lecture on sampling of signals

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    Lecture 1Sampling of Signals

    by

    Graham C. GoodwinUniversity of Newcastle

    Australia

    Lecture 1

    Presented at the Zaborszky Distinguished Lecture Series

    December 3rd, 4th and 5th, 2007

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    Recall Basic Idea of Sampling

    and Quantization

    Quantization

    Sampling

    t1 t3t2 t4t

    0

    1

    2

    3

    4

    5

    6

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    In this lecture we will ignore quantizationissues and focus on the impact of differentsampling patterns for scalar and

    multidimensional signals

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    Outline

    1. One Dimensional Sampling

    2. Multidimensional Sampling

    3. Sampling and Reciprocal Lattices

    4. Undersampled Signals5. Filter Banks

    6. Generalized Sampling Expansion (GSE)

    7. Recurrent Sampling

    8. Application: Video Compression at Source9. Conclusions

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    Sampling: Assume amplitude quantizationsufficiently fine to be negligible.

    Question: Say we are given

    Under what conditions can we recover

    from the samples?

    ( );f t t

    ( );if t i Z

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    A Well Known Result (Shannons

    Reconstruction Theorem for Uniform

    Sampling)

    Consider a scalar signal f(t) consisting of

    frequency components in the range . If

    this signal is sampled at period , then thesignal can be perfectly reconstructed from the

    samples using:

    [ ]

    ( )

    ( )

    sin2

    ( )

    2

    s

    sk

    t k

    y t y k

    t k

    w

    w

    = -

    - D = - D

    ,2 2

    s sw w-

    2

    s

    pwD