design in Time-Eoling Dely-Tolernt Networks with Unrelile Links Minsu Hung Siyun Chen Fn Li Yu Wng Deprtment of Computer Science, Uniersity of North Crolin t Chrlotte, Chrlotte, NC 83, USA. School

More information

Engineer-to-Engineer Note

Engineer-to-Engineer Note Engineer-to-Engineer Note EE-297 Technicl notes on using Anlog Devices DSPs, processors nd development tools Visit our Web resources http://www.nlog.com/ee-notes nd http://www.nlog.com/processors or e-mil

More information

The Discussion of this exercise covers the following points:

The Discussion of this exercise covers the following points: Exercise 4 Bttery Chrging Methods EXERCISE OBJECTIVE When you hve completed this exercise, you will be fmilir with the different chrging methods nd chrge-control techniques commonly used when chrging Ni-MI

More information

Open Access A Novel Parallel Current-sharing Control Method of Switch Power Supply

Open Access A Novel Parallel Current-sharing Control Method of Switch Power Supply Send Orders for Reprints to reprints@enthmscience.e 170 The Open Electricl & Electronic Engineering Journl, 2014, 8, 170-177 Open Access A Novel Prllel Current-shring Control Method of Switch Power Supply

More information

Temporal Secondary Access Opportunities for WLAN in Radar Bands

Temporal Secondary Access Opportunities for WLAN in Radar Bands The 4th Interntionl Symposium on Wireless Personl Multimedi Communictions WPMC'), Temporl Secondry Access Opportunities for WLAN in Rdr Bnds Miurel Tercero, Ki Won Sung, nd Jens Znder Wireless@KTH, Royl

More information

Exercise 1-1. The Sine Wave EXERCISE OBJECTIVE DISCUSSION OUTLINE. Relationship between a rotating phasor and a sine wave DISCUSSION

Exercise 1-1. The Sine Wave EXERCISE OBJECTIVE DISCUSSION OUTLINE. Relationship between a rotating phasor and a sine wave DISCUSSION Exercise 1-1 The Sine Wve EXERCISE OBJECTIVE When you hve completed this exercise, you will be fmilir with the notion of sine wve nd how it cn be expressed s phsor rotting round the center of circle. You

More information

On the Prediction of EPON Traffic Using Polynomial Fitting in Optical Network Units

On the Prediction of EPON Traffic Using Polynomial Fitting in Optical Network Units On the Prediction of EP Trffic Using Polynomil Fitting in Opticl Networ Units I. Mmounis (1),(3), K. Yinnopoulos (2), G. Ppdimitriou (4), E. Vrvrigos (1),(3) (1) Computer Technology Institute nd Press

More information

Simulation of Transformer Based Z-Source Inverter to Obtain High Voltage Boost Ability

Simulation of Transformer Based Z-Source Inverter to Obtain High Voltage Boost Ability Interntionl Journl of cience, Engineering nd Technology Reserch (IJETR), olume 4, Issue 1, October 15 imultion of Trnsformer Bsed Z-ource Inverter to Obtin High oltge Boost Ability A.hnmugpriy 1, M.Ishwry

More information

Th ELI1 09 Broadband Processing of West of Shetland Data

Th ELI1 09 Broadband Processing of West of Shetland Data Th ELI 9 Brodnd Processing of West of Shetlnd Dt R. Telling* (Dolphin Geophysicl Limited), N. Riddlls (Dolphin Geophysicl Ltd), A. Azmi (Dolphin Geophysicl Ltd), S. Grion (Dolphin Geophysicl Ltd) & G.

More information

Distance dependent Call Blocking Probability, and Area Erlang Efficiency of Cellular Networks

Distance dependent Call Blocking Probability, and Area Erlang Efficiency of Cellular Networks Distnce dependent Cll Blocking Probbility, nd Are Erlng Efficiency of Cellulr Networks Subhendu Btbyl 1, Suvr Sekhr Ds 1,2 1 G.S.Snyl School of Telecommuniction, Indin Institute of Technology Khrgpur,

More information

Jamming-Resistant Collaborative Broadcast In Wireless Networks, Part II: Multihop Networks

Jamming-Resistant Collaborative Broadcast In Wireless Networks, Part II: Multihop Networks Jmming-Resistnt ollbortive Brodcst In Wireless Networks, Prt II: Multihop Networks Ling Xio Ximen University, hin 361005 Emil: lxio@xmu.edu.cn Huiyu Di N Stte University, Rleigh, N 27695 Emil: huiyu di@ncsu.edu

More information

Redundancy Data Elimination Scheme Based on Stitching Technique in Image Senor Networks

Redundancy Data Elimination Scheme Based on Stitching Technique in Image Senor Networks Sensors & Trnsducers 204 by IFSA Publishing, S. L. http://www.sensorsportl.com Redundncy Dt Elimintion Scheme Bsed on Stitching Technique in Imge Senor Networks hunling Tng hongqing Technology nd Business

More information

CDMA One. International summer students courses: "Plugged In: Modern Networks and Services in Telecommunication"

CDMA One. International summer students courses: Plugged In: Modern Networks and Services in Telecommunication INTRAROM S.A. ROMANIAN TELECOMMUNICATIONS AND ELECTRONICS INDUSTRY ROMANIA, Buchrest, 17 Fbric de Glucoz St., Sector 2 Cod 72322, Tel:(+40 1) 2040600 Fx:(+40 1) 2040611 http://www.intrrom.ro Interntionl

More information

Address for Correspondence

Address for Correspondence Mrndn et l., Interntionl Journl of Advnced Engineering Technology E-ISSN 0976-3945 Reserch Pper A LATTICE REDUCTION-AIDED INFORMATION PRECODER FOR MULTIUSER COMMUNICATION SYSTEM S. Mrndn, N. Venteswrn

More information

Understanding Basic Analog Ideal Op Amps

Understanding Basic Analog Ideal Op Amps Appliction Report SLAA068A - April 2000 Understnding Bsic Anlog Idel Op Amps Ron Mncini Mixed Signl Products ABSTRACT This ppliction report develops the equtions for the idel opertionl mplifier (op mp).

More information

Experimental Application of H Output-Feedback Controller on Two Links of SCARA Robot

Experimental Application of H Output-Feedback Controller on Two Links of SCARA Robot INTERNATIONAL JOURNAL OF CONTROL, AUTOMATION AND SYSTEMS VOL.5 NO. Jnury 6 ISSN 65-877 (Print) ISSN 65-885 (Online) http://www.reserchpu.org/journl/jc/jc.html Experimentl Appliction of H Output-Feedck

More information

A Cluster-based TDMA System for Inter-Vehicle Communications *

A Cluster-based TDMA System for Inter-Vehicle Communications * JOURNAL OF INFORMATION SCIENCE AND ENGINEERING 30, 213-231 (2014) A Cluster-bsed TDMA System for Inter-Vehicle Communictions * Deprtment of Electricl Engineering Ntionl Sun Yt-Sen University Kohsiung,

More information

Software for the automatic scaling of critical frequency f 0 F2 and MUF(3000)F2 from ionograms applied at the Ionospheric Observatory of Gibilmanna

Software for the automatic scaling of critical frequency f 0 F2 and MUF(3000)F2 from ionograms applied at the Ionospheric Observatory of Gibilmanna ANNALS OF GEOPHYSICS, VOL. 47, N. 6, Decemer 2004 Softwre for the utomtic scling of criticl frequency f 0 F2 nd MUF(3000)F2 from ionogrms pplied t the Ionospheric Oservtory of Giilmnn Michel Pezzopne nd

More information

Distributed two-hop proportional fair resource allocation in Long Term Evolution Advanced networks

Distributed two-hop proportional fair resource allocation in Long Term Evolution Advanced networks WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2016; 16:264 278 Published online 12 August 2014 in Wiley Online Librry (wileyonlinelibrry.com)..2517 RESEARCH ARTICLE Distributed

More information

Magnetic monopole field exposed by electrons

Magnetic monopole field exposed by electrons Mgnetic monopole field exposed y electrons A. Béché, R. Vn Boxem, G. Vn Tendeloo, nd J. Vereeck EMAT, University of Antwerp, Groenenorgerln 171, 22 Antwerp, Belgium Opticl xis Opticl xis Needle Smple Needle

More information

DIGITAL multipliers [1], [2] are the core components of

DIGITAL multipliers [1], [2] are the core components of World Acdemy of Science, Engineering nd Technology 9 8 A Reduced-Bit Multipliction Algorithm for Digitl Arithmetic Hrpreet Singh Dhillon nd Ahijit Mitr Astrct A reduced-it multipliction lgorithm sed on

More information

Energy-efficient scheduling and hybrid communication architecture for underwater littoral surveillance

Energy-efficient scheduling and hybrid communication architecture for underwater littoral surveillance Computer Communictions xxx (26) xxx xxx www.elsevier.com/locte/comcom Energy-efficient scheduling nd hybrid communiction rchitecture for underwter littorl surveillnce Mihel Crdei * Deprtment of Computer

More information

A Comparative Analysis of Algorithms for Determining the Peak Position of a Stripe to Sub-pixel Accuracy

A Comparative Analysis of Algorithms for Determining the Peak Position of a Stripe to Sub-pixel Accuracy A Comprtive Anlysis of Algorithms for Determining the Pek Position of Stripe to Sub-pixel Accurcy D.K.Nidu R.B.Fisher Deprtment of Artificil Intelligence, University of Edinburgh 5 Forrest Hill, Edinburgh

More information

Implementation of Different Architectures of Forward 4x4 Integer DCT For H.264/AVC Encoder

Implementation of Different Architectures of Forward 4x4 Integer DCT For H.264/AVC Encoder Implementtion of Different Architectures of Forwrd 4x4 Integer DCT For H.64/AVC Encoder Bunji Antoinette Ringnyu, Ali Tngel, Emre Krulut 3 Koceli University, Institute of Science nd Technology, Koceli,

More information

4110 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 66, NO. 5, MAY 2017

4110 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 66, NO. 5, MAY 2017 40 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 66, NO. 5, MAY 07 Trnsmit Power Control for DD-Underlid Cellulr Networs Bsed on Sttisticl Fetures Peng Sun, Kng G. Shin, Life Fellow, IEEE, Hilin Zhng,

More information

D I G I TA L C A M E R A S PA RT 4

D I G I TA L C A M E R A S PA RT 4 Digitl Cmer Technologies for Scientific Bio-Imging. Prt 4: Signl-to-Noise Rtio nd Imge Comprison of Cmers Yshvinder Shrwl, Solexis Advisors LLC, Austin, TX, USA B I O G R A P H Y Yshvinder Shrwl hs BS

More information

Asynchronous Data-Driven Circuit Synthesis

Asynchronous Data-Driven Circuit Synthesis Asynchronous Dt-Driven Circuit Synthesis Sm Tylor, Doug Edwrds, Luis A Pln, Senior Memer, IEEE nd Luis A. Trzon D., Student Memer, IEEE Astrct A method is descried for synthesising synchronous circuits

More information

Convolutional Networks. Lecture slides for Chapter 9 of Deep Learning Ian Goodfellow

Convolutional Networks. Lecture slides for Chapter 9 of Deep Learning Ian Goodfellow Convolutionl Networks Lecture slides for Chpter 9 of Deep Lerning In Goodfellow 2016-09-12 Convolutionl Networks Scle up neurl networks to process very lrge imges / video sequences Sprse connections Prmeter

More information

Available online at ScienceDirect. Procedia Engineering 89 (2014 )

Available online at   ScienceDirect. Procedia Engineering 89 (2014 ) Aville online t www.sciencedirect.com ScienceDirect Procedi Engineering 89 (2014 ) 411 417 16th Conference on Wter Distriution System Anlysis, WDSA 2014 A New Indictor for Rel-Time Lek Detection in Wter

More information

arxiv: v1 [cs.cc] 29 Mar 2012

arxiv: v1 [cs.cc] 29 Mar 2012 Solving Mhjong Solitire ords with peeking Michiel de Bondt rxiv:1203.6559v1 [cs.cc] 29 Mr 2012 Decemer 22, 2013 Astrct We first prove tht solving Mhjong Solitire ords with peeking is NPcomplete, even if

More information

Analysis of circuits containing active elements by using modified T - graphs

Analysis of circuits containing active elements by using modified T - graphs Anlsis of circuits contining ctive elements using modified T - grphs DALBO BOLEK *) nd EA BOLKOA**) Deprtment of Telecommunictions *) dioelectronics **) Brno Universit of Technolog Purknov 8, 6 Brno CECH

More information

Nevery electronic device, since all the semiconductor

Nevery electronic device, since all the semiconductor Proceedings of Interntionl Joint Conference on Neurl Networks, Orlndo, Florid, USA, August 12-17, 2007 A Self-tuning for Rel-time Voltge Regultion Weiming Li, Xio-Hu Yu Abstrct In this reserch, self-tuning

More information

Synchronous Machine Parameter Measurement

Synchronous Machine Parameter Measurement Synchronous Mchine Prmeter Mesurement 1 Synchronous Mchine Prmeter Mesurement Introduction Wound field synchronous mchines re mostly used for power genertion but lso re well suited for motor pplictions

More information

Localization of Latent Image in Heterophase AgBr(I) Tabular Microcrystals

Localization of Latent Image in Heterophase AgBr(I) Tabular Microcrystals Interntionl ymposium on ilver Hlide Technology Locliztion of Ltent Imge in Heterophse AgBr(I) Tulr Microcrystls Elen V. Prosvirkin, Aigul B. Aishev, Timothy A. Lrichev, Boris A. echkrev Kemerovo tte University,

More information

Alternating-Current Circuits

Alternating-Current Circuits chpter 33 Alternting-Current Circuits 33.1 AC Sources 33.2 esistors in n AC Circuit 33.3 Inductors in n AC Circuit 33.4 Cpcitors in n AC Circuit 33.5 The LC Series Circuit 33.6 Power in n AC Circuit 33.7

More information

Design and Modeling of Substrate Integrated Waveguide based Antenna to Study the Effect of Different Dielectric Materials

Design and Modeling of Substrate Integrated Waveguide based Antenna to Study the Effect of Different Dielectric Materials Design nd Modeling of Substrte Integrted Wveguide bsed Antenn to Study the Effect of Different Dielectric Mterils Jgmeet Kour 1, Gurpdm Singh 1, Sndeep Ary 2 1Deprtment of Electronics nd Communiction Engineering,

More information

Two-layer slotted-waveguide antenna array with broad reflection/gain bandwidth at millimetre-wave frequencies

Two-layer slotted-waveguide antenna array with broad reflection/gain bandwidth at millimetre-wave frequencies Two-lyer slotted-wveguide ntenn rry with rod reflection/gin ndwidth t millimetre-wve frequencies S.-S. Oh, J.-W. Lee, M.-S. Song nd Y.-S. Kim Astrct: A 24 24 slotted-wveguide rry ntenn is presented in

More information

A Novel Back EMF Zero Crossing Detection of Brushless DC Motor Based on PWM

A Novel Back EMF Zero Crossing Detection of Brushless DC Motor Based on PWM A ovel Bck EMF Zero Crossing Detection of Brushless DC Motor Bsed on PWM Zhu Bo-peng Wei Hi-feng School of Electricl nd Informtion, Jingsu niversity of Science nd Technology, Zhenjing 1003 Chin) Abstrct:

More information

Application of Wavelet De-noising in Vibration Torque Measurement

Application of Wavelet De-noising in Vibration Torque Measurement IJCSI Interntionl Journl of Computer Science Issues, Vol. 9, Issue 5, No 3, September 01 www.ijcsi.org 9 Appliction of Wvelet De-noising in Vibrtion orque Mesurement Ho Zho 1 1 Jixing University, Jixing,

More information

Discontinued AN6262N, AN6263N. (planed maintenance type, maintenance type, planed discontinued typed, discontinued type)

Discontinued AN6262N, AN6263N. (planed maintenance type, maintenance type, planed discontinued typed, discontinued type) ICs for Cssette, Cssette Deck ANN, ANN Puse Detection s of Rdio Cssette, Cssette Deck Overview The ANN nd the ANN re the puse detection integrted circuits which select the progrm on the cssette tpe. In

More information

An Analog Baseband Approach for Designing Full-Duplex Radios

An Analog Baseband Approach for Designing Full-Duplex Radios An Anlog Bsend Approch for Designing Full-Duplex Rdios Brett Kufmn, Jorm Lilleerg, nd Behnm Azhng Center for Multimedi Communiction, Rice University, Houston, Texs, USA Centre for Wireless Communictions,

More information

A Development of Earthing-Resistance-Estimation Instrument

A Development of Earthing-Resistance-Estimation Instrument A Development of Erthing-Resistnce-Estimtion Instrument HITOSHI KIJIMA Abstrct: - Whenever erth construction work is done, the implnted number nd depth of electrodes hve to be estimted in order to obtin

More information

Digital Design. Sequential Logic Design -- Controllers. Copyright 2007 Frank Vahid

Digital Design. Sequential Logic Design -- Controllers. Copyright 2007 Frank Vahid Digitl Design Sequentil Logic Design -- Controllers Slides to ccompny the tetook Digitl Design, First Edition, y, John Wiley nd Sons Pulishers, 27. http://www.ddvhid.com Copyright 27 Instructors of courses

More information

Math Circles Finite Automata Question Sheet 3 (Solutions)

Math Circles Finite Automata Question Sheet 3 (Solutions) Mth Circles Finite Automt Question Sheet 3 (Solutions) Nickols Rollick nrollick@uwterloo.c Novemer 2, 28 Note: These solutions my give you the nswers to ll the prolems, ut they usully won t tell you how

More information

BP-P2P: Belief Propagation-Based Trust and Reputation Management for P2P Networks

BP-P2P: Belief Propagation-Based Trust and Reputation Management for P2P Networks BP-PP: Belief Propgtion-Bsed Trust nd Reputtion Mngement for PP Networs Ermn Aydy School of Electricl nd Comp. Eng. Georgi Institute of Technology Atlnt, GA 333, USA Emil: eydy@gtech.edu Frmrz Feri School

More information

Multipath Mitigation for Bridge Deformation Monitoring

Multipath Mitigation for Bridge Deformation Monitoring Journl of Globl Positioning Systems (22) Vol. 1, No. 1: 25-33 Multipth Mitigtion for Bridge Deformtion Monitoring G. W. Roberts, X. Meng, A. H. Dodson, E. Cosser Institute of Engineering Surveying nd Spce

More information

Fair Coalitions for Power-Aware Routing in Wireless Networks

Fair Coalitions for Power-Aware Routing in Wireless Networks Fir Colitions for Power-Awre Routing in Wireless Networks Rtul K. Guh, Crl A. Gunter nd Sswti Srkr University of Pennsylvni {rguh@ses, gunter@.cis, swti@.ee }.upenn.edu Astrct Severl power wre routing

More information

Performance Monitoring Fundamentals: Demystifying Performance Assessment Techniques

Performance Monitoring Fundamentals: Demystifying Performance Assessment Techniques Simplifying PID Control. Optimizing Plnt Performnce. Performnce Monitoring Fundmentls: Demystifying Performnce Assessment Techniques Roert C. Rice, PhD Rchelle R. Jyringi Dougls J. Cooper, PhD Control

More information

This is a repository copy of Four-port diplexer for high Tx/Rx isolation for integrated transceivers.

This is a repository copy of Four-port diplexer for high Tx/Rx isolation for integrated transceivers. This is repository copy of Four-port diplexer for high Tx/Rx isoltion for integrted trnsceivers. White Rose Reserch Online URL for this pper: http://eprints.whiterose.c.uk/124000/ Version: Accepted Version

More information