statistical multipath model lecture4.pdf

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  • 7/30/2019 Statistical Multipath model lecture4.pdf

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    1

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    !

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    & "$

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    (

    !!)

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    2

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    *+ ,-.

    /

    !

    !

    01!

    ))(()(),(1

    )(tettc n

    N

    n

    tj

    nn =

    =

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    3

    *

    Time-invariant case

    Time-varying case

    2/

    2

    1

    -

    2!!

    !

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    4

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    !

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    =

    )(

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    )(2)()()(

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    n

    tj

    n

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    ""##

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    5

    2/2

    6 .789)

    (!)

    . :+()

    2

    ; 222

    ( )

    0

    ( ) ( )cos( ( ))N t

    I n n

    n

    r t t t =

    = ( )

    0

    ( ) ( ) sin( ( ))N t

    Q n n

    n

    r t t t =

    =

  • 7/30/2019 Statistical Multipath model lecture4.pdf

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    5

    %%

    2?$@

    =+

    .!

    %% 2?$@

    2:+

    --:+

    2

    /cos],2[cos5.)()( nDDprr vffEAAnnnQI

    ===

    )(]2[sin5.)( ,, QInnQI rrDprr AfEA ==

    )2sin()()2cos()()( , crrcrr fAfAA QII =

    )(]2[sin5.)( ,, QInnQI rrDprr AfEA ==

    )2sin()()2cos()()( , crrcrr fAfAA QII =

    =0

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    6

    &&%'%%'% =+

    1

    )2(5.)()( 0 Dprr fJAA QI ==

    Decorrelates over roughly half a wavelength

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    ffSffSfS

    I

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    Used to generate simulation values fc+fDf

    c

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    fc-f

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    6

    .+

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    ( 1) /( 2 )Z Dt e f =

    Z

    t1 t2 t3

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    10

    %)*%)*

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    2 2%%))

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    2E?+!!

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    6+-6

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    6 +

    Frequency correlation function

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    A 0%

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    T

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    B

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    Channel appears static for

    transmitted digital symbols

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    16

    ))

    Double

    Fourier

    Transform

    t=0

    Fourier

    Transform

    FourierTransform

    f=0

    "" 6!

    34

    2

    5!(!/

    0)1)%!

    %(