HSPA Evolution - eit.lth.se · –Reduction in call-setuppy,p ... (SDU) data flow –Comprised of a data segment and ... Throughput Analysis for a UMTS High Speed Downlink Packet

3G EvolutionChapter: 1212

HSPA EvolutionHSPA Evolution

Department of Electrical and Information Technology

Ruiyuan Tian

p gy

2009-04-02 13G Evolution - HSPA and LTE for Mobile Broadband

Outline

• Introduction

• Evolved Features– HSDPA-MIMO– Higher-order modulation– Continuous packet connectivity– Enhanced CELL FACH operation (about “wake-from-idle” time)_ p ( )– Layer 2 protocol enhancement– Advanced receiver

• Summary

2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 2

Outline

• Introduction

• Evolved Features– HSDPA-MIMO– Higher-order modulation– Continuous packet connectivity– Enhanced operation about “wake-from-idle”p– Layer 2 protocol enhancement– Advanced receiver

• Summary


Introduction

• Evolved High-Speed Packet Access (HSPA+, I-HSPA)By S. Parkvall

– a wireless broadband standard defined in 3GPP Release 7+– DL: 42 Mbit/s (14 Mbit/s in HSPA)– UL: 22 Mbit/s (5 8 Mbit/s in HSPA)– UL: 22 Mbit/s (5.8 Mbit/s in HSPA)

• An optional all-IP architecture for the network • Significant battery life improvements, dramatically quicker g y p y q

wake-from-idle time, a true “always-on” connection• 1st commercial launched late 2008 (Australia)


Evolution?

• Increase in performance and capability• Evolved Features:Evolved Features:

– MIMO • dual-stream

Higher order modulation– Higher-order modulation • 64QAM in DL, 16QAM in UL

– Continues packet connectivity• “always-on”

– Enhanced operation• quicker “wake-from-idle” time

http://www.slashphone.com/qualcomm-completed-20-mbps-hspa-data-call-311077

– Layer 2 protocol enhancement– Advanced receiver


Outline

• Introduction


• Summary


HSDPA-MIMO (1)

• MIMO– Cell-edge: to increase carrier-to-interference ratio (CIR)g ( )

• Diversity, beamforming– Close to BS (high CIR): to “data-rate booster”

• Spatial multiplexing: multiple layers/streams transmissionSpatial multiplexing: multiple layers/streams transmission

• HSDPA-MIMO: dual-stream Tx adaptive array (D-TxAA)– Up to 2 streams supported– each with same PHY processing (coding, spreading, modulation…) – Linear pre-coding: mapping to the 2 Tx antennas

• Tx diversity• Beamforming• Orthogonal layers: signal pre-distortion for reduced interference

• Main evolution in PHYMain evolution in PHY– Small impact to the protocol layer


HSDPA-MIMO (2)

• HS-DSCH (HS-DLSharedChannel)DLSharedChannel)– Modified to support up

to 2 transport blocks per TTI (2 ms)

– Virtual antennasP di HS DSCH MAC h d

HS-DSCH processing of MIMO transmission• Pre-coding

– Mapping between virtual and physical

HS-DSCH : MAC-hs and PHY processingMIMO transmission

virtual and physical antennas


HSDPA-MIMO (3)3GPP TS 25.214 V4.4.0,

Release 99

TX diversity

Pre-coding Control Indication (PCI)

feedback from UE

Phase rotation in mode 1

• Closed loop mode 1: phase adjustment•Equal Gain combining @ Tx

• Closed loop mode 2: phase & amplitude adjustment


Closed loop mode 2: phase & amplitude adjustment•Maximum Ratio combining @ Tx

HSDPA-MIMO (4)

11s12s 11s12s∗− 11y21y 11s 12s

12s11s∗

12y22y

Si l t

OSTBC Combiner

ˆ ˆ

Single stream transmission

12 11s s

22 21s s12 11s s

22 21s s

12 11ˆ ˆs s

22 21ˆ ˆs s

11 12y y

21 22y yPre-coding

Dual stream transmission


transmissionBy M. Zhu

HSDPA-MIMO (5)

• Rate control for HSDPA-MIMO– Also to determine # of streams and pre-coding matrixp g

• Hybrid-ARQ with Soft Combining for HSDPA-MIMO– One hybrid-ARQ ACK per stream

• HS-SCCH (Shared Control Channel): Out-band DL controlPart 1 Part 2

• Channelization codes• Modulation scheme

• UE ID• Transport block sizeModulation scheme Transport block size• Hybrid ARQ information• # of streams

• Pre-coding matrix • Transport block size, stream 2• Hybrid ARQ information, stream 2

HS DPCCH (D di t d Ph i l C t l Ch l)• HS-DPCCH (Dedicated Physical Control Channel)• Out-band UL control signal• Hybrid-ARQ ACK (1 or 2 streams)• Channel Quality Indicator (CQI): recommended data rate (# of streams)


• Channel Quality Indicator (CQI): recommended data rate (# of streams)• Pre-coding Control Information (PCI): pre-coding matrix

Outline

• Introduction


• Summary


Higher-order modulation

• MIMO gain– Relies on certain propagation conditionsp p g– LOS: high CIR, but no multi-stream

• Higher-order modulation64 QAM i DL 16 QAM i UL– 64 QAM in DL, 16 QAM in UL

DL peak rate(Mbits/s)

UL peak rate(Mbits/s)( ) ( )

Non-MIMO MIMO

16QAM 64QAM 16QAM 64QAM BPSK/QPSK 16QAM16QAM 64QAM 16QAM 64QAM BPSK/QPSK 16QAM

14 21 28 42 5.7 11


Outline

• Introduction


• Summary


Continuous packet connectivity (CPC)

• WCDMA state model– CELL_PCH/URA_PCH: low power consumption, paging states_ _ p p , p g g– CELL_FACH: accessing (small data), DL monitor– CELL_DCH: high-transmission activity, HS-DSCH, E-DCH (dedicated)

Continuous packet connectivity• Continuous packet connectivity– “always-on”, keeping CELL-DCH– Less states switch

Radio Resource Control (RRC) signaling

• Discontinuous Transmission (DTX)• Discontinuous Reception (DRX)• HS-SCCH-less operation


DTX-reducing UL overhead

• E-DCH (user data)– Interference & Overhead source: UL DPCCH– Solution: less frequent DPCCH if no activity

Longer cycle

No activityy

• HS-DPCCH (control signal)– CQI

No CQI reports if not coincide with DTX cycle


No recent HS-DSCH transmission

DRX-reducing UE power consumption

• UE – Monitor 4 HS-SCCHs in each subframe– Full scheduling flexibility, but power-consumption

• DRXA UE DRX l ft i d f HS DSCH i ti it– A UE DRX cycle after a period of HS-DSCH inactivity

– Combined with DTX No activity

Longer DTX cycle

Coordinated DRX cycle


Coordinated DRX cycle

HS-SCCH-less operation: DL overhead reduction

• Overhead– HS-SCCH for DL scheduling, significant in small payloads (VoIP)g, g p y ( )

• HS-SCCH-less operation– To perform HS-DSCH transmission without HS-SCCH

Bli d d di f t i f t ( d l ti d )– Blind decoding for certain formats (modulation, code)

No SCCH accompanied


No NAK to be transmitted for overhead reduction

Enhanced CELL_FACH operation

• CELL_FACH (Forward Access Channel)– No dedicated physical channelp y– UE to monitor DL– Latency for state switch from CELL_FACH to CELL_DCH

Enhanced CELL FACH operation• Enhanced CELL_FACH operation– HS-DSCH signaling (DL) allowed in CELL_FACH state

• User data transfer during the state switch from FACH to DCH– E-DCH signaling (UL) activated in CELL_FACH state

• Reduce delay from switching to DCH– Reduction in call-setup delay, improved user perceptionp y, p p p


Layer 2 protocol enhancement

• Radio Link Control (RLC)– In the control plane of layer 2p y– Offer services to higher layers

• RLC Protocol Data Unit (PDU)A t f S i D t U it (SDU) d t fl– A segment of Service Data Unit (SDU) data flow

– Comprised of a data segment and the RLC header• RLC PDU size

– Semi-static: limit the peak data rate– Flexible RLC PDU size

• Match the instantaneous radio condition• Match the instantaneous radio condition


Outline

• Introduction


• Summary


Advanced receiver (1)

• More advanced receiver algorithms– No specified receiver structurep– Specified performance requirement

• Developed with a baseline receiver

• Advanced UE receivers in 3GPP• Advanced UE receivers in 3GPP– Type 1: RX diversity– Type 2: LMMSE chip-level equalizer (EQ)– Type 3: RX diversity + LMMSE EQ– Type 4: RX diversity + interference-aware EQ



• Type 1: RX diversity(optional) up to 2

• Type 2Reference receiver– (optional) up to 2

antennas– Limitation: branch

– Reference receiver structure: LMMSE chip-level equalizer

imbalance, form factor of UE…

– Any receivers, e.g., Generalized RAKE

– … – …



2 dB gain for LMMSE over RAKE G-RAKE equalizes the channel to be flat

[] K. Freudenthaler, et al., Throughput Analysis for a UMTS High Speed

[] Gregory E. Bottomley, et al., Advanced receivers for WCDMA terminal


Throughput Analysis for a UMTS High SpeedDownlink Packet Access LMMSE Equalizer

Advanced receivers for WCDMA terminalplatforms and base stations


• Type 3– Combination of RX diversity and EQ (Type 1 + 2)y ( yp )

Type 2

Type 1Type 3

RAKE


Outline

• Introduction


• Summary


Summary

• HSPA Evolution– Evolution of WCDMA: backwards compatibilityp y– MIMO: increased peak data rate– Higher order modulation

Continuous Packet Connectivity: “always on”– Continuous Packet Connectivity: always-on– Advanced receiver

• More to evolve– BW extension: combine of multiple 5 MHz HSPA carriers

LTE-WiMAX contest winner could be

HSPA+ for now2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 27

HSPA+ for now

3G EvolutionChapter: 12 HSPA Evolution

ThanksThanksThanksThanks

Department of Electrical and Information Technology

Ruiyuan Tian

p gy

2009-04-02 283G Evolution - HSPA and LTE for Mobile Broadband

Documents

HSPA Evolution - eit.lth.se · –Reduction in call-setuppy,p ... (SDU) data flow –Comprised of a data segment and ... Throughput Analysis for a UMTS High Speed Downlink Packet