isdb-t: japanese digital terrestrial television ... television broadcasting (dttb) ... high quality

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  • ISDB-T : มาตรฐานการแพร่ภาพโทรทัศน์ภาคพืน้ดนิระบบดิจติลัของญีปุ่่น

    ISDB-T: Japanese Digital Terrestrial

    Television Broadcasting (DTTB)

    มาตรฐานการแพร่ภาพโทรทัศน์ระบบดิจิตอลภาคพืน้ดินของญีปุ่่น

    1

    18 2543

    รศ.ดร.ธีรภัทร สงวนกชกร ส านักวิชาวิศวกรรมและเทคโนโลยี สถาบันเทคโนโลยีแห่งเอเชีย

    Teerapat Sanguankotchakorn, D.Eng. Associate Professor

    School of Engineering and Technology Asian Institute of Technology

    ISDB-T: Integrated Services Digital Broadcasting - Terrestrial (Japanese DTTB)

    มิถุนายน

    คณะวศิวกรรมศาสตร์ จุฬาลงกรณ์มหาวทิยาลยั

  • ISDB-T : มาตรฐานการแพร่ภาพโทรทัศน์ภาคพืน้ดนิระบบดิจติลัของญีปุ่่น

    2

    Contents

     Features of ISDB-T

     Key technology for ISDB-T

     OFDM  Frequency & Time interleaving technology  Hierarchical transmission

     Mobile reception of ISDB-T

     One-segment service for handheld receivers  Emergency warning system (EWS)  HDTV vehicular technology

     Single Frequency Network (SFN)

     Specifications Comparison of main DTTB systems in the world

     ISDB-T System Performance in 6,7 and 8 MHz Bandwidth

     ISDB-T Current Situation

     Summary of ISDB-T

    ISDB-T: Integrated Services Digital Broadcasting - Terrestrial (Japanese DTTB)

  • ISDB-T : มาตรฐานการแพร่ภาพโทรทัศน์ภาคพืน้ดนิระบบดิจติลัของญีปุ่่น

    3

     High quality TV (HDTV) and sound or Multi-broadcasting program

     Robustness for interferences  OFDM  Time and frequency interleaving technology (for Vehicular receivers)

     Hierarchical transmission up to 3 layers  Modulation, coding rates, length of time interleaving  Parameters are sent in TMCC (transmission and multiplexing configuration control) signal

     Multimedia Services  Data broadcasting: Regional information service  Interaction: Quizzes, questionnaires, requests, voting  Combined with communication services

     Inter-operability with Other Broadcasting Media  ISDB-S (for satellite) and ISDB-C (for cable)

     Partial reception with handheld receivers  Simultaneous with HDTV service

     Mobile reception with vehicular receivers

     SFN (Single Frequency Network) Operation

    Features of ISDB-T

    ISDB-T: Integrated Services Digital Broadcasting - Terrestrial (Japanese DTTB)

  • 4

    Outline of ISDB-T transmission scheme

    ISDB-T: Integrated Services Digital Broadcasting - Terrestrial (Japanese DTTB)

    Contents ARIB

    Standards ITU-R

    Recommendations MPEG-2 Video (ISO/IEC 13818-2) STD-B32 BT.1208 MPEG-2 AAC (ISO/IEC 13818-7) STD-B33 BS.1115

    BML(XHTML), ECMA Script STD-B24 BT.1699

    MPEG-2 Systems (ISO/IEC 13818-1) STD-B10, STD-B32

    BT.1300, BT.1209

    Multi 2 STD-B25 --- ISDB-T transmission 6MHz, 7MHz, 8MHz

    Segmented OFDM (13 segment/ch)

    Mode: 1, 2, 3 Guard Interval Ratio: 1/4, 1/8, 1/16, 1/32

    QPSK, 16QAM, 64QAM, DQPSK

    Inner Convolutional code

    (Coding rate: 1/2, 2/3, 3/4, 5/6, 7/8) Outer (204, 188) Reed-Solomon code

    Frequency and Time Interleave Time Interleave : 0 - 0.5 sec

    6MHz : 3.7 - 23.2 Mbit/s 7MHz : 4.3 - 27.1 Mbit/s 8MHz : 4.9 - 31.0 Mbit/s

    ISDB-T receiver STD-B21 --- ISDB-T broadcasting operation TR-B14 ---

    STD-B31 BT.1306 System C

    Information bit rate (depend on parameters)

    Receiver Operational guideline

    Error correction

    Modulation

    Mode, Guard

    Carrier Modulation

    Interleave

    Multiplex

    Conditional access Transmission

    Channel Bandwidth

    Item

    Video coding Audio coding

    Data broadcasting

  • 5

    ISDB-T Main Specifications

     Hierarchical transmission

     Transmission segment groups with different transmission parameters

     Maximum of three layers can be transmitted simultaneously in a channel

     Possible to select parameters to adjust services such as HDTV, vehicular and so

    on

    ISDB-T in Japanese 6MHz system

    Transmission Parameter Mode 1 Mode 2 Mode 3

    No. of OFDM segments

    Bandwidth 5.575 MHz 5.573 MHz 5.572 MHz

    Carrier interval 3.968 kHz 1.984 kHz 0.992 kHz

    No. of carriers 1405 2809 5617

    Carrier modulation

    Effective symbol length 252 s 504 s 1.008 ms

    Guard-interval length

    No. of symbols per frame

    Time interleave

    Frequency interleave

    Inner code

    Outer code

    Information bit rate

    Hierarchical transmission

    13

    QPSK, 16QAM,64QAM,DQPSK

    1/4, 1/8, 1/16, 1/32 of effective symbol length

    204

    3.65 Mbps - 23.23 Mbps

    Maximum 3 levels (Layer A, B, and C)

    Maximum 4 values : 0, 0.1, 0.2, 0.4 sec

    Intra-segment and inter-segment interleaving

    Convolutional coding (1/2, 2/3, 3/4, 5/6, 7/8)

    RS (204, 188)

    ISDB-T: Integrated Services Digital Broadcasting - Terrestrial (Japanese DTTB)

  • ISDB-T : มาตรฐานการแพร่ภาพโทรทัศน์ภาคพืน้ดนิระบบดิจติลัของญีปุ่่น

    6

    Receiving environment for terrestrial TV broadcasting

    Fixed reception

    Receiving environment is very severe.

    Vehicular reception

    Handheld reception

    • Multipath interference

    • Fading interference

    • Impulse, man-made noise

    • Shadowing

    ISDB-T: Integrated Services Digital Broadcasting - Terrestrial (Japanese DTTB)

  • ISDB-T : มาตรฐานการแพร่ภาพโทรทัศน์ภาคพืน้ดนิระบบดิจติลัของญีปุ่่น

     OFDM Modulated signal

     Multipath signal

     Received signal

    amplitude of received signal decreases

    Signal degradation due to Multipath

      ftjAets 2

         tfjAetu 2

         

      

     fjftj

    tfjftj

    eAe

    AeAetuts

    22

    22

    1

    

    

      kfkf  22

    Power of specific sub-carrier decreases

    Degradation of C/N of specific sub-carrier

    7*Official Information: NHK Science and Technology Research labs, Japan

  • ISDB-T : มาตรฐานการแพร่ภาพโทรทัศน์ภาคพืน้ดนิระบบดิจติลัของญีปุ่่น

    8

    Key technologies for ISDB-T

     To overcome the terrestrial severe receiving environment

     OFDM

     Frequency & Time-interleaving

     To realize the effective and smart transmission

     Hierarchical transmission by Band Segmented Transmission OFDM  Realization of One-Segment service for handheld reception

    ISDB-T: Integrated Services Digital Broadcasting - Terrestrial (Japanese DTTB)

  • ISDB-T : มาตรฐานการแพร่ภาพโทรทัศน์ภาคพืน้ดนิระบบดิจติลัของญีปุ่่น

    Digital Transmission Diagram

    Information

    coding

    Error

    Correction

    coding

    Digital

    Modulation Transmitter

    Channel

    Receiver Digital

    Demodulation

    Error

    correction

    decoding

    Information

    Decoding

    Info.

    Received

    Info.

    Bit stream Digital Modulated Signal

    9ISDB-T: Integrated Services Digital Broadcasting - Terrestrial (Japanese DTTB)

  • ISDB-T : มาตรฐานการแพร่ภาพโทรทัศน์ภาคพืน้ดนิระบบดิจติลัของญีปุ่่น

    ISDB-T Configuration

    Carrier modulation

    IFFT

    TMCC Signal

    adding

    Guard

    interval

    Pilot Signal

    OFDM

    Frame

    H L

    C o m

    b in

    in g

    Bit interleave Time

    interleave

    Frequency

    interleave

    mapping

    Convolution

    coding

    byte

    interleave

    Energy

    dispersal

    Delay

    Compensate

    Division

    Into HL

    RScoding

    (204,188)

    TS

    Re-mux

    byte→ bit

    bit→ byte

    byte→ bit

    TS: Transport stream

    Convolution coding

    byte

    interleave

    Energy

    dispersal

    Delay

    compensate Byte→ bit

    bit→ byte

    byte→ bit

    Convolution

    c

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