introduction to digital signal processing · digital or analog? digital signal processing is easier...

《数字信号处理》：导论 �Digital Signal Processing: Introduction

Introduction to Digital Signal Processing

DSP MOOC Course

What is Signal?

Signals: functions conveying information about the behavior or attributes of somephenomenon.

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Signal Processing

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Analog and Digital Signal

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Digital Signal Processing

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Digital or Analog?

Digital signal processing is• easier for storage• more reliable and flexible• stronger immunity to noise• …

than directly processing Analog signals.

But Digital is less accurate, harder to implement ultra-high frequencies, more powerconsumption ...

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Evolution of Mobile Phone

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Evolution of Memory Storage

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Evolution of TV

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Some Applications of DSPSignal spectral analysis:

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Some Applications of DSP

Noise removal for speech:

Music in Time-domain Freq.-domain

Org.

Noisy

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Some Applications of DSP

Amp. Resp.

before filtering

after filtering

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Some Applications of DSP

Music synthesis by Karplus-Strong:

HL(z)+x[n] y[n]

z−L

produces harmonics with fundamental freq. ω0 = 2π/(L+0.5)

[1] http://legacy.spa.aalto.fi/demos/tunable-disp/[2] http://theneuralbit.com/comfortably-numb-synth.html[3] http://www.music.mcgill.ca/ gary/courses/papers/Jaffe-Extensions-CMJ-1983.pdf

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Some Applications of DSPImage Restoration:

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What will be learnt from DSP?

• Bridge from A to D:• Sampling• Quantification

• DSP in Time-Domain:• Convolution / Correlation• Filters / Filter Design

• DSP in Frequency-Domain:• DTFT / DFT / FFT• ZT• Filter Design

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