12 lt e coexistence studies

IEEE Communications Magazine • April 200960 0163-6804/09/$25.00 © 2009 IEEE

INTRODUCTION

The first release of the Long Term Evolution(LTE) standards was targeted to be completedin the Third Generation Partnership ProjectRadio Access Network (3GPP RAN) by early2009, and the commercial deployment is expect-ed to start as early as 2009. During the initialroll-out of LTE networks, it is anticipated thatLTE would be deployed as an overlay of theoperators’ existing second generation (2G)/thirdgeneration (3G) mobile networks. This isbecause currently there is no dedicated frequen-cy spectrum allocated for LTE use, and theoperators would gradually migrate the spectrumuse from 2G/3G to LTE use, in order to enhancethe broadband data capacity of their networkswhile maintaining sufficient services on their2G/3G networks. Consequently, it is essential toensure that the LTE system can coexist withother anticipated mobile systems (GSM, CDMA,Universal Mobile Telecommunications System[UMTS], etc.) operating in the same geographi-cal area, or the LTE base station (BS) can becollocated with other system BS, especially thoseoperating in the adjacent frequency spectrum.This means that the coexisting systems will notsignificantly degrade the performance (in termsof capacity, availability, etc.) of each other.

In 3GPP RAN Working Group 4, coexistenceof LTE with other mobile systems has been stud-ied using system scenarios, together with imple-mentation issues, that reflect the environmentsin which LTE is expected to operate, and theLTE radio transmission and reception character-istics have been specified accordingly to facilitateLTE coexistence with other mobile systems. Inthis article we give an overview of the coexis-tence studies between LTE and other mobilesystems, focusing on the work that has beendone in 3GPP RAN Working Group 4 duringthe LTE standardization process. We first pro-vide an overview of the basic terminologies forcoexistent studies. We then introduce how adeterministic analysis could be done, followed bya discussion of simulation assumptions andresults for some LTE coexistence scenarios.Then we list 3GPP requirements specified inRAN Working Group 4 to ensure smooth coex-istence between LTE and other mobile systems.We provide our conclusions in the final section.

BASIC TERMINOLOGIESHere we introduce the basic terminologies thatare commonly used in coexistence studies.

Minimum Coupling Loss — Minimum cou-pling loss (MCL) gives the minimum loss in sig-nal power between a transmitter and a receiver,and is defined as the minimum path loss (includ-ing antenna gains and cable loss) measuredbetween the transmitter and receiver EquipmentAntenna Connector (EAC).

Antenna Isolation — To ensure two coexist-ing transmission systems will not cause too muchharmful interference to each other, we need toensure there is sufficient antenna isolationbetween them. Antenna isolation is defined asthe path loss (including antenna gains, cablelosses, and propagation loss through the air)from an interfering transmitter EAC to an affect-ed receiver EAC. The antenna isolation require-ments are usually derived by the followingcriteria:• The interfering transmitter out-of-band

(OOB)/spurious emission received by theaffected receiver is sufficiently below theaffected receiver noise floor.

• The affected receiver 3rd order inter-modu-lation product (IMP) caused by two inter-

ABSTRACT

To ensure LTE systems can coexist with othermobile systems operating in the same geographi-cal area, or the LTE Base Station (BS) can becollocated with other mobile system BSs, coexis-tence studies for LTE with other systems havebeen carried out in 3GPP. In this article, we pro-vide an overview of the coexistence studies thathave been done. First we list the terminologiesthat are commonly used for coexistence studies,and explain how deterministic analysis can bedone for the BS to BS interference scenario.Then we provide the system simulation method-ology and assumptions used in the coexistencestudies, and show some simulation results for thepossible impacts with different system parame-ters. Finally we provide the references to the3GPP standards where the LTE BS and UE radiotransmission and reception requirements arespecified to facilitate LTE coexistence with othermobile systems.

LTE PART II: 3GPP RELEASE 8

Man Hung Ng, Shen-De Lin, Jimmy Li, and Said Tatesh, Alcatel-Lucent

Coexistence Studies for 3GPP LTE withOther Mobile Systems

TATESH LAYOUT 3/25/09 2:11 PM Page 60

IEEE Communications Magazine • April 2009 61

fering carriers is sufficiently below theaffected receiver noise floor.

• The total interfering carrier power attenuat-ed by the affected receiver radio frequency(RF), intermediate frequency (IF), andbaseband filters is sufficiently below theaffected receiver noise floor.

• The total interfering carrier power attenuat-ed by the affected receive filters is suffi-ciently below the affected receiver 1 dBcompression point.Typically, the isolation guideline between Sys-

tem 1 and System 2 is equal to the maximum ofthe isolation estimate from the System 1 trans-mitter to the System 2 receiver, and the isolationestimate from the System 2 transmitter to theSystem 1 receiver.

Noise Floor — There is some backgroundnoise inherent in the receiver. This is dependenton the bandwidth and the intrinsic temperatureof the receiver. The level of this noise is referredto as the noise floor. It generally sets the lowerbound of the receiver performance.

OOB/Spurious Emission — OOB/spuriousemissions are unwanted emissions outside thetransmit band (resulting from the modulationprocess and non-linearity in the transmitter)observed in the receive band.

Receiver 3rd Order IMP — IMP is any inter-modulation product that is created at the receiv-er due to any order of mixing of primarycommunication carriers/tones. Usually the 3rdorder IMP are the strongest tones that fall in thereceive band.

Receiver Sensitivity — The reference sensi-tivity level is the minimum mean desired signalpower received at the receiver antenna connec-tor at which certain performance criteria (e.g.,bit error rate or throughput) shall be met.

Receiver Desensitization — This is defined asthe degradation in the receiver sensitivity due toan increase in the receiver noise floor by theinterfering OOB/spurious emission or IMP. Themost significant case is when the transmit bandof the interfering system is adjacent to thereceive band of the victim system, where theinterfering OOB (referred to as adjacent chan-nel interference) will be largest.

Receiver Blocking — Blocking occurs whenthe interfering carrier power passing through theaffected receiver filtering including RF filter, IFfilter, and base-band responses, is high enoughsuch that the affected receiver cannot maintainthe reference sensitivity or cannot detect a lowdesired signal power.

Receiver Overload — This is caused by a sig-nal at the receiver EAC that is too strong. Whena receiver is driven into overload, its amplifica-tion gain is depressed. A receiver performanceparameter known as the 1 dB-compression pointdetermines when the receiver will overload.

Adjacent Channel Leakage Power Ratio —Adjacent channel leakage power ratio (ACLR)is defined as the ratio of the transmitter meanpower centered on the assigned channel fre-quency to the mean power centered on an adja-cent channel frequency. ACLR provides theamount of interference that a transmitter couldcause to a receiver operating in the adjacentchannel.

Adjacent Channel Selectivity — Adjacentchannel selectivity (ACS) is defined as the ratioof the receive filter attenuation on the assignedchannel frequency to the receive filter attenua-tion on the adjacent channel frequency. ACS is ameasure of the receiver’s ability to receive awanted signal in the presence of an adjacentchannel signal.

Adjacent Channel Interference Ratio — Adja-cent channel interference ratio (ACIR) isdefined as

(1)

ACIR is a measure of the total interferencecaused by a transmitter to an adjacent channelreceiver, due to the imperfection of the transmit-ter filters to filter the OOB emission and thereceiver filters to attenuate the adjacent channelsignal.

Performance Metric — The metric for thedegradation of a victim system by the presenceof an interfering system on adjacent channel isusually specified as the voice capacity loss ordata throughput loss.

DETERMINISTIC ANALYSISThe BS to BS interference case for coexistingBS (in the same geographical area or co-sited)could be studied using deterministic analysis,since the BS positions are fixed and in the worstcase they transmit at full power most of thetime. For example, in order to protect a LTEfrequency division duplex (FDD) BS receiverfrom being desensitized by emissions from a co-sited LTE time division duplex (TDD) BS trans-mitter operating at another frequency, thefollowing analysis gives the required OOB/spuri-ous emission limit from the interfering transmit-ter to the victim receiver. Here we assume 9MHz receive bandwidth (90 percent utilizationfor 10 MHz channel bandwidth), 60 dB antennaisolation between the transmitter (Tx) andreceiver (Rx) EAC, 5 dB noise figure, and 0.8dB desensitization:

Receiver noise floor = –174 dBm/Hz + 10log (9e6)dBHz + 5 dB = –99.5 dBm

Interference level below noise floor = 10log[1/(100.8/10 – 1)] dB = 7 dB

Interference level at receiver EAC = –99.5 dBm – 7 dB = –106.5 dBm

Interference level at transmitter EAC = –106.5 dBm + 60 dB = –46.5 dBm

Thus the OOB/spurious emission limit fromthe transmitter into the receive bandwidth shallbe –46.5 dBm/9 MHz = –66 dBm/100 kHz.

Besides, we can derive the LTE FDD BSreceive filter rejection required to prevent receiv-er blocking. Assuming a 46 dBm LTE TDD BStransmit power, we obtain that the required LTEFDD BS receiver selectivity should be 46 dBm –60 dB – (–106.5 dBm) = 92.5 dB.

ACIR

ACLR ACS

=+

11 1

In 3GPP RAN

Working Group 4,

coexistence of LTE

with other mobile

systems has been

studied using system

scenarios, together

with implementation

issues, that reflect

the environments in

which LTE is

expected to operate.


IEEE Communications Magazine • April 200962

SYSTEM SIMULATION

System simulation is required for coexistence stud-ies on the interference cases involving user equip-ment (UE), i.e., BS_UE, UE_BS, UE_UE. This isbecause the UE positions are not fixed and theyare not expected to transmit with full power mostof the time due to power control. Hence usingdeterministic analysis could result in findings thatare too conservative, which in turn lead to unnec-essarily tight coexistence requirements.

In this section we provide an overview of thesystem simulation that has been performed in3GPP RAN Working Group 4 for the coexis-tence studies between LTE and UMTS. First wedescribe the simulation assumptions and param-eters used in the studies. Then we provide somesimulation results to show the system perfor-mance with different parameter settings.

SIMULATION FLOWCHARTThe simulation flowcharts for a LTE system anda UMTS system are shown in Fig. 1.

As a quick summary, static simulation snap-shots are performed to obtain LTE interferenceand LTE data throughput based on the LTE linklevel simulation results for carrier-to-interfer-ence ratio (C/I) versus throughput. Inputsinclude ACIR and other system parameters,which are described in more detail below, andoutputs include the impact of LTE interferenceon LTE average and 5 percent CDF throughput.

An outage for a UMTS user occurs when,due to a limitation on the maximum Tx power,the achieved Eb/N0 of a connection is lower thanthe Eb/N0 target –0.5 dB. And the UMTS systemcapacity is obtained as the number of satisfiedusers, having the achieved Eb/N0 of a connectionat the end of a snapshot higher than a valueequal to Eb/N0 target –0.5 dB. For 8 kb/s speechservice, the downlink (DL) and uplink (UL)Eb/N0 targets are assumed to be 7.9 dB and 6.1dB, respectively [1].

CELL LAYOUT

For uncoordinated network simulations, theworst inter-system site shifting case (where theUMTS sites are located at the edge of the LTEcell coverage) is assumed. Here an interferingUE could be at the cell edge of its serving BS(and thus transmitting with the highest power)but very close to the victim BS (and thus causingthe highest interference). The cell layout isshown in Fig. 2.

ANTENNA RADIATION PATTERNThe UE antenna radiation pattern is assumed tobe omni-directional.

The BS antenna radiation pattern, assumedfor each sector in 3-sector cell sites, is given by:

(2)

where θ3dB = 65 degrees is the 3 dB beam width,and AM = 20 dB is the maximum attenuation.

PROPAGATION MODELINGFor macro-cell deployment in urban or suburbanareas, the urban propagation model is used:

L(R) = 40*(1 – 0.004*DHb)*LOG10(R) – 18*LOG10(DHb) + 21*LOG10(f)

+ 80 dB (3)

where DHb is the BS antenna height above aver-age building top, f is the frequency in MHz, andR is the distance between BS and UE in km.

Considering a carrier frequency of 2 GHzand a BS antenna height of 15 m above averagerooftop level, the propagation model is given by:

L(R) = 37.6* LOG10(R) + 128.1 (4)

The path loss from a transmitter EAC to a

A Am( ) min ,θ θθ3

= −

−

12

1

2

dB

where 880 180≤ ≤θ

nn

Figure 1. Simulation flowcharts: a) LTE; b) UMTS.

Powerstabilization iterations

YesNo Sufficientsnapshots?

(b)

Outage calculationand capacity

estimate

Cell selection/handoff status

Mobile location,Path loss and Lognormal

fade determination

Static system levelsimulation

Cell layout

C/I derivation

Mapping C/I intouser throughput

YesNo Sufficientsnapshots?

(a)

Throughputstatistics

Cell selection

Mobile location,Path loss and Lognormal

fade determination

Static LTE systemlevel simulation

Cell layout

System simulation is

required for

coexistence studies

on the interference

cases involving user

equipment. This is

because the UE

positions are not

fixed and they are

not expected to

transmit with full

power most of the

time due to

power control.



receiver EAC (including both antenna gains andcable losses) is determined by:Path_Loss = max(L(R) + Log_normal_Fading

– G_Tx – G_Rx, Free_Space_Loss + Log_normal_Fading – G_Tx – G_Rx, MCL)

(5)

where G_Tx is the transmitter antenna gain in thedirection toward the receiver antenna, taking intoaccount the transmitter antenna pattern and cableloss; G_Rx is the receiver antenna gain in the direc-tion toward the transmitter antenna, taking intoaccount the receiver antenna pattern and cable loss;Log_normal_Fading is the shadowing fade follow-ing the log-normal distribution, assuming a 10 dBstandard deviation; and MCL is assumed to be 70dB in an urban or suburban macro-cell case.

ACIR MODELINGFor LTE DL a common ACIR for all frequencyresource blocks (RB) is used [2].

For LTE UL it is assumed that the ACIR isdominated by the UE ACLR, and the UE ACLRis assumed to be larger when the allocated RBsfor interfering UE and victim UE are not adja-cent to each other. The UE ACLR models aredepicted in Tables 1 and 2.

POWER CONTROL MODELINGFor LTE DL, no power control is used, andfixed power per frequency RB is assumed.

For LTE UL, the following power controlequation is used:

(6)

where Pmax is the maximum transmit power,Rmin is the minimum power reduction ratio toprevent UEs with good channels to transmit atvery low power level, PL is the path loss for theUE, PLx-ile is the x-percentile path loss (plusshadowing fade) value, and 0 < γ < = 1 is thebalancing factor for UEs with bad channel andUEs with good channel. Note that this meansthe x percent of UEs that have the highest pathloss will transmit at Pmax.

Also two parameter sets, provided in Table 3,are specified to show the possible impacts of dif-ferent LTE UL power control algorithms [2].

ASSUMPTIONS AND PARAMETERSThe other simulation assumptions and parame-ters are summarized in Table 4 [2].

SIMULATION RESULTSWe now present some simulation results usingthe simulation methodology and assumptionsdescribed above for the 5 MHz LTE FDD – 5MHz UMTS FDD (victim) scenario, and for the10 MHz LTE FDD – 10 MHz LTE FDD (vic-tim) scenario.

The simulation results for DL capacity lossversus ACIR with LTE BS interference areshown in Fig. 3. The UMTS FDD (8 kb/s speechsystem) DL capacity loss versus ACIR for thescenario where the 5 MHz LTE BSs interferewith the UMTS UEs is shown in Fig. 3a. It isobserved that with 25 dB ACIR, the UMTS

capacity loss is about 6.7 percent; if the ACIRincreases to 30 dB, the UMTS capacity lossbecomes about 2.3 percent. Based on the exist-ing UMTS FDD technical specifications, theACIR could be dictated by the UMTS UEreceiver ACS of 33 dB. Therefore, the associat-ed UMTS DL capacity loss caused by LTE BSinterference might be less than 3 percent.

The LTE DL throughput loss versus ACIR forthe scenario where 10 MHz LTE BSs interferewith the 10MHz LTE UEs is shown in Fig. 3b.Both 5 percent CDF and average user throughputdegradations are presented. It is observed thatwith 25 dB ACIR, the LTE 5 percent CDFthroughput loss is about 17 percent and the aver-

P P RPL

PLt = ×

max minmin ,max ,1

x-ile

γ

nn

Figure 2. Uncoordinated UMTS/LTE cell layout.

Cellrange

UMTS

LTE

nn

Table 1. ACLR model for 5 MHz LTE interferer and UMTS victim.

nn

Table 2. ACLR model for LTE interferer and 10MHz LTE victim.

Location of aggressor4 RBs

Adjacent to victimchannel edge

At least 4 RBs awayfrom channel edge

ACLR dBc/3.84 MHz 30 + X 43 + X

X serves as the step size for simulations, X = … –10, –5, 0, 5, 10 … dB

LTENo. ofRBsper UE

Bandwidth(BAggressor)

ACLR dB/BAggressor

Adjacent to edgeof victim RBs

Non Adjacent toedge of victim RBs

5 MHz 4 4 RB 30 + X (less than4 RBs away)

43 + X (more than4 RBs away)







X serves as the step size for simulations, X = … –10, –5, 0, 5, 10 … dB


IEEE Communications Magazine • April 200964

age throughput loss is about 4 percent; if theACIR increases to 35 dB, the LTE 5 percent CDFthroughput loss becomes about 3 percent and theaverage throughput loss is about 1 percent.

The simulation results for UL capacity loss vs.ACIR offset with LTE UEs interference areshown in Fig. 4. The average UMTS FDD (8 kb/sspeech system) UL capacity loss versus ACIRoffset (X in Tables 1 and 2) for the scenariowhere 5 MHz LTE UEs interfere with the UMTSBSs is shown in Fig. 4a. For power control set 1(γ = 1, PLx-ile = 115 dB), it is observed that with0 dB ACIR offset, the UMTS capacity loss isabout 45.3 percent; if the ACIR offset increasesto 15 dB, the UMTS capacity loss becomes about1.3 percent. For power control set 2 (γ = 0.8,PLx-ile = 133 dB), it is observed that with 0 dBACIR offset, the UMTS capacity loss is about 3.0percent; if the ACIR offset increases to 5 dB, theUMTS capacity loss becomes about 0.9 percent.

The 10 MHz LTE FDD UL throughput lossversus ACIR offset (X in Tables 1 and 2) for thescenario where 10 MHz LTE UEs interfere with

the 10 MHz LTE BSs is shown in Fig. 4b. Theimpact is given in both average throughput loss andloss at the 5 percent CDF throughput. For powercontrol set 1 (γ = 1, PLx-ile = 115 dB), it is observedthat with 0 dB ACIR offset, the LTE capacity lossis about 2.1 percent; if the ACIR offset increases to5 dB, the LTE capacity loss becomes about 0.8 per-cent. For power control set 2 (γ = 0.8, PLx-ile = 133dB), it is observed that with 0 dB ACIR offset, theLTE capacity loss is about 1.3 percent; if the ACIRoffset increases to 5 dB, the LTE capacity lossbecomes about 0.5 percent.

3GPP REQUIREMENTSWith the findings from the coexistence studies,also considering the implementation issues, cer-tain requirements for LTE BS and UE transmit-ter and receiver have been specified in 3GPPRAN Working Group 4 to facilitate the coexis-tence of an LTE network with other mobile sys-tems. The transmitter requirements includeACLR, spectrum emission mask, spurious emis-sions, and intermodulation, while the receiverrequirements include ACS, blocking, spuriousemissions, and intermodulation. These require-ments are specified in TS 36.101 [3] andTS36.104 [4] for LTE UE and BS, respectively.

CONCLUSIONSIn this article, we have provided an overview of thecoexistence studies performed in 3GPP RANWorking Group 4 for LTE with other mobile sys-tems. We have described the terminologies com-monly used in the coexistence studies, explainedwhen and how deterministic analysis could be use-ful, given the simulation methodology and assump-tions used in the system simulation, and providedsome simulation results to show the system impactswhen different system parameters are used.

REFERENCES[1] 3GPP TS 25.942, “Radio Frequency (RF) System Scenar-

ios,” v. 7.0.0, Mar. 2007.[2] 3GPP TR 36.942, Nokia Siemens Networks R4-071753,

v. 1.4.0, Oct. 2007.[3] 3GPP TS 36.101, “Evolved Universal Terrestrial Radio

Access (LTE): User Equipment (UE) Radio Transmissionand Reception,” v. 8.2.0, May 2008.

[4] 3GPP TS 36.104, “Evolved Universal Terrestrial RadioAccess (LTE): Base Station (BS) Radio Transmission andReception,” v. 8.2.0, May 2008.

BIOGRAPHIESMAN-HUNG NG received a B.Sc. degree in Computer Studiesfrom City University of Hong Kong in 1991. He worked asa computer programmer in Hong Kong from 1991 to1995. In 1996 he obtained a M.Sc. degree in Communica-tion and Radio Engineering from King's College London. Hejoined the University of Hong Kong as a research assistantin 1997, and completed a Ph.D. degree in mobile commu-nications in 2001. He joined Lucent Technologies N.S. (nowAlcatel-Lucent Telecom Limited) United Kingdom in 2001and is now a principal standards engineer.

SHEN-DE LIN received his B.S. degree in electronics engineer-ing from Fu Jen Catholic University in Taiwan in 1982, andhis M.S. and Ph.D. degrees from State University of NewYork (SUNY) at Stony Brook, USA in 1987 and 1991,respectively. After graduating from SUNY, he jointed AT&TBell Laboratories as a cellular system engineer and waspromoted to the Consulting Member of Technical Staff in2000. He has worked on a wide array of international cel-lular technologies and standards including analog, TDMA,

nn

Table 3. Uplink power control parameter sets.

Parameterset Gamma

PLx-ile

20 MHzbandwidth

15 MHzbandwidth

10 MHzbandwidth

5 MHzbandwidth

Set 1 1 109 110 112 115

Set 2 0,8 — — 129 133

nn

Table 4. Simulation assumptions and parameters.

Carrier frequency 2 GHz

Cell layout Wrap-around 36 tri-sectorcells, uncoordinated

Cell range 500 m

Lognormal fade correlation coefficientbetween sectors at the same site 1

Lognormal fade correlation coefficientbetween different sites 0.5

LTE/UMTS BS antenna gain 15 dBi

LTE/UMTS UE antenna gain 0 dBi

LTE/UMTS BS noise figure 5 dB

LTE/UMTS UE noise figure 9 dB

Maximum LTE BS transmit power43 dBm for ≤ 5 MHz carrier,46 dBm for ≥ 10 MHz carrier

Maximum UMTS BS transmit power 43 dBm

Maximum LTE UE transmit power 24 dBm

Maximum UMTS UE transmit power 21 dBm



GSM, CDMA, WiMAX, and LTE. He has been responsible forwireless system performance evaluation , mobile systemrequirement definition, link budgets, inter-system interfer-ence study, and RF engineering guidelines. He has pub-lished seven technical papers and more than 100 internaltechnical memoranda. He gave a talk entitled “RF FilterNeeds for Wireless Applications," at the IEEE MicrowaveTheory and Techniques Workshop in 1993. He held onepatent regarding CDMA handoff. He is the co-author ofthe book Handbook of CDMA System Design, Engineering,and Optimization published by Prentice Hall in 2000.

JIMMY KWOK-ON LI received a B.S. degree in electrical engi-neering from the Rensselaer Polytechnic Institute in 1994,and an M.S. degree from the University of Southern Cali-fornia as a Hughes Master's Fellow in 1996. He is a sys-tems engineer and has experience in modeling and

analyzing various air-interface technologies in the field ofsatellite and mobile wireless communications. Prior to join-ing Lucent Technologies in 2000, he had his college intern-ship at NASA Langley Research Center, and has worked forHughes Space and Communications and ITT.

SAID TATESH received his B.Sc. degree in electrical engineer-ing from the University of Damascus, Syria in 1988. In1992 he received an M.Sc. degree in satellite communica-tion from Surrey University, followed by a Ph.D. in mobilecommunications. He joined Alcatel-Lucent in 1997 wherehe worked on multiple projects, including the AMR codec,voice over GPRS, GERAN evolution, UMTS, and HSPA stan-dardization. Currently, he heads the Radio Technologydepartment responsible for UMTS/LTE standards. He andhis team are actively working on the LTE air interfacedesign and standardization in 3GPP.

nn

Figure 3. DL throughput loss vs. ACIR with LTE BS interference: a) UMTS DL capacity loss vs. ACIR with 5 MHz LTE BSinterference; b) 10 MHz LTE DL throughput loss vs. ACIR with 10 MHz LTE BS interference.

ACR (dB)

(a)

30

10

WCD

MA

DL

capa

city

loss

(%)

0

20

30

40

50

60

70

80

25 35 40

ACR (dB)

(b)

30

10

Use

r th

roug

hput

deg

rada

tion

(%)

0

20

30

40

50

60

70

100

80

90

15 25 45 50403520

Mean user throughput degradation (%)5% CDF user throughput degradation (%)

nn

Figure 4. UL throughput loss vs. ACIR offset with LTE UE interference: a) 5 MHz UMTS UL capacity loss vs. ACIR offset with 5MHz LTE UE interference; b) 10 MHz LTE UL throughput loss vs. ACIR offset with 10 MHz LTE UE interference.

Offset to ACIR (dBc/3.84 MHz)

(a)

5 MHz E-UTRA FDD to 5 MHz UTRA FDD UL impact

-10

5

0

UL

capa

city

loss

(%)

10

15

20

25

30

35

40

-15 -5 0 5 10 15 20

Offset to ACIR (dBc/8*375 kHz

(b)

10 MHz E-UTRA FDD to 10 MHz E-UTRA FDD UL impact

-10

10

0

Use

r th

roug

hput

loss

(%)

5

15

20

25

30

35

40

45

-15 -5 0 5 10 15 20

Avg E-UTRA UL user throughput loss(%) for PC set 1Avg E-UTRA UL user throughput loss(%) for PC set 2CDF E-UTRA UL user throughput loss(%) for PC set 1CDF E-UTRA UL user throughput loss(%) for PC set 2

Avg UTRA UL capacity loss(%) for PC set 1Avg UTRA UL capacity loss(%) for PC set 2

TATESH LAYOUT 3/25/09 2:11 PM 5

12 lt e coexistence studies

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