Read Microsoft PowerPoint - 3G Evolution ­ HSPA and LTE for Mobile Broadband text version

3G Evolution ­ HSPA and LTE for Mobile Broadband

Dr Stefan Parkvall Senior Specialist, Adaptive Radio Access Ericsson Research

Mobile Broadband

SPA H

-3G rbo Tu

LTE

Ericsson Internal

2

2008-02-29

More Than 400* HSPA Devices!

203 HSPA phones, media players, camera (50%) 161 PC with embedded HSPA, PC cards, USB modems (40%) 39 wireless routers (10%)

*Commercially launched as of August 2007

Ericsson Internal

3

2008-02-29

So...what is HSPA and LTE?

Trend ­ Data is overtaking Voice

Data is overtaking voice... ...but previs cellular systems designed primarily for voice

70

WCDMA & HSPA world average

3

400

60

350

50

GBit/RNC/h

40

Packet

250 200 150 100

300

30

20

10

Voice

50 0 sep-06 okt-06 nov-06 dec-06 jan-07 feb-07 mar-07 apr-07 maj-07 jun-07 jul-07 aug-07 sep-07 okt-07 nov-07 dec-07 Sum of Meas RNCs Sum of Packet (DCH+HS) traffic (GBit/RNC/h) Sum of CS64 traffic (GBit/RNC/h) Sum of Total traffic (GBit/RNC/h) Sum of DCH Packet traffic (GBit/RNC/h) Sum of Others traffic (GBit/RNC/h)

Ct r l +Shi f t +E

0

Sum of Speech traffic (GBit/RNC/h) Sum of HS Packet traffic (GBit/RNC/h)

Source: NetQB

Ericsson Internal 5 2008-02-29

# RNCs

HSPA and LTE = Mobile Broadband

HSPA ­ High-Speed Packet Access

­ ­ ­

R99

Evolution of 3G/WCDMA Gradually improved performance at a low additional cost Data rates up to ~20 Mbit/s in 5 MHz

Rel4 Rel5 Rel6 Rel7 Rel8 Rel10

WCDMA

HSDPA

HSPA

HSPA evolution

"4G"

LTE LTE Advanced

LTE ­ Long-Term Evolution

­ ­ ­ Significantly improved performance in a wide range of spectrum allocations Data rates up to ~300 Mbit/s in 20 MHz First step towards IMT-Advanced ("4G")

Different systems ­ but many basic principles are similar!

Ericsson Internal 6 2008-02-29

Wireless vs Wireline

Wireless seems simple... D = B = 0 ×E = - B t D ×H = J + t ...so what's the problem?

Ericsson Internal

7

2008-02-29

Radio Channels and Packet Data

Radio channel quality varies...

­ ­ ...distance to base station ... random variations in the environment

Traffic pattern varies...

­ ­ ...user behavior ...server load

Adapt to and exploit channel and traffic variations!

Ericsson Internal 8 2008-02-29

Rate Control

Reliable reception requires a certain Eb/N0 How to control Eb?

­ Eb = P·T

Power Control

Rate Control

Data Rate

Tx Power

Varying instantaneous data rate acceptable for packet-data services

­ Rapid ­ tracks fast fading

Rate control more efficient than power control!

Ericsson Internal 9 2008-02-29

Data Rate

Tx Power

Channel Quality

Channel Quality

Rate Control

Data rate controlled through... ...different channel coding rates

­ ­ Advantageous channel conditions Code rates from 1/3 to ~1 high code rate

...different modulation schemes

­ Advantageous channel conditions higher-order modulation

QPSK

16QAM

64QAM

...different multi-antenna schemes

Ericsson Internal

10

2008-02-29

Shared-Channel Transmission

Dedicated channel

­ ­ User resources assigned at "call setup" Independent of instantaneous traffic situation

Shared channel

­ ­ Dynamic sharing of common rerouce Adapts to instantaneous traffic situation

Ericsson Internal

11

2008-02-29

Channel-dependent Scheduling

Scheduling determines at each time instant...

­ ­ ...to whom to assign the shared channel ...which data rate to use

Basic idea: transmit at fading peaks

­ ­ May lead to large variations in data rate between users Tradeoff: fairness vs cell throughput

Effective channel variations seen by the base station Channel Quality

User #1 User #2 User #3

Time #1 #3

Ericsson Internal

#2

12

#3

#1

2008-02-29

Channel-dependent Scheduling

­ ­ Cyclically assign the channel to users without taking channel conditions into account Simple but poor performance

Radio Link Quality

Round Robin (RR)

Time

­ ­

Assign the channel to the user with the best channel quality High system throughput but not fair

Radio Link Quality

Max C/I

Time

Proportional Fair (PF)

Radio Link Quality

­ ­

Assign the channel to the user with the best relative channel quality High throughput, fair

Time

Ericsson Internal

13

2008-02-29

Channel-dependent Scheduling

HSPA ­ channel-dependent scheduling in time-domain only LTE ­ channel-dependent scheduling in time and frequency domains

Time-frequency fading, user #1 data1

data2 data3 data4 Time-frequency

fading, user #2

User #1 scheduled User #2 scheduled

1m s

Tim e

cy Frequen

180 kHz

Ericsson Internal

14

2008-02-29

Channel Quality Indication

Scheduling and rate control adapts to channel variations Problem: need channel knowledge at the base station Solution: terminals transmit channel-quality reports to base station Reporting rate configurable

­ ­ HSPA ­ reports as often as every 2 ms LTE ­ reprots as often as every 1 ms

Ericsson Internal

15

2008-02-29

Hybrid ARQ with Soft Combining

Retransmsision of erroneously received packets

­ Fast no disturbance of TCP behavior improved performance

Soft combining of multiple transmission attempts

­ Soft combining

P1,1 Transmitter

NAK

P1,2

ACK

P2,1

K NAC

P2,2

ACK

P3,1

ACK

P1,1 Receiver

P1,2 + P1,1

P2,1

P2,2 + P2,2

P3,1

Ericsson Internal

16

2008-02-29

Hybrid ARQ with Soft Combining

Incremental redundancy

Data

CRC insertion, Turbo coding Puncturing to · generate different redundancy versions · match the number of coded bits to the channel

Transmitted bits

redundancy version 1 redundancy version 2 redundancy version 3 redundancy version 1

Initial transmission

First retransmission

Second retransmission

Third retransmission

Bits input to decoder Accumulated energy Resulting code rate Eb R=3/4

Ericsson Internal

2Eb R=3/8

17

3Eb R=1/4

4Eb R=1/4

2008-02-29

Basic Principles ­ Summary

Shared channel transmission

Channel-dependent scheduling

Rate control

Hybrid-ARQ with soft combining

Ericsson Internal

18

2008-02-29

Summary

Radio channel quality is time varying

Traffic pattern is time varying

Adapt to and exploit

­ variations in radio channel quality ­ variations in the traffic pattern

...instead of combating them!

Ericsson Internal

19

2008-02-29

Work in 3GPP

History

NMT, ...

Analog, speech

30 kHz 200 kHz 5 MHz 20 MHz

Research and standardization

GSM, ...

Digital, speech and low-rate data low-

Research and standardization

WCDMA/HSPA

High-speed data (up to ~20 Mbps) High-

Research and standardization

LTE

High-speed data (up to 300 Mbps) High-

1980

1990

2000

2010

Ericsson Internal

21

2008-02-29

3G Evolution

1999

R99 Rel4

2002

Rel5

2005

Rel6

2007

Rel7

2008

Rel8 Rel10

WCDMA

HSDPA

HSPA

HSPA evolution

"4G"

LTE LTE Advanced

HSPA evolution

­ gradually improved performance at a low additional cost in 5MHz spectrum allocation

LTE

­ ­ significantly improved performance in a wide range of spectrum allocations further evolved into IMT-Advanced

Ericsson Internal 22 2008-02-29

3GPP

International organization

­ Vendors and operators co-operate ­ Develop specifications for GSM, WCDMA/HSPA, LTE

PCG

(Project coordination group)

TSG GERAN

(GSM EDGE Radio Access Network)

TSG RAN

(Radio Access Network)

TSG SA

(Services & System Aspects)

TSG CT

(Core Network & Terminals)

WG1

Radio Aspects

WG1

Radio Layer 1

WG1

Services

WG1

MM/CC/SM (Iu)

WG2

Protocol aspects

WG2

Radio Layer 2 & Layer 3 RR

WG2

Architecture

WG3

Interworking with External Networks

WG3

Terminal testing

WG3

Iub, Iuc, Iur & UTRAN GSM Req.

WG3

Security

WG4

MAP/GTP/BCH/SS

WG4

Radio Performance & Protocol Aspects.

WG4

Codec

WG5

OSA

Open Services Access

WG5

Mobile Terminal Conformance Test Ericsson Internal 23

WG5

Telecom Management

WG6

Smart Card Application Aspects 2008-02-29

Standardization ­ a Flying Circus?

RAN1 meetings held ~8 times a year

­ ­ Meetings run from Monday to Friday Held in various countries in Europe, North America, and Asia

Meeting schedule 2007

­ ­ ­ ­ ­ ­ ­ ­ ­ January 15-19, February 12-16, March 26-30, April 17-20, May 7-11, June 25-29, August 20-24, October 8-12, November 5-9, Sorrento, St Louis, St Juliens, Beijing, Kobe, Orlando, Athens, Shanghai Seoul Italy USA Malta China Japan USA Greece China Korea

Ericsson Internal

24

2008-02-29

100

120

20

40

60

80

0

Approval of the agenda Approval of the minutes from previous meetings Liaison statement handling Maintenance of Release 99 ­ Release 7 Evolved UTRA and UTRAN TDD Frame Structure Finalization of TS 36.211 Downlink reference signals

Typical RAN1 Meeting

Approx 200 delegates attending and ~550 documents submitted...

Ericsson Internal

Uplink reference signals Downlink Control Signalling

Number of Contributions per Agenda Item

25

Uplink Control Signalling Mapping of virtual resource blocks to physical resource blocks Bit scrambling sequences for UL/DL transmissions RACH Finalization of TS 36.212 Finalization of TS 36.213 Timing synchronization UL/DL Power Control Inter-cell Interference Coordination RACH timing and preamble sequence selection UE Procedures for downlink shared channel UE Procedures for uplink shared channel Finalization of TS 36.214 Finalization of TS 36.201 UE Categories Combination of Higher Order Modulation and MIMO in HSDPA (FDD) Enhanced Uplink for Cell_FACH State in FDD Study Item on Synchronized E-DCH

2008-02-29

Taking You Forward...

Ericsson Internal

26

2008-02-29

Ericsson Internal

27

2008-02-29

Information

Microsoft PowerPoint - 3G Evolution ­ HSPA and LTE for Mobile Broadband

27 pages

Find more like this

Report File (DMCA)

Our content is added by our users. We aim to remove reported files within 1 working day. Please use this link to notify us:

Report this file as copyright or inappropriate

1263288