HSDPA Link Budget Presentation v1%2E09
Transcript of HSDPA Link Budget Presentation v1%2E09
2 Nortel Confidential Information
HSDPA Link Budget Presentation
Core WNE, 22nd June 2006
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Agenda
Uplink Link Budget
Downlink Link Budget
HSDPA Throughput
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> Uplink Link Budget
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Uplink Link Budget
BS
BSUE S -GSlantloss-Cableloss -G Tx LossPath ReverseMax UE
> Aim: UL capacity and Max Available Path Loss
• UL capacity thanks to N-pole Formula• Cell Size with Cost Hata model
> Same parameters as R’99 link budget except BS Eb/No • Frequency : 1980Mhz• Environment : Dense Urban, Urban, Suburban, Rural• Services : Speech 12.2, CS 64, PS 64, PS 128• BTS : Noise Figure, Antenna Gain,• UE : Noise Figure, UE Power • Margin / loss : Shadow Margin, penetration loss, body loss, cable & connectors loss, slant loss• For more information about R’99 Link budget see the guidelines at this link : http://navigate.us.nortel.com/imds?pg=/eng/wne/umts/acc/rf/lb
Margins - PathLoss ReverseMax PathLoss Reverse Available
Uplink Link Budget
General CS 64
RX Frequency band (MHz) 1980 TX Frequency band (MHz) 2170 Spreading bandwidth (kHz) 3840 Thermal noise (kTB) (dBm) -108.2 Data rate (kb/s) 64.0 Processing gain (dB) 17.8
BS RX Eb/No (dB) 4.2 dB Thermal noise (kTB) (dBm) -108.2 dBm BS RX noise figure (dB) 2.5 dB BS RX sensitivity (dBm) -119.7 dBm BS RX antenna gain (dBi) 17.0 dBi
Maximum UE TX power (dBm)/MEAN 21.0 dBm UE TX antenna gain (dBi) 0.0 dBi Total UE TX EIRP (dBm) 21.0 dBm BS RX cable & connector losses (dB) 3.0 dB Slant losses (dB) 1.5 dB Maximum allowable isotropic path loss (dB) 153.2 dB
Area Reliability 90% Total Standard Deviation 13.3 dB Shadowing Margin 5.2 dB Penetration Factor 18.0 dB UL Interference margin due to traffic loading (dB) 3.0 dB Body loss (dB) 1.0 dB Reverse Total required margin (dB) 27.2 dB
Available Reverse Link Budget (dB) 126.0 dB Capacity Activity factor 1.0 Frequency reuse efficiency 0.6 UL loading factor (%) 50% Eb/No gain due to diversity with SHO 1.0 dB Pole capacity per sector (# of links) 20.0 UL Capacity per sector (# of links) 10.0 Troughput (kbps) 639.4 Cell dimensioning Site antenna height (m) 30.0 Propagation coefficient 35.2 Path loss at 1 km 137.6 Selected environment correction 0.0 Maximum coverage range (km) 0.47 km Area covered by 1 Site (km²) 0.43 km²
TMA No
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Node B performance : Eb/No
>HS-DPCCH impact
DPDCHn I
j
cd,1 d
Sdpch,n
I+jQ
DPDCH1
Q
cd,3 d
cd,2 d
DPDCH2
cc c
DPCCH
S
chs
HS-DPCCH (If Nmax-dpdch mod 2 = 1)
chs
HS-DPCCH (If Nmax-dpdch mod 2 = 0)
hs
hs
cd,6 d
DPDCHn+1
222
22
log10LOSShscd
cd
22
1*c
hs
c
dDPCCHPerMaxUETxPow
222
22
222
22
log*10)()(
*
hsdc
dcDCH
hsdc
dcDCH
dBerMaxUETxPowdBP
erMaxUETxPowP
222
2
1*hsdc
hs
DPCCHHS
erMaxUETxPow
PerMaxUETxPow
>The maximum UE TX power deduced
>So the DCH available power is:
And
>The loss in performance is given by the following formula:
See 3GPP TS25.213
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>HS-DPCCH impact
•Eb /No loss due to HS- DPCCH:
• iCEM
More repetitions less losses
•QoS• HS-DPCCH : 4% BLER on ACK/NACK and CQI• Speech : 10-1 BLER• PS64/128/384: 10-1 BLER
Loss (dB)
Speech 1.5
CS 64 1.3
PS 64 1.3
PS 128 0.6
PS 384 0.3
lossN
E
N
E
RiCEM
b
HSDPA
b
99'00
Node B performance : Eb/No
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> The N-pole formula gives the maximum number of channels that the radio can carry:
• PG is the processing gain• FR is the frequency reuse efficiency • V is the activity factor• Eb/N0 is the UL performances requirements• GSHO is the gain obtained on the Eb/N0 due to uplink • selection diversity when doing soft/softer handover
> Assumptions :• Pedestrian A @3km/h• FR = 60 % • GSHO = 1 dB
Service
Without HSDPA
With HSDPA
PS 64 12 10
PS 128 7 6
PS 384 3 3
Real capacity – 50% loaded cell
SHO0
bpole
.
PG.FR1
GN
EV
N
HSDPA impact on the N-pole capacity
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> Downlink Link Budget
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Downlink Link Budget
> Aim : Power allocated to HSDPA traffic
Max Available
Reverse PathlossMax Down-Link Pathloss
PA Dimensioning
(% of PA for
Common Channels,
traffic channels)
HSDPA Traffic
Power
HSDPA Throughput
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Downlink Link Budget
Max Available Reverse PathlossMax Down Link Pathloss =
Available Reverse Pathloss + Frequency shift UL/DL + Penetration factor + Body Loss
+ Slant loss + Cable/feeders loss + Shadow margin – BS Antenna Gain
PA DDM
TMA
BS Antenna Gain
Tx Cable Loss
Node B
Max available Air interface pathloss given by UL link Budget
Penetration Losses
PA power at PA output connector
Body Loss
UE Antenna Gain
UE Rx Sensitivity
Shadow MarginMean Path loss
Measured Path loss
PA DDM
TMA
BS Antenna Gain
Tx Cable Loss
Node B
Max available Air interface pathloss given by UL link Budget
Penetration LossesPenetration Losses
PA power at PA output connector
Body Loss
UE Antenna Gain
UE Rx Sensitivity
Shadow MarginMean Path loss
Measured Path loss
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Downlink Link Budget
Max Available Reverse PathlossMax Down Link Pathloss =
Available Reverse Pathloss + Frequency shift UL/DL + Penetration factor + Body Loss
+ Slant loss + Cable/feeders loss + Shadow margin – BS Antenna Gain
Uplink Link Budget
General CS 64
RX Frequency band (MHz) 1980 TX Frequency band (MHz) 2170 Spreading bandwidth (kHz) 3840 Thermal noise (kTB) (dBm) -108.2 Data rate (kb/s) 64.0 Processing gain (dB) 17.8
BS RX Eb/No (dB) 3.8 dB Thermal noise (kTB) (dBm) -108.2 dBm BS RX noise figure (dB) 2.5 dB BS RX sensitivity (dBm) -119.7 dBm BS RX antenna gain (dBi) 17.0 dBi
Maximum UE TX power (dBm)/MEAN 21.0 dBm UE TX antenna gain (dBi) 0.0 dBi Total UE TX EIRP (dBm) 21.0 dBm BS RX cable & connector losses (dB) 3.0 dB Slant losses (dB) 1.5 dB Maximum allowable isotropic path loss (dB) 153.2 dB
Area Reliability 90% Total Standard Deviation 13.3 dB Shadowing Margin 5.2 dB Penetration Factor 18.0 dB UL Interference margin due to traffic loading (dB) 3.0 dB Body loss (dB) 1.0 dB Reverse Total required margin (dB) 27.2 dB
Available Reverse Link Budget (dB) 126.0 dB Capacity Activity factor 1.0 Frequency reuse efficiency 0.6 UL loading factor (%) 50% Eb/No gain due to diversity with SHO 1.0 dB Pole capacity per sector (# of links) 20.0 UL Capacity per sector (# of links) 10.0 Troughput (kbps) 639.4 Cell dimensioning Site antenna height (m) 30.0 Propagation coefficient 35.2 Path loss at 1 km 137.6 Selected environment correction 0.0 Maximum coverage range (km) 0.47 km Area covered by 1 Site (km²) 0.43 km²
TMA No
PA Dimensioning
(% of PA for
Common Channels,
traffic channels)
Downlink Link Budget
General Body loss (dB) 1 dB BS RX antenna gain 17 dB BS TX cable & connector losses (dB) 3 dB Penetration Factor 18 dB Slant loss (dB) 1.5 dB Shadowing Margin 5.2 dB Frequency Shift UL/DL 1.3 dB Coupling loss 1.3 dB Additive DL Loss/UL Air interface 14.3 dB BS RX noise figure 3 dB BS Transmitter Power (W) 45.0 W BS Transmitter Power (dBm) 46.5 dBm Orthogonnality Factor 0.15 MS Noise Figure 7. dB Noise Spectral Density (dBm/Hz) -167.0 dB MS Thermal noise -101.2 dBm Out-of-Cell to In-Cell Interf. Ratio (f) at 90% 190% CPICH Ec/ Io Target at 90% -15 dB I i = Interference intracell -93.8 dBm Ie = Interference intercell -91.0 dBm CPICH Power 36.4 dBm CPICH Power ratio 10.3% HS-SCCH relative to P-CPICH 0 dB Com. Control Channels Power (d) including CPICH 35.6% HS-PDSCH Power ratio 64.4% DCH Power ratio 0.0% Max UL Air interface Path Loss 126.0 dB Max DL Path Losses (from PA to UE antenna connector) 140.3 dB
+
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CQI Offset
HS-SCCH/CPICH (dB)
1 – 7 0
8 – 9 -3
10 – 12 -5
13 – 30 -8
> PA Dimensioning• We set the CPICH target, typical value = -15 dB . • HSDPA adds a new common channel: the HS-SCCH that impacts the PA dimensioning and therefore the ratio
of PA for the traffic. The main goal of downlink link budget is to determine the allocated power HS-SCCH and therefore the available power of traffic channels.
• We set the HS-SCCH power relative to the CPICH as it is done for common channels • At the beginning the HS-SCCH power relative is set to 0.
PA Dimensioning
Relative to Power (W) Time P-CPICH(dB) multiplexed
PA Power ---- 45.0 W P-CPICH ---- 4.4 W 4.4 W P-SCH -5.0 dB 1.4 W ---- S-SCH -5.0 dB 1.4 W ----
P-CCPCH -2.0 dB 2.8 W 2.8 W S-CCPCH -3.0 dB 2.2 W 2.2 W
PICH -5.0 dB 1.4 W 1.4 W AICH -7.0 dB 0.9 W 0.9 W
HS-SCCH 0.0 dB 4.4 W 4.4 W
Power allocated to common 16.0 W
Common/PA Ratio (included HS-SCCH) 35.6%
%(DCH+CCH) for DCH Margin 0.0 W
Power allocated to HSDPA traffic channel 29.0 W
Power allocated to R99 traffic channel 0.0 W
Power allocated to traffic channel 29.0 W
Traffic/ PA Ratio 64.4%
HSDPA Traffic
Power
Downlink Link Budget
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> HSDPA Throughput
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HSDPA Throughput – C/I formula
HSDPA Traffic
Power
C/I CQI Throughput
With:• DL_PL is downlink path loss• Pth is the thermal noise (=INoise)• Ptraffic_HSDPA is the HS-PDSCH power, HDPA traffic power• RxDivGain is the UE Rx diversity gain • n is the number of code used• α is the orthogonallity loss factor• PA is total power of BTS
• Ie is equal to :
yGainRxDiversit*PL_DL*P
yGainRxDiversit*PA*
Ii
I)
n
PPA(*
P
I
C
theHSDPA_Traffic
HSDPA_Traffic
11
PL_DL
PA*
I
II*
I
II
i
ei
i
ee
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CQI according to C/I(dB)
5
10
15
20
25
30
-10 -5 0 5 10 15
C/I (dB)
CQ
I
CQI - category 6
CQI - category 10
CQI - category 12
HSDPA Traffic
Power
C/I CQI Throughput
C/I
CQI = 8
CQI
Throughput @ cell edge = 288 kbps
CQI mapping table for UE categories 6
Number of
CQI value Transport Block Size
# MAC-d PDUs
per TrBlk RLC Throughput per HS-
PDSCH HS-PDSCH Modulation
0 N/A Out of range
1 137 0 0 kbps 1 QPSK
2 173 0 0 kbps 1 QPSK
3 233 0 0 kbps 1 QPSK
4 317 0 0 kbps 1 QPSK
5 377 1 144 kbps 1 QPSK
6 461 1 144 kbps 1 QPSK
7 650 1 144 kbps 2 QPSK
8 792 2 288 kbps 2 QPSK
9 931 2 288 kbps 2 QPSK
10 1262 3 432 kbps 3 QPSK
11 1483 4 576 kbps 3 QPSK
12 1742 5 720 kbps 3 QPSK
13 2279 6 864 kbps 4 QPSK
14 2583 7 1008 kbps 4 QPSK
15 3319 9 1296 kbps 5 QPSK
16 3565 10 1440 kbps 5 16-QAM
17 4189 12 1728 kbps 5 16-QAM
18 4664 13 1872 kbps 5 16-QAM
19 5287 15 2160 kbps 5 16-QAM
20 5887 17 2448 kbps 5 16-QAM
21 6554 19 2736 kbps 5 16-QAM
22 7168 21 3024 kbps 5 16-QAM
23 7168 21 3024 kbps 5 16-QAM
24 7168 21 3024 kbps 5 16-QAM
25 7168 21 3024 kbps 5 16-QAM
26 7168 21 3024 kbps 5 16-QAM
27 7168 21 3024 kbps 5 16-QAM
28 7168 21 3024 kbps 5 16-QAM
29 7168 21 3024 kbps 5 16-QAM
30 7168 21 3024 kbps 5 16-QAM
See: 3GPP TS25.214
yGainRxDiversit*PL_DL*P
yGainRxDiversit*PA*
Ii
I)
n
PPA(*
P
I
C
theHSDPA_Traffic
HSDPA_Traffic
11
CQI = 8
HSDPA Throughput @ cell edge
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Ie/Ii according to DL PL - Dense Urban environment A
0%
20%
40%
60%
80%
100%
120%
140%
160%
180%
200%
60 dB 80 dB 100 dB 120 dB 140 dB 160 dB
Down Link Pathloss (dB)
Ie/I
i (%
)
CQI according to C/I(dB)
5
10
15
20
25
30
-10 -5 0 5 10 15
C/I (dB)
CQ
ICQI - category 6
CQI - category 10
CQI - category 12
yGainRxDiversit*PL_DL*P
yGainRxDiversit*PA*
Ii
I)
n
PPA(*
P
I
C
theHSDPA_Traffic
HSDPA_Traffic
11
C/I
CQI =19
Cell Throughput = 2160 kbpsDown Link Pathloss
Ie/Ii
Down Link PathlossDistance Up Link Pathloss
CQI =19
HSDPA Throughput in the cell
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Multi-user gain
> Two different contributions increase the Multi-user gain (MUG):• The number of users scheduled per TTI: TTI_MUG• The scheduler strategy: Scheduler MUG
> There are several scheduler strategies:• Round-Robin• Proportional Fair • Max-Rate
> Multi-users scheduling per TTI• 1 or 2 HS-SCCH required• Tradeoff: one HS-SCCH per cell limits cell throughput (only one UE is
scheduled in each TTI=2ms) but increase the available power for the HS-DSCH =>higher throughput
• A second user is scheduler if there is still some unused power available (power adjustment used for the 1st user)
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Multi-user gain: TTI_MUG
> TTI_MUG is dependent on:• The available power for HSDPA traffic• The Maximum allowable HSDPA power per user, defined by the
MPO (measurement power offset)
> The MPO restricts the power used by the first user, to schedule a second user with the remaining power, this results in:• A higher cell throughput.• A higher user throughput as the number of users per TTI is
increased (for a constant number of HSDPA active users in the cell).• Even if the first user receives less power, the throughput is not
necessary degraded, in good radio conditions. Typically, used with a proportional fair scheduler, the two users scheduled with TTI MUG should benefit from high throughputs.
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Multi-User gain: Scheduler gain
User 2 scheduled User 1 scheduled
A user is not scheduled if in deep fading !
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2-35
-30
-25
-20
-15
-10
-5
0
5
Time (sec)F
as
t F
ad
ing
am
plit
ud
e (
dB
)
Proportional Fair Scheduling principle
User 1User 2
> Transmitting to users with favorable short term radio conditions can increase significantly the throughput compared to a Round-Robin scheduler.
> The scheduler MUG increases as the cell load increases. Indeed, the probability to have one user with very good radio conditions varies with the number of active HSDPA users in the cell.
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Scheduler MUG & Rx Diversity
0 5 10 15 20 25 300
20
40
60
80
100
120Multi-User Gain - Single - 3 km/h
#users per cell
MU
G %
1 RX2 RX
0 5 10 15 20 25 300
10
20
30
40
50
60
70
80Multi-User Gain - Pedestrian_a - 3 km/h
#users per cell
MU
G %
1 RX2 RX
> The MUG decreases when • The #RX antennae increase• The UE speed increases• The channel profile delay spread
increases
> Proportional fair is up to 100% gain over the Round-Robin.
> Link Budget assumption : 20 simultaneous users per cell
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Scheduler MUG & Rx Diversity
> The mean user throughput decreases with the #users but not linearly thanks to MUG (Multi-User Gain).
> RX diversity offers 15-20% extra again • 1 Rx diversity : 1 antenna• 2 Rx diversity : 2 antennas
0 5 10 15 20 25 300
200
400
600
800
1000
1200
1400
1600
1800
2000
#users per sector
Me
an
us
er
thro
ug
hp
ut
(kb
/s)
Mean User Throughput vs. #users Single - 3 km/h - UE category 6
1 RX2 RX
0 5 10 15 20 25 300
200
400
600
800
1000
1200
1400
1600
1800
2000
#users per sector
Me
an
us
er
thro
ug
hp
ut
(kb
/s)
Mean User Throughput vs. #users Pedestrian_a - 3 km/h - UE category 6
1 RX2 RX
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HSDPA Throughput – RLC/MAC
> MAC-d SDU size is 336 bits (320 bits of payload and 16 bits of header) so the number of SDU per transport block size is:
> The RLC Throughput per HS-PDSCH value in bps is:
> With TTI is 2 ms and PDU size is 320 bits and BLER = 10 %
)size_SDU_dMac
size_block_Transport(round_floorSDU_NB
TTI
size_PDU*SDU_NBThroughput_RLC
BLER*TTI
size_PDU*SDU_NBThroughput_RLC 1
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Betas settingDefault values
> The values are set per RAB, compliant with the 3GPP specifications 25.213.
> Different power offset recommendations for the CQI and ACK/NACK
RAB CS 12.2 kb/s PS 64 kb/s PS 128 kb/s PS 384 kb/s
Beta d1 1 1 1
Beta c11/15 8/15 5/15 3/15
Beta hs/Beta c
CQI
1 1 1 1
Beta hs/Beta c
ACK/NACK
19/15 19/15 19/15 19/15
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