A Transportation Problem Based Resource Allocation Scheme for an LTE-Advanced System With CA

8/10/2019 A Transportation Problem Based Resource Allocation Scheme for an LTE-Advanced System With CA

1/6

A Transportation Problem based Resource AllocationScheme for an TE-Advanced System with Carier

Aggregation*

M Bmby n Ke M F syeDeptment of Electronics and Electrical Commications Engineerng, Cairo Universit

Giza, Egypt [email protected], [email protected]

We formulate the downlink cross-carrier resourceallocation problem in TE-Advanced carrier aggregation (CA)systems as an unbalanced transportation problem (TP). The

component carriers (CC's), or their associated sub-bands,represent the supply points whereas the users requesting tracrepresent the demand points. The cost of shipping from a supplypoint to a demand point is set as a function of the proportional

fairness (PF) metric. To balance the problem, an articial supplypoint is added to represent the shortage in satisfying the demandin case of an overloaded system. Backward compatibility withTE Release 8 (Rel-8) is guaranteed by adjusting the cost ofshipping to Rel-8 users to restrict them to operate on a single C.

The results show that using Vogel approximation method (VAM),which is a sub-optimal ecient method, provides near-optimumresults in terms of throughput and fairness and is much faster

than the simplex method for optimal solution. The proposed TPbased scheduler is shown to achieve considerable performanceimprovement over a PF scheduler that handles multiple CC's in

the presence of both Rel-8 and TE-A users.Kyw v; ;

; ; NTRODUTONI as a aa a

qus IMT-Ava as IaaTua (T) T aPas Pj (3PP) as u a aa(A) as L T vu-Ava (LT-A)aus a u sv s a []. W a aau a us a as ('s) aaa s a a us a su suaus u 's us aa as a av.

A a a ass su sus A s awa a. Bawa a su

aa su a a a R-8 us qu () wauall ol suos a sigl soul sill al o oxisw R-O (LT-A ) w a su aa 's. Fu w a suaa LT-A su av s wuas a vs su a aa.F xa a aa R-8 uss a LT-Auss su s a wa a uua ass u a s a xs's. I a a-awa a su (PS) squ x a vs ussass a v u as a v us ass u s

This work is part of the 4G++ project supported by the National TelecomRegulatory Authority of Egypt.

978-1-4673-4404-3/12/$31.00 2012 IEEE

v qu a su a. Ts as a ws s su a su aa

w s s a a qus a assa w FMA-as wssass sss.

T a a A v as s

vaua [2]. Sua sus a ssw a A a a uu ass a a. I[3] a aa s ass 's a vsa sws a us Ru R (RR) a aa s a as (MH) aa R-8 uss v 's wasLT-A uss a su ass 's. I as swsa s ss a su (PS) avs a a su .A u su aa aw A-as LT-Asss s s [4]. Pa vauas sus swa A w s s a vsfa f t ava a ll t uss tuutaua w a a s. a us uu LT-A 's aas sa v a as R-8 's. I [5] suaa I 802.16 a-AM M s as auaa asa a sv s a aw s z w a a sas w uss.

T a u s a s ua A Rsu Aa as a asa a s su a su aas LT-A uss a R-8 uss. T s s asa s us a aa ass a ass uss a awa. T ua asa s v aa a (LP) a sv us xasx su a V Axa M (VAM).

T VAM svs a vs a-usus as a w sx u a u st [6].

T s s a s az as ws. I s 2 wv a vvw a aa a ss. I s 3 w suss asa a u su aa ua as aasa a s su s.Sua aas a a vaua a s s 4. Fa s 5 us a.


2/6

RELMNARESA. Overview /Carrier Aggregation Concept

a aa (A) s LT-A Ras 10 (R-10) a aus. LT-A s s a aa asqu IMT-Ava: 1 s w a 500Ms u [7]. Ts qus uss' ass a aaw u 100 MHz. S axu su

aw LT s 20 MHz aw s xa uaa u v 's. Ts 's a a-a(a a sa a) -a (a a as). T a-a 's a uus uus su avaa. Tsuas a F. . Mv A s s awa a w as a LT R-8 aLT-A us qu () a su sa R-0 NB (NB).

(a

-

f

)

fc

-

-

-

f)

Figure 1. arrier aggregation spectrum congurations: a) intra-bandcontiguous; b) intra-band non-contiguous; c) inter-band non-contiguous.

B. System ModelW s a s LT-A ss w w us

su aa w . T u 's ss s qua a as sa sus (PB) w PB s sas aa u su. W assu a u as w a PB w s as w a 'sa Fqu-vs ux (F) a aw a u asss a a 's.a s a a s 's :

{1[2 {L1 R-8

LT-A .

(1)

(2)

As R-8 's a aa s aa aa s s su a ass's. Ru R s us aa as a's. I s sw [3] a RR a aa vs a a as (MH) aa s.

T xa v SINR Ma (SM) [8]s us SINR a sua a PBs' v SINR w s:

SINReff = -n

1

Ie-SINRj( N )

= (3)w SINR s SINR sua a s u suas a su .

T ss s s a a NB (NB) a 's (u R-8 uss a LT-A uss) a

au. a us quss a s u s(a aa w a aa a ) aasss va (TT) 1 s w s sua sz LT. T su aa s aa a sua ass. sas a a asua s auua a a xsua. T a a-awa su aa x uss' a Qua Ia (QI) s s .I a A ss us a aa su s ass 's su s ua L TAva sas v a vss QI A sss. S -PRB QI v a's wu a a a sa va u a LT-Ava vs a QI's u a a u aua. u s x uas QI Asss a xs s su a w xa w sus.

C. CQJ Reporting Mode

T a awa PS qus a QI ass 's. Ts vs s a u va. Ru sa va s QI s suas (SBs). a SB as a u PB's a s QI a . Ts sx s su as w suss a Tas w s a QI s SBs ssaaz 3PP [9] a s as ws:

1- T ss a s

SBs a sz

kPRBs a (w

ka

aw).

2- T s QI vau s avaa qua s s SBs.

3- T as a wa QI vau a w s aua assu asss a SBs.

T a SBs a assa w a QIvaus. A s s v [10] su vaus s ua SBs; assus a ua QI'sav a vau w s w wa QI a s.Ts s s aua su a ava QI sa ua QI us quas wa Q.

1: - / R

I Q QFigure 2. Example of the difference between the actual and constructed Q.


3/6

A s a w vaus a ass w a ava s vau s SBs a wa vau us s vau a SBs.F. 2 vs a xa w u (aua)QI a su a 20 MHz a as 100PB's v 25 SBs. Bs 6 SBs av vau w s ava vaus. T a SBs av vauw s aua a av .

ODELNG THE CROSSCC ESOURE LLOATON AS

A RANSPORTATON ROBLEM

W ua ss- su aa as auaa asa w uss' a axss aa sus. Ts ssa s a a ss. T a za s aa sus uss axz va ss uu a aa ass w ussw aas.

A. Transportation Problem Basics

A asa zs s s us su s a s s a s a a s sas a a su svs ws aa. I s sa ass u sua a us . T a aas asa a s Ta A aaasa a sv as aa (LP) za . T a uaa w w ass. T s s w a u us a su s s a a u qu us a a s. Is as s aa a a aa ua w s a vau as xss avaa us su. S u a asu w z s as aua s s w u.

TABLE . R RB RRrmtr crtn Number of supply points. Number of demand points.

Si Number of available units at supply point i, i 1,2, .. .,S}.dj Number of needed units at demand point},} 1,2, ,O}Cij ost of transferring one unit om supply point ito demand

point i.

Xij Number of assigned units from supply point ito demand pointT s as a as asa

uaa s w a u us su ss ss a s a a s. T s

aa a a aa u su w ssu vau as sa qu us. T s s u su a a su was s a us w s a s u ss a u us. Asv us a a s s su w s sas a. I asss a vs a aa asa w s ua as ws:

suj

min

c x LL ] ]=l =l L =L

=l =l

L = =l

L = =l

w av aas a Ta I.

B. Mapping of the Resource Allocation Problem as aTransportation Problem

(4)

T a su s w QI qu su. I s a waQI w w s as su . I QI a s a -s SB ass (s

vus s) w SB w av QI vaua a SB s a w s a saa su a a u PB's. Ts s aus s s a u a su a a s av a (as w suss a) s s a u us's QI.

T w uss' quus a NB w aa a a a sua w s a s.T a a a s s u PRB'squ sas us's a. T us's a a s xss s s a s a a u PB's us us's avaa sa. Ts s aua ava QI us v a as. T a s a v s as sz (TBS) PB a s vau QI. Ts vs a s PB's. T TBSa a a QI x sMua a S (MS) v a TBSas [9] a us sz s. Ta A a asa sua xa F. 3 w usas as us quus a NB's qus a u PB's a su s 's a s aus SB's a su a u PB's sas a.

W u s ass a su a us(w s z a s) a a

ass (PF) as ws:

R[ = _] (5)w s s ass u /SB us R s saaus a us /SB a =L s sa a ava a us vusaas v a 's s ava a us v/SB Ts s s s aass s a w ass s.


4/6

I

I

YPR

Rl TEA

CC,

I

I "B'Supply Pints

Dmn Pints

TEAFigure 3. Mapping of A problem to a transportation problem

S NB s assu as w u wsu u ass 's av a s a au uss QI .

A u su w a s sa

sas a s a a avaa sus.T s ass s su s s a a avaa ss ij as u uss aa a a su .

W assu s uss ss a R-8 uss w aaa a a . Ts uss w ass a a us Ru R aaa . T s s s uss 's s s a vau Ts sus a s uss w aa sus s Ts vau w aus s s vaus sv was a

vaus a av. T av s w a sa w ss vaus s a a w a av. T sua asu vau su axa 100 s ava avaa ss as av s vau as su. sw a w a s a su w u a s a a vau as s us xa vau s a auaa as as vs ass a 's.

C. Solution Methods

T s as a a a (LP) a sv us sx . T sx a s a susaa aza saaauss-Ja (J) a a aa. sas v a w s sa v us sv

sss a quas u ss v us us a u a s vu a x u a s v w. Ts usa xa [11]. B w s w us asu asa s a a a u vs.

Hwv a s s w a sv s aa .. a u avaasu us quas a a. T V's AxaM (V AM) a us a a as su a ss a . S xa sa sw a ava V AM a su au 20%

a a su w au 0.5% ss a au 80% [6]. T VAM s as ws:

su a ass ax ws s s S D, w a s uaa.

1. u a w a a u w ws a x ws s w

u.2. A s ws a us s w

axu .

3. Aa as u as ss w wss s w u. as s su a a. w a/u ws su a s z.

4. Ma a aas w uaa as a w u. A u s su a as a w a/ u a S 4 as ssa.

5. S ws a us a. ws u S 1 w u .

A a TP s sus. sas a w a us su s aa s av a vau a as as sus ' u a su as av vaus.

PEONCE VLUTIONT s su s sua us MATLAB. T

a s s WINR II 2 ass [12]. T a as us sua asuaz Ta II. F a x w a 50 a a us sus a a ava 20 xs as vau. T a a uss s a s a sa a (BR) aa.T a s a a ss a. Wassu a a asss s HARQa s a. T a s s sa aas a aa vs Pa Fa (PF)su w u 's a A su. Tssu aas a su a a us w s PF us s s . Ta s a ava us uu a ass xxss Ja's Fass Ix (FI) [13] w sua as ws:

F = CIR)

UIJ/

(6)

w

s u 's ss. Ts x asus

ass aa as w uss a as vau a as w z a w assav as w a s .

I s x w as a aasu ava uu a ass a a s s w aa PFsu. T sus sw a ava uuass w as as u a vau s saua as aa s u avaa PB's as sw F. 4 a F. 5 a


5/6

a LT-A uss 100% a 50% sv. Asa PF su s s a avau 4% uu a a a as a uss a LT-Aa 3% a a LT-A. A w as uss as w a avaa sus s aa w ss s x.As s a a a as as ss aa s aa. Tus a a ua x a w ss a av sa uu. F. 6 s ava R- uua ava LT-A uu vsus a w ss. T uu LT-A uss s a as asu aw. I s sw a u suavs uu a PF su a as sa R- uss w avs u 5%uu a. B sv w s LT-Auss R- xs ss s' a vaa a ass ss as .

TABLE . Rrmtr u/dcrtn

Layout scenario Typical urban macro-cell [12]

arrier aggregation paern 4 x 10 MHz non-contiguous 's at A band INumber of P's per 50 PR,each contains 12 subcriersDuplex mode FDD

Sub-ame duration 1 ms

FFT size 1024

Sampling equency 15.36 MHz

Antenna conguration 1*1

Modulation schemes QPSK, 16-QAM, 64-QAM

Trac model BR

Number of UE's 20

UE distribution Uniform over cell area

Q reporting Best-M sub-band reporting

Simulation time 1000 subames repeated 50 times

T s s as avs ass a a as; s s aus PF su as s us(.. us w s ) s su a a aa was TP-as su as a ass a global wa w s a uss a a a su. T TP-as su avs ass -.I ass ass ass w as a uas a ava a (av 0.9).

I s x w assss sus VAM as a w a sx . T s aza ava uu s sw F. 7. T u s a

sas: w a uss a LT-A a uss a LT-A a s R- uss a a uss aR-. VAM a s s a w au 0.5%ss u su-a s. Hwv su sx s a 30 s a a a V AM .

!Q Q

2

------

. . . . . .. . . . . . . . . . . . .

-

Offered Lad ps

/

Figure 4. Average UE throughput and Fairness (100% of users are LTE-A)

!Q! .Q / !2

Offered Lad psFigure 5. Average UE throughput and Fairness (50% of users e LTE-A,

rest e Rel-8)

QQ 2

Oere La ps

Figure 6. Average Rel-8 UE throughput and average L TE-A UE throughput(50% of users are LTE-A,rest e Rel-8)


6/6

I x w assss avaa as a LT-A aa us. F. 8 usas uu a vsus a LT-A ussa a a (100 Ms). I s sw a sss as a LT-A uss ass; u LT-A uss a sav as uss a ass a a s a a avaa s a sas PRB's avaa 's avaa Aa x. T a s a w PF su vas 3-4% w V AM s us V AM ssu su-a s awas ss a 1%.

I u s s as saa a a aa PF su s uu a ass us V AM sx .

5

4.5 4::e 3.5Iw 9AII LTE-A, VAM--"- 50% LTE-A, VAM oAII Rel-S, VAM

3 All L TE-A, simplex-50% LTE-A, simplex All Rel-S, simplex

2.550 100 150 00 50 300

Offered Lad (Mbps)

Figure 7. YAM versus simplex method in obtaining average UE throughput

4.4

4.3 4.2: 4.1:eI 4w

3.9

3.8o 20 40 60

LTE-A Users (%)80 100

Figure 8. Average UE throughput versus percentage of LTE-A users fordifferent schedulers

CONLUSONSI s a w ss-a su

aa a L T-A su w a-aa sua as a asa (TP). Sua sussa a s s a av uu s R-8 uss a LT-A uss.Tuu ass as u LT-A uss as. I sas sw a s TP su w s a s

s PF avs a a Pa Fa (PF) su. B sx (u) a V Axa M (V AM) sv TP. VAM s a su-a u su a svsTP u sa a sx . u uuw w s assss ss a u aua QI 's. W was s u- su aa xs - a ss su asaa-qu us a s-qu us.

EFERENES

[I ] 3GPP, "Feasibili study for Further Advancements for E-UTA (LTEAdvced), Tech. Spec. 36.912 V9.2.,M. 2010.

[2]

1.hen, W. hen,

XZhg, and D. g: "Analysis d

Simulation for Spectrum Aggregation in LTE-Advanced System, inrOc. IEEE Vehicular Technolo Conference Fall, Sep. 2009.

[3] . Wg, K. Pedersen, T. Srensen, d P. Mogensen, "arrier loadbalancing and packet scheduling for multi-carrier systems, IEEE Trans.Wireless Commun., vol. 9,pp. 17801789, May 2010.

[4] H. Wg, Rosa, and K. Pedersen: "Uplink omponent arrierSelection for LTE-Advanced Systems with arrier Aggregation, inProc. IEEE International Conference on Communications, June 20 I I.

[5] Mina AA Sok, and Khaed M.F. Elsayed, "A dynamic radio resourcemanagement scheme for the EEE 802.16 band-adaptive modulation andcoding mode with proportional rate constraints, Wiley's EuropeanTransactions on Telecommunications, Article first published online: 9Dec. 2011,: 10.1 002/ett529.

[6] M Mathiraj, and B. Meenakshi, "Experimental Analysis of Someits of ogel's Approximation Method, Asia-Pacc Journal ofperational Research,vol. 21,no. 4,pp. 447-462,2004.

[7] GX u,X Zhg, W.B. Wang, and . ang, "arrier Aggregationfor LTE-Advanced Mobile ommunication Systems, IEEE Commun.Mag, Feb. 2010,pp. 8893.

[8] K. Brueninghaus, D. Astely, Salzer et a., "Link performance modelsfor system level simulations of broadband radio access systems, in Proc.

IEEE PIMRC,vol. 4,Sep. 2005,pp. 23062311.

[9] 3GPP, "Evolved universal terrestrial radio access (E-UTRA); physicallayer procedures, Tech. Spec. 36.213 I.,Dec. 2011.

[10]K. Pedersen, Kolding, . Kovacs, G. Monghal, F. Frederiksen, and P.Mogensen, "Performce alysis of simple channel feedback schemesfor a practical OFDMA system, IEEE Transactions on VehicularThnolovol 58 pp 53095314 Nov 009

[11]D. Gale, Line Programming and the simplex method, Notices of theAmerican Mathematical Socie, vol. 54,pp. 364369,M. 2007.

[12]ST-2003-507581 WNER, "D5: Final Report on Link Level andSystem Level hannel Models, Nov. 2005.

[13]R. Jain, W. Hawe, d D. hiu, "A Quantitative Measure of Fairness andDiscrimination for Resource Allocation in Shared omputer Systems,DE-TR-301,Sep. 1984.

A Transportation Problem Based Resource Allocation Scheme for an LTE-Advanced System With CA

Documents

Transcript of A Transportation Problem Based Resource Allocation Scheme for an LTE-Advanced System With CA