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Copyright © 2014 Huawei Technologies Co., Ltd. All rights reserved.

HSPA & HSPA+

Introduction

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) :18pt


Objectives

Upon completion of this course, you will be able to:

Understand the basic principle and features of HSPA and HSPA+

Page1

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Contents

1. HSPA & HSPA+ Overview

2. HSDPA Introduction

3. HSUPA Introduction

4. HSPA+ Introduction

Page2

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UMTS Data Rate Evolution

Page3

GSM GPRS

EDGE

WCDMA

R99

HSDPA

R5

HSUPA

R6

Mobile Network Uplink Peak Data Rate Downlink Peak Data Rate

GSM 9.6Kbps 9.6Kbps

GPRS 20Kbps 40Kbps

EDGE 60Kbps 120Kbps

WCDMA Release 99 384Kbps 384Kbps

HSDPA Release 5 384Kbps 14.4Mbps

HSUPA Release 6 5.76Mbps 14.4Mbps

HSPA+ Release 7 11.5Mbps 28Mbps

HSPA+ Release 8 11.5Mbps 42Mbps

HSPA+

R7

HSPA+

R8

DL 64QAM

MIMO

16QAM

…

DL 64QAM+MIMO

DC-HSDPA

…

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High Speed Downlink Packet Access

What are the benefits of HSDPA

Higher Data Rates

Peak data rate up to 14Mbps per user (Release 5)

Higher Capacity

More subscribers and throughput

Further reduces the cost per megabyte

Richer Application

Low latency – improvement for streaming ,interactive, background

applications

Page4

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Release 99 Downlink Packet Data

How is Packet Data handled in Release 99 (FDD) ?

DCH ( Dedicated Channel )

Spreading codes assigned per user

Closed loop power control

Soft handover

FACH ( Common Channel )

Common Spreading code

No closed loop power control

No soft handover

Page5

Node B

Node B

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Release 99 Downlink Limitation

Dedicated Channel Features ( DCH )

Maximum implemented downlink of 384kbps

OVSF code limitation for high data rate users

Rate change according to burst throughput is slow

Outer loop power control responds slowly to channel

Common Channel Features ( FACH )

Good for burst data application

Only low data rates supported

Fixed transmit power

Page6

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HSDPA Basic Concepts

Set of high data rate channel

Channels are shared by multiple users

Each user may be assigned all or part of the resource every 2ms

Page7

HSDPA user#1

HSDPA user#2

HSDPA user#3

HSDPA user#4

Node B

a set of HS-PDSCHs

Code multiplexing for HSDPA

2ms

“Big shared pipe”

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HSDPA Basic Concepts (cont.)

How will HSDPA figure out the limitations of R99

Adaptive modulation and coding

Fast feedback of Channel condition

QPSK and16QAM

Channel coding rate from 1/3 to 1

Multi-code operation

Multiple codes allocated per user

Fixed spreading factor

NodeB fast Scheduling

Physical Layer HARQ ( Hybrid Automatic Repeat reQuest )

Page8

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Comparison between R99 and HSDPA

Page9

Mode DCH FACH HSDPA

Channel Type Dedicated Shared Shared

Power Control Closed Inner Loop

at 1500Hz & Closed

Outer Loop

No Fixed Power with

link adaptation

Soft Handover Supported Not Supported Not Supported

Suitability for

Bursty Poor Good Good

Data Rate Medium Low High

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High Speed Uplink Packet Access

Driver force for HSUPA

Data Rate – demand for higher peak data rates in uplink

Qos – lower latency

Capacity – better uplink throughput

Coverage – better uplink coverage for higher data rate

Page10

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Release 99 Uplink Packet Data

DCH (Dedicated Channel)

Variable spreading factor

Closed loop power control

Macro diversity (soft handover)

RACH

Common spreading code

Fixed spreading factor

No closed loop power control

No soft handover

Page11

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Release 99 Uplink Limitation

Large scheduling delay

Radio resource is controlled from RNC

Uplink DCCC (Dynamic channel configuration control)

Large latency

Transmission time interval duration of 10/20/40/80ms

RNC based retransmission in case of errors (RLC layer)

Limited uplink data rate

Deployed peak data rate is 384kbps with limited subscriber

number

Page12

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HSUPA Basic Concepts

E-DCH channel has been introduced

Interference is shared by multiple users

NodeB controls all UEs data rate with fast scheduling

Page13

E-DCH

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Improved Characters by HSUPA

Higher peak data rate in uplink

Reduced latency

Faster retransmission to improve throughput

Fast scheduling

Optimize the resource allocation to maximize the total throughput

Quality of Service support

Improve QoS control and resource utilization

Page14

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HSPA+ Introduction

HSPA refers to HSDPA and HSUPA which are introduced in

3GPP Release 5 and Release 6. It can provide significant

throughput, latency, and capacity gains on the downlink and

uplink, compared to Release 99.

HSPA+ (also known as HSPA evolution) is introduced in 3GPP

Release 7 and develops continuously in the following Release. It

is an enhancement to HSPA.

Page15

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Goals for HSPA+

Reduced service delay

Increase peak data rates

Improve spectrum efficiency

Increase system capacity

Reduce UE power consumption

Page16

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Contents





Page17

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HSDPA Key Techniques

Page18

AMC (Adaptive Modulation & Coding)

Data rate adapted to radio condition on 2ms

Fast Scheduling based on CQI and fairness

Scheduling of user on 2ms

HARQ（Hybrid ARQ）with

Soft combing

Reduce round trip time

16QAM

16QAM in complement to QPSK for higher peak bit rates

SF16, 2ms and CDM/TDM

Dynamic shared in Time and code domain

3 New Physical Channels

Block 1 Block 2 Block 1

Block 1?

Block 1 Block 1?

+

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Adaptive Modulation and Coding

AMC ( Adaptive Modulation and Coding ) in accordance with

CQI ( Channel Quality Indicator )

Adjust data rate to compensation channel condition

Good channel condition – higher data rate

Bad channel condition – lower data rate

Adjust channel coding rate to compensation channel condition

Good channel condition – channel coding rate is higher e.g. 3/4

Bad channel condition –channel coding rate is lower e.g. 1/3

Adjust the modulation scheme to compensation channel condition

Good channel condition – high order modulation scheme e.g. 16QAM

Bad channel condition – low order modulation scheme e.g. QPSK

Page19

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Adaptive Modulation and Coding (cont.)

AMC ( Adaptive Modulation and Coding ) based on CQI

( Channel Quality Indicator )

CQI ( channel quality indicator )

UE measures the channel quality and reports to NodeB every 2ms or a

longer cycle

NodeB selects modulation scheme ,data block size based on CQI

Page20

Bad channel condition

→ More power Node B Node B

Power Control Rate Adaptation

Good channel condition

Bad channel condition

Good channel condition

→ less power

→ low data rate

→ high data rate

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CQI mapping table for UE category 10

Page21

CQI value Transport

Block Size

Number of

HS-PDSCH Modulation

Reference power

adjustment

0 N/A Out of range

1 137 1 QPSK 0

2 173 1 QPSK 0

…… …… …… …… ……

13 2279 4 QPSK 0

14 2583 4 QPSK 0

15 3319 5 QPSK 0

16 3565 5 16-QAM 0

17 4189 5 16-QAM 0

18 4664 5 16-QAM 0

…… …… …… …… ……

28 23370 15 16-QAM 0

29 24222 15 16-QAM 0

30 25558 15 16-QAM 0

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HSDPA UE Categories

Page22

HS-DSCH

Category

Maximum

Number of

HS-DSCH

Codes

Received

Minimum

Inter-TTI

Interval

Maximum Number of

Bits of an HS-DSCH

Transport Block

Received Within an HS-

DSCH TTI

Total Number of

Soft Channel Bits

Category 1 5 3 7298 19200

Category 2 5 3 7298 28800

Category 3 5 2 7298 28800

Category 4 5 2 7298 38400

Category 5 5 1 7298 57600

Category 6 5 1 7298 67200

Category 7 10 1 14411 115200

Category 8 10 1 14411 134400

Category 9 15 1 20251 172800

Category 10 15 1 27952 172800

Category 11 5 2 3630 14400

Category 12 5 1 3630 28800

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Hybrid Automatic Repeat ReQuest

Conventional ARQ

In a conventional ARQ scheme, received data blocks that can not be

correctly decoded are discarded and retransmitted data blocks are

separately decoded

Hybrid ARQ ( HARQ )

In case of Hybrid ARQ with soft combining, received data blocks that can

not be correctly decoded are not discarded. Instead the corresponding

received signal is buffered and soft combined with later received

retransmission of information bits. Decoding is then applied to the

combined signal

Page23

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Hybrid Automatic Repeat ReQuest (cont.)

Illustration of HARQ:

The use of HARQ with soft combining increases the effective

received Eb/Io for each retransmission and thus increases the

probability for correct decoding of retransmissions, compare to

conventional ARQ

Page24

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HARQ Combining

There are many different schemes for HARQ with soft

combining

In case of Chase combining ( CC ) each retransmission is an

identical copy of the original transmission

In case of Incremental Redundancy ( IR ) each retransmission may

add new redundancy

Page25

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HARQ Process

Each HSDPA assignment is handled by a HARQ process runing

in NodeB and UE

The UE HARQ process is responsible for:

Attempting to decode the data

Deciding whether to send ACK or NACK

Soft combining of retransmitted data

The NodeB HARQ process is responsible for:

Selecting the corrected bits to send according to the selected

retransmission scheme and UE capability

Page26

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Short TTI (2ms)

Shorter TTI ( Transmission Time Interval ) is to reduce RTT

( round trip time )

Shorter TTI is necessary to benefit from other functionalities

such as AMC, scheduling algorithm and HARQ

Page27

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Shared Channel Transmission

In HSDPA, a new DL transport channel is introduced call HS-

DSCH

A part of the total downlink code resource is dynamically

shared between HSDPA and Release 99

Page28

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Power Sharing for Channel Transmission

A part of the total downlink power resource is dynamically

shared between HSDPA and Release 99

Page29

Time

Allowed power for HSDPA

Total Power

DPCH

Power for CCH

Higher power

utility efficiency

Power margin for DCH power

control

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Resource Allocation

Page30

Resources are assigned to HSDPA user only when they are

actually to be used for transmission, which leads to efficient

code and power utilization

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Higher-Order Modulation Scheme

HSDPA modulation scheme

QPSK

16QAM: 16QAM can provide higher peak rate

Page31

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Fast Scheduling

Fast scheduling is about to decided to which terminal the shared

channel transmission should be directed at any given moment

Page32

Scheduler may be based on:

•Channel condition

•Amount of data waiting in the queue

•Fairness (Satisfied users)

•Cell throughput, etc

Some basic scheduling algorithms:

•Round Robin (RR)

•Maximum C/I (MAX C/I)

•Proportional Fair (PF)

•Enhanced Proportional Fair (EPF)

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HSDPA New Physical Channels

Page33

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HSDPA Channel Mapping

Page34

DCCH DTCH

HS-DSCH

HS-SCCH

HS-PDSCH

HS-DPCCH

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Theoretical HSDPA Maximum Data Rate

Theoretical HSDPA Maximum data rate is 14.4Mbps

How do we get to 14.4Mbps ?

Multi-code transmission

NodeB must allocate all 15 OVSF codes ( SF =16 ) to one UE

Consecutive assignments using multiple HARQ process

NodeB must allocate all time slots to one UE

UE must decode all transmission correctly on the first transmission

Low channel coding gain

Effective code rate = 1

Requires very good channel conditions to decode

16QAM

Requires very good channel condition

Page35

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A Example of Calculating HSDPA Data

Rate

Try to calculate the HSDPA data rate assuming

5 OVSF code for HS-PDSCH

Consecutive assignment

QPSK

Turbo code rate =1/3

Retransmission

75% of data block decoded on first transmission

25% of data block decoded on second transmission

Page36

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Contents





Page37

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HSUPA Key Technology Overview

HSUPA key technologies

Page38

2ms TTI

Fast scheduling

Lower SF

New Channels

Fast L1 HARQ

Improved

Cell Capacity

Higher Peak

Data Rate

Lower Latency

Improved QoS

Support

Fast Resource

Scheduling

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HSUPA vs. HSDPA

Page39

HSDPA HSUPA

New high-speed shared channel Dedicated channel with enhanced

capabilities

HARQ with fast retransmission at layer 1

Rate/modulation adaptation

Single serving cell

Fast power control

Soft handover

Fast NodeB scheduler

Shared NodeB power and code

Fast NodeB scheduler

Rise-over-Thermal (ROT)

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Rise-over-Thermal Noise

In order to decode received data correctly, the uplink

interference shall be controlled.

Rise-over-Thermal is a measure of the uplink load.

Page40

NodeB monitors uplink interference and tells UE

how much power can be used to transmit uplink data.

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NodeB Scheduler for HSUPA

The HSUPA scheduler considers the trade-off between the

following two points:

Several users those want to transmit at high data rate all the time

Satisfying all requested grants while preventing overloading and

maximizing resource utilization

Page41

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HSUPA Operation

The UE sends a transmission request to

the NodeB for getting resources.

The NodeB responds to the UE with a

grant assignment, allocating uplink band

to the UE.

The UE uses the grant to select the

appropriate transport format for the

Data transmission to the NodeB.

The NodeB attempts to decode the

received data and send ACK/NACK to the

UE. In case of NACK, data may be

retransmitted.

Page42

NodeB

1. R

EQU

EST

3. D

ATA

2. G

RA

NT

4. A

CK

/NA

CK

UE

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HSUPA Operation (continued)

1. Transmission Request

The UE request data

transmission by the scheduling

information (SI), which is

determined according to the UE

power and buffer data

availability.

The scheduling information is

sent to the NodeB.

Page43

UE

UE Buffer UE Power

Scheduling Information (SI)

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2. Grant Assignment

The Node B determines the

UE grant by monitoring

uplink interference (RoT at he

receiver), and by considering

the UE transmission requests

and level of satisfaction.

The grant is signaled to the

UE by new grant channels.

Page44

NodeB

RoT SI

GRANT

Satisfaction

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3. Data Transmission

The UE uses the received grant

and, based on its power and

data availability, selects the E-

DCH transport format and the

corresponding transmit power.

Data are transmitted by the UE

on together with the related

control information.

Page45

UE

GRANT

UE Power

Data and related

control information

UE Buffer

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4. Data Acknowledgment

The NodeB attempts to

decode the received data and

indicates to the UE with

ACK/NACK.

If no ACK is received by he UE,

the data may be retransmitted.

Page46

NodeB

ACK/NACK

Data and related

control information

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New Channels for HSUPA

Uplink Transport Channel

E-DCH: Carries high speed uplink data

Uplink Physical Channels

E-DPDCH: Carries E-DCH

E-DPCCH: Carries control signal for E-DPDCH

Downlink Physical Channels

E-HICH: Carries HARQ ACK/NACK indicator for E-DCH

E-RGCH: Carries relative grant determined by the scheduler

E-AGCH: Carries absolute grant determined by the scheduler

Page47

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HSUPA Channel Mapping

Page48

DCCH DTCH

E-DCH

E-DPCCH

E-DPDCH

E-HICH

E-AGCH

E-RGCH

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New Channels in HSUPA Operation

1. The UE sends a request for resources.

The request includes status of its data

buffers and is sent on E-DPDCH.

2. Based on the request from the UE, the

Node B allocates a resource grant to the

UE. The grant is sent on the E-AGCH

channel.

3. This grant can be modified by the Node

B every TTI using the E-RGCH channel.

4. The UE transmits data on E-DPDCH.

Control information needed to decode the

data is sent on E-DPCCH.

5. The Node B decodes the received

packet and informs the UE whether it

could decode the data successfully or not

on the E-HICH channel.

Page49

E-DPDCH

E-DPCCH

E-AGCH

E-RGCH

E-HICH

1

4

3 5 2 1

4

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HSUPA Features

Shorter TTI of 2ms

In HSUPA both 10ms TTI and 2ms TTI are supported.

A shorter TTI allows reduction of the latency and increasing the

average and peak cell throughput.

Higher Peak Data Rate

For a 10-ms TTI UE, peak data rate is limited to 2 Mbps.

Higher peak data rates can be achieved with a 2ms TTI UE

5.76Mbps is the maximum peak data rate for HSUPA.

Page50

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HSUPA Features (continued)

Hybrid-ARQ

N-channel stop-and-wait protocol, with 4 HARQ processes for

10ms TTI and 8 HARQ processes for 2ms TTI

Synchronous retransmission

Separate HARQ feedback is provided per radio link.

Page51

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E-DCH Active Set and Mobility Support

There are three different types of

radio links in the UE E-DCH active

set:

Serving E-DCH Cell: The cell from

which UE receives AGCH.

Serving E-DCH RLS: Set of cells that

contain at least the serving cell and

from which the UE can receive

RGCH

No-Serving RL: Cell that belongs to

the E-DCH active set but not belong

to the serving RLS and from which

the UE can receive a RGCH.

Page52

Serving

E-DCH cell

Serving E-DCH

Radio Link Set

(RLS)

Non-Serving

E-DCH Radio

Link (RL)

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Theoretical HSUPA Maximum Data Rate

How to get 5.76Mbps:

Lower channel coding gain

Effective code rate = 1

Requires very good channel conditions to decode

Lower spreading factor

UE uses SF 2

Multi-code transmission

UE uses 4 codes, 2 with SF2 and 2 with SF4

2ms TTI

Page53

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E-DPDCH with SF4 and Puncturing

Maximum payload for spreading factor of 4, TTI of 2 ms and coding

rate of 1 is 1920 bits and the corresponding data rate is 960kbps.

Page54

1920 bits payload

1920 parity

1920 symbols

1920 modulation

symbols

1920 systematic 1920 parity

7690 chips

R = 1/3

Turbo Coding

SF=4

BPSK Modulation

Puncturing

2ms

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Lower Spreading Factor SF2

Maximum payload for spreading factor of 2, TTI of 2 ms and coding

rate of 1 is 3840 bits and the corresponding data rate is 1920kbps.

Page55

3840 bits payload

3840 parity

3840 symbols

3840 modulation

symbols

3840 systematic 3840 parity

7690 chips

R = 1/3

Turbo Coding

SF=2

BPSK Modulation

Puncturing

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Multi-code Transmission

For one UE in HSUPA operation, up to 4 E-DPDCH can be used

simultaneously, two using SF4 and two using SF2.

Use of 4 codes transmission 2*SF2 + 2*SF4:

(2*1920kbps) + (2*960kbps) = 5760kbps

Page56

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HSUPA UE Capabilities

Page57

E-DCH

category

Max number

of E-DPDCH

channels

Minimum

SF

Supported

TTI

Peak rate

for TTI =

10MS

Peak rate

for TTI =

2ms

Category 1 1 SF4 10ms 711kbps --

Category 2 2 SF4 2&10 ms 1448kbps 1448kbps


Category 4 2 SF2 2&10 ms 2000kbps 2886kbps


Category 6 4 SF2 2&10ms 2000kbps 5742kbps

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