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PROPRIETARY1
Data Throughput in CDMA2000 1X
Dr. Joseph Shapira
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PROPRIETARY2
Throughput
The forward link throughput is limited by the available power.
Link efficiency is the power required to deliver one bit/sec
The power required to support users at location is
;;; rPGGGrErP RTbT
Sector
bitsdtransmitteofNumberThroughputTP
sec
;r
;;; rRrLErP bT Link efficiency
Energy/bit for this service
Data rate
GT,R Antenna gain
PG Path gain (1/path loss)
b
b
R
E
LE
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PROPRIETARY3
Link Efficiency
Efficiency decreases with 4th exponent of the range
Efficiency depends on the antenna pattern
RequiredEb depends on the interference
Eb/It is a set requirement per type of transmission/service
I
C
W
R
I
E b
t
b
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PROPRIETARY4
Throughput is Translated into
Required Eb/It (or C/I) ValuesLatency vs. requiredEb/It
HARQ allows for higher FER and lower Eb/It, but higher latency
Data ratevs. requiredEb/It
Higher data rate requires higher, more sensitive modulation
constellation and less code protection, thus higher Eb/It,
Each Data Transmission Type/ service
has itsEb/Itvs. Max Data-Rate Curve
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PROPRIETARY6
Types of Data Transmission
Conversationallow end-to-end delay, symmetric traffic.Mainly circuit-switched voice services, and (circuit or
packet-switched) video telephony.
StreamingTransmission of data that can be processed as asteady continuous stream. Asymmetric, latency-tolerant.Typical services are web broadcast and video on demand.
InteractiveRequest response pattern. Short round-tripdelay. Typical applications are web browsing, videogames, location-based services.
BackgroundApplications that do not require immediateattention. Starting from SMS, email services and to filestransfer.
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PROPRIETARY7
CDMA2000 FL Configurations
Six forward linkRadio Configurations (RC) are defined for 1x,
- Different length Walsh codes, from 4 to 128 chips, to suit the application.
- QPSK modulation
- Turbo codes
- Fast FL power control (800Hz). There are 1, 0.5 and 0.25 dB steps- Transmit diversity
- Additional channels to accommodate a variety of applications.
- Frame lengths20 ms for signaling and user information, 5 ms for control
information.
- Forward Common Auxiliary Pilot Channel (FCAPiCh), and Forward.
- Dedicated Auxiliary Pilot Channel (FDAPiCh) to support smart antennatransmission
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PROPRIETARY8
Radio Configurations
RC Data rate (Kbps) FEC Encoder rate Modulation TD
1 1.2; 2.4; 4.8; 9.6 1/2 BPSK
2 1.8; 3.6; 7.2; 14.4 1/2 BPSK
3 1.2; 1.35; 1.5; 2.4; 2.7; 4.8; 9.6;
19.2; 38.4; 76.8; 153.6
1/4 QPSK +
4 1.2; 1.35; 1.5; 2.4; 2.7; 4.8; 9.6;
19.2; 38.4; 76.8; 153.6; 307.2
1/2 QPSK +
5 1.8; 3.6; 7.2; 14.4; 28.8; 57.6; 115.2; 230.4 1/4 QPSK +
10 81.6; 158.4; 163.2; 312.0; 316.8; 326.4; 465.6; 619.2;624.0; 633.6; 772.8; 931.2; 1238.4; 1248.0; 1545.6; 1862.4;
2476.8; 3091.2
1/5 QPSK,
8-PSK,
16 QAM
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PROPRIETARY9
FL: Cell Throughput Parameters
Users activity requirements
Distribution of the needs per type within the cell coverage.
This is an operators inputCell resources
Power, channel cards, antenna gain
Cell environmentC/I map. Depends on path-gain, antenna pattern, fading,
diversity, neighboring cells
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PROPRIETARY10
C/I vs. range
for different orthogonality values
-15
-10
-5
0
5
10
15
0.05
0.15
0.25
0.35
0.45
0.55
0.65
0.75
0.85
0.95
1.05
1.15
r/R
C/I[dB]
al=.99 al=.95 al=.7 al=.5 al=al(r)
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PROPRIETARY11
Addressing the Throughput
1. C/I map (by prediction or drive test)
2. Required C/I - Get the required data rate per service typein each location (from operator or audit)
3. By comparing mapsget the max DR per service ineach location
4. Power allocation per service type
5. Integrate power over sector
6. Modify coverage/ service mix to meet power limit
EIRPPilotIEICnP tcBin _*
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PROPRIETARY12
Planning/ Optimization Approach
Divide the cell into bins according to environment and
activity.
Represent average values per bin
Trade-off coverage with max throughput per service per
bin, and service mix, to meet power limit.
Incorporate resource management rules ( vendor
dependent).
Validate by drive test
Monitor over time and change the allocations per actual
activity
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PROPRIETARY13
Throughput Enhancement
Enhance C/I in deficient bins by:
1. Distributed access (repeaters)
2. Polarization matching
3. Beam directivity
4. Transmit diversity5. Load balancing (beam tilt/ shift/ shape)
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PROPRIETARY14
Throughput Validation Methodology
Drive test
Measure C/I ,Ec, Ec/Itmaps
Conduct sessions of each type of data
transmission
Compare with prediction
Calibrate prediction
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PROPRIETARY15
Attention to Resource Management
Each vendor has its resource managementalgorithms:
AOC for controlling power saturation Hashing and channel (FA) transfer for
balancing load and controlling SHO
Etc.These have to be reviewed and incorporated
into the optimization.
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PROPRIETARY16
CDMA2000 1X Rev D RL
- Independent fundamental and supplementalchannels.
- Supplemental R-PDCH (after request and grant)- Scheduler according to data type and link status
- Coherent reverse link with a continuous pilot peruser.
- Frame lengths - 20 ms for signaling and userinformation, 5 ms for control information.
- Adaptive threshold Soft Handoff
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PROPRIETARY17
Noise rise considerations
The noise rise is limitedby max. slope (powercontrol stability).
A data burst shifts thenoise rise.
Admission is based onthe noise rise marginavailable.
This is a policy issue(resource allocation
between services).
Nominal full load
ST dB Max. slope
Data burst
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PROPRIETARY18
Thank YouContact
Dr. Joseph Shapira
PresidentComm&Sens
Tel. +972 4 8251653
Cell +972 54 660708
Email:[email protected]