Title: Theoretical Foundation Behind Strong ...

Title: Theoretical Foundation Behind Strong Growth of Smartphones

Speaker: 黃正能 / 華盛頓大學電機系教授

  • Qualcomm's Awareness
  • AT&T's Digital Home/Life
  • Wearable Computing and Bendable Display
    • Google glass - 華大教授三、四年前被 google 挖角過去做的東西
    • Samsung bendable display
  • Apple TV AirPlay and Google Chromecast
    • display device 不需要永遠都在 mobile device 上
    • google chromecast USD$35.00
  • Transparent Smart Windows

What are Theoretical Foundations behind these technology?

Energy Efficient + CPU, GPU

SoC Based Powerful Engine

Qualcomm SnapDragon 600


根據不同狀況使用 CPU 或 GPU

Power Efficient Design

  • 省電
  • Thermal Design Power
  • Leakage 的耗電越來越大

Run-Time System-Level Energy Self-Optimization

  • Optimization - 控管 Device 內的各個 chip



Human Psychoacoustics

  • Hearing Sensitivity - 只聽得到對 20~20000 Hz 的頻率
  • Frequency Masking - 某個頻率的聲音特別明顯的時候,會聽不到這段時間其他頻率的聲音
    • Saving More Bits with Frequency Masking
  • Temporal Masking - 某段時間音量特別大的話,會聽不到在這段時間前後的其他聲音


Audio Coding Standards

  • MP3 (128Kbps)
  • AC3
  • AAC (64Kbps)
  • HE-AAC (48 or 24 Kbps)


Digital Video Coding

  • Digitize
  • Infra-frame compression (Simlliar to JPEG)
    • A DCT Based Intra-Frame Encoding
      • img -> DCT -> Quantize -> Zig-zag -> ...
    • Coding Block
    • Motion Vector Search - 拿 difference 去作 DCD 再作壓縮,省略掉重複的部份
  • Symbol Entropy coding - 機率因素
  • Rate Control

Video Coding Evolution

  • MPEG-2 - 1994
  • AVC/H.264 - 2003
  • AVC Scalable Extension
  • HEVC/H.265 - 2013
    H.265 用 50% 的 bitrate 壓縮出來的效果跟 H.264 100% bitrate 差不多

Multi- and Free-View of Video Scenes

  • Users can dynamic select and viewpoint they want to use
  • Virtual Viewpoint Not Captured by the real camera - 可以透過多個 Camera 模擬出實際上不是由真的 Camera 拍攝出來的視角

What will be 5G?

1991 - Voice - SMS - 2G
2001 - App - SNS - 3G
2009 - Big Data - Cloud - 4G
2020 - ??? - ??? - 5G #沒記到- -"

Earlier Generations of Mobile Technologies

  • 2G
  • CDMA
  • Hive technology

Toward ALL-IP 4G Wireless

  • LTE (Long Term Evolution) of 3GPP
  • WiMAX
  • 4G


Channel Quality Dependent Scheduling

MIMO (Multiple Input Multiple Output)


SD(Spatial Diversity) & SM(Spatial Multiplexing)

Coordinated MIMO


Adaptive Modulation & Coding (AMC)

加入調變或 error correction code 讓收訊的效果更好

QoS(Quality of Service) and QoE(Quality of Experience)

  • Packet lost

Scheduling and Resource Allocation


Heterogeneous Wireless Networks


Secured and Right Protected Usage

Digital Right Management (DRM)

  • DRM License Server - 認證

What is Encryption

  • Symmetric encryption (secret key cryptography)
  • Asymmetric encryption (public key cryptography) - 為了要傳送 secret key

Secret Key

  • DES - IBM
  • AES - NIST
  • Fast and efficient
  • to use public key cryptography only to a private secret key

Public Key

  • RSA (明天要考密碼學期中考 還只能用手算 現在看到這個真的超親切的啊)


  • Smartphones will evolve to all kinds of wearable devices, sensors, attached to our bodies (wireless chargeable), and displays are avaailable anywhere surrounding us.
  • HCIs(speech, gesture, facial, etc) will replace keypads
  • Internet of things(IoTs) will be all ubiquitous in our living environment
  • Information are collectd, indexed, and available in/from clouds

作 low power 技術的教授都被 Google 挖走了XDD

Academic Research: It is Easier Than You Think

Important Features (M2I4) You should have

+ Motivation: really enjoy digging deeper into the scientific truth
+ Maturity: never afraid of being failed or left alone
+ Innovation: always think of what is (or can be) new and different?
+ Intelligence: filter useful information to become usable knowledge
+ Independence: a step-by-step problem formulation and module solving
+ Integrity: always be honest in reporting and research

Getting Ready for Research

  • Research topics selection and switching
    • Extend from senior graduate students' topics
    • Existing research projects in the Lab
    • Something your advisor is willing to learn closely with you
  • Depth knowledge
    • A good series of class taking, or self study related tutorial background
    • Most updated Conference/Journal papers (IEEE Xplore)
    • Joint project discussions and group collaborations, or new class offering
  • Breadth Knowledge
    • Attend technical presentation and active questioning (key messages?)
    • Magazine and Hi-Tech News
    • 到最後很多領域會殊途同歸,都會彼此相關,所以有機會的話可以瞭解一下其他領域在做什麼,尤其是一些 Conference。
    • 透過瞭解其他領域的新聞及期刊,可以瞭解到整個市場的趨勢。
    • 研究生有人去面試的時候,被問到的問題剛好是他在聽同學的 group meeting 時聽到的。

Jumping into Research

  • Extensive literature survey and problem formulation
  • Summarize others' paper in their block diagrams (flow charts) - look for weak links or not convincing blocks
    • 看完別人的 paper 以後,要有辦法自己畫出剛剛那篇 paper 的 block diagram ,如果畫不出來的話,代表你還不夠瞭解那篇論文在幹嘛。
  • Conclusion meet the original problem formulation?
  • Methodologies: integration -> evolution -> revolution
  • Always use the data and compare the results with the most recent or best reported results
  • Clear and detailed interpretation of simulation results
    • 做完 simulation 以後,要把結果好好想清楚,再跟自己的 leader 討論,而不是把整個 simulation 的結果原封不動的丟出來。
  • Confidence and leadership building (organized speech in group or individual meetings)
    • 出去就業後不該是只幫別人寫程式碼,而是應該當個 leader ,因為研究給你訓練就是如此。得到一個新的題目、開始 survey、嘗試、失敗,這是你已經學到的東西,所以你應該已經瞭解如何處理,所以你應該當個 leader。

Persistence in Research

  • Never expect a smooth path, refine the research scopes all the time (backoff slightly to find brighter road ahead)
  • Learn from any failure
  • Never hide from your professor

Research Publications and Technical Reports

  • Practice Engilish writing of thesis and papers: practice by mimicking
  • Always seek publication opportunities: from conferences to periodical journals
    • 自己主動去找有什麼地方可以投稿。
  • Learn the standard writing style and outline of manuscript (a good outline, 70% done!)
    • 能夠把自己大綱全部列出來,並且瞭解大綱在做什麼,這樣大概就完成百分之七十了。
  • Learn from the grammatical errors corrected by your advisor or technical editing persons.
    • 寫論文的文法很重要,設法知道老師幫你改了哪些部分,並從中學習。
  • Discuss clearly the flow charts and simulation results in your papers, never leave the weak links
  • Never be afraid/frustrated of major/minor revision of paper submission - reviewers are never your enemies
    • 別人有什麼意見的話要用心傾聽,如果有好的意見的話就記得要更改。



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