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Y80-H0539-1, Rev. x1 Link Budget of cdma2000 1xEV-DO

Wireless Internet Access System

Submitted ICC 2002 ii Submitted ICC 2002

QUALCOMM Incorporated5775 Morehouse Dr.San Diego, CA 92121-1714

Copyright © 2001 QUALCOMM Incorporated. All rights reserved.


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Submitted ICC 2002 1 Submitted ICC 2002

Link Budget of cdma2000 1xEV-DO Wireless Internet Access System

Peter J. Black and Qiang Wu

Abstract-This paper presents the analysis and simulationresults for a 1xEV-DO link budget. The traditional fixed rateCDMA link budget calculation has been extended to include linkadaptation and multi-user diversity gains. The main conclusionis that 1xEV-DO provides a link budget advantage over IS-95-Aof approximately 10 dB on the forward link and 1.5 dB on thereverse link.

I. INTRODUCTION

The cdma2000 1xEV-DO standard, also known as IS-856[1], is developed to provide spectrally efficient packet dataservices for wide area wireless Internet access. Due to theasymmetric characteristic of this type of services, the forwardlink is the more critical link. By utilizing technologies such asvirtual soft handoff, rate control, hybrid-ARQ and multi-userdiversity, the 1xEV-DO system achieves a spectral efficiencyof approximately 1bit/chip/sector on the forward link for amix of mobile/portable users [2]. An additional advantage ofthe efficient waveform designs is the improved link budget orcell coverage, which will be investigated in this paper.

A link budget determines the maximum allowable path lossof a given communication link. For wireless systems, it issimply the difference between the transmitter EIRP and thereceiver sensitivity, plus receiver antenna gain and less fademargin, building penetration loss and body (or cable) loss (allin decibel scale).

Given a certain transmitter power and antenna gain, oneobserves certain maximum radiation intensity. Thetransmitter EIRP is the effective input power to ahypothetical isotropic antenna that achieves such radiationintensity in any direction. It is a function of transmitterpower, transmitter antenna gain and cable (or body) loss. Inother words, the transmitter EIRP is calculated as follows,

Transmitter EIRP (dBm) =Transmitter Power (dBm) + Tx Antenna Gain (dBi) - Cable (or

Body) Loss (dB)

The receiver sensitivity denotes the minimum signal levelat the antenna connector required to close the communicationlink at a given data rate and under the worst-case fadingchannel, i.e.,

Receiver Sensitivity (dBm) =Thermal Noise (dBm/Hz) + (Ior/No)req(dB) + Bandwidth(dB-Hz)

It can also be expressed as,Receiver Sensitivity (dBm) =

Thermal Noise (dBm/Hz) + ( Eb/No)req(dB) + Data Rate(dB-Hz)

The required Ior/No or average Eb/No is a commonmeasure of modem efficiency, which will be discussed in thefollowing sections1.

II. FORWARD TRAFFIC CHANNEL LINK BUDGET

ASSUMPTIONS

1 Standard CDMA terms and conventions have been used, for definitionsrefer to [3].

This section summarizes the assumptions and method usedto derive the required Ior/No to achieve a certain forward linkuser throughput for a given geometry and under worst-casefading conditions.

A. Geometry

A mobile at the edge of one base station's coverage is verylikely to be also covered by a neighboring base station. Assuch the model assumes 2-way soft handoff with equal pathloss from the two candidate serving base stations. The co-channel interference is represented by a third cell 6dB down.Therefore, the total noise and interference power spectrumdensity is No+1.25Ior. Total sector throughput is simulatedversus Ior/No based on the above geometry. Given that thetotal sector throughput assumes 100% of the available timeslots, the single user throughput is derived from scaling thesector throughput by the serving fraction for the user.

B. Forward Link User Throughput

For the IS-95-A Code Division Multiplex approach at thefixed data rate of 9.6kbps, the traffic channel power onaverage is typically not allowed to exceed –12.7dB of theBTS power (average traffic channel gain). The forward linkbudget calculation for IS-95-A assumes 2-way powercombined soft handoff, thus, the effective traffic channelpower normalized to a single serving sector is –9.7dB of theBTS power (equivalent to 10.72%). Assuming 30% of powerdedicated to pilot, paging and sync channel overhead this isequivalent to 15.3% of the available traffic channel power.Given the 1xEV-DO forward traffic channel is variable rate,time division multiplexed and uses selection diversity softhandoff, a fair link budget comparison would be for the sameaverage user throughput of 9.6kbps and with the same servingfraction of the traffic channel time slots. In a 1xEV-DOsystem, taking into account the control channel overhead,15.3% of the available traffic channel slots is equivalent to14.3% of the total serving slots. All results are presented asaggregate sector throughput, which assumes 100% of servingslots are utilized, therefore the user throughput is calculatedas 14.3% of the sector throughput.

C. Fading Channel

For the purpose of the link budget calculation, only theworst-case fading channel that corresponds to the highestrequired Ior/No is of interest. The following ITU channelmodels are simulated: Pedestrian A and B, Vehicular A, andRice [4].

D. Multi-user Diversity Gain

The single user simulations assume 100% of the servingtime is dedicated to one user. An N user simulation, with allthe users at the same geometry, is also run to take intoaccount the multi-user diversity gain achieved through packetscheduling [2] – serving of users at local peaks in SINRsubject to fairness criterion. In all cases sector throughput


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versus Ior/No is plotted. For a given user throughput, thedifference between the required Ior/No for the single usercase and the N user case indicates the gain achieved by multi-user diversity. The multi-user network simulation is limitedto the case of N=4 users2.

E. Rx Diversity Gain

For mobiles with dual receive antennas the receivediversity gain is included. An N dual-antenna user simulation,with all the users at the same geometry, is run to take intoaccount receive diversity gain. For a given user throughput,the difference between the required Ior/No for N single-antenna user case and the required Ior/No per antenna for Ndual-antenna user case indicates the gain achieved by receivediversity.

F. Example: Multi-user and Rx Diversity Gain

The forward link sector throughput vs. Ior/No for a singleuser with single antenna is shown in Fig. 2.1, for N=4 userswith single antenna is shown in Fig. 2.2, and for N=4 userswith dual antennas is shown in Fig. 2.3. The worst casefading condition occurs in the PedA 3km/hr channel forsingle user case and in the VehA 30km/hr channel for themulti-user case. The worst case is found from Figs. 2.1-2.3 asthe rightmost curve for a sector throughput of 67.1 kbps. Thiscorresponds to a user throughput of 9.6 kbps assuming a14.3% fraction of serving time. The corresponding requiredIor/No per antenna are -5.0dB, -7.0dB and -11.6dB for singleuser link, N-user network and N-user network with dualreceive antennas, respectively. As a result, the multi-userdiversity gain equals 2.0dB and the receive diversity gainequals 4.6dB (excluding multi-user diversity gain).

III. FORWARD CONTROL CHANNEL LINK BUDGET

ASSUMPTIONS

In this section, we derive the required Ior/No to ensure areliable Forward Control Channel transmitted at a fixed datarate of 38.4kbps or 76.8kbps. The same geometry as specifiedin Section 2 is used and a packet error rate of 2% is targetedunder the worst case fading condition. Since the ControlChannel is a broadcast channel the multi-user diversity gaindoes not apply.

Figs. 3.1 and 3.2 show the Forward Control Channel PERversus Ior/No at 38.4kbps for single antenna case and dualantenna case, respectively. Figs. 3.3 and 3.4 show theForward Control Channel PER versus Ior/No at 76.8kbps forsingle antenna case and dual antenna case, respectively. InFigs. 3.1 and 3.2, only the worst-case channels at 3km/hr areshown.

2 The multi-user gain increases with the number of simultaneous activeusers. The link budget comparison assumes 14.3% or 1/7 of the serving slots.The choice of N=4 yields a conservative multi-user gain estimate.

Geometry: {Ior, Ior, 0.25Ior}, Single Antenna, 1 User

10

100

1000

-12 -10 -8 -6 -4 -2 0 2 4 6 8

Ior/No

Sec

tor

Th

rou

gh

pu

t(k

bp

s)

channel 1 (PedA, 1 path, 3kmph)

channel 2 (PedB, 3 paths, 10kmph)

channel 3 (VehA, 2 paths, 30kmph)


channel 5 (Rice, K=10dB, 0.826kmph)

Fig. 2.1 Single User Link Simulations

Geometry: {Ior, Ior, 0.25Ior}, Single Antenna, 4 Users

10

100

1000

-12 -10 -8 -6 -4 -2 0 2 4 6 8

Ior/No

Sec

tor

Th

rou

gh

pu

t(k

bp

s)


channel 2 (PedB, 3 paths, 10kmph)

channel 3 (VehA, 2 paths, 30kmph)


channel 5 (Rice, K=10dB, 0.826kmph)

Fig. 2.2 N-user Network Simulations (N=4)

Geometry: {Ior, Ior, 0.25Ior}, Dual Antenna, 4 Users

10

100

1000

10000

-12 -10 -8 -6 -4 -2 0 2 4 6 8

Ior/No per antenna

Sec

tor

Th

rou

gh

pu

t(k

bp

s)

channel 1 (PedA, 1 path, 3kmph)channel 2 (PedB, 3 paths, 10kmph)channel 3 (VehA, 2 paths, 30kmph)channel 4 (PedA, 1 path, 120kmph)channel 5 (Rice, K=10dB, 0.826kmph)

Fig. 2.3 N-user Network Simulations with Dual ReceiveAntenna Diversity (N=4)

For 38.4kbps, the worst case occurs in PedA 3km/hr forsingle antenna case and PedB 3km/hr for dual antenna case.The required Ior/No’s are 4.0dB and -8.0dB, respectively. Asa result, for the Control Channel transmitted at 38.4kbps theRx diversity gain equals 12.0dB.


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Since the assumed geometry sets a limit on Ior/Nt equal toIor/1.25Ior, the Control Channel transmitted at 76.8kbpscannot achieve a 2% PER for single antenna and the worstchannel condition of PedA 3km/hr. For the Control Channeloperating at 76.8kbps in the dual antenna case, the requiredIor/No for 2% PER is -4.5 dB under the worst-case channelof PedA 3km/hr.

For the single antenna case, given the worst case channelcondition and an Ior/No of 4.0 dB, the Control Channelachieves a 2% PER at 38.4kbps, and a 6% PER at 76.8kbps.

Geometry: {Ior, Ior, 0.25Ior}, Single Antenna, Fixed Rate at 38.4kbps

0.001

0.01

0.1

1

-10 -8 -6 -4 -2 0 2 4 6

Ior/No

PE

R

PedA 3kmph

PedB 3kmph

Fig. 3.1 Single Receive Antenna, 38.4kbps

Geometry: {Ior, Ior, 0.25Ior}, Dual Antenna, Fixed Rate at 38.4kbps

0.001

0.01

0.1

1

-10 -8 -6 -4 -2 0 2 4

Ior/No per antenna

PE

R

PedA 3kmph

PedB 3kmph

Fig. 3.2 Dual Receive Antenna, 38.4 kbps

Geometry: {Ior, Ior, 0.25Ior}, Single Antenna, Fixed Rate 76.8kbps

0.001

0.01

0.1

1

-10 -8 -6 -4 -2 0 2 4 6

Ior/No

PE

R

PedA 3kmph

PedB 3kmph

120kmph 1pth

Fig. 3.3 Single Receive Antenna, 76.8kbps

Geometry: {Ior, Ior, 0.25Ior}, Dual Antenna, Fixed Rate at 76.8kbps

0.001

0.01

0.1

1

-10 -8 -6 -4 -2 0 2 4

Ior/No per antenna

PE

R

PedA 3kmph

PedB 3kmph

120kmph 1pth

Fig. 3.4 Dual Receive Antenna, 76.8kbps

IV. REVERSE TRAFFIC CHANNEL LINK BUDGET

ASSUMPTIONS

In this section, we derive the required average Eb/No toensure reliable operation of the Reverse Traffic Channelunder 50% system load, worst-case fading channel, and atarget PER of 2%.

A. Dual Receive Antennas

Dual receive antennas at the base station receiver isassumed. For the link budget calculation, the requiredaverage Eb/No per antenna is the parameter of interest.Therefore, in the following sections the average Eb/No refersto the average Eb/No per antenna.

B. % Power for the Data Channel

The Reverse Traffic Data Channel of the 1xEV-DO systemtransmits at a fraction α of the total transmitter power. Forthe purpose of link budget calculation, the datachannel Eb/No is scaled by 1/α to obtain the total Eb/No.Such Eb/No is the ratio of the total energy (including pilot,DRC and ACK) received per information bit to the thermalnoise power spectrum density.

C. System Load

The required Eb/No is obtained assuming no system load,which is defined by Io/(No+Io). The effective system load isincluded through a system load margin, which is calculatedby -10Log10 (1-system load). In IS-95-A link budgetcalculations it is customary to assume a 50% system load.

D. No Power Control

A link budget derives the maximum allowable path loss forwhich link closure can occur. In this case it is assumed that amobile unit is transmitting at the maximum power level,effectively disabling the effects of power control.

E. 2-way Soft Handoff

A mobile at the cell edge is very likely covered by aneighboring base station, in which case the 1xEV-DO systemwould place such a mobile in soft handoff. Since the reverselink employs selection diversity on a frame-by-frame basis, it


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combats not only shadowing but also multi-path fading. Areconstructed frame in the switching center is in error only ifboth reverse link frames are in error. Thus, therequired Eb/No is determined by noting where the product ofthe two reverse link PERs is at the specified operating point.As an example, if the overall target PER is 2%, each link canhave 14% PER. This effect provides a significant gain inslow speed conditions.

F. Differential Fade Margin

The 14% target PER calculation explicitly assumes the twosoft handoff links are equally balanced. Such an assumptionmaximizes the selection diversity gain on the two multi-pathfading processes. However, the standard 4.1dB selection softhandoff gain [5] for shadowing only guarantees the betterlink and implicitly allows a differential between the links. Asa result, the soft handoff gain is overstated relative to theequal path required Eb/No. The differential path loss can beincluded in the soft handoff gain by defining the outagecriterion as the set of pairs of Eb/No for each link such thatthe product of the link PERs is equal to the target. For theworse case PedA curve shown in Fig. 4.1 and given a 0.5correlation between the shadowing process for each link, therequired fade margin is increased by 2.1dB. This reduction isreferred to as the differential fade margin.

Fig. 4.1 shows the Reverse Traffic Channel PER versuspilot Ec/Nt (or pilot Ec/No at no system load in whichsituation Nt = No). The worst case occurs in the PedA 3km/hrchannel. In this case, the required pilot Ec/No is -22.5 dB.This assumes a 9.6 kbps link, a 14% PER, no power controland no system load.We can derive the total Eb/No per antenna as:

++++

+= 101010

0

,

0

1010101log10R

Wlog10

ACKGainDRCGainDataGainpcb

N

E

N

E

All the gains in the above equation define the relativepower levels of the corresponding channels to the pilotchannel. We will assume DataGain = 3.75 dB for 9.6kbps,DRCGain = -3.0 dB (with DRCLength = 4 slots under thesoft handoff geometry assumed) and ACKGain = 4.0 dB [2].Using these gain values and pilot Ec/No = -22.5 dB in theabove equation returns a total Eb/No = 6.6 dB, which isrequired to achieve a 2% effective PER at the data rate of9.6kbps under no system load.

With careful selection of the data to pilot channel gains allreverse link data rates achieve similar PER for the same valueof pilot Ec/Nt and therefore Fig. 4.1 can be applied to allreverse link data rates. Table 4.1 shows the requiredtotal Eb/No for each reverse link data rate, assuming onceagain an unloaded system and a 2% PER.

As observed, higher data rates come with lower relativeoverhead of the Pilot, DRC and ACK Channels, and thusresult in lower required total Eb/No under the same requireddata channel Eb/No. In the case of 153.6kbps, thehigher Eb/No is due to the reduced coding gain provided bythe Rate 1/2 vs. the Rate 1/4 code used in all the lower rates.

−25 −24 −23 −22 −21 −20 −19 −18 −17 −16 −1510

−3

10−2

10−1

100

9.6 kbps, r=1/4, Traffic Gain = 3.75 dB, No Power Control, 2 RX Antennas

PE

R

Avg. Pilot Ec/Nt per Antenna, dB

PED. A 3km/h, 10% PER =>−21.4dB PED. B 3km/h, 10% PER =>−21.8dB VEH. A 120km/h, 10% PER =>−24.1dBVEH. B 120km/h, 10% PER =>−23.6dB

Fig 4.1 Reverse Traffic Channel PER at fixed data rate of9.6kps with power control off

Table 4.1 The required total Eb/No @ no system loadData Rate (bps) 9,600 19,200 38,400 76,800 153,600DataGain (dB) 3.75 6.75 9.75 13.25 18.5Required total Eb/No per

antenna (dB)6.62 4.98 3.84 3.55 5.27

V. LINK BUDGET CALCULATION

The link budget for a 1xEV-DO system is derived andcompared with that of an IS-95-A system under the conditionof equal effective served rate. Since service providers maywant to deploy 1xEV-DO systems using the same networkplans as IS-95-A but on a separate carrier frequency, it is alsoof interest to derive the 1xEV-DO forward user throughputunder an IS-95-A link budget.

The Forward Traffic Channel and Control Channel in1xEV-DO find their counterparts in IS-95-A as the ForwardTraffic Channel and Paging Channel. In the following weshow the link budgets for both traffic channels and control(paging) channels for both systems.

A. Comparison between 1xEV-DO and IS-95-A ForwardTraffic Channel Link Budgets

From Tables 5.1 and 5.2 we find that the 1xEV-DO linkbudget for the Forward Traffic channel is 147.7 dB for thesingle antenna case and 152.3 dB for the dual antenna case.This is derived assuming a 9.6 kbps user throughput, 14.3%serving fraction of time, and 90% probability of cell edgecoverage. The corresponding value for an IS-95 trafficchannel is found in Table 5.3 to be 138.2 dB, in which casewe again assume 90% edge coverage, 9.6 kbps, and aneffective traffic channel gain of –9.7 dB.

1xEV-DO provides approximately 10 dB link budget gainover IS-95-A on the forward link. Under the IS-95-A linkbudget (138.2 dB), a 1xEV-DO single receive antennaterminal would achieve a long-term average forward userthroughput of 32.2kbps or equivalently a short-term averageburst rate of 225kbps. The 1xEV-DO dual receive antennaterminals would achieve long-term average forward userthroughput of 70.8kbps or equivalent short-term burst rate of495kbps.


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YLink Budget of cdma2000 1xEV-DO 80-H0539-1, Rev. x1Wireless Internet Access System


B. Comparison between 1xEV-DO and IS-95-AControl/Paging Channel Link Budgets

From Table 5.3, we can conclude that with 20% of thetransmitter power allocated to the Paging Channel and a 10%target PER, the IS-95-A Paging Channel link budget is 134.2dB, 4 dB lower than that of the IS-95-A Forward TrafficChannel.

While for the 1xEV-DO Control Channel, under the IS-95-A Forward Traffic Channel link budget, 2% PER is ensuredat receiver for 38.4kpbs and 76.8kbps with dual receiveantenna diversity. With single receive antenna, for theControl Channel transmitted at 38.4kbps and 76.8kbps, a 3%PER and a 7% PER are ensured, respectively, under the IS-95-A Forward Traffic Channel link budget.

C. Comparison between 1xEV-DO and IS-95-A ReverseLink Budgets

From table 5.4, we conclude that for 90% cell edgecoverage and data rates 9.6kbps and 19.2kbps, the 1xEV-DOreverse link budgets are 135.3dB and 133.9dB, respectively.While for IS-95-A, for 90% cell edge coverage of the datarate at 9.6kpbs, the reverse link budget is 133.9 dB. 1xEV-DO provides approximately 1.5 dB link budget gain over IS-95-A on the reverse link.

The service providers can plan an 1xEV-DO network foradequate coverage of reverse link data rate at 19.2kpbs andstill achieve the same link budget as that of an IS-95-Anetwork which only has adequate coverage of reverse linkdata rate at 9.6kbps.

D. Fwd/Rev Average Burst Rate vs. Path Loss

Fig. 5.1 shows the 1xEV-DO forward link average burstrate and reverse link data rate achievable for 90% cell edgecoverage vs. path loss. For the forward link, single and dualreceive antenna cases are presented. For the reverse link,system load margins of 3dB and 5dB are shown. Whileplanning the networks, service providers can optimize thesystem load by trading off the reverse link capacity and cellcoverage. Based on Fig. 5.1, one can easily obtain themaximum path loss, based on the minimum required reverselink data rate, and then find the forward link average burstrate that can be achieved under that path loss. For example, ifone wants to support at least 19.2kbps on the reverse link for90% cell coverage under a system load margin of 5dB, themaximum allowable path loss is 131.9 dB. For the singlereceiver antenna case this corresponds to a forward linkaverage burst rate over 260kbps, while for a dual receiverantenna case, it corresponds to a forward link average burstrate over 600kbps.

VI. CONCLUSION

In this paper, we presented the analysis and simulationresults for the link budgets of a cdma2000 1xEV-DO system.It is shown that 1xEV-DO has link budget advantages overIS-95-A of approximately 10 dB on the forward link and 1.5dB on the reverse link.

The 1xEV-DO forward link provides the link budget gainover IS-95-A from the following sources: 1) Coding gain of2.0 dB: 1xEV-DO uses turbo-code as opposed toconvolutional code in IS-95-A; 2) Variable rate gain of 7.0dB: 1xEV-DO uses rate control and ARQ as opposed topower control in IS-95-A forward link; 3) Multi-user

diversity gain of 2.0 dB: 1xEV-DO uses proportional fairscheduling algorithm that exploits multi-user diversity. At thesame time, 1xEV-DO loses 1.5 dB of soft handoff gainbecause 1xEV-DO uses selection diversity soft handoff asopposed to the power combined diversity soft handoff of IS-95-A. These factors contribute to approximately 10 dBforward link budget gain for 1xEV-DO over IS-95-A.

Fwd/Rev Link Burst Rate vs. Path Loss

1

10

100

1000

125 130 135 140 145 150 155

Path Loss (dB)B

urs

tR

ate

(kb

ps)

Fwd. Link, Single AntennaFwd. Link, Dual AntennaRev. Link, Dual Antenna, System Load=3dBRev. Link, Dual Antenna, System Load=5dB

Fig. 5.1 Fwd/Rev Link Burst Rate vs. Path Loss for 1xEV-DO

Table 5.1. 1xEV-DO Forward Link Budget for Single Antenna TerminalTraffic Traffic Control Control Equation

Average Throughput (or datarate) (bps)

9,600 32,175 38,400 76,800

Average Burst Rate (bps) 67,100 225,000 N/A N/AServing Time Fraction (%) 14.3 14.3 N/A N/ABandwidth (Hz) 1228.8k 1228.8k 1228.8k 1228.8kBandwidth (dB-Hz) 60.9 60.9 60.9 60.9 ABTS Tx Power (Watts) 15.0 15.0 15.0 15.0BTS Tx Power (dBm) 41.8 41.8 41.8 41.8 BBTS Antenna Gain (dBi) 17.0 17.0 17.0 17.0 CBTS Cable Loss (dB) 3.0 3.0 3.0 3.0 DBTS EIRP (dBm) 55.8 55.8 55.8 55.8 E=B+C-DMS Rx Antenna Gain (dBi) 0.0 0.0 0.0 0.0 FBody Loss (dB) 3.03 3.0 3.0 3.0 G

Noise Figure (dB) 9.0 9.0 9.0 9.0 HThermal Noise (dBm/Hz) -165.0 -165.0 -165.0 -165.0 I = -174.0 +

HTarget PER (%) 2 2 2 6(Ior/No)req Per Antenna (dB) -7.0 2.5 4.0 4.0 JMulti-user Diversity Gain (dB) 2.0 1.0 N/A N/ARx Diversity Gain (dB) N/A N/A N/A N/AMS Receiver Sensitivity (dBm) -111.1 -101.6 -100.1 -100.1 K=I+J+ALog-normal Std. Deviation (dB) 8 8 8 8Log-normal Fade Margin (dB) 10.3 10.3 10.3 10.3 L

Soft Handoff Gain (dB)4 4.1 4.1 4.1 4.1 M

Building Penetration Loss (dB) 10.0 10.0 10.0 10.0 NMaximum Pass Loss (dB) 147.7 138.2 136.7 136.7 O=E-K+F-

G-L+M-N

3 For non hand-held terminals, e.g., wireless data modems, the body loss canbe assumed to be zero.4 The 1xEV-DO forward link uses selection diversity when in handoff. Morespecifically, the mobile selects a base station that has the best signal level asits serving base station. For selection diversity soft handoff, it is shown thatthe required fade margin is 6.2dB, which leads to a soft handoff gain is4.1dB compared with the required fade margin of 10.3dB for hard handoff[5].


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Table 5.2. 1xEV-DO Forward Link Budget for Dual Antenna TerminalTraffic Traffic Control Control Equation

Average Throughput (or datarate) (bps)

9,600 70,785 38,400 76,800

Average Burst Rate (bps) 67,100 495,000 N/A N/AServing Time Fraction (%) 14.3 14.3 N/A N/ABandwidth (Hz) 1228.8k 1228.8k 1228.8k 1228.8kBandwidth (dB-Hz) 60.9 60.9 60.9 60.9 ABTS Tx Power (Watts) 15.0 15.0 15.0 15.0BTS Tx Power (dBm) 41.8 41.8 41.8 41.8 BBTS Antenna Gain (dBi) 17.0 17.0 17.0 17.0 CBTS Cable Loss (dB) 3.0 3.0 3.0 3.0 DBTS EIRP (dBm) 55.8 55.8 55.8 55.8 E=B+C-DMS Rx Antenna Gain (dBi) 0.0 0.0 0.0 0.0 FBody Loss (dB) 3.0 3.0 3.0 3.0 GNoise Figure (dB) 9.0 9.0 9.0 9.0 HThermal Noise (dBm/Hz) -165.0 -165.0 -165.0 -165.0 I = -174.0 +

HTarget PER (%) 2 2 2 2(Ior/No)req Per Antenna (dB) -11.6 2.5 -8.0 -4.5 JMulti-user Diversity Gain (dB) 2.0 N/A5 N/A N/A

Rx Diversity Gain (dB) 4.6 ∞6 12.0 ∞

MS Receiver Sensitivity (dBm) -115.7 -101.6 -112.1 -108.6 K=I+J+ALog-normal Std. Deviation (dB) 8 8 8 8Log-normal Fade Margin (dB) 10.3 10.3 10.3 10.3 LSoft Handoff Gain (dB) 4.1 4.1 4.1 4.1 MBuilding Penetration Loss (dB) 10.0 10.0 10.0 10.0 NMaximum Pass Loss (dB) 152.3 138.2 148.7 145.2 O=E-K+F-

G-L+M-N

Table 5.3 IS-95-A Forward Link BudgetTraffic Paging Equation

Data Rate (bps) 9,600 9,600Data Rate (dB-Hz) 39.8 39.8 ABTS Tx Power (Watts) 15.0 15.0BTS Tx Power (dBm) 41.8 41.8Max. % Power for Each Channel 5.3 20Max. Power Allocated per CH (Watts) 0.8 3.0Max. Power Allocated per CH (dBm) 29.0 34.8 BBTS Antenna Gain (dBi) 17.0 17.0 CBTS Cable Loss (dB) 3.0 3.0 DBTS EIRP per TCH (dBm) 43.0 48.8 E=B+C-DMS Rx Antenna Gain (dBi) 0.0 0.0 FBody Loss (dB) 3.0 3.0 GNoise Figure (dB) 9.0 9.0 HThermal Noise (dBm/Hz) -165.0 -165.0 I=-174.0+GTarget PER (%) 3 10( Eb/No)req for Single Antenna (dB) 12.37 20.6 J

MS Receiver Sensitivity (dBm) -112.9 -104.6 K=I+J+ALog-normal Std. Deviation (dB) 8 8Log-normal Fade Margin (dB) 10.3 10.3 LSoft Handoff Gain (dB) 5.6 4.1 MBuilding Penetration Loss (dB) 10.0 10.0 NMaximum Pass Loss (dB) 138.2 134.2 O=E-K+F-G-L+M-N

5 Due to the assumed geometry, the average throughput of 70.8kbps cannotbe achieved for single antenna terminals, thus multi-user diversity gain wedefined cannot be derived for this case.6 Due to the same reason above, the Rx diversity gain is ∞.7 Assume 2-way soft handoff with two received signals having the samepower spectrum density. No third cell interference, i.e., Ioc=0. So it is bettergeometry than what we assumed for 1xEV-DO link budget calculation. Also,the required average Eb/No is obtained assuming 3% target FER, a looserconstraint than the 2% target PER assumed in 1xEV-DO.

Table 5.4 1xEV-DO and IS-95-A Reverse Link Budgets1xEV-

DO1xEV-

DOIS-95 Equation

Data Rate (bps) 9,600 19,200 9,600Data Rate (dB-Hz) 39.8 42.8 39.8 AMS Tx Power (mWatts) 200 200 200MS Tx Power (dBm) 23.0 23.0 23.0 BMS Antenna Gain (dBi) 0.08 0.0 0.0 C

Body Loss (dB) 3.0 3.0 3.0 DMS EIRP for Data Channel (dBm) 20.0 20.0 20.0 E=B+C-DBTS Rx Antenna Gain (dBi) 17.0 17.0 17.0 FBTS Cable Loss (dB) 3.0 3.0 3.0 GBTS Noise Figure (dB) 5.0 5.0 5.0 HBTS Thermal Noise (dBm/Hz) -169.0 -169.0 -169.0 I=-174.0+HTarget PER (%) 2 2 3Total ( Eb/No)req per Antenna @no system load (dB)

6.6 5.0 8.0 J

System Load Margin (dB) 3.0 3.0 3.0 KBTS Receiver Sensitivity (dBm) -119.6 -118.2 -118.2 L=I+J+K+ALog-normal Std. Deviation 8 8 8Log-normal Fade Margin (dB) 10.3 10.3 10.3 MSoft Handoff Gain (dB) 4.1 4.1 4.1 NDifferential Fade Margin (dB) 2.1 2.1 2.1 OBuilding Penetration Loss (dB) 10.0 10.0 10.0 PMaximum Path Loss (dB) 135.3 133.9 133.9 Q=E-L+F-G-

M+N-O-P

ACKNOWLEDGMENT

The authors thank Mehmet Gurelli and Eduardo Estevesfor their assistance providing the simulation and RobertoPadovani for his constructive comments that led to manyimprovements in this paper.

REFERENCES

[1] 3rd Generation Partnership Project 2 (3GPP2) "cdma2000High Rate Packet Data Air Interface Specification",C.S20024 v2.0 October 2000.

[2] P. J. Black, et. al. “Capacity simulation of cdma20001xEV wireless internet access system,” IEEE MWCN2001, pp. 90-96, August 2001.

[3] TIA/EIA-98-C Recommended Minimum PerformanceStandards for Dual-Mode Spread Spectrum MobileStations.

[4] Rec.ITU-R M.1225 Guidelines for Evaluation of RadioTransmission Technologies for IMT-2000.

[5] A. J. Viterbi, et. al. “Soft handoff extends CDMA cellcoverage and increase reverse link capacity,” IEEEJournal on Selected Areas in Communications, vol. 12,No. 8, pp. 1281-1288, October 1994.

8 Non hand-held terminals may yield higher antenna gain. The comparisonhere assumes mobile handset.

link budget of cdma2000 1xev-do.pdf

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