- Open Access
- Total Downloads : 295
- Authors : K.Prasada Rao, A.S.Srinivasa Rao, P.V.Muralidhar
- Paper ID : IJERTV2IS100766
- Volume & Issue : Volume 02, Issue 10 (October 2013)
- Published (First Online): 26-10-2013
- ISSN (Online) : 2278-0181
- Publisher Name : IJERT
- License: This work is licensed under a Creative Commons Attribution 4.0 International License
Analysis clonal algorithm based window Using Fractional Fourier Transform
K.Prasada Rao 1, A.S.Srinivasa Rao 2, P.V.Muralidhar 3
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Aditya Institute of Technology and Management, Tekkali 532001 (A. P., India)
-
Professor & HOD, Dept. of ECE. College of Engineering, AITAM,Tekkali 532001
(A. P., India)
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Associate Professor, Dept. of ECE.College of Engineering, AITAM,Tekkali 532001 (A. P., India),
Abstract
An Approximated Exponential Fractional Fourier Transforms(FrFT) Mathematical derivation for clonal algorithm based window is proposed. By control the parameter of FrFT,it is possible to control the Spectral parameters of above windows like Half Bandwidth (HBW), Maximum Side Lobe Attenuation(MSLA) and Side Lobe Fall Of Ratio(SLFOR).This proposed derivation is also holds good for generalization of FrFT with Fourier Transform(FT).
Index TermsFractional Fourier transform, clonal algorithm based window.
NOMENCLATURE
FT: Fourier Transform
FrFT: Fractional Fourier Transform
-
INTRODUCTION
In order to reduce the effects of spectral leakages in Harmonic analysis, windows are used [1]. window functions successfully used in the areas like interpolation factors to design Anti-Imaging filters, speech processing systems, digital filter design and beam forming [2]-[3].windows are also useful to solve reconstructive errors which are objective functions to
-
Fractional Fourier Transform
Fractional Fourier Transform widely used in quantum mechanics and quantum optics [13].Fractional Fourier Analysis can obtain the mixed time and frequency components of signals[14].it finds various applications like pattern recognisition with some spatial distortion, Image representation , compression and noise removal in signal processing [15]-[17].FrFT used for Interpretation of sinusoidal signals and design of Digital FIR Filters[18]-[19].
The continuous time Fractional Fourier Transform of a signal
()is defined through an interval [3]
() = ()(, ) (1)
Where the transform kernel (, ) of the FRFT is Given by
(, )
design the prototype filters [4].windows are essentially Applicable in spectral analysis of signals[5]- [6].According to [3],as the parameter of FrFTi.e =
2
1 ()
= [ (
2
2 + 2 2
) cot()
which could not holds good for generalization of FrFT to FT [7].In this proposed Derivation of FrFT, An attempt is made to study the variations of window parameters like HBW,MSLA and MSLFOR by different values of fluid parameter of FrFT to FT at =
This paper is organized as follows. ::section-II gives
2
an overview of FT, and mathematical model of
windows by using FT. section-III gives an overview of FrFT, and mathematical model of windows by using FRFT. Later conclusive remarks are discussed in section-IV.
()]
= ( ) 2
= ( + ) + 2 (2)
Where indicates rotation of angle of the Transformed signal for FrFT.
2.1) window function based on Clonal Algorithm
The Expression for clonal Algorithm based window is [16]
() = 0.5154 0.4711 cos( 2)
+ 0.08cos(4) || < 1 (1)
= 0 otherwise.
() =
2 ()1() [ (2+2) cot()
Now solving for I4
4 2
4 2
I =2(0.4711)cos(2) exp ( 2 cot()
1
()) – – – – (10) According to [17]
exp(2) + exp(2)
1
2 2
cos(2) =
2 (11)
()] (2)
Substitute equation-(11) in equation-(10) then
=
1()
2
2cot()
2 (3)
I4=2((0.4711)
1
Then equation-(21) becomes
(exp(2)+exp(2)) )exp ( 2 cot()
2
2 2
2
2
2
() = () exp ( cot()
1
()) —————————————- (12)
= 0.23555((2 exp(2) exp ( 2 cot()
()) (4) 4
1 2
Substitute equation-(20) in equation-(23) then
()) ) +
(2 exp(2) exp ( 2 cot() ())))
2
() = (0.5154
1
2
– – – (13)
2
2
2
1
0.4711 cos( 2)
2
Now multiply both sides with
results to
cot()
which
+ 0.0135 cos(4)) exp ( 2 cot()
()) (5)
2
2 cot()4 =
2 cot()
2 ( )
2 ( )
2
(0.23555((1 exp 2
exp ( cot
2
Equation-(5) divided into four parts like I3,I4,I5,I6where
3 2
3 2
I =2(0.5154)exp ( 2 cot()
1
()) ) +
2
2
(2 exp(2) exp ( 2 cot()
1
())))) ———- (14)
()) (6)
I =2(0.4711)cos(2) exp ( 2 cot()
2cot()
2
4 = 0.23555(( (exp(2
1
2
2
())))
4 1 2
2
+ ( (exp(2
()) – – – (7)
5 2
5 2
I =2(0.0135)cos(4) exp ( 2 cot()
1
1
())))) (15)
Integration above equation and applying limits, you
()) – – – (8)
Now solving for I3
will get
2cot()
exp(2 t ())
I3=2
(0.5154)exp ( 2 cot() ())
2
2
= 0.23555 ( 2 2
4
4
2()
1
According to that
2()
1()
exp(211())) – – -(16)
2()
Now Integrate both sides with limits t1 and t2
I3= 0.5154
( () () )
( )+() 33) – – – – – (9)
2 1 6 ( 2 1
2
2
2
(
1
2
2cot()
4)
exp(22 t2())
Finally I4
4 =
exp(22t2()) exp(211())
= (0.23555 (
2 ()
0.23555(
2()
2() )(21)
1
(2 1) () 3 3
exp(2 ())
6 2 1
( )
( )
1 1 )) (17)
2 ()
Now solving for I5
– – – (25)
The above equation can be written as
I4=
2(0.23555(exp(22t2())exp(211())))
I =2(0.01 35)cos(4) exp ( 2 cot()
5 2
5 2
1
()) – – – – (26)
1
2()
2()
(18)
2(
1
2cot()
)
According to [17]
2
2
Now equation-(18) can be divided into two parts x1 and x2
Where
1
cos(4) =
exp(4) + exp(4) 2
(27)
2
= (0.23555 (
1
exp(22 t2())
2 ()
Substitute equation-(27) in equation-(26) then
I5=2((0.4711)
exp(2 ())
1
1 1 ))
(exp(4)+exp(4)) )exp ( 2 cot()
2 () 2 2
And
2
2 = (
2 cot()
) /p>
()) —————————————- (28)
2
2
1
= 0.23555((2 exp(4) exp ( 2 cot()
5 1 2
Now solving for 1
Integrating 1 and applying lilits
()) ) +
(2 exp(4) exp ( 2 cot() ())))-
1
= 0.23555 (exp(22t2())
2()
1
2
——— (29)
exp(211())) (
) – – – (19)
2() 2 1
Now solving for 2
2
2
2
Now multiply both sides with 2 cot() which results to
2
2 = (
1
2 cot()
) (20)
2
2 cot()5 =
2 cot()
2
2
According to [17]
2
(0.23555((1 exp(4) exp ( 2 cot()
2 ( )
2
()) ) +
2 cot
= 1
cot() (21)
(2 exp(4) exp ( 2 cot()
2
Substitute equation-(21) in
equation-(20) to get
1 2
= 2 (1 2 cot())
– – – (22)
())))) ———- (30)
2 1 2
2
2
Integrating and applying limits to get
2 cot()5 = 0.23555(( (exp(4
1
())))
2
2 =
1
() 2
2
2 (23)
1
2
+ ( (exp(4
1
())))) (31)
= ( ) () (3 3) – – – (24)
Integration above equation and applying limits, you
2 2 1
6 2 1
will get
2
2
2cot()
5
Substitute equation-(37) in equation-(20) to get
= 0.23555 (exp(42 t2())
= 2 (1 2 cot()) (36)
4 () 2 1 2
exp(41 1())) (32)
Integrating and applying limits to get
4 ()
2
() 2
Now Integrate both sides with limits t1 and t2
2 =
1
2 (38)
2
2
1
2
(
2cot()
5)
= ( ) () (3 3) (39)
2
2
1
2
exp(42 t2())
2 2 1
6 2 1
= (0.23555 (
1
4 ()
Finally I5
exp(41 1()))) (33)
4 ()
5 =
0.23555(exp(42t2())exp(411()))(21)
4() 4() (40)
( )
( )
(2 1) () 3 3
The above equation can be written as
I5=
2(0.23555(exp(42t2())exp(411())))
Finally
6 2 1
1
4()
4()
(34)
() = 3 4 + 5 (41)
2(
1
2cot()
)
Thus equation-(41) is the FRFT based clonal
2
2
Now equation-(34) can be divided into two parts x1 and x2
Where
1
algorithm based window.
When substitute = = 1 in equation-
2
(41) results to generalized Fourier Transform based
2
= (0.23555 (
1
exp(42 t2())
4 ()
clonal
algorithm based window.
exp(41 1())))
4 ()
And
The spectral parameters of above window is shown in Table and its spectral responses are shown from Fig1 to Fig6.
2
2
2
2 = (
1
Now solving for 1
2 cot()
)
Table:
Spectral Parameters of FrFT Based clonal algorithm based window for variations in a
A |
SLA in dB |
HBW in dB |
SLFOR in dB |
0.93 |
-57 |
0.0195 |
-73.94 |
0.94 |
-60.8 |
0.0195 |
-71.85 |
0.95 |
-65.5 |
0.0185 |
-71.87 |
0.96 |
-63.9 |
0.0185 |
-72.55 |
0.97 |
-62.2 |
0.0185 |
-72.09 |
0.98 |
-61.0 |
0.0185 |
-70.76 |
0.99 |
-60.3 |
0.0185 |
-69.49 |
1 |
-60 |
0.0185 |
-69.1 |
A |
SLA in dB |
HBW in dB |
SLFOR in dB |
0.93 |
-57 |
0.0195 |
-73.94 |
0.94 |
-60.8 |
0.0195 |
-71.85 |
0.95 |
-65.5 |
0.0185 |
-71.87 |
0.96 |
-63.9 |
0.0185 |
-72.55 |
0.97 |
-62.2 |
0.0185 |
-72.09 |
0.98 |
-61.0 |
0.0185 |
-70.76 |
0.99 |
-60.3 |
0.0185 |
-69.49 |
1 |
-60 |
0.0185 |
-69.1 |
Integrating 1 and applying lilits
1
= 0.23555 (exp(42t2())
4()
exp(411())) (
) – – – (35)
4()
Now solving for 2
2
2 1
2
2 = ( 2 cot()) (36)
1
According to [17]
2
2
2 cot()
2
= 1 2 cot() (37)
Fig1:Spectral Response of window for a=0.93
Fig2:Spectral Response of window for a=0.94
Fig3:Spectral Response of window for a=0.95
Fig4:Spectral Response of window for a=0.96
Fig5:Spectral Response of window for a=0.97
Fig6:Spectral Response of window for a=0.98
Fig7:Spectral Response of window for a=0.99
Fig8:Spectral Response of window for a=1
3 Conclusion:
From the study of Exponential derivation of FrFT for clonal algorithm based window, The controllability of window parameters like HBW,MSLA and SLFOR is possible..i.e. The MSLA increases from -60 dB to –
65.5 dB for a= 1 to a=0.95 decreases to -57 dB for a=0.93[Table].so that from the table it is observed that the spectral parameters of clonal based window is improved by controlling the a parameter of FrFT. and
also one of the property of FrFT is Generalization of
-
Miguel Angel Platas-Garzan,JoseAntoniodela o Serena-Dynamic harmonic Analysis Through Taylor- Fourier Transform-IEEE Transactions on Instrumentation and Measurment,Vol:60,No:3,march- 2011
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L.R. Rabiner, B. Gold, Theory and Applications of Digital Signal Processing, Prentice-Hall, 1975.
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Dr.B.S.Grewal-Engineering Mathematics,ISBN NO:81-7409-2196,25th edition, October 2006,Khanna Publications
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Namias.V-The FrFT and Time Frequency
FrFTto FT i.e. when =
2
where a=1;then The FrFT
representation-
J.Inst.Math.Applications,Vol:25,pp.241-265,1980.
should equals to FT .This proposed Mathematical derivation of FrFT fulfills the Property of FT.
4:References
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Qiusheng Wang*, Shaokun Gao, Jingpo Zhao
– A Novel FIR Filter Design Based on Clonal Selection Algorithm- Seventh International Symposium on Instrumentation and Control Technology: Measurement Theory and Systems [17]V.AshokNarayanan,K.M.M.Prabhu-The FrFT: Theory, Implementation and error Analysis, Microprocessor and Microsystems 27(2003),511- 521,Elsevier Publications.
[18]Ran Tao, Kiang-Yi meng,Yue Wang-Image encryption with multi orders Fractional Fourier Transforms, IEEE transactions on Information Forensics and Security,vol:05,No:04,December 2010. [19].P.V.Muralidhar,A.S.SrnivasaRao,Dr.S.K.Nayak- Spectral Interpretation of Sinusoidal wave using Fractional Fourier Transform based FIR window functions,vol:04,N0:6,PP:652-657,International Review on computers and software, November 2009.Prasada rao Koppala obtained bachelor degree under JNTU Hyderabad, pursuing M.Tech Under JNTU Kakinada His areas of interest are Automation of Industrial process, Tuning of Controllers, Signal Processing and Designing of Digital
Filters
Adari Satya Srinivasa Rao received his M Tech. degree from Andhra University, Vishakapatnam in 2004 and he is a PhD student in
Andhra University. He is having 15 years of teaching experience in various engineering colleges. Presently, he is
working as Professor, Department of ECE, Aditya Institute of Technology and Management,Tekkali. His interests include signal processing,adaptive antenna arrays and communication systems.
First Other:P.V.Muralidhaar obtained
M. Tech from JNTU, Hyderabad, pursuing PhD form Berhampur University. He is having an experience more than 10 years and also having more number of both national and international journals, conferences. His area of interest is signal processing,presently working with AITAM , Tekkali, Srikakulam, A.P