3G Evolution Chapter: 12 12 HSPA Evolution HSPA Evolution Ruiyuan Tian Department of Electrical and Information Technology p gy 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 1
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 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 3
Introduction By S. Parkvall • Evolved High-Speed Packet Access ( HSPA+, I-HSPA ) – 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 • 1 st commercial launched late 2008 (Australia) 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 4
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 http://www.slashphone.com/qualcomm- • quicker “wake-from-idle” time completed-20-mbps-hspa-data-call-311077 – Layer 2 protocol enhancement – Advanced receiver 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 5
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 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 6
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 transmission Spatial 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 PHY Main evolution in PHY – Small impact to the protocol layer 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 7
HSDPA-MIMO (2) • HS-DSCH (HS- DLSharedChannel) DLSharedChannel) – Modified to support up to 2 transport blocks per TTI (2 ms) – Virtual antennas HS-DSCH processing of MIMO transmission MIMO transmission • Pre-coding P di HS DSCH HS-DSCH : MAC-hs and MAC h d PHY processing – Mapping between virtual and physical virtual and physical antennas 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 8
HSDPA-MIMO (3) 3GPP TS 25.214 V4.4.0, Release 99 TX diversity Phase rotation Pre-coding Control in mode 1 Indication (PCI) feedback from UE • 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 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 9
HSDPA-MIMO (4) − s ∗ s y y s s ˆ s ˆ s 11 11 12 21 11 12 11 12 OSTBC Combiner s ∗ s y y 11 12 22 12 Si Single stream l t transmission y y ˆ ˆ ˆ ˆ s s s s s s 11 12 12 11 12 11 12 11 Pre-coding s s s s y y ˆ ˆ s s 22 21 22 21 21 22 22 21 Dual stream transmission transmission By M. Zhu 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 10
HSDPA-MIMO (5) • Rate control for HSDPA-MIMO – Also to determine # of streams and pre-coding matrix p g • Hybrid-ARQ with Soft Combining for HSDPA-MIMO – One hybrid-ARQ ACK per stream • HS-SCCH (Shared Control Channel): Out-band DL control Part 1 Part 2 • Channelization codes • UE ID • Modulation scheme Modulation scheme • Transport block size Transport block size • Hybrid ARQ information • # of streams • Transport block size, stream 2 • Pre-coding matrix • Hybrid ARQ information, stream 2 HS-DPCCH (Dedicated Physical Control Channel) HS DPCCH (D di t d Ph i l C t l Ch l) • • 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 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 11
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 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 12
Higher-order modulation • MIMO gain – Relies on certain propagation conditions p p g – LOS: high CIR, but no multi-stream • Higher-order modulation – 64 QAM in DL, 16 QAM in UL 64 QAM i DL 16 QAM i UL DL peak rate UL peak rate ( (Mbits/s) ) (Mbits/s) ( ) Non-MIMO MIMO 16QAM 16QAM 64QAM 64QAM 16QAM 16QAM 64QAM 64QAM BPSK/QPSK BPSK/QPSK 16QAM 16QAM 14 21 28 42 5.7 11 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 13
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 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 14
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 Radio Resource Control – “always-on”, keeping CELL-DCH (RRC) signaling – Less states switch • Discontinuous Transmission (DTX) • Discontinuous Reception (DRX) • HS-SCCH-less operation 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 15
DTX-reducing UL overhead • E-DCH (user data) – Interference & Overhead source: UL DPCCH – Solution: less frequent DPCCH if no activity Longer cycle No activity • HS-DPCCH (control signal) No CQI reports if not coincide – CQI with DTX cycle No recent HS-DSCH transmission 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 16
DRX-reducing UE power consumption • UE – Monitor 4 HS-SCCHs in each subframe – Full scheduling flexibility, but power-consumption • DRX – A UE DRX cycle after a period of HS-DSCH inactivity A UE DRX l ft i d f HS DSCH i ti it – Combined with DTX No activity Longer DTX cycle Coordinated DRX cycle Coordinated DRX cycle 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 17
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 – Blind decoding for certain formats (modulation, code) Bli d d di f t i f t ( d l ti d ) No SCCH accompanied No NAK to be transmitted for overhead reduction 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 18
Enhanced CELL_FACH operation • CELL_FACH (Forward Access Channel) – No dedicated physical channel p 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 perception p y, p p p 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 19
Layer 2 protocol enhancement • Radio Link Control (RLC) – In the control plane of layer 2 p y – Offer services to higher layers • RLC Protocol Data Unit (PDU) – A segment of Service Data Unit (SDU) data flow A t f S i D t U it (SDU) d t fl – 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 2009-04-02 3G Evolution - HSPA and LTE for Mobile Broadband 20
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