WCDMA HSPA

26
MobileComm Professionals, Inc. Your Partner for Wireless Engineering Solutions

description

WCDMA

Transcript of WCDMA HSPA

  • MobileComm Professionals, Inc.

    Your Partner for Wireless Engineering Solutions

  • High Speed Packet Access

  • MobileComm Professionals, Inc.

    HSPA

    HSUPA

    HSDPA

    Agenda

  • MobileComm Professionals, Inc. HSPA Evolution

    HSPA has improved performance and spectral efficiency in DL and UL by introducing a shared channel principle: Significant enhancement with peak rates up to 14.4 Mbps in DL Huge capacity increase per site; no site pre-planning necessary Improved end user experience: reduced delay/latency, high response time

    Introduced by 3GPP in Dec. 99, WCDMA Based Tech., Matured GSM/GPRS CN, up to 384 kbps (2Mbps)

    Rel.99 Rel. 4 Rel. 5 Rel. 6

    Bearer independent CS Core Network, CAMEL Phase 4, low chip rate TDD mode, UTRA FDD Repeater .

    HSDPA (14 Mbps), IMS phase 1, W-AMR, Location Services, 1800/1900 MHz

    HSUPA (5.76 Mbps), IMS Phase 2, MMS enhancement, MBMS, WLAN-Internetworking

  • MobileComm Professionals, Inc.

    Peak data rates of HSDPA increased to significantly higher than 2 Mbps; Theoretically exceeding 10 Mbps.

    Packet data throughput increased 50-100% compared to 3GPP release 4

    Reduced delay from retransmissions.

    Solutions

    Adaptive Modulation and Coding

    Layer1 hybrid ARQ

    Short frame2 ms

    Schedule in 3GPP

    Part of Release 5

    First specifications version completed 03/02

    HSDPA Features

  • MobileComm Professionals, Inc. HSDPA Principle

    Fast Hybrid ARQ with Soft Combining

    Reduced round trip delay

    Fast Link Adaptation

    Data rate adapted to radio conditions on 2 ms time basis

    t

    P

    Dynamic Power Allocation

    Efficient power & spectrum utilisation

    Higher-order Modulation

    16QAM in complement to QPSK for higher peak bit rates

    HSDPA

    Shared Channel Transmission

    Dynamically shared in time & code domain

  • MobileComm Professionals, Inc. Hybrid Automatic Repeat Request

    Server RNC Node-B

    UE

    RLC retransmissions

    TCP retransmissions

    H-ARQ: MAC-hs Layer-1

    retransmissions

    Round-Trip Time: 16 ms

    HARQ

  • MobileComm Professionals, Inc. Dynamic Power Allocation

    3GPP Release 99 3GPP Release 5

    Dedicated channels (power controlled)

    Common channels

    Power usage with dedicated channels

    t

    Unused power

    Power

    To

    tal

    ce

    ll p

    ow

    er

    Dedicated channels (power controlled)

    Common channels

    Power usage with dedicated channels

    t

    Used for HSDPA

    Power

    To

    tal

    ce

    ll p

    ow

    er

  • MobileComm Professionals, Inc. Adaptive Modulation & Coding (1/3)

    HSDPA uses: QPSK 16QAM Dynamically based on quality of the radio link

  • MobileComm Professionals, Inc. Adaptive Modulation & Coding (2/3)

  • MobileComm Professionals, Inc.

    HSDPA adapts the Modulation to the current Radio Link Quality (Ec/Io) HSDPA uses: QPSK at low Radio Link Quality 16QAM at high Radio Link Quality

    HSDPA adapts the Coding to the current Radio Link Quality (Ec/Io) HSDPA varies the Coding between 1/4 3/4 (theoretically 1/6 0.98)

    Adaptive Modulation & Coding (3/3)

  • MobileComm Professionals, Inc. Fast Link Adaptation

    WCDMA used Power control to compensate for differences and variations in radio channel conditions.

    So available o/p power was not fully used as power needed to be reserved for ongoing connections.

    Surplus of o/p power cannot be used to increase the throughput of the system. HSDPA - Relies on bit-rate adjustment (known as Link Adaptation)

    High data rate

    Low data rate

    Fast Radio Channel Dependent Scheduling

    Scheduling of users on 2 ms time basis

    2 ms

    Short TTI (2 ms)

    Reduced round trip delay

  • MobileComm Professionals, Inc. Scheduling

    Fast Scheduling in the Time domain (2): - Transmission is based on:

    Channel Quality, UE Capabilities Current load in the cell (available resources / buffer status) Traffic Priority classes / QoS classes UE Feedback (ACK/NACK)

    Fast Scheduling in the code Domain - Up to 15 codes in parallel per TTI

  • MobileComm Professionals, Inc. Shared Channel Transmission

    Channelization codes allocated

    for HS-DSCH transmission

    5 codes (example)

    SF=16

    SF=8

    SF=4

    SF=2

    SF=1

    User #1 User #2 User #3 User #4

    TTI

    Shared

    channelization

    codes

  • MobileComm Professionals, Inc.

    Multi Code Operation

    C1,0 = [1]

    C2,1 = [1-1]

    C2,0 = [11]

    C4,0 = [1111]

    C4,1 = [11-1-1]

    C4,2 = [1-11-1]

    C4,3 = [1-1-11]

    C8,1 = [1111-1-1-1-1]

    C8,2 = [11-1-111-1-1]

    C8,3 = [11-1-1-1-111]

    C8,4 = [1-11-11-11-1]

    C8,5 = [1-11-1-11-11]

    C8,6 = [1-1-111-1-11]

    C8,7 = [1-1-11-111-1]

    C16,1 =

    [.........]

    C16,15 =

    [........]

    C16,14 =

    [........]

    C16,13 =

    [........]

    C16,12 =

    [........]

    C16,11 = [........]

    C16,10 =

    [........]

    C16,9 =

    [.........]

    C16,8 =

    [.........]

    C16,7=

    [.........]

    C16,6 =

    [.........]

    C16,5 =

    [.........]

    C16,4 =

    [.........]

    C16,3 =

    [.........]

    C16,2 =

    [.........]

    C8,0 = [11111111] C16,0 =

    [.........]

    SF = 1 2 4 8 SF = 16 256 512 ...

    Shared Channel Transmission

  • MobileComm Professionals, Inc.

    Peak data rates increased to significantly higher than 2 Mbps; Theoretically reaching 5.8 Mbps

    Packet data throughput increased, though not quite high numbers expected as with HSDPA

    Reduced delay from retransmissions.

    Solutions Layer1 hybrid-ARQ Node B based scheduling for uplink Frame sizes 2ms & 10ms

    Schedule in 3GPP Part of Release 6

    HSUPA Features

  • MobileComm Professionals, Inc.

    HSUPA

    Fast Power Control

    Hybrid ARQ with incr.

    redundancy NodeB Controlled

    Scheduling

    Shorter TTI [TTI = 10 ms or 2 ms]

    HSUPA Principles

  • MobileComm Professionals, Inc. Shorter Transmission Time Interval

    10 ms TTI:

    Improved cell edge

    performance

    2 ms TTI:

    reduced latency

    higher peak rates

    (up to 5.8 Mbps)

    The use of a shorter TTI within 3G HSPA reduces the round trip time and enables improvements in adapting to fast channel variations and provides for reductions in latency.

  • MobileComm Professionals, Inc. Node B Controlled Scheduling

    R6 E-DCH

    Data

    transmission

    L3 Resource

    Allocation

    Scheduling Info

    Scheduling

    Assignment

    DCH services

    (eg voice and visio)

    UE 2

    UE 1

    UE 1

    UE 2

    UE 3

    UE 1

    UE 2

    UE 3

    UE 1

    TTI 0 TTI 1 TTI 2 TTI 3

    RoT

    Time

    Maximum

    allowable

    noise rise

  • MobileComm Professionals, Inc. H-ARQ

    HARQ Mechanism

    The Stop and Wait (SAW) protocol for multi-channel or multi-process is performed through four (TTI=10 ms) or eight (TTI=2 ms) processes.

    Each Radio Link (RL) sends the feedback respectively. Each RL establishes one E-HICH. The E-HICH information sent by each Radio Links set (RLs) is the same and can be combined. If any E-HICHs return ACK, then the transmission succeeds

    For Fast retransmissions

  • MobileComm Professionals, Inc. HSDPA

    SINR is used instead of Eb/No in HSDPA performance evaluation

    Modulation and coding Bit rate can be changed every 2 ms

    Definition of HS-DSCH SINR:

    Narrowband signal-to-interference-plus-noise-ratio after

    despreading of the HS-PDSCH

    SINR includes the SF16 processing gain for the HS-PDSCH and the

    effect of using orthogonal codes

    Average HS-DSCH SINR:

    This is the experienced HS-DSCH SINR by a user average over fast

    fading.

  • MobileComm Professionals, Inc. Required SINR

    PDSCHHSSFI

    CSINR

    NothownDL PIII )1(

    Where: C = received power Iown = total power received from the serving cell Ioth = total power received from other cells PN = noise power = orthogonality factor SFHS-PDSCH = Spreading factor on HSDPA (= 16)

  • MobileComm Professionals, Inc. Channels Needed for HSDPA Operation

    Iub

    Node B RNC

  • MobileComm Professionals, Inc.

    UE

    Iub Uu

    Node B RNC

    Channels Needed for HSUPA Operation

  • MobileComm Professionals, Inc.

    HSPA

    HSUPA

    HSDPA

    Summary

  • MobileComm Professionals, Inc.

    HAPPY LEARNING

    MobileComm Professionals, Inc. www.mcpsinc.com