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![Jaewook Kang PhD,
KIT seminar, 24th March 2017
Related Works
• Academic Researches
• Acoustic OFDM [Matsuoka06]
• Embedding information in 6.4~8 kHz of source audio
• 240 bps in a few meters
• Dhwani [Nandakumar13]
• OFDM w/ BPSK @ 6~7 kHz
• 800 bps @ < 20 cm (substituting NFC)
• Commercial Services
• Naratte Zoosh [Zoosh]
• Ultrasound-transmitting screen in taxis
• Payment system & App
• ShopKick [ShopKick]
• Ultrasound transmitter at the entrance of malls
• Provide coupons and/or discount information
13](https://image.slidesharecdn.com/170324kitseminarjwkang-170402101138/75/Introduction-to-Soundlly-2nd-screen-services-and-technology-Seminar-in-at-20170324-13-2048.jpg)
![Jaewook Kang PhD,
KIT seminar, 24th March 2017
We use Linear Frequency Modulation (Chirp) !
• Revisit “Rader pulse coding based technology”
• High received power + good resolution
• But Trade off! btw signal power ßà resolution
• Linear FM (Chirp) tech. enables high power
transmission while maintaining a constant bandwidth.
21
[The Figure is
borrowed from
C. Allen @The
University of Kansas]](https://image.slidesharecdn.com/170324kitseminarjwkang-170402101138/75/Introduction-to-Soundlly-2nd-screen-services-and-technology-Seminar-in-at-20170324-21-2048.jpg)
![Jaewook Kang PhD,
KIT seminar, 24th March 2017
We use Linear Frequency Modulation (BOK) !
• Binary Orthogonal Keying (BOK) Chirp
• 1 bit / symbol
𝑠" 𝑡 = cos 2𝜋𝑓" 𝑡 +
𝜇𝑡-
2
𝑠- 𝑡 = cos 2𝜋𝑓- 𝑡 −
𝜇𝑡-
2
Up chirp Down chirp
1 1
22
𝜇 (sweep rate)
22
[Winkley62] M. R. Winkley, “Chirp signals for communications,” in WESCON Convention Record, vol.
14, no. 2, 1962.
[Berni73] A. J. Berni and W. Gregg, “On the utility of chirp modulation for digital signaling,” IEEE Trans.
Commun., vol. 21, no. 6, June 1973.](https://image.slidesharecdn.com/170324kitseminarjwkang-170402101138/75/Introduction-to-Soundlly-2nd-screen-services-and-technology-Seminar-in-at-20170324-22-2048.jpg)
Uploaded byJaewook. Kang
Introduction to Soundlly 2nd screen services and technology: Seminar in 금오공대 at 20170324
The document outlines a seminar by Jaewook Kang, Ph.D., discussing aerial acoustic communication technologies developed by Soundlly for indoor environments, enabling smart devices to transmit data through near ultrasounds. It highlights the advantages of using inaudible signals, such as low battery consumption and long-range capabilities, as well as the performance evaluation for data reception in various environments. Future directions for improving response times and data rates were also mentioned, along with a call for team recruitment to further develop the technology.
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Introduction to Soundlly 2nd screen services and technology: Seminar in 금오공대 at 20170324
- 1. Jaewook Kang PhD, KIT seminar, 24th March 2017 Aerial AcousticCommunication via Soundlly Technology Jaewook Kang, Ph.D jwkang@soundl.ly
- 2. Jaewook Kang PhD, KIT seminar, 24th March 2017 The ideais.. Indoor environment Smart devices and TVs 2 Hmmm looks yummy.. I want a recipe for that!
- 3. Jaewook Kang PhD, KIT seminar, 24th March 2017 The ideais.. Indoor environment Smart devices and TVs Data transmission via near ultrasounds 3 Signal ID embedded in the cook show
- 4. Jaewook Kang PhD, KIT seminar, 24th March 2017 The ideais.. Indoor environment Smart devices and TVs Data transmission via near ultrasounds Back-end server 4 ID 30? URL address http://www.recipe.kr/…
- 5. Jaewook Kang PhD, KIT seminar, 24th March 2017 The ideais.. 5 Indoor environment Smart devices and TVs Data transmission via near ultrasounds Back-end server Contents acquired! URL address http://www.recipe.kr/… Recipe ID 30?
- 6. Jaewook Kang PhD, KIT seminar, 24th March 2017 It's betterto watch than listen a hundred times! • https://www.youtube.com/watch?v=P0p8pw7Zxmg 6
- 7. Jaewook Kang PhD, KIT seminar, 24th March 2017 Service isworking over real-world !! • Soundlly helps TV/video audiences receive useful information or rewards on smart devices 7 KT CLiP 과 2nd-Screen 광고 서비스 중 (2017.3~)
- 8. Jaewook Kang PhD, KIT seminar, 24th March 2017 Service isworking over real-world !! • Soundlly helps TV/video audiences receive useful information or rewards on smart devices 8 태광그룹 쇼핑엔T 홈쇼핑 채널 (’15. 11 ~ ’16. 4*) 예매앱을 활용한 롯데시네마 극장광고- 스마트폰 연계 광고 (2016.10 ~) 재방문 시 2,000원 할인쿠폰!
- 9. Jaewook Kang PhD, KIT seminar, 24th March 2017 Academic Milestones 2013.사운들리-서울대 서울시 기술개발 과제 진행 2013. 사운들리-한양대 중기청 산학협력 과제 진행 2015. 사운들리-서울대-한양대 K-ICT 기술개발 진행중 논문명: Near-Ultrasound Communication Modem Design for TV’s 2nd Screen Services 논문명: Chirp Signal-Based Aerial Acoustic Communication for Smart Devices
- 10. Jaewook Kang PhD, KIT seminar, 24th March 2017 Wanted!! 10 사운들리와 함께글로벌 시장을 혁신할 팀원을 찾습니다! 근무 조건 등 자세한 공고는 job@soundl.ly에 문의 ANDROID 개발 채용 - 업무: 사운들리 SDK 및 앱 개발 및 유지보수 - Android Service, RPC, NDK, GCM 개발 경력 . REST API 를 이용한 클라이언트 개발 경력 . Git 코드 관리 숙련자 - 우대: 앱 퍼블리싱 및 지속 업데이트 경험 개인 레파지토리(github 등) 지속 운영 경험 신호처리 엔지니어 - 업무: 음파신호 송수신기 연구개발 - Strong DSP background - Detection and estimation theory - Machine learning - Communication theory - C/ C++ / MATLAB / Python - 우대: 신호처리/무선통신/음향 박석사학위자 사운들리는 안 들리는 소리를 사용해서 기기간 연결을 하는 UX를 세상에서 가장 간편하게 만드는 기술 기반 B2B 스타트업입니다.
- 11. Jaewook Kang PhD, KIT seminar, 24th March 2017 Technology: AerialAcoustic Communications • System Model • Acoustic channels • Speaker – Air medium – Microphone • Received signal model 11 Pinot Noir Order More Tx: Speaker Indoor Aerial Acoustic Channel Rx: Smart dev. Mic.
- 12. Jaewook Kang PhD, KIT seminar, 24th March 2017 Indoor AerialAcoustic Channels • Delay Spread in Indoor Office Environment • 40 msec delay spread @ –6 dB threshold 5 m, LOS, open space 5 m, NLOS indoor 12
- 13. Jaewook Kang PhD, KIT seminar, 24th March 2017 Related Works •Academic Researches • Acoustic OFDM [Matsuoka06] • Embedding information in 6.4~8 kHz of source audio • 240 bps in a few meters • Dhwani [Nandakumar13] • OFDM w/ BPSK @ 6~7 kHz • 800 bps @ < 20 cm (substituting NFC) • Commercial Services • Naratte Zoosh [Zoosh] • Ultrasound-transmitting screen in taxis • Payment system & App • ShopKick [ShopKick] • Ultrasound transmitter at the entrance of malls • Provide coupons and/or discount information 13
- 14. Jaewook Kang PhD, KIT seminar, 24th March 2017 Limitation ofRelated Works Audible Band Signal Specific Interfaces Short Range Audible band (< 18 kHz) Requires audio source Custom transmitters Flat-frequency devices Up to a few meters 14
- 15. Jaewook Kang PhD, KIT seminar, 24th March 2017 Strengths ofTechnology • Advantages of the Solution Inaudible Signal General Audio Interface Long Range Low battery consumption Inaudible high frequency band Up to 25 m in indoor LOS environment Low-power content recognition Supports frequency-selective devices 15
- 16. Jaewook Kang PhD, KIT seminar, 24th March 2017 Inaudible signalwith small pressure 16 1KHZ 15KHZ 19KHZ
- 17. Jaewook Kang PhD, KIT seminar, 24th March 2017 Popular PHYModulation Schemes 17 Frequency Shift Keying (FSK) - Low complexity - Robust against fading - Low data rate - 예) HAM, FM radio Phase Shift Keying (PSK) - High complexity - Vulnerable to fading - High data rate - 예) 802.11, CDMA, LTE
- 18. Jaewook Kang PhD, KIT seminar, 24th March 2017 Popular PHYModulation Schemes 18 Frequency Shift Keying (FSK) - Low complexity - Robust against fading - Low data rate - 예) HAM, FM radio Phase Shift Keying (PSK) - High complexity - Vulnerable to fading - High data rate - 예) 802.11, CDMA, LTE
- 19. Jaewook Kang PhD, KIT seminar, 24th March 2017 FSK isworking bad in high frequency band • An example: Binary FSK • Bit ‘0’ with 19 kHz tone • Bit ‘1’ with 22 kHz tone • Significant distortion due to MIC freq. response. 19 Freq.19k 22k Speaker/ MIC response 22 kHz tones disappear! Galaxy S3, 5m Line of Sight Galaxy S4, 5m Line of Sight 22kHz tone Region 19kHz tone Region 22kHz tone Region 19kHz tone Region
- 20. Jaewook Kang PhD, KIT seminar, 24th March 2017 • Magnituderesponse of Smart Device MIC (무향실 tx-rx 거리 1m) • • Severe frequency selectivity over 20 kHz 20 Smart device MIC characteristic
- 21. Jaewook Kang PhD, KIT seminar, 24th March 2017 We useLinear Frequency Modulation (Chirp) ! • Revisit “Rader pulse coding based technology” • High received power + good resolution • But Trade off! btw signal power ßà resolution • Linear FM (Chirp) tech. enables high power transmission while maintaining a constant bandwidth. 21 [The Figure is borrowed from C. Allen @The University of Kansas]
- 22. Jaewook Kang PhD, KIT seminar, 24th March 2017 We useLinear Frequency Modulation (BOK) ! • Binary Orthogonal Keying (BOK) Chirp • 1 bit / symbol 𝑠" 𝑡 = cos 2𝜋𝑓" 𝑡 + 𝜇𝑡- 2 𝑠- 𝑡 = cos 2𝜋𝑓- 𝑡 − 𝜇𝑡- 2 Up chirp Down chirp 1 1 22 𝜇 (sweep rate) 22 [Winkley62] M. R. Winkley, “Chirp signals for communications,” in WESCON Convention Record, vol. 14, no. 2, 1962. [Berni73] A. J. Berni and W. Gregg, “On the utility of chirp modulation for digital signaling,” IEEE Trans. Commun., vol. 21, no. 6, June 1973.
- 23. Jaewook Kang PhD, KIT seminar, 24th March 2017 We useLinear Frequency Modulation (BOK) ! • BOK correlation properties • Demodulation example 23 Frequency time 0 1 0 1 0
- 24. Jaewook Kang PhD, KIT seminar, 24th March 2017 • ReceiverProcess 24 Recording Frame synchronization Symbol demodulation Preamble Preamble Acoustic Modem Basic Architecture Single Frame • Signal of the same ID is repeatedly played • Record a signal of frame length by microphone in smart device to guarantee recording a whole preamble
- 25. Jaewook Kang PhD, KIT seminar, 24th March 2017 • ReceiverProcess 25 Recording Frame synchronization Symbol demodulation • Signal of the same ID is repeatedly played • Record a signal of frame length by microphone in smart device to guarantee recording a whole preamble Preamble Preamble Single Frame Acoustic Modem Basic Architecture
- 26. Jaewook Kang PhD, KIT seminar, 24th March 2017 • ReceiverProcess 26 • Frame synchronization by preamble detection • Matched filtering (convolution) Recording Frame synchronization Symbol demodulation Preamble Acoustic Modem Basic Architecture
- 27. Jaewook Kang PhD, KIT seminar, 24th March 2017 • ReceiverProcess 27 Envelope output of preamble and up/down chirp. Recording Frame synchronization Symbol demodulation Preamble Acoustic Modem Basic Architecture
- 28. Jaewook Kang PhD, KIT seminar, 24th March 2017 Performance Evaluation •Demodulation Example • Recording size (1.1 sec) • Frame size (1.1 sec) • BOK chirp symbols • Guarantees at least one full preamble per recording • Decoding process • Preamble detection à Data demodulation Preamble offset Preamble Recorded AudioData Envelope 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 U U U U D D U D D U D U D D D U Preamble 28
- 29. Jaewook Kang PhD, KIT seminar, 24th March 2017 Performance Evaluation •Long-range Reception Ratio • Most devices can receive with 97% probability 10 ~ 25 m Randomly-moving people 29 97%
- 30. Jaewook Kang PhD, KIT seminar, 24th March 2017 Future directions •Faster Response ! • More datarate! • Smaller false-alarm Rate • Precise MAC protocal 30
- 31.