Ultra-cheap SDR Digital Television Transmission: ISDB-T with an osmo-fl2k and an RTL-SDR Federico Larroca, Pablo Flores Guridi, David Artenstein, Lucas Inglés and Gastón Morales Instituto de Ingeniería Eléctrica, Facultad de Ingeniería, Universidad de la República, Uruguay 10th Annual GNU Radio Conference September 16th 2020
Background ■ Plenty of Digital TV standards: ATSC, DTMB, DVB-T, ISDB-T DVB-T ATSC ISDB-T DTMB F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 2/19 •
Background ■ Plenty of Digital TV standards: ATSC, DTMB, DVB-T, ISDB-T ■ ISDB-T → ISDB-T International (ISDB-Tb) DVB-T ATSC ISDB-T DTMB F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 2/19 •
Background ■ Although there are many benefits in the DTV Transition... ● Increased spectral efficiency (a) PAL (b) ISDB-T F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 3/19 •
Background ■ Although there are many benefits in the DTV Transition... ● Increased spectral efficiency ⇒ Improved audio/video quality ⇒ $$$(Digital Dividend) (a) PAL (b) ISDB-T F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 3/19 •
Background ■ Although there are many benefits in the DTV Transition... ... the job is far from completed. F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 4/19 •
Background ■ Back in 2016 we presented gr-isdbt : an open and free receiver for ISDB-T implemented in GNU Radio F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 5/19 •
Background ■ Back in 2016 we presented gr-isdbt : an open and free receiver for ISDB-T implemented in GNU Radio ■ We are now presenting the “completion” of the project: an SDR-based open source ISDB-T transmitter ■ What for? F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 5/19 •
Background ■ Back in 2016 we presented gr-isdbt : an open and free receiver for ISDB-T implemented in GNU Radio ■ We are now presenting the “completion” of the project: an SDR-based open source ISDB-T transmitter ■ What for? ● Deep understanding of the technology ● No true expertise can be achieved without dealing with actual implementations • We don’t manufacture/design receivers or transmitters ● A complete transceiver has further uses. For instance: ● Cheap transmitter ● Simulation and system configuration ● The availability of receivers and transmitters that are inexpensive and open should accelerate the DTV transition F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 5/19 •
Agenda Introduction 1 The ISDB-T Standard 2 Our Implementation 3 Ultra-cheap setup: osmo-fl2k 4 Conclusion 5 F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 6/19 •
ISDB-T, introduction ■ Stands for Integrated Services Digital Broadcasting - Terrestrial ■ Japanese digital and terrestrial television standard, based on DVB-T ■ Adopted and adapted by Brazil: ● Ginga instead of BML for interactivity ● MPEG-4 instead of MPEG-2 for source coding ■ New version of the standard was named ISDB-Tb ■ ISDB-Tb was lated adopted by most of South American countries F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 7/19 •
ISDB-T, briefly described Energy Byte Bit Convolutional TMCC Mapping dispersal interleaving interleaving encoder signal TS Hierarchical Energy Byte Bit Frequency Convolutional Hierarchical Time OFDM frame RS(204,188) Mapping IFFT GI insertion dispersal interleaving interleaving REMUX division encoder combination interleaving interleaving structure Energy Byte Convolutional Bit Mapping Pilots dispersal interleaving encoder interleaving Parameters Values Modulation BST-OFDM, with CP Total Bandwidth 6 MHz Number of segments 13 Segments bandwidth 6000/14 ≈ 428 . 57 kHz Number of carriers mode 3: 8192, active: 5617 (432 per segment) mode 2: 4096, active: 2809 (216 per segment) mode 1: 2048, active: 1405 (108 per segment) Sampling rate 512 / 63 ≈ 8 . 126 MHz Cyclic Prefix duration 1/4, 1/8, 1/16, 1/32 (of active symbol duration) 252 µ s (mode 1) Active symbol duration 504 µ s (mode 2) 1004 µ s (mode 3) Convolutional Code Rate 1/2, 2/3, 3/4, 5/6, 7/8 0, 1, 2, 4 (mode 1) Time interleaving parameter 0, 2, 4, 8 (mode 2) 0, 4, 8, 16 (mode 3) Modulation schemes DQPSK, QPSK, 16QAM, 64 QAM F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 8/19 •
ISDB-T, briefly described Energy Byte Bit Convolutional TMCC Mapping dispersal interleaving interleaving encoder signal TS Hierarchical Energy Byte Bit Frequency Convolutional Hierarchical Time OFDM frame RS(204,188) Mapping IFFT GI insertion dispersal interleaving interleaving REMUX division encoder combination interleaving interleaving structure Energy Byte Convolutional Bit Mapping Pilots dispersal interleaving encoder interleaving ■ (up to) three Transport Streams Parameters Values Modulation BST-OFDM, with CP ( Layers in ISDB-T lingo) Total Bandwidth 6 MHz Number of segments 13 transmitted at the same time Segments bandwidth 6000/14 ≈ 428 . 57 kHz Number of carriers mode 3: 8192, active: 5617 (432 per segment) ■ Each Layer may use its own set mode 2: 4096, active: 2809 (216 per segment) mode 1: 2048, active: 1405 (108 per segment) of transmission parameters Sampling rate 512 / 63 ≈ 8 . 126 MHz Cyclic Prefix duration 1/4, 1/8, 1/16, 1/32 (of active symbol duration) ■ Since the MPEG TS cannot be 252 µ s (mode 1) Active symbol duration 504 µ s (mode 2) used for hierarchical 1004 µ s (mode 3) Convolutional Code Rate 1/2, 2/3, 3/4, 5/6, 7/8 transmissions, ISDB-T defines 0, 1, 2, 4 (mode 1) Time interleaving parameter 0, 2, 4, 8 (mode 2) the so-called Broadcast 0, 4, 8, 16 (mode 3) Modulation schemes DQPSK, QPSK, 16QAM, 64 QAM Transport Stream (BTS) F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 8/19 •
ISDB-T, briefly described Energy Byte Bit Convolutional TMCC Mapping dispersal interleaving interleaving encoder signal TS Hierarchical Energy Byte Bit Frequency Convolutional Hierarchical Time OFDM frame RS(204,188) Mapping IFFT GI insertion dispersal interleaving interleaving REMUX division encoder combination interleaving interleaving structure Energy Byte Convolutional Bit Mapping Pilots dispersal interleaving encoder interleaving ■ OFDM with configurable number Parameters Values Modulation BST-OFDM, with CP of carriers Total Bandwidth 6 MHz Number of segments 13 ■ Each Layer is sent over a set of Segments bandwidth 6000/14 ≈ 428 . 57 kHz Number of carriers mode 3: 8192, active: 5617 (432 per segment) particular carriers mode 2: 4096, active: 2809 (216 per segment) mode 1: 2048, active: 1405 (108 per segment) ■ Carriers are partitioned into Sampling rate 512 / 63 ≈ 8 . 126 MHz Cyclic Prefix duration 1/4, 1/8, 1/16, 1/32 (of active symbol duration) Segments 252 µ s (mode 1) Active symbol duration 504 µ s (mode 2) 1004 µ s (mode 3) Layer A (1-seg) Layer B Convolutional Code Rate 1/2, 2/3, 3/4, 5/6, 7/8 Segment 11 Segment 9 Segment 7 Segment 5 Segment 3 Segment 1 Segment 2 Segment 10 Segment 12 Segment 0 Segment 4 Segment 6 Segment 8 0, 1, 2, 4 (mode 1) Time interleaving parameter 0, 2, 4, 8 (mode 2) 0, 4, 8, 16 (mode 3) Modulation schemes DQPSK, QPSK, 16QAM, 64 QAM 6 MHz channel F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 8/19 •
ISDB-T, briefly described Energy Byte Bit Convolutional TMCC Mapping dispersal interleaving interleaving encoder signal TS Hierarchical Energy Byte Bit Frequency Convolutional Hierarchical Time OFDM frame RS(204,188) Mapping IFFT GI insertion dispersal interleaving interleaving REMUX division encoder combination interleaving interleaving structure Energy Byte Convolutional Bit Mapping Pilots dispersal interleaving encoder interleaving ■ Sampling rate is fixed Parameters Values Modulation BST-OFDM, with CP ■ Cyclic prefix is configurable Total Bandwidth 6 MHz Number of segments 13 Segments bandwidth 6000/14 ≈ 428 . 57 kHz ■ Resulting rates: Number of carriers mode 3: 8192, active: 5617 (432 per segment) mode 2: 4096, active: 2809 (216 per segment) mode 1: 2048, active: 1405 (108 per segment) Sampling rate 512 / 63 ≈ 8 . 126 MHz Cyclic Prefix duration 1/4, 1/8, 1/16, 1/32 (of active symbol duration) 252 µ s (mode 1) Active symbol duration 504 µ s (mode 2) 1004 µ s (mode 3) Convolutional Code Rate 1/2, 2/3, 3/4, 5/6, 7/8 0, 1, 2, 4 (mode 1) Time interleaving parameter 0, 2, 4, 8 (mode 2) 0, 4, 8, 16 (mode 3) Modulation schemes DQPSK, QPSK, 16QAM, 64 QAM F. Larroca, P. Flores Guridi, D. Artenstein, L. Inglés and G. Morales Ultra-cheap SDR Digital Television Transmission 8/19 •
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