HSPA.pptx

8/11/2019 HSPA.pptx

1/35

8/11/2019 HSPA.pptx

2/35

Page2

Contents

2. Key Technologies of HSPA+

2.1 Downlink Enhanced L2

2.2 Downlink 64QAM

2.3 MIMO

2.4 Enhanced CELL_FACH Operation

2.5 CPC

8/11/2019 HSPA.pptx

3/35

Page3

Limitation of Original L2 Function

MIMO and 64QAM increase the DL rates on

the Uu interface. The original DL L2 function

cannot adapt to such high rates. To prevent L2

from becoming the bottleneck of network

performance, 3GPP Release 7 introduces

enhancements to L2.

8/11/2019 HSPA.pptx

4/35

Page4

Downlink Enhanced L2 in Release 7

Downlink enhanced L2 includes the following

two features:

Improving the RLC entity to support flexible RLC

PDU sizes

Adding a new entity, the MAC-ehs, implementing

data segmentation at the MAC layer, and

supporting the multiplexing of multiple priorityqueues

8/11/2019 HSPA.pptx

5/35

Page5

Flexible RLC PDU size

With introduction of flexible RLC PDU sizes,

the RLC layer will not segment higher-layer

packets with sizes less than maximum RLC

PDU size (the maximum RLC PDU size is

configurable and maximum value is 1500

bytes). Thus, the RLC layer can flexibly adapt

to variations in traffic volume and reduce theoverhead of the RLC PDU header.

8/11/2019 HSPA.pptx

6/35

Page6

MAC-hs Entity (UTRAN side) in Release 6

MAC-hs

MAC Control

HS-DSCH

TFRC selection

Priority Queuedistribution

Associated DownlinkSignalling

Associated UplinkSignalling

MAC-d flows

HARQ entity


PriorityQueue

PriorityQueue

PriorityQueue

PriorityQueue

Scheduling/Priority handling

8/11/2019 HSPA.pptx

7/35

Page7

MAC-ehs Entity (UTRAN side) in Release 7

MAC-ehs

MAC Control

HS-DSCH

TFRC selection


AssociatedDownlink Signalling

AssociatedUplink Signalling

MAC-d flows

PriorityQueue

Scheduling/Priority handling

PriorityQueue

PriorityQueue

Segmentation

Priority Queue MUX

HARQ entity

Segmentation

Segmentation

8/11/2019 HSPA.pptx

8/35

Page8

Contents



2.2 Downlink 64QAM

2.3 MIMO


2.5 CPC

8/11/2019 HSPA.pptx

9/35

Page9

Modulation Modes for HSPA+

Three modulation modes can be used for HS-PDSCH

64QAM allows more bits per

Symbol to be transmitted

Higher peak rate achieved in

good channel condition

8/11/2019 HSPA.pptx

10/35

Page10

CQI Mapping Table Change for 64QAM

CQI TBS CodesModulati

on

1 136 1 QPSK

25 14424 10 16-QAM

26 15776 10 64-QAM

27 21768 12 64-QAM

28 26504 13 64-QAM29 32264 14 64-QAM

30 38576 15 64-QAM

64QAM configured 64QAM not configured

CQI TBS CodesModulati

on

1 137 1 QPSK

25 14411 10 16-QAM

26 17237 12 16-QAM

27 21754 15 16-QAM

28 23370 15 16-QAM

29 24222 15 16-QAM

30 25558 15 16-QAM

8/11/2019 HSPA.pptx

11/35

Page11

HS-SCCH Change for 64QAM

Channel izat ion Code Set

Modulat ion Scheme

0: QPSK

1: 16QAM

MUX

HS-SCCH part 1

Channel izat ion Code Set

Last bit: 0:16QAM

Last bit 1: 64QAM

Modulat ion Scheme

0: QPSK

1: QAM

MUX

HS-SCCH part 1

Release 6 Release 7

8/11/2019 HSPA.pptx

12/35

Page12

Prerequisites for Downlink 64QAM

UE capability

UE category 13, 14, 17 and 18 can support

downlink 64QAM.

Service type

64QAM modulation mode is only used for HSDPA

service.

Cell capability

The Serving cell must support downlink enhanced

L2 and 64 QAM.

8/11/2019 HSPA.pptx

13/35

Page13

Contents



2.2 Downlink 64QAM

2.3 MIMO


2.5 CPC

8/11/2019 HSPA.pptx

14/35

Page14

What is MIMO?

MIMO: Multiple Input Multiple Output

Transmitter ReceiverWirelessChannel

N M

Channel Condition Feedback

8/11/2019 HSPA.pptx

15/35

Page15

What can MIMO provide?

2*2 MIMO can increase peak data rate to28Mbps

Transmitter ReceiverWireless Channel

Channel Condition Feedback

Data Stream 1

Data Stream 2

8/11/2019 HSPA.pptx

16/35

Page16

Effect of Channel Condition to MIMO

MIMO operation is affected by channel

condition of UE.

Only when the channel conditions are good,

two parallel data streams can be carried in

different transmitters. This is dual-stream case.

Otherwise only one data stream is carried

even though two transmitters are used. This issingle-stream case.

8/11/2019 HSPA.pptx

17/35

Page17

HSDPA with MIMO in Release 7

Operation is similar to Release 5 HSDPA, but with different signaling:

Via HS-DPCCH UE reports

Channel Condition

Preferred antenna weight

Dual stream or single stream preference

Based on UE report, NodeB

Determines number of data streams, TB size, modulation and coding scheme and

antenna weighting

Informs UE of the decision via HS-SCCH

NodeB transmits the data via HS-PDSCH channel.

Upon receiving the data, UE sends ACK/NACK via HS-DPCCH.

8/11/2019 HSPA.pptx

18/35

Page18

Illustration of 2*2 MIMO

Pre-coding

Pilot for channel

estimation

8/11/2019 HSPA.pptx

19/35

Page19

Pre-coding

In single-stream case pre-coding is used to

achieve transmit diversity. It is similar to

closed-loop transmit diversity.

In dual-stream case pre-coding is used to

reduce the interference between two

streams and try to make them orthogonal.

Four predefined antenna weighting vectors

are used, identified by PCI (Pre-coding

8/11/2019 HSPA.pptx

20/35

Page20

Pilots for Channel Estimation

On each antenna, a common pilot channel

is transmitted. It is used to estimate the

channels between NodeB and UE.

In 2*2 MIMO mode the channel between

transmitter and receiver can be expressed

as the following format, where hi,j is the

estimate of the channel between the

physical antenna i at the base station and

2,2

2,1

1,2

1,1

h

h

h

hH

8/11/2019 HSPA.pptx

21/35

Page21

HS-DPCCH Signaling UE reports on HS-DPCCH

Preferred number of transport blocks 2 TBs = dual stream transmission

1 TBs = single stream transmission

Channel Quality Indicator (CQI)

Type A: provide CQI for each TB when 2 TBs are preferred

Type B: provide CQI when only one TB should be sent

Preferred pre-coding (Pre-coding Control Indication: PCI)

Indicate 1 of 4 predefined pre-coding vectors

ACK/NACK

If one TB was transmitted, UE sends one ACK or NACK If two TBs were transmitted, UE reports one out of four possible values for

ACK/ACK, ACK/NACK, NACK/ACK, NACK/NACK

Each TB is acknowledged independently.

8/11/2019 HSPA.pptx

22/35

Page22

Two Types of CQI Feedback

Two types of CQI is reported by UE: type A and type B

In type A report, UE indicates:

Preferred pre-coding vectors (2 bits)

Preferred number of TBs per TTI

CQI (8 bits)

Old31-level CQI report, if one TB is preferred

New255-level CQI report, if two TBs is preferred

In type B report, UE indicates:

Preferred pre-coding vectors (2 bits)

CQI (5 bits)

8/11/2019 HSPA.pptx

23/35

Page23

Two Types of CQI Feedback (continued)

Type A Type A Type A Type A Type B Type A Type A Type A Type BType ATime

Configurtion N/M = 4/5, CQI feedback cycle = 1 (2ms)

Type A Type A Type B Time

Configuration N/M = 2/3, CQI feedback cycle = 4 (8ms)

NodeB Configures UE to use N type Areports every period of M CQI reports. UE

uses type B in remaining time.

The following are two examples for type A/Breporting:

8/11/2019 HSPA.pptx

24/35

Page24

HS-SCCH SignalingPart 1

New HS-SCCH format Part 1 Transmitted in the first slot of the 3-slot HS-

SCCH TTI

Supports single stream (8 bits) or dualstreams (12bits)

For dual stream operation (12 bits)

Channelization code set (7 bits)

Modulation Scheme and number of TBs (3 bits)

Pre-coding vector (2 bits)

8/11/2019 HSPA.pptx

25/35

Page25

HS-SCCH SignalingPart 2

Transmitted in the second and third slots of

the HS-SCCH TTI

Supports single stream (12 bits) or dual

stream (20 bits)

For dual stream transmission (20 bits):

Transport block size (6 bits per TB)

HARQ IDs (4bits)

Redundancy version (2 bits per TB)

8/11/2019 HSPA.pptx

26/35

Page26

Prerequisites for MIMO

UE capability

UE category 15, 16, 17, 18, 19 and 20 can MIMO

Service type

MIMO modulation mode is only used for HSPDA

service.

Cell capability

The Serving cell must support downlink enhanced

L2 and MIMO.

8/11/2019 HSPA.pptx

27/35

Page27

Contents



2.2Downlink 64QAM

2.3 MIMO


2.5 CPC

8/11/2019 HSPA.pptx

28/35

8/11/2019 HSPA.pptx

29/35

Page29

Benefits of Enhanced CELL_FACH Operation

UE can reduce the state transitions from

CELL_FACH to CELL_DCH

UE can receive high speed downlink traffic

(data or signaling) in CELL_FACH.

UL transmission is still possible in CELL_FACH

and uplink traffic (data or signaling) is carried

on RACH. (as in Release 6)

8/11/2019 HSPA.pptx

30/35

8/11/2019 HSPA.pptx

31/35

Page31

UE Reception in Enhanced CELL_FACH

UE can decode HS-SCCH using: Dedicated H-RNTI (from prior dedicated RRC

signaling)

Or an H-RNTI selected from list of common H-RNTI in SIB5

UE use HS-SCCH channelization code from

SIB5.

UE decodes HS-PDSCH to receive DL data

transmissions.

BCCH/CCCH/DTCH/DCCH

8/11/2019 HSPA.pptx

32/35

Page32

State TransitionIdle to CELL_FACH/CELL_DCH

UE procedures in state transition from idle to CELL_FACH/CELL_DCH1. Read system information in SIB5

2. Sends an RRC Connection Request on PRACH to request PS service

3. Selects an H-RNTI from common H-RNTI listed, HS-SCCH channelization code from

SIB5.

4. Monitor HS-SCCH using selected common H-RNTI. Decode HS-PDSCH to receive RRC Connection Setup.

5. Transitions to CELL_FACH or CELL_DCH based on the reconfiguration message.

Uses new assigned H-RNTI for further HS-PDSCH reception.

6. May receive subsequent data in CELL_FACH or CELL_DCH

8/11/2019 HSPA.pptx

33/35

Page33

Contents



2.2 Downlink 64QAM

2.3 MIMO


2.5 CPC

8/11/2019 HSPA.pptx

34/35

Page34

CPC Motivation

CPC allows packet data users to remain inCELL_DCH state to a larger extent, thusavoiding frequent packet connection re-

establishments. CPC motivation is mainly to allow more

efficient use of continuous packet dataconnections:

Higher capacity

Lower UE battery consumption

8/11/2019 HSPA.pptx

35/35

Documents

HSPA.pptx