fourier transform of discrete time signal using matlab
Các phương pháp xử lý tín hiệu dùng bộ lọc, phương pháp Fourier Transform, STFT( Short Time Fourier Transform)
Ngày tải lên :
01/04/2013, 16:14
... Trong miền tần số: phương pháp Fourier Transform.
- Trong miền thời gian và tần số: STFT( Short Time Fourier Transform) .
2.4.1. Phương pháp Fourier:
2.4.1.1. Biến đổi Fourier:
Cho một hàm f(t) ... kết thúc của sự
kiện thì Fourier không phát hiện được.
2.4.2. Phương pháp STFT:
Để đạt được một biến đổi Fourier cục bộ, chúng ta có thể định nghĩa một biến đổi
Fourier cửa sổ. Tín hiệu đầu ... đổi Fourier của nó được định nghĩa:
() () ()
tfedtetfF
titj
,
ωω
ω ==
∫
∞
∞−
−
(2.14)
Biến đổi Fourier ngược là:
() ()
∫
∞
∞−
= ωω
π
ω
deFtf
tj
2
1
(2.15)
Giả sử rằng biến đổi Fourier...
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06 Quantization of Discrete Time Signals
Ngày tải lên :
18/10/2013, 04:15
... continuous time, continuous amplitude signal. If the range
of x(t) is the set of integers Z, then x(t) is said to be a continuous time, discrete amplitude signal. In
contrast, a discrete time signal ... its domain. A discrete time, continuous amplitude signal
has R as its range. A discrete time, discrete amplitude signal has Z as its range. Here, the focus is
on discrete time signals. Quantization ... signals. Quantization is the process of approximating any discrete time, continuous
amplitude signal into one of a finite set of discrete time, continuous amplitude signals based on a
particular distortion...
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Real-Time Digital Signal Processing - Chapter 7: Fast Fourier Transform and Its Applications
Ngày tải lên :
28/10/2013, 05:15
... Circular Convolution
The Fourier transform, the Laplace transform, and the z -transform of the linear con-
volution of two time functions are simply the products of the transforms of the
individual functions. ... properties of the DFT directly relate to the performance of spectral
analysis. If a discrete- time signal is periodic, it is possible to calculate its spectrum using
the DFT. For an aperiodic signal, ... function psd to average the period-
ograms of windowed segments of a signal. This MATLAB function estimates the
PDS of the signal given in the vector x using the following statement:
pxx psd(x,...
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Báo cáo khoa học: Determination of thioxylo-oligosaccharide binding to family 11 xylanases using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry and X-ray crystallography pot
Ngày tải lên :
07/03/2014, 17:20
... Jackson GS (1998)
Fourier transform ion cyclotron resonance mass spec-
trometry: a primer. Mass Spectrom Rev 17, 1–35.
56 Smith RD (2000) Evolution of ESI-mass spectrometry
and Fourier transform ion ... dry
weight of softwoods, 15–30% of hardwoods and up to
30% of annual graminaceous plants [7,8].
Endo-1,4-b-xylanases (EC 3.2.1.8) are O-glycoside
hydrolases that catalyze a random hydrolysis of inter-
nal ... J
& Vainiotalo P (2004) Characterization of mutant xyla-
nases using Fourier transform ion cyclotron resonance
mass spectrometry: stabilizing contributions of disulfide
bridges and N-terminal extensions....
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mathematics of the discrete fourier transform
Ngày tải lên :
31/03/2014, 15:21
... F. Warshofsky, and the Editors of Time- Life Books,
Sound and Hearing, Life Science Library, Time- Life Books, Alexandria, VA, 1965, p.
173.
DRAFT of “Mathematics of the Discrete Fourier Transform ... the time
domain?
Finally, we will study a variety of practical spectrum analysis exam-
ples, using primarily Matlab to analyze and display signals and their
spectra.
DRAFT of “Mathematics of the ... tape,
companding is often used. “Dolby A” adds approximately 10 dB to the
dynamic range that will fit on magnetic tape (by compressing the signal
DRAFT of “Mathematics of the Discrete Fourier Transform...
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The Discrete Fourier Transform
Ngày tải lên :
13/09/2012, 09:49
... shape of the waveform being decomposed.
Chapter 8- The Discrete Fourier Transform 145
Type of Transform Example Signal
Fourier Transform
Fourier Series
Discrete Time Fourier Transform
Discrete Fourier ... themselves in a periodic fashion. This type of
Fourier transform is called the Discrete Time Fourier Transform.
Periodic -Discrete
These are discrete signals that repeat themselves in a periodic ... from
negative to positive infinity. This class of Fourier Transform is sometimes
called the Discrete Fourier Series, but is most often called the Discrete
Fourier Transform.
You might be thinking that...
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Tài liệu Table of Fourier Transform Pairs ppt
Ngày tải lên :
13/12/2013, 12:15
... Series
()
ồ
Ơ
=
++=
1
000
)sin()cos()(
n
nn
ntbntaatf
ww
where
ũ
ũũ
=
==
T
n
T
T
n
dtnttf
T
b
dtnttf
T
adttf
T
a
0
0
0
0
0
0
)sin()(
2
and, )cos()(
2
, )(
1
w
w
ỉ Complex Exponential Fourier Series
ũ
ồ
-
Ơ
-Ơ=
==
T
ntj
n
n
ntj
n
dtetf
T
FeFtf
0
0
)(
1
where, )(
w
w
Signals & Systems - Reference Tables
4
Some Useful ...
ò
dxe
xa
a
e
x
a
ò
dxxe
xa
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32
2
22
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x
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ò
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ba
b
+
ln
1
ò
+
222
x
dx
ba
)(tan
1
1
a
b
ab
x
-
Signals & Systems - Reference Tables
2
t
j
p
1
)sgn(
w
)(
tu
w
wpd
j
1
)(
+
ồ
Ơ
-Ơ=n
tjn
n
eF
0
w
ồ
Ơ
-Ơ=
-
n
n
nF
)(2
0
wwdp
)(
t
t
rect
)
2
(
w
t
tSa
)
2
(
2
Bt
Sa
B
p
)(
B
rect
w
)(ttri
)
2
(
2
w
Sa
)
2
()
2
cos(
tt
p
t
rect
t
A
22
)
2
(
)cos(
w
t
p
w
t
t
p
-
A
)cos(
0
t
w
[]
)()(
00
wwdwwdp ...
j
)cos()(
0
ttu
w
[]
22
0
00
)()(
2
ww
w
wwdwwd
p
-
+++-
j
)sin()(
0
ttu
w
[]
22
0
2
00
)()(
2
ww
w
wwdwwd
p
-
++
j
)cos()(
0
tetu
t
w
a-
22
0
)(
)(
waw
wa
j
j
++
+
Signals & Systems - Reference Tables
3
)sin()(
0
tetu
t
w
a-
22
0
0
)( waw
w
j++
t
e
a-
22
2
wa
a
+
)2/(
22
s
t
e
-
2/
22
...
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Tài liệu Digital Signal Processing Laboratory - Using Matlab doc
Ngày tải lên :
25/01/2014, 08:20
... A brief explanation
of the MATLAB functions used here can be found in Appendix B.
3.4 Discrete- Time Fourier Transform
The discrete- time Fourier transform (DTFT) X(e
jω
) of a sequence x[n] is ... representations are the discrete- time Fourier transform
(DTFT), the discrete Fourier transform (DFT), and the z -transform. In this exercise you
will study all three representations of a discrete- time sequence.
3.2 ... Background Review 33
3.3 MATLAB Commands Used 37
3.4 Discrete- Time Fourier Transform 39
3.5 Discrete Fourier Transform 45
3.6 z -Transform 50
3.7 Background Reading 52
4 LTI Discrete- Time Systems in the...
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Tài liệu Real-time, on-line monitoring of organic chemical reactions using extractive electrospray ionization tandem mass spectrometry pdf
Ngày tải lên :
14/02/2014, 08:20
... acetate signal
increased in the early stage of the reaction, but started to
Figure 4. Proposed reaction mechanism of catalytic acet-
ylation of acetic anhydride and benzyl alcohol in the presence
of ... which is carried out on a quadrupole time -of- flight
(Q-TOF) mass spectrometer. The relatively simple setup
allows this method to be implemented on any type of MS
instrument equipped with an ESI/APCI ... after a short time, but also forms a side product, 3-
[(2-cyanoethyl)phenylethylamino]propionitrile (CPEAP, MW 227)
after a longer reaction time, by addition of a second molecule
of acrylonitrile...
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Performance Evaluation of Active Suspension for Passenger Cars.Using MATLAB
Ngày tải lên :
16/02/2014, 09:13
... the animation of both the systems
along with the graphs of Displacement Vs. time just below the animation window of each of the suspension
system. By comparing the performance of the passive ... quarter car by using MATLAB/ SIMULINK software will
be performed. Performances of the suspension system in term of ride quality and car handling will be observed,
Performance Evaluation of Active ... the
enhancement of its road handling and comfort. Comparison between passive and active suspensions system are
performed by using road profile as an input. The performance of the active suspension...
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Báo cáo khoa học: Light-induced reactions of Escherichia coli DNA photolyase monitored by Fourier transform infrared spectroscopy pot
Ngày tải lên :
16/03/2014, 18:20
... irradiation. Difference Fourier transform infra-
red (FT-IR) spectroscopy was used to monitor vibronic bands of the blue
radical form and of the fully reduced FADH
)
form of the enzyme.
Preliminary ... elucidation of a detailed molecular picture of the light-
driven DNA repair process.
Abbreviations
DTT, dithiothreitol; FT-IR, Fourier transform infrared; MTHF, 5,10-methenyltetrahydrofolylpolyglutamate; ... cycle was repeated five
times to give a final D
2
O enrichment of 95–99%.
Preparation of substrate
A 4-mm solution of single-strand oligo-(dT)
18
DNA was irra-
diated for 45 min using a 254 nm G8W...
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