Subcarrier Grouping with Environmental Sensing for MIMO-OFDM Systems over Correlated Double-selective Fading Channels

Size: px
Start display at page:

Download "Subcarrier Grouping with Environmental Sensing for MIMO-OFDM Systems over Correlated Double-selective Fading Channels"

Transcription

1 1 Subcarrier Groupig with Evirometal Sesig for MIMO-OFDM Systems over Correlated Double-selective Fadig Chaels arxiv: v2 [cs.it] 19 Ju 2017 Jiaxu Lu, Zhegchua Che, Pigyi Fa, Khaled B. Letaief Tsighua Natioal Laboratory for Iformatio Sciece ad TechologyTNList), Departmet of Electroic Egieerig, Tsighua Uiversity,Beijig,Chia. Departmet of Electroic ad Computer Egieerig, Hog Kog Uiversity of Sciece ad Techology, Hog Kog Abstract MIMO-OFDM is a promisig techique i 5G wireless commuicatios. I high mobility scearios, the trasmissio eviromets are time varyig ad/or the relative movig velocity betwee the trasmitter ad receiver is also time varyig. I the literature, most of previous works maily focused o fixed subcarrier group size ad precoded the MIMO sigals with uitary chael state iformatio CSI). I this way, the subcarrier groupig may aturally lead to big loss of chael capacity i high mobility scearios due to the CSI differece o the subcarriers i each group. To employ the MIMO-OFDM techique, adaptive subcarrier groupig scheme may be a efficiet way. I this paper, we first cosider MIMO-OFDM systems over double-selective i.i.d. Rayleigh chaels ad ivestigate the quatitative relatio betwee subcarrier group size ad capacity loss theoretically. With developed theoretical results, we also propose a adaptive subcarrier groupig scheme to satisfy the preset capacity loss threshold by adjustig groupig size with the sesed evirometal iformatio ad mobile velocity. Theoretical aalysis ad simulatio results show that to achieve a better system capacity, a sparse scatterig, lower SNR ad lower velocity as well as properly large atea umber are matched with larger subcarrier group size. Oe importat observatio is that if the atea umber is too large ad higher tha a threshold, which will ot brig ay additioal gai to the subcarrier groupig. That is, the system

2 2 capacity loss will coverge to a lower-boud expeditiously with respect to atea umber, which is give i theory also. Idex Terms MIMO-OFDM, double-selective fadig chael, chael correlatio, adaptive subcarrier groupig. I. INTRODUCTION HIGH mobility is oe of the key scearios to 5G wireless commuicatios, i which, the trasmissio eviromets are time varyig ad/or the relative movig velocity betwee the trasmitter ad receiver is also time varyig. Thus, how to keep high spectrum efficiecy ad reliable trasmissio performace i such a scearios is becomig a full of challegig topic. As we kow, the OFDM modulatio scheme ca provide high spectrum efficiecy ad ehace system performace i frequecy selective fadig chaels [1], while the multi-atea structure improves system capacity, especially for the massive MIMO regimes [2]. Also, MIMO regimes ehaces system reliability as well as improves coverage [3], [4]. Therefore, MIMO-OFDM is a promisig techique i 5G systems, due to its provisio capability of high capacity ad spectrum efficiecy i rich scatterig wireless chaels [5]. But most of the joit desig works o MIMO- OFDM are assumed that its workig scearios are relatively qusi-static. Thus, the trasmissio scheme of MIMO-OFDM i mobility scearios eeds to be carefully desiged. That is, it should be capable of evirometal sesig ad adaptively adjustig to varyig trasmit eviromet ad movig velocity. I MIMO-OFDM regimes, various methods like frequecy ad spatial water-fillig are performed to maximize the capacity of wireless chaels [6]. Also, [7] proposes a liear precodig scheme to ehace the miimum user rate o multicast MIMO-OFDM systems. I additio, for coveiece of symbol modulatio ad sigal decodig at the trasmit ad receive side, liear or oliear sigal precodig schemes o each idividual subcarrier are carried out [8] [10]. For istace i [10], the sigal precodig scheme decomposes MIMO chaels ito several uiform sub-chaels, which simplifies subsequet modulatio ad improve diversity gais of system sigificatly. However, either water-fillig or sigal precodig demads perfect chael state iformatio at the trasmitter CSIT). Whe CSIT is ot readily available, it is ofte possible to use a feedback chael to provide chael state iformatio CSI) to the trasmitter or just

3 3 estimate CSI at the trasmit side via reciprocal priciple whe time divisio duplex is used. The procedure i achievig CSIT ad obtaiig sigal precodig matrices may occupy much too system resources, either frequecy badwidth or computatioal complexity. Especially i high subcarrier or atea umber regimes [11], [12]. A effective scheme to reduce system cost is to precode with subcarrier groupig, which is ot a ew idea [12] [15]. I subcarrier groupig regimes, trasmissio system will group subcarriers via a specific scheme ad apply a uitary precodig matrix to the subcarriers i oe group. Thus, oe ca liearly reduce the computatioal complexity of precodig process as well as decrease the system feedback CSI amout. However, the subcarrier groupig scheme aturally leads to system capacity loss caused by the differece of CSIT at subcarriers i oe subcarrier group, the larger the subcarrier group is, the greater the capacity loss suffers. This meas that there exists a tradeoff betwee the subcarrier group size ad system chael capacity. However, previous works i [12] [15] focused o the process of feedback iformatio, but eglected the adaptive adjustmet of subcarrier group size. Hece, previous precodig schemes with fixed groupig size may ot keep a effective adaptio of system services performace to varyig double-selective chaels. [16] proposes a adaptive subchael groupig scheme to simplify the multichael optimizatio problem, while satisfyig system services performace costrait. Similarly, [17] discussed the adaptive subcarrier groupig method oly i frequecy-selective chaels. Now we will exted it to double-selective chaels i this work. I this paper, we firstly ivestigate how the differece of CSIT affects chael capacity loss. The, by exploitig the relatios betwee chael correlatio ad the secod order of CSIT differece, we derive quatitative relatios betwee chael capacity loss ad subcarrier group size. The quatitative relatios reveal the explicit tradeoff betwee system service capacity ad system cost. I additio, based o the ew obtaied theoretical results, we also propose a adaptive subcarrier groupig based MIMO-OFDM sigal precodig algorithm to satisfy the preset capacity loss threshold, which adjusts the subcarrier group size adaptively with the sesed trasmit eviromet iformatio ad mobile velocity. The rest of this paper is orgaized as follows. Sectio II presets the system model ad its sceario of the subcarrier groupig based precodig scheme. I this sectio, we explai what the CSI differece is ad its relatios with CSIT differece. Sectio III derives the chael capacity with CSI differece i the view of iformatio theory. Meawhile, we also discuss the approximatio of correspodig ergodic capacity i this sectio. I Sectio IV, the relatios

4 Serial/Parallel IFFT Parallel/Serial Serial/Parallel FFT Parallel/Serial Serial/Parallel IFFT Parallel/Serial Serial/Parallel FFT Parallel/Serial 4 betwee CSI differece ad chael correlatio are ivestigated. The, the subcarrier groupig method, give the capacity loss costrait, is established with a mappig method. Based o the obtaied theoretical results, we propose a adaptive subcarrier groupig based precodig algorithm i Sectio IV ad give the theoretical performace aalysis i various scearios. Sectio V examies the effectiveess ad applicatio coditios of proposed subcarrier groupig scheme. Coclusios of this work are give i Sectio VI. Notatio: ) 1 ad ) deote the iverse ad cojugate traspose of ), respectively. The symbols 0 ad I deote the zero ad the idetical matrix, respectively. II. SYSTEM MODEL AND PROBLEM FORMULATION I this sectio, we shall first review the system model of MIMO-OFDM system. The, we explai how a subcarrier groupig based MIMO-OFDM sigal precodig algorithm works ad itroduce how the CSI differece caused by subcarrier groupig schemes affects the MIMO- OFDM commuicatio systems. A. Review of System Structure 1) x 1, 1) r 1, x 1, K 1) x - 1, K) x 1, 1 1 r - K 1) 1, K) r 1, R 1, 1) x 1, 1) r 1, x Nt, K 1) x - 1, N t N r R N r, K 1) r - 1, K) x 1, K) r 1, 1-st Precoder K-1)-th Precoder K-th Precoder 1-st Decoder K-1)-th Decoder K-th Decoder Fig. 1. Subcarrier groupig based MIMO-OFDM sigal precodig system. Let us cosider a MIMO-OFDM commuicatio system as show i Fig. 1. It ivolves withn t trasmit ateas ad N r receive ateas. K subcarriers are take ito accout i each OFDM blocks. For the cocise of aalysis, cyclic prefixes are igored ad let the, k)-th subcarrier deote the k-th subcarrier i the -th OFDM block. Deote the trasmit symbol vector at the

5 5,k)-th subcarrier as X k) = [x k) 1,,x k) 2,,,x k) N t, ]T. The correspodig N r N t chael fadig matrix is H k) ad the N t N t precodig matrix is F k). Thus, the precoded trasmit symbol vector ca be writte as X k) = Fk) Xk). 1) At the receiver, the correspodig received symbol vector R k) ca be obtaied by where R k) = [r k) R k) = H k) 1,,rk) 2,,,rk) X k) +W k) = H k) F k) X k) +W k), 2) N t, ]T ad W k) is the ormalized circular complex additive white Gaussia oise AWGN). I FDD regimes, the receiver eeds to feed back the CSI, i.e. H k), to trasmitter, while i TDD regimes it ca obtai the CSI via the reciprocal priciple. The obtaiig of CSI may acquire extra feedback badwidth or computatioal complexity cost, which may decrease system service performace. Especially for the fast time varyig chaels, the computatioal complexity ad the overhead cost for chael estimatio ca be usustaiable i practice. B. Subcarrier Groupig Ad Chael Model with CSI Differece I this part, we shall itroduce the subcarrier groupig method ad the correspodig chael model with CSI differece. Let c,k c ) be the ceter subcarrier. The correspodig subcarrier group is deoted as c,k c ), which is composed by the adjacet subcarriers of c,k c ) via specific method. For all subcarriers with subscript,k) c,k c ), oe ca apply precodig matrix F kc) c to precode trasmit vectors at the,k)-th subcarrier. Thus, the subcarrier groupig method ca be modeled by R k) = Hk) Fkc) c X k) +Wk). 3) Therefore, oly the CSI ad precodig matrix at the c,k c )-th subcarrier eeds to be acquired ad geerated. As see i 3), it shows that subcarrier groupig scheme aturally leads to the CSI differece betwee the,k)- ad c,k c )-th subcarriers, defied as M k,kc) = H k) Hkc) c. 4)

6 6 Obviously, the CSI differece itroduces iterferece to systems ad reduce chael capacity. This is the cost by usig subcarrier groupig techique, which limits the applicatio of subcarrier groupig i certai degree. That is, there exists a tradeoff betwee subcarrier group size ad chael capacity loss. We shall discuss it i the sequel. Substitutig 4) ito 3), the subcarrier groupig model ca be rewritte as R k) =Hkc) c +M, k,kc) c )F kc) c X k) +Wk) =H kc) c F kc) c X k) +M, k,kc) c F kc) c X k) +W k) } {{ } N k,kc), 5) where M k,kc) F kc) c X k) is the additioal iterferece itroduced by CSI differece. Deote the total iterferece icludig the additioal iterferece ad AWGN as the equivalet iterferece N k,kc). It ca be proved that it s related to chael self-correlatio, based o which, the quatitive relatio betwee capacity loss ad subcarrier group size will be show i Sectio III. Later, we preset a algorithm to satisfy the give capacity loss threshold by adaptively adjustig the size of subcarrier groups with the cocurret trasmit eviromet ad mobile velocity. That is, we shall ivestigate the quatitative relatioship betwee subcarrier group size ad capacity loss ad desig a feasible subcarrier groupig algorithm to adaptively track the sesed chael time varyig. III. CAPACITY ANALYSIS I this sectio, we derive the capacity loss of each idividual subcarrier i terms of CSI differece. We first preset a result o capacity loss uder the sceario with CSI differece ad the aalyze the approximate ergodic capacity whe the subcarrier groupig based precodig algorithm is employed. A. Capacity Lower Boud With CSI differece Cosiderig the fact, over a wide rage of SNR, the gai of water-fillig is very small, especially i high SNR. I this case, allocatig equal power at all sub-chaels is almost optimal [6]. Thus, we assume the equal power allocatio scheme over both the frequecy ad spatial domais are adopted i our cosidered systems. Hece, the desig of the precodig matrix F kc) c ca degrade ito the search of uitary matrix [10]. It is well kow that the uitary precodig

7 7 matrix does t chage the distributio of radom variables. Based o this result, we ca rewrite 5) i a equivalet form as where the precodig matrix F kc) c R k) = ) H kc) c +M, k,kc) c X k) +W k) =H kc) c X k) +M, k,kc) c X k) +W k) } {{ } N k,kc), 6) has bee absorbed ito the radom vectors X k). I the chael fadig matrix H k), the i-th row represets the fadig factor from the i-th receive atea to N t trasmitters at the,k)-th subcarrier, which will simply be deoted by g k) i, for subsequet use. Similarly, we deote the j-th colum of Hk) as h k), which represets the fadig factor from the i-th trasmit atea to N r receivers at the,k)-th subcarrier. Deote j, u = max{n t,n r }, v = mi{n t,n r }. 7) Give the chael fadig matrix H k), the capacity of the,k)-th subcarrier without CSI differece i.e. M k,kc) = 0) is C k) = log 2 det ) I+γS k), 8) where the v v matrix S k) is defied by H k) S k) = H k) H k) H k) = u i=1 hk) i, hk), if N i, t N r = u i=1 gk) i, g k) i,, if N t < N r. 9) For simplifyig the calculatio, we assume that S k) is ormalized so that trace{e[s k) ]}/v = 1, where E ) represets the expectatio otatio. Accordigly, the SNR at each subcarrier o oe atea is γ = ρ t /N t, where ρ t is the total trasmit power. As to the scearios with CSI differece i.e. M k,kc) 0), the capacity loss varies with M k,kc). Thus, oe caot adjust trasmit rate without exact CSI, which caot be acquired i this subcarrier groupig scheme. For sake of trasmissio reliability, as a alterative, we use the followig lower-boud istead. C k) log 2 det I+γ e S kc) c ), 10)

8 8 where γ e is the equivalet-snr ESNR) i the worst case, which is give by γ e =σ 2 Xk) =σ 2 x k) σ 2 N k,kc) 1 = σ 2 X k) /vσ 2 σ 2 m k,kc) x k) σ 2 1 N k,kc) +σ 2 ). w k) The variables σ 2, σ 2 ad σ 2 are the secod-momet of the elemets of X k) x k) m k,kc) w k), M, k,kc) c ad W k), respectively. Appedix A gives a brief derivatio of this lower-boud. It s clearly see from 10) that M k,kc) 11) is totally cotributed to iterferece i the worst case. Combiig 8) with 10), the upper-boud of capacity loss caused by CSI differece ca be described via the followig lemma. Lemma 1. Suppose the ceter subcarrier is the c,k c )-th subcarrier. The upper-boud of the chael capacity loss with CSI differece at the, k)-th subcarrier is give by L k,kc) log 2 det I+γS k) ) log2 det ) I+γ e S k). It s worthy to ote that the lower-boud of the chael capacity with CSI differece is very importat, sice it ca clearly characterize the worst case o chael capacity loss. I this way, we ca derive the maximal capacity loss of chael with CSI differece at, k)-th subcarrier with Lemma 1 ad make guaratee the reliability of our cosidered systems. B. Approximate Ergodic Capacity Notice that L k,kc) varies with S k) ad oe caot acquire H kc) c without the exact c,k c ), which are related to the subcarrier group size. Thus, it is reasoable to determie the size of subcarrier group first. I order to determie the group size, we eed to fid a capacity loss evaluatio metric without the istataeous of chael fadig matrix H kc) c. To this ed, oe eeds to calculate the ergodic capacity loss ad ivestigate the average performace of the subcarrier groupig system.

9 9 Lemma 2. Defie the ceter subcarrier as the c,k c )-th subcarrier. The ergodic capacity loss at the, k)-th subcarrier ca be upper-bouded by E k,kc) = log 2 1+ ) v k 1 α k γ) u i) k=1 log 2 1+ i=1 v α k γ e )e k=1 k 1 i=0 ψu i) ) where α k γ) = γ k vv 1) v k +1)/k!. γ ad γ e is the SNR ad ESNR at the c,k c )- ad,k)-th subcarrier, respectively. ψx) is defied by ψx) = ζ + x 1 1 r=1, where ζ = r is the Euler s costat. Moreover, the relative ergodic capacity loss is, 12) R k,kc) = 1 log 2 1+ v k=1 α kγ e )e k 1 i=0 ψu i) ) log 2 1+ v k=1 α kγ) k 1 i=1 u i) ). 13) Proof. See appedix B. Lemma 2 shows that the ergodic capacity loss gives the average evaluatio of the,k)-th subcarrier capacity loss. Hece, give a specific capacity loss threshold, oe ca easily derive the CSI differece parameter σ 2 m k,kc) with 11) ad 12). IV. SUBCARRIER GROUPING AND PERFORMANCE EVALUATION Accordig to the theoretical results obtaied previously, i this sectio we shall employ the chael self-correlatio property to propose a adaptive subcarrier groupig based precodig algorithm. It ca be oted that the chael self-correlatio is related to the trasmit eviromet ad mobile velocity. The sesig of trasmit eviromet is out of the scope of this paper ad the mobile velocity ca be easily acquired via positioig systems, e.g. GPS, Beidou, etc. At last of this sectio, we aalyze the performace of the proposed algorithm regardig the system cost, SNR ad atea umber. A. Subcarrier Groupig Method i Double-Selective Chaels Theoretical results i Lemma 2 shows that the capacity loss are maily depeded o the secod order statistics of M k,kc). I order to ivestigate the relatio betwee capacity loss ad

10 10 subcarrier group size, oe eeds to observe M k,kc) associated with the trasmit eviromet ad mobile velocity, i.e. delay spread ad Doppler spread. Its secod momet ca be characterized by chael self-correlatio deoted by Rf k),f kc),t ),f c) )). That is { = 2 R f kc),f kc),t c),t c)) σ 2 M k,kc) R f k),f kc),t ),t c))}. where f k) ad f kc) deote the carrier frequecy of the k-th ad k c -th subcarrier, respectively. t ) ad t c) deote the time slot of the -th ad c -th OFDM block, respectively. Note that the correlatio fuctio i 14) depeds o four variables, with a rather complicated form. For characterizig the CSI differece properties with the correlatio fuctio, oe usually itroduces further assumptios about the physics of chael ad simplifyrf k),f kc),t ),f c) ). The most frequetly used assumptios are Wide-Sese Statioary WSS) assumptio ad Ucorrelated Scatterers US) assumptio, where WSS meas that self-correlatio depeds oly o time differece t ) = t ) t c), while US meas that self-correlatio depeds oly o frequecy differece f k,kc) = f k) f kc). By ivolvig both assumptios simultaeously as WSSUS model [18], we ca simplify 14) as 14) σ 2 M k,kc) = 2 R0,0) R f k,kc),t ))). 15) Furthermore, usig the idepedece betwee the delay spread ad frequecy spread of double-selective chaels, oe ca decompose the self-correlatio of chael respose ito as R f k,kc),t )) = R f k,kc),0 ) R 0,t )) = R f f k,k c) ) R t t ) ). where R ) f f k,k c) ad R ) t t ) are defied as R ) f f k,k c) R f k,kc),0 ) R ) t t ) R 0,t )), 16) 17) both of them deote the frequecy-domai correlatio betwee the k- ad k c -th subcarrier i oe OFDM block ad the time-domai correlatio betwee the - ad c -th OFDM block at oe subcarrier, respectively.

11 11 As H k,kc) is ormalized ad its etries are assumed to be i.i.d. Rayleigh fadig, the correlatio matrices R0,0) ad R f k,kc),t )) are v-by-v diagoal matrices with equal diagoal elemets v ad vr f k,kc),t )). I additio, R f k,kc),t )) ) = E h k) h kc) c, where h k) ad h kc) c where are the etries of H k) ad H kc) c. Thus, 15) ca be simplified as σ 2 m k,kc) σ 2 M k,c) = vσ 2 I m k,kc) v 18) = 2 1 R f f k,k c) ) R t t ) )) 19) Sice the chael fadig matrix is ormalized, i.e. traces )/v = 1, it ca be iferred that σ 2 m k,kc) [0,2]. Substitutig 11) ad 19) ito 13) ad deote R k,kc) as RR f,r t ), oe ca observe that R f f k,k c) ) ad R t t. c) ) play the similar role i RR f,r t ). Thus, for a give costrait of the ergodic capacity loss RR f,r t ) ζ r, the feasible zoe is showed i Fig. 2. It is observed that whe deote 1,1) as the origi, the distace from the origi to the itersectios of the border ad the ordiate abscissa ) is R 1 f ζ r) R 1 t ζ r ) ). The feasible zoes i.e. the areas iside the curves) is covex, which is show i the followig lemma ζ r =0.5 ζ r =0.6 ζ r =0.7 ζ r =0.8 ζ r = R f ) R ) t Fig. 2. The feasible zoe of correlatios whe relative capacity loss threshold ζ r=0.5, 0.6, 0.7, 0.8 ad 0.9. Lemma 3. The feasible zoe described above is covex, i.e. λrr f1,r t1 )+1 λ)rr f2,r t2 ) RλR f1 +1 λ)r f2,λr t1 +1 λ)r t2 ),

12 frequecy 12 f time t Fig. 3. Groupig scheme vaires with the chael correlatio status. where λ [0,1]. R f1 ad R f2 as well as R t1 ad R t2 are the istace of frequecy ad time domai correlatios, respectively. Furthermore, λrr f f 1 ),R t t 1 ))+1 λ)rr f f 2 ),R t t 2 )) RR f λf 1 +1 λ)f 2 ),R t λt 1 +1 λ)t 2 )) holds. f 1 ad f 2 as well as t 1 ad t 2 are the istace of frequecy ad time, respectively. Proof. Notice that RR f,r t ) = ζ r is equivalet to σ 2 = 21 R m k,kc) f f k,kc) )R t t ) )) = C, where C is a costat derived from 13). Thus, the curve is a hyperbola ad the covex property is obvious. Cosiderig the correlatio fuctio R f f) ad R t t) are mootoe decreasig, the covex property holds whe usig t ad f as the abscissa ad ordiate. The secod equatio i Lemma 3 shows that the covex property holds for the boudary, whe usig t ad f as the abscissa ad ordiate. Thus, coect the four itersectios betwee the boudary ad coordiate axes with segmets ad form a rhombus with the trasverse ad logitudial diagoal legth as 2R 1 t ζ r ) ad 2R 1 f ζ r), all the subcarriers iside this rhombus satisfy the capacity loss costrait RR f,r t ) ζ r. Thus, the subcarriers iside oe rhombus ca be grouped ad apply a uitary precodig matrix, which is show i Fig. 3. It ca be oticed that the subcarrier groupig scheme varies with chael correlatio status, which is determied by trasmit eviromet ad mobile velocity. The theoretical result is summarized i Theorem 1. Theorem 1. Give the capacity loss costrait RR f,r t ) ζ r with trasmit power ρ t, all the

13 13 subcarriers with idetificatio, k) that satisfy { c,k c ) =,k) Rf k,kc),t ) 2 σ 2 } m k,kc) 2 are grouped ito subcarrier group c,k c ). The secod momet σ 2 m k,kc) is give by where 1 γ e = log 2 γ = 1+ v k=1 α kγ e )e k 1 i=0 ψu i) ) log 2 1+ v k=1 α kγ) k 1 i=1 u i) ) = ζ r, σ 2 x k) vσ 2 σ 2 +σ 2 m k,kc) x k) w k) σ 2 x k) σ 2 w k) = ρ t N t. = ρ t vσ 2 m k,kc) ρ t +N t. where β = 2 σ 2 m k,kc) 2 represets the correlatio threshold. The subcarrier groupig method is to divide the whole space with a serious of rhombuses, where the trasverse ad logitudial diagoal is 2Rt 1 β) ad 2R 1 β), respectively. All the subcarriers iside the same rhombus f ca be put ito oe group ad apply the same precodig matrix. Theorem 1 idicates that the groupig scheme is maily determied by the capacity loss threshold ζ r ad chael correlatio status Rf,t) i double selective fadig chaels. Hece, the groupig scheme is stable whe capacity loss threshold ζ r ad wireless chael correlatio status remai uchaged. O the cotrary, if chael correlatio status varies, the correspodig groupig scheme must be modified immediately for sustaiig chael capacity loss threshold, which is show i Fig. 3. Algorithm 1 explais the correspodig subcarrier groupig procedure i detail. Furthermore, we also derive the relatio amog the subcarrier group size, ζ r ad Rf,t), which is give i the followig theorem. Theorem 2. I double-selective chaels, give the chael correlatio threshold β, which ca be drive from theorem 1, the subcarrier group size ca be determied by S = 1 2 2R 1 f β) 2R 1 t β), 20) B t B f

14 14 where the parameter B f ad B t are the frequecy distace betwee adjacet subcarriers ad the time iterval betwee adjacet OFDM blocks, respectively. x deotes the largest iteger less tha or equal to x. Proof. For the subcarriers are grouped ito a serious of rhombuses, where the trasverse ad logitudial diagoal legth equal to 2Rt 1 β) ad 2R 1 β), respectively. The correspodig OFDM block umber ad subcarrier umber are, respectively, ad S f = 2R 1 f β) B f S t = 2R 1 t β) B t. Therefore, the umber of subcarriers cotaied i this subcarrier groupig rhombus ca be drive by the area formula of rhombuses, i.e. S = 1 2 S ts f = 1 2 2R 1 f β) 2R 1 t β). B t B f f This theorem ca be used to estimate algorithm complexity ad computatio cost for subcarrier groupig. B. Performace Aalysis I this subsectio, we give the brief performace aalysis of proposed subcarrier groupig scheme regardig the system cost, SNR ad atea umber. 1) System Cost: The system cost i oe sigle subcarrier is cosidered. Comparig to the subcarrier groupig scheme with fixed group size, the proposed scheme eeds to estimate chael correlatio status. Deote the subcarrier umber i the cosidered domai is KM t, where K is subcarrier umber i oe OFDM block ad M t is the umber of OFDM blocks. As kow to all, the most commo precodig algorithm i each idividual subcarrier requires Ov 3 ) operatios [8] [10]. Thus, the precodig complexity o all subcarriers is OKM t v 3 ). I additio, estimatig chael correlatio requires OK 2 M t )+OMt)) 2 operatios [19]. Note that the computatio of correlatio threshold β oly eeds to calculate a determiistic fuctio oe time i the cosidered domai. Hece, its computatio complexity is O1). Thus,

15 15 Algorithm 1 Precode with subcarrier groupig method. Iput: 1) The set of system parameters, {N t,n r,k}; 2) Chael state traiig sequece, S; 3) The workig SNR at the receivers, γ = σ 2 x /σ2 w ; 4) Capacity loss threshold, ζ r. Output: precoded sigals F kc) c X k) Iitializatio: Estimate the chael self-correlatio Rt, f) ad give the subcarrier groupig scheme by Theorem 1 with capacity loss threshold ζ r ; Repeat: 1) Estimate the chael state iformatio H kc) c the traiig sequece S; 2) Geerate F kc) c with H kc) c ; at the ceter of each subcarrier groups from 3) Get the CSI differece σ 2 by 19) ad derive the exact capacity lower bouds at m k,kc) each idividual subcarriers by 10); 4) Arrage the bit rates to symbols at each idividual subcarriers by the capacities derived i Step. 3 ad precode the symbols with F kc) c ; Util: The subcarrier groupig size chaged. the total system computatioal complexity composed by the computig of precodig matrices ad the estimatio of chael correlatio is ) KMt = O +OK 2 M t )+OMt 2 )+O1) S v3 KMt = O S v3 +K 2 M t +Mt 2 where S is the subcarrier group size deoted i Theorem 2. Moreover, the average precodig complexity o each idividual subcarriers i the cosidered domai is ave = ) ) v 3 Mt = O +OK)+O KM t S K v 3 = O S +K + M ) t. K 2) Sigal to Noise Ratio: Lemma 2 shows that the itroduced iterferece caused by CSI differece ca reduce the chael capacity, especially i the scearios with high SNR. The ), 21) 22)

16 16 effects of SNR o capacity loss is aalyzed as follows i the scearios with low ad high SNRs, respectively. a) Low SNR scearios: The ESNR satisfies limγ e = γ. Hece, lim γ 0 eglected i low SNR scearios. b) High SNR scearios: γ 0 C k) = C kc) c ad the capacity loss L k,kc) ca be 1 The ESNR satisfies lim γ e = ad lim C γ vσ 2 k) = log 2 det I+ Sk), which is a m k,kc) γ vσ 2 m k,kc) costat. Thus, chael capacity at the, k)-th subcarrier caot be improved limitlessly by icreasig SNR idividually, ad capacity loss L k,kc) approaches ifiity at extremely high SNR regimes. Therefore, properly SNR eeds to carefully geerated to achieve the balace betwee chael capacity ad capacity loss at the, k)-th subcarrier. Simulatio results i Sectio V-A shows that the optimum SNR is γ = 1. 23) vσm 2 I that SNR, the itroduced iterferece is equal to the AWGN ad system reaches the balace betwee spectrum efficiecy ad eergy efficiecy. 3) atea umber: The commuicatio system i this paper is assumed to be power costraied. If the trasmit power is uiformly allocated to all trasmit ateas, the the SNR ad ESNR at the c,k c )- ad,k)-th subcarrier are ) γ = ρ N t ad respectively. The property of R k,kc) Corollary. γ,k) e = ρ/n t vσ 2 ρ/n m k,kc) t +1, with respect to atea umber ca be summarized by followig Corollary 1. The relative capacity loss is mootoic decreasig with respect to the atea umber. As the atea umber approaches ifiity, R, k,kc) c coverges to ) lim v Rk,kc) = 1 log 1+ ρ t ρ tσ 2 m k,kc) log1+ρ t ) )

17 17 where the ceter subcarrier of this subcarrier group is assumed to be c,k c ) Proof. The mootoicity of R k,kc) is easily to get. Sice the total power is fixed, the power allocated ito each sigle trasmit atea will decreases as the atea umber icreases, resultig i R k,kc) decreasig with respect to γ. As the atea umber goes to ifiity,v, e.g. i the massive MIMO regimes, lim S k) = v ui v [3]. I this case, the chael capacity at the,k)-th subcarrier is = vlog 1+ C k) ρ t ρ t σ 2 m k,kc) ad the chael capacity at the c,k c )-th subcarrier is C kc) c = vlog1+ρ t )., +1 Hece, the relative capacity loss at the, k)-th subcarrier is which is costat. R k,kc) = Ckc) c C k C kc) c = 1 log 1+ ρ t ρ tσ 2 m k,kc) log1+ρ t ) +1 ), V. NUMERICAL RESULTS I this sectio, some umerical results are preseted to show the validity of our theoretical aalysis ad the effectiveess of proposed adaptive subcarrier groupig based precodig algorithm. I the simulatios, the total trasmit power ρ is allocated to each trasmit atea equally. Hece, the SNR at each idividual ateas is γ = ρ/n t. B f is assumed as 14KHz ad B t = 1 B f = 71us, referecig datas from [20]. The fadig chaels are assumed to be i.i.d. Rayleigh chaels. With these assumptios, we evaluate the theoretical results with COST207 chael model ad Jakes multipath model, which are widely used for simulatig the frequecy-selectivity ad the time-selectivity of wireless chael fadig models. For the mootoicity of the chael capacity loss fuctio with respect to SNR ad the variace of CSI differece, the variatio tedecy betwee absolute capacity loss ad relative capacity loss is idetical. Thus, for sake of cocise, oly the results o relative capacity loss is simulated.

18 18 A. Theoretical Results o variat correlatio thresholds ad atea umbers The capacity loss o variat chael correlatio is depicted i Fig. 4, wherei the atea regime is 8 8. It ca be observed that the relative capacity loss grows i S-type regardig SNR. This is because i low, medium ad high SNR regimes, vσ 2 σ 2 i.e. itroduced m k,kc) x k) iterferece) is relatively low, comparable ad much too high compared to σ 2 i.e. AWGN), w k) respectively. Therefore, the relative capacity loss grows sharply at medium SNR, ad as show i previous aalysis i Sectio IV-B, the relative capacity loss grows slowly at low ad high SNR. Thus, proposed subcarrier groupig scheme may perform well i low SNR regimes ad achieve balace betwee chael capacity ad capacity loss i medium SNR, which has bee metioed i 23). Aother importat observatio is that with the icreasig of β i.e. correlatio threshold), the system ca acquire less capacity loss at the same SNR, which is ituitioistic. This is because whe R tf i.e. the chael correlatio betwee the,k)- ad c,k c )-th subcarrier) icreases, the required SNR must be lower i order to keep vσ 2 σ 2 ivariable. m k,kc) x k) The effects of atea umbers are show i Fig. 5, i which β=0.95 ad SNR=10dB, respectively. It ca be observed that R k,kc) decreases with the growth of atea umbers. Especially, it reduces sharply at the first several atea umbers. Thus, properly atea umbers ca efficietly reduce the capacity loss caused by CSI differece. Aother importat observatio is that, as atea umber further icreases, the relative capacity loss coverges to 25.28%. Hece, oe caot decrease the capacity loss limitlessly by icreasig atea umber, because the capacity loss is lower-bouded by 24). B. Groupig Performace of Proposed Algorithm For evaluatig the algorithm performace ad summarizig the applicatio coditios, we build differet trasmissio scearios with the help of COST207 ad Jakes model, which are widely used i wireless chael simulatios. The subcarrier groupig performace at differet SNR, movig velocity ad trasmit eviromet are aalyzed umerically i this part. The effects o SNR of 0 db, 10 db ad 15 db are show i Fig. 6, where the trasmittig eviromet is RA i.e. rural area) ad the movig velocity is 10 m/s. It ca be observed that the subcarrier group sizes at the three SNRs grow expoetially with the capacity loss threshold, ad i the 0 db regime, the groupig size grows about 5 times faster tha that i the 15 db regime.

19 19 80 Relative Capacity Loss % β =90% β =95% β =99% N t = N r = SNRdB) Fig. 4. Relative capacity loss versus correlatio σ M =0.01, 0.05, 0.1 whe MIMO atea umber N t = N r = Capacity Loss Capacity Loss Limitatio 28.5 Relative Capacity loss % R ft =0.95 SNR=10dB % Atea Numbers Fig. 5. Relative capacity loss versus MIMO atea umber N t = N r = 1,2,,80 ad the limitatio whe mi{n t,n r} whe costrait R tf = 0.95 ad SNR = 10dB. It meas that the system cost ca be sigificatly reduced by sacrificig chael capacity ad it s especially efficiet i low SNR regime. I additio, from 20) oe ca observe that the groupig size is determied by the subcarrier groupig legth i frequecy domai as well as time domai i.e. S f ad S t ). As show i Fig. 6, the cotributios from S f ad S t are deoted as frequecy stages ad time stages, respectively. It ca be oted that, i simulated trasmittig regimes, time stages is relatively smaller tha the frequecy stages. Thus, the marked time stages i Fig. 6 are the time stages with oe uitary S f. The stages are caused by the varyig of S t. The frequecy stages are related to chael correlatios, i.e. multipath scatterig ad small scale fadig. As to the time stages, they are related to chael time variatios, i.e. Doppler

20 Subcarrier Groupig Size frequecy stage time stages ρ=0db ρ=10db ρ=15db Trasmit Eviromet: RA 500 Movig Speeds: 50m/s N t = N r = Relative Capacity loss % Fig. 6. Subcarrier groupig performace versus variat SNR 0 db, 10 db ad 15 db) whe the trasmit eviromet is rural area RA), movig speed is 10 m/s ad the MIMO atea regime is 8 8. spread. Therefore, the frequecy stages ad time stages are separately determied by trasmittig eviromets ad atea movig velocities, which are depicted i Fig Fig. 7 shows that i rich scatterig eviromets e.g. typical urba TU)), the subcarrier group size suffers 50% loss ad 80% more loss compared to low scatterig eviromets e.g. hilly terrai HT) ad RA). Observe the frequecy stages i three simulated eviromets, oe ca observe that the frequecy stages is much smaller i rich scatterig trasmittig scearios. This is because as the chael scatterig icreases, the chael frequecy correlatios decreases. Thus, smaller frequecy subcarrier groupig legth is eeded to achieve the same capacity loss, which leads to smaller frequecy stages. Fig. 8 shows that compared to 10 m/s ad 30 m/s mobility scearios, the subcarrier group size i 100 m/s suffers 70% ad 40% more capacity loss, respectively. It ca be observed that the legth of frequecy stages i this three simulated velocities are equal. This is because the trasmit eviromet is fixed ad thus, the chael frequecy correlatios i these three simulatio regimes are idetical. As to the time stages, that i low velocity scearios is obviously larger tha the oe i high velocity scearios. That is, i low velocity scearios, the chael time variatio is slow ad larger time subcarrier groupig legth ca be achieved. From the simulatio results show i Fig. 7-8, we ca simply justify that the SNR, evirometal multipath scatterig ad Doppler frequecy shift ca greatly affect the subcarrier groupig performace. We ca also get some isights o the suitable coditios of proposed subcarrier groupig scheme: the subcarrier group size ca be extremely large i some specific scearios

21 Subcarrier Groupig Size RA HT TU SNR = 10dB Movig Speeds: 50m/s N t = N r = 8 frequecy stage time stages Relative Capacity loss % Fig. 7. Subcarrier groupig performace versus variat eviromets RA, HT ad TU) whe the SNR is 10dB, movig speed is 10m/s ad the MIMO atea umber is N t = N r = speed=10m/s speed=30m/s speed=100m/s Subcarrier Groupig Size SNR=10dB Trasmit Eviromet: RA N t = N r = 8 frequecy stage time stages Relative Capacity loss % Fig. 8. Subcarrier groupig performace versus variat movig speeds 10m/s, 30m/s, 100m/s) whe the SNR is 10dB, trasmit eviromet is rural area RA) ad the MIMO atea umber is N t = N r = 8. i.e. sparse scatterig eviromet or low Doppler frequecy spread scearios). For istace, rural areas, low mobility, etc. I these suitable scearios, the proposed subcarrier ca achieve low system cost or low capacity loss. Furthermore, we cosider the other subcarriers i the same subcarrier group. As kow to all, some cotiuous fuctios ca be approximately deoted by the Taylor expasio of itself, if its derivatives exists. For our discussed subcarrier groupig problem, i order to avoid excess capacity loss, the correlatio thresholdβ ca ot be too large. Thus, either the chael correlatio fuctio R tf t,f) or the relatio fuctios 13) ad 12) ca be approximated by usig its first order derivative, meaig that we ca geerate the CSI differece i liear mode. That is, the

22 22 capacity loss of the etire system is the average capacity loss of the best subcarrier ad the worst subcarrier. Therefore, we ca summarize that the system capacity loss is half of the worst subcarrier capacity loss, sice the best subcarrier is at the ceter of the subcarrier group ad it s correspodig capacity loss is zero. VI. CONCLUSION I this paper, we aalyzed the relatios betwee the OFDM subcarrier group size ad the correspodig system capacity loss over i.i.d. double-selective correlated Rayleigh fadig MIMO chaels. Uder the bridge of the secod order statistic of CSI differece betwee the, k)- ad c,k c )-th subcarriers i.e. M k,kc) ), the quatitative mappig from subcarrier group size to chael capacity loss is derived. It ca be oted that the secod order statistic of CSI differece is related to chael self-correlatio ad is determied by trasmit eviromets ad atea velocity, which ca be sesed via specific sigal processig methods ad positioig systems, respectively. I summary, theoretical results i this paper show that the subcarrier group size is related to SNR, MIMO structure ad chael self-correlatio, whe the capacity loss is costrait. More specifically, the capacity loss decreases with respect to atea umbers ad chael correlatio. By cotrast, it icreases with respect to SNR. Oe more importat observatio is that the relative capacity loss decreases sharply with the first few ateas, ad coverges to a lower-boud expeditiously. Thus, whe the total trasmit power is costat, few additioal ateas ca efficietly decrease the capacity loss, but much too more additioal ateas are ot helpful. Based o the developed theoretical results, we also provided a subcarrier groupig algorithm, which adaptively adjust the subcarrier group size uder the sesed trasmit eviromet to satisfy the preset capacity loss threshold. If oe adjusts the capacity loss threshold, the proposed subcarrier groupig algorithm ca achieve tradeoff betwee system service capacity ad system cost. Simulatio results show that proposed tradeoff ca be extremely effective i some specific trasmit regimes i.e. low SNR, properly high atea umbers or sparse scatterig scearios). I these trasmit regimes, sacrificig acceptable system capacity, oe ca achieve large subcarrier group size ad reduce system resource cost o subcarrier precodig efficietly, which agrees with developed theoretical results ad provide valuable isights for the desig of MIMO-OFDM commuicatio systems.

23 23 ACKNOWLEDGMENT This work was partly supported by the Chia Major State Basic Research Developmet Program 973 Program) o.2012cb ), Natioal Natural Sciece Foudatio of Chia NSFC) o ad NSFC o APPENDIX A A similar rage of the mutual iformatio o the chael with CSI differece has bee give i [21], i.e. IX k) ;Yk) Hk) log 2 det ) I+H k) σ 2 X k) H k) σ 2 M k,kc) Xk) ) 25) +σ 2 ) 1 W k) The lower-boud of the chael capacity o the, k)-th subcarrier ca be acquired via followig derivatios. As to the idepedece betwee the variablesx k),h k),m, k,kc) c adw k), we haveσ 2 M k,kc) Xk) are diagoal matrices with the = σ 2 σ 2 ad the square matrix σ 2, σ 2 ad σ 2 M k,kc) X k) X k) M k,kc) W k) same diagoal elemet. Thus, the right had of 25) ca be rewritte as log det =logdet =log 2 deti+ I+H k) σ2 X k) I+σ 2 X k) H k) σ 2 M k,kc) Xk) S k) σ2 M k,kc) Xk) σ 2 x k) vσ 2 σ 2 +σ 2 m k,kc) x k) w k) ) +σ 2 ) 1 W k) ) +σ 2 ) 1 W k) S k) ) With γ e i 11), we ca get the lower-boud of the chael capacity o the,k)-th subcarrier. 26) APPENDIX B The ergodic capacity of i.i.d. Rayleigh fadig MIMO chaels is give by [22] as log 2 1+ k=1 ) k 1 α k γ)e i=0 ψm i) EC) log 2 1+ ) k 1 α k γ) m i), wherei, α k γ) ad ψx) have the same defiitio as lemma 2 ad E ) is the expectatio fuctio. k=1 i=1 27)

24 24 By usig the ESNR i 11) to 27), oe ca get the ergodic capacity at the,k)-th subcarrier is lower-bouded by EC k) ) log 2 1+ k=1 ) k 1 α k γ e )e i=0 ψm i). Similarly, the ergodic capacity at the c,k c )-th subcarrier is upper-bouded by EC kc) c ) log 2 1+ ) k 1 α k γ) m i). k=1 Thus, the results i Lemma 2 ca be easily derived. i=1 REFERENCES [1] G. L. Stuber, J. R. Barry, S. W. Mclaughli, Y. Li, M. A. Igram, ad T. G. Pratt, Broadbad mimo-ofdm wireless commuicatios, Proceedigs of the IEEE, vol. 92, o. 2, pp , [2] E. Larsso, O. Edfors, F. Tufvesso, ad T. Marzetta, Massive mimo for ext geeratio wireless systems, Commuicatios Magazie, IEEE, vol. 52, o. 2, pp , [3] M. Sellathurai ad S. Hayki, Mimo chael capacity, Space-Time Layered Iformatio Processig for Wireless Commuicatios, pp. 8 32, [4] A. Paulraj, R. Nabar, ad D. Gore, Itroductio to space-time wireless commuicatios. Cambridge uiversity press, [5] L. You, X. Gao, A. L. Swidlehurst, ad W. Zhog, Adjustable phase shift pilots for sparse massive mimo-ofdm chaels, i 2015 IEEE 16th Iteratioal Workshop o Sigal Processig Advaces i Wireless Commuicatios SPAWC). IEEE, 2015, pp [6] D. Tse ad P. Viswaath, Fudametals of wireless commuicatio. Cambridge uiversity press, [7] J. Joug, H. D. Nguye, P. H. Ta, ad S. Su, Multicast liear precodig for mimo-ofdm systems, Commuicatios Letters, IEEE, vol. 19, o. 6, pp , [8] M. Vu ad A. Paulraj, Mimo wireless liear precodig, Sigal Processig Magazie, IEEE, vol. 24, o. 5, pp , [9] Y. Jiag, J. Li, ad W. W. Hager, Joit trasceiver desig for mimo commuicatios usig geometric mea decompositio, IEEE Trasactios o Sigal Processig, vol. 53, o. 10, pp , [10], Uiform chael decompositio for mimo commuicatios, IEEE Trasactios o Sigal Processig, vol. 53, o. 11, pp , [11] O. Edfors ad F. Tufvesso, Massive mimo for ext geeratio wireless systems, IEEE Commuicatios Magazie, p. 187, [12] T. Pade, D. J. Love, ad J. V. Krogmeier, Reduced feedback mimo-ofdm precodig ad atea selectio, IEEE Trasactios o Sigal Processig, vol. 55, o. 5, pp , [13] J. Choi, B. Modal, ad R. W. Heath, Iterpolatio based uitary precodig for spatial multiplexig mimo-ofdm with limited feedback, IEEE Trasactios o Sigal Processig, vol. 54, o. 12, pp , 2006.

25 25 [14] H. Zhag, Y. Li, V. Stolpma, ad N. Va Waes, A reduced csi feedback approach for precoded mimo-ofdm systems, IEEE Trasactios o Wireless Commuicatios, vol. 6, o. 1, pp , [15] Y.-P. Li, T.-H. Chou, ad S.-M. Phoog, Feedback for time-correlated mimo-ofdm system usig predictive quatizatio of bit loadig ad subcarrier clusterig, i 2015 IEEE Iteratioal Coferece o Digital Sigal Processig DSP). IEEE, 2015, pp [16] X. Ge, X. Huag, Y. Wag, M. Che, Q. Li, T. Ha, ad C.-X. Wag, Eergy-efficiecy optimizatio for mimo-ofdm mobile multimedia commuicatio systems with qos costraits, IEEE Trasactios o Vehicular Techology, vol. 63, o. 5, pp , [17] J. Lu ad P. Fa, Precodig with adaptive subcarrier groupig i mimo-ofdm systems, i 2014 Iteratioal Workshop o High Mobility Wireless Commuicatios HMWC). IEEE, 2014, pp [18] A. F. Molisch, Wireless commuicatios. Joh Wiley & Sos, [19] C. W. Therrie, Discrete radom sigals ad statistical sigal processig. Pretice Hall PTR, [20] E. Dahlma, S. Parkvall, J. Skld, ad P. Bemig, 3g evolutio, hspa ad lte for mobile broadbad, academic press, Jorda Hill, Oxford, UK, [21] M. Medard, The effect upo chael capacity i wireless commuicatios of perfect ad imperfect kowledge of the chael, IEEE Trasactios o Iformatio Theory, vol. 46, o. 3, pp , [22] Q. Zhag, X. Cui, ad X. Li, Very tight capacity bouds for mimo-correlated rayleigh-fadig chaels, IEEE Trasactios o Wireless Commuicatios, vol. 4, o. 2, pp , 2005.

26 ζ = R f ) R t )

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

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

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

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

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

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

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

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

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

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

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

Analysis of SDR GNSS Using MATLAB

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

More information

A New 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

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

Introduction to CPM-OFDM: An Energy Efficient Multiple Access Transmission Scheme

Introduction to CPM-OFDM: An Energy Efficient Multiple Access Transmission Scheme Joural of Commuicatio ad Computer 1 (015) 37-43 doi: 10.1765/1548-7709/015.01.007 D DAVID PUBLISHING Itroductio to CPM-OFDM: A Eergy Efficiet Multiple Access Trasmissio Scheme Mohammad Irfa, Sag Hoo Lee

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

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

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

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

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

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

On Parity based Divide and Conquer Recursive Functions

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

More information

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

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

IJSER. S.A.Yuvaraj 1,K.Periyar Selvam 2 K.R.Jayachitra 3

IJSER. S.A.Yuvaraj 1,K.Periyar Selvam 2 K.R.Jayachitra 3 Iteratioal Joural of Scietific & Egieerig Research, Volume 5, Issue 4, April14 18 Adaptive Chael Estimatio Techiques for MIMO OFDM Systems S.A.Yuvaraj 1,K.Periyar Selvam 2 K.R.Jayachitra 3 Abstract I this

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

Fingerprint Classification Based on Directional Image Constructed Using Wavelet Transform Domains

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

More information

Capacity Analysis for OFDM Systems with Transceiver I/Q Imbalance

Capacity Analysis for OFDM Systems with Transceiver I/Q Imbalance Capacity Aalysis for OFDM Systems with Trasceiver I/Q Imbalace Stefa Kroe ad Gerhard Fettweis Vodafoe Chair Mobile Commuicatios Systems Techische Uiversität Dresde, 6 Dresde, Germay E-mail: {stefa.kroe,

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

Symbol Error Rate Evaluation for OFDM Systems with MPSK Modulation

Symbol Error Rate Evaluation for OFDM Systems with MPSK Modulation Symbol Error Rate Evaluatio for OFDM Systems with MPS Modulatio Yuhog Wag ad Xiao-Pig Zhag Departmet of Electrical ad Computer Egieerig, Ryerso Uiversity 35 Victoria Street, Toroto, Otario, Caada, M5B

More information

Encode Decode Sample Quantize [ ] [ ]

Encode Decode Sample Quantize [ ] [ ] Referece Audio Sigal Processig I Shyh-Kag Jeg Departmet of Electrical Egieerig/ Graduate Istitute of Commuicatio Egieerig M. Bosi ad R. E. Goldberg, Itroductio to Digital Audio Codig ad Stadards, Kluwer

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

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

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 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

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

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

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

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

Summary of Random Variable Concepts April 19, 2000

Summary of Random Variable Concepts April 19, 2000 Summary of Radom Variable Cocepts April 9, 2000 his is a list of importat cocepts we have covered, rather tha a review that derives or explais them. he first ad primary viewpoit: A radom process is a idexed

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

信號與系統 Signals and Systems

信號與系統 Signals and Systems Sprig 2 信號與系統 Sigals ad Systems Chapter SS- Sigals ad Systems Feg-Li Lia NTU-EE Feb Ju Figures ad images used i these lecture otes are adopted from Sigals & Systems by Ala V. Oppeheim ad Ala S. Willsky,

More information

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

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

More information

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

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

An Adaptive Image Denoising Method based on Thresholding

An Adaptive Image Denoising Method based on Thresholding A Adaptive Image Deoisig Method based o Thresholdig HARI OM AND MANTOSH BISWAS Departmet of Computer Sciece & Egieerig Idia School of Mies, Dhabad Jharkad-86004 INDIA {hariom4idia, matoshb}@gmail.com Abstract

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

Simulation of Frequency, Timing Acquisition, and Cell Search Algorithms for OFDMA Based Mobile WiMAX

Simulation of Frequency, Timing Acquisition, and Cell Search Algorithms for OFDMA Based Mobile WiMAX 2011 Iteratioal Coferece o Commuicatio Egieerig ad Networks IPCSIT vol.19 (2011) (2011) IACSIT Press, Sigapore Simulatio of Frequecy, Timig Acquisitio, ad Cell Search Algorithms for OFDMA Based Mobile

More information

History and Advancement of the Family of Log Periodic Toothed Planer Microstrip Antenna

History and Advancement of the Family of Log Periodic Toothed Planer Microstrip Antenna Joural of Electromagetic Aalysis ad Applicatios, 2011, 3, 242-247 doi:10.4236/jemaa.2011.36039 Published Olie Jue 2011 (http://www.scirp.org/joural/jemaa) History ad Advacemet of the Family of Log Periodic

More information

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

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

More information

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

信號與系統 Signals and Systems

信號與系統 Signals and Systems Sprig 24 信號與系統 Sigals ad Systems Chapter SS- Sigals ad Systems Feg-Li Lia NTU-EE Feb4 Ju4 Figures ad images used i these lecture otes are adopted from Sigals & Systems by Ala V. Oppeheim ad Ala S. Willsky,

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

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

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

More information

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

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

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

More information

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

Comparison of RLS&LMS Algorithms for OFDM Systems

Comparison of RLS&LMS Algorithms for OFDM Systems Iteratioal Joural of Emergig Techology ad Advaced Egieerig Compariso of RLS&LMS Algorithms for OFDM Systems Vidya S.Bhosale 1, V. N. Ghodke 2 1 PG Studet, 2 Assistat Professor, Departmet of E&TC, Pue Uiversity,

More information

OFDM-BPSK Wireless Communication System Performance under Employment of Generalized Receiver

OFDM-BPSK Wireless Communication System Performance under Employment of Generalized Receiver OFDM-BPSK Wireless Commuicatio System Performace uder Employmet of Geeralized Receiver XUEFEI LI, VYACHESLAV TUZLUKOV School of Electroics Egieerig, College of IT Egieerig Kyugpook Natioal Uiversity 7

More information

PERFORMANCE OF MULTIBEAM MIMO FOR NLOS MILLIMETER WAVE INDOOR COMMUNICATION SYSTEMS CHAPTER 6

PERFORMANCE OF MULTIBEAM MIMO FOR NLOS MILLIMETER WAVE INDOOR COMMUNICATION SYSTEMS CHAPTER 6 PERFORMANCE OF MULTIBEAM MIMO FOR NLOS MILLIMETER WAVE INDOOR COMMUNICATION SYSTEMS CAPTER 6 1 PERFORMANCE OF MULTIBEAM MIMO FOR NLOS MILLIMETER WAVE INDOOR COMMUNICATION SYSTEMS CAPTER 6 igh data rate

More information

H2 Mathematics Pure Mathematics Section A Comprehensive Checklist of Concepts and Skills by Mr Wee Wen Shih. Visit: wenshih.wordpress.

H2 Mathematics Pure Mathematics Section A Comprehensive Checklist of Concepts and Skills by Mr Wee Wen Shih. Visit: wenshih.wordpress. H2 Mathematics Pure Mathematics Sectio A Comprehesive Checklist of Cocepts ad Skills by Mr Wee We Shih Visit: weshih.wordpress.com Updated: Ja 2010 Syllabus topic 1: Fuctios ad graphs 1.1 Checklist o Fuctios

More information

Information-Theoretic Analysis of an Energy Harvesting Communication System

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

More information

A Study on Performance Analysis for Error Probability in SWSK Systems

A Study on Performance Analysis for Error Probability in SWSK Systems 556 Tae-Il Jeog, et al.: A STUDY ON PERFORMANCE ANALYSIS FOR ERROR PROBABILITY IN SWSK SYSTEMS A Study o Performace Aalysis for Error Probability i SWSK Systems Tae-Il Jeog, wag-seo Moo, ad Jog-Nam Kim,

More information

Data Mining of Bayesian Networks to Select Fusion Nodes from Wireless Sensor Networks

Data Mining of Bayesian Networks to Select Fusion Nodes from Wireless Sensor Networks www.ijcsi.org http://dx.doi.org/10.20943/01201604.1115 11 Data Miig of Bayesia Networks to Select Fusio Nodes from Wireless Networks Yee Mig Che 1 Chi-Shu Hsueh 2 Chu-Kai Wag 3 1,3 Departmet of Idustrial

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

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

A Fuzzy Rule Base Assisted Adaptive Coding and Modulation Scheme for OFDM Systems

A Fuzzy Rule Base Assisted Adaptive Coding and Modulation Scheme for OFDM Systems 2012, TextRoad Publicatio ISSN 2090-4304 Joural of Basic ad Applied Scietific Research www.textroad.com A Fuzzy Rule Base Assisted Adaptive Codig ad Modulatio Scheme for OFDM Systems Atta-ur-Rahma a,c,*,

More information

IEEE TRANSACTIONS ON COMMUNICATIONS 1

IEEE TRANSACTIONS ON COMMUNICATIONS 1 IEEE TRANSACTIONS ON COMMUNICATIONS 3 5 6 7 8 9 0 3 5 6 7 8 9 0 3 5 6 7 Adaptive Buffer-Aided Distributed Space-Time Codig for Cooperative Wireless Networks Tog Peg ad Rodrigo C. de Lamare, Seior Member,

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

Research Article A Hybrid Single-Carrier/Multicarrier Transmission Scheme with Power Allocation

Research Article A Hybrid Single-Carrier/Multicarrier Transmission Scheme with Power Allocation Hidawi Publishig Corporatio EURASIP Joural o Wireless Commuicatios ad etworkig Volume 08, Article ID 68032, pages doi:055/08/68032 Research Article A Hybrid Sigle-Carrier/Multicarrier Trasmissio Scheme

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

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

Integrated Detection Method of Underwater Acoustic Fuze Based on IEMD, VIFD and ED

Integrated Detection Method of Underwater Acoustic Fuze Based on IEMD, VIFD and ED Advaces i Applied Acoustics Vol. Iss., November Itegrated Detectio Method of Uderwater Acoustic Fuze Based o IEMD, VIFD ad ED Qiao Hu Sciece ad Techology o Uderwater Iformatio ad Cotrol Laboratory, Xi

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

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

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

Multi-Carrier Transmission over Mobile Radio Channels. Jean-Paul M.G. Linnartz Philips Research and TU/e

Multi-Carrier Transmission over Mobile Radio Channels. Jean-Paul M.G. Linnartz Philips Research and TU/e Multi-Carrier Trasmissio over Mobile Radio Chaels Jea-Paul M.G. Liartz Philips Research ad TU/e Outlie Itroductio to OFDM Discussio of receivers for OFDM ad MC-CDMA Itercarrier Iterferece, FFT Leakage

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

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

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

More information

Adaptive Modulation for OFDM Systems J.Faezah 1, and K.Sabira 2

Adaptive Modulation for OFDM Systems J.Faezah 1, and K.Sabira 2 Iteratioal Joural of Commuicatio Networks ad Iformatio Security (IJCNIS) Vol., No., August 9 Adaptive Modulatio for OFDM Systems J.Faezah, ad K.Sabira Cetre for Foudatios Studies ad Extesio Educatio, Multimedia

More information

Noncoherent Detection of Satellite-Based AIS Signal with Phase Offset Compensation

Noncoherent Detection of Satellite-Based AIS Signal with Phase Offset Compensation Sesors & Trasducers Vol. 166 Issue 3 March 2014 pp. 128-134 Sesors & Trasducers 2014 by IFSA Publishig S. L. http://www.sesorsportal.com Nocoheret Detectio of Satellite-Based AIS Sigal with Phase Offset

More information

Research Article Rate-Optimized Power Allocation for DF-Relayed OFDM Transmission under Sum and Individual Power Constraints

Research Article Rate-Optimized Power Allocation for DF-Relayed OFDM Transmission under Sum and Individual Power Constraints Hidawi Publishig Corporatio EURASIP Joural o Wireless Commuicatios ad Networig Volume 9, Article ID 81478, 11 pages doi:1.1155/9/81478 Research Article Rate-Optimized Power Allocatio for DF-Relayed OFDM

More information

Broadcast Throughput Capacity of Wireless Ad Hoc Networks with Multipacket Reception

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

More information

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

Nonlinear System Identification Based on Reduced Complexity Volterra Models Guodong Jin1,a* and Libin Lu1,b

Nonlinear System Identification Based on Reduced Complexity Volterra Models Guodong Jin1,a* and Libin Lu1,b 6th Iteratioal Coferece o Electroics, Mechaics, Culture ad Medicie (EMCM 205) Noliear System Idetificatio Based o Reduced Complexity Volterra Models Guodog Ji,a* ad Libi Lu,b Xi a research istitute of

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

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

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

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

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

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

More information

3. Error Correcting Codes

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

More information

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

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

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

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

ADSP ADSP ADSP ADSP. Advanced Digital Signal Processing (18-792) Spring Fall Semester, Department of Electrical and Computer Engineering

ADSP ADSP ADSP ADSP. Advanced Digital Signal Processing (18-792) Spring Fall Semester, Department of Electrical and Computer Engineering ADSP ADSP ADSP ADSP Advaced Digital Sigal Processig (8-79) Sprig Fall Semester, 7 Departmet of Electrical ad Computer Egieerig OTES O RADOM PROCESSES I. Itroductio Radom processes are at the heart of most

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

Optimal Arrangement of Buoys Observable by Means of Radar

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

More information