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7/21/2019 Romanyuk YuA Osnovy Tsifrovoi Obrabotki Signalov Chast 1 Svoistva i Preobrazovaniya Diskretnyh Signalov
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..
3-
1
- -
( )
- ( )
L 2005
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I C O
681.3.06P69 :
()
, , () ..
..69 . 3- .
4.1. : . - .: , 2005. - 332 .
ISBN 5-7417-0144-2 (. 1)
- . .
,
. , .
, , .
, . 681.3.06
( 3- )
1.
.. . .. 16.12.2005. 60 X 84 Vie- .
. . . . 20,75. . -. . 20,0. 700 . -458.
- ( ) - 141700, ., . , ., 9
ISBN 5-7417-0144-2 (. 1) .., 2005ISBN 5-7417-0145-0 - ( ), 2005
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() - , - .
,
. ,
. . - , . ,
. ,
.
(6- ) (9-, 10- ) -
. [6]-[10].
, ,
. : ;
; ; ;
3
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. - - .
. 1. . 2.
. 3. . .
.
. .
.
.
. , . , .
. , (1.10.15) 15-
10- 1. , , .
. . .
, ,
, .
, , - .
4
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A 1.
1.1.
, . , .
, *(/),
/(, ), , . .
x{t).
- .*(/),
, (. 1.1.1).
( \ ^ *('>/
/ \/ t ~ \f k \ i t()=A-( -v(/) (0 = / - )
/
* 1
y'i/
/
r i 1 V /
)
V \ t
.
5
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(/)
*(/) y{t\
, At (. 1.1.1). - (. 1.1.16).
:(:)
(. 1.1.2), . . , - mq, q -
, a w - ,
-0, 1, 2,..., -1, -2", - .
4
*1-
\ ''
*- kV . 1.1.2
, .
,
.
( ) X ( f )
, -
, /].
, , . . , .
, .
x(t) , *(/) = 0 /< 0.
. .
6
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1.2.
, , S.
, . . , . , ,
d(\ , ) , .
, , .
. d(\, )
, :
) d(, ) > 0 d(, ) = 0, = ;
) d{x ,y ) = d ( , ) ();
) d(, z ) < d(, y) + d(y , z ) ( ).
S d
. , , . .
, [,],
( 1.2.1)
( 1.2.2)
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-
* = ( * - 1 * 1 *) = ( -, )) :
4 x . y ) = Z [ * . ^ 3 ( L2-7)/= 0
2: 1+ 0 = 0 +1 = 1, 0 + 0 = 1+1 =
. (1.2.7) .
, , . [13].
.
,, 2, , ,
, = 0
= ! , = 0.
N
S,
:
=0
S N-
. {}
S , S
. N { }
. .
d 3(x, ) = max |x( k) - y (k) |. (1.2.6)
8
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.1. .
2.
(, ), ,
, . :
(X. ) = ( , ) ;
(, + )= (, )+ (, z); (1.2.9)
(, ) = (, ), (, ) = (, );
(, ) > ,
(, ) = 0 , = 0.
.3. .
||||= V (X, ) > 0. (1.2.10)
0 , :
(*> ) - (*> ) .2.11)
V *) (> ) II! IIII . ,
, . . (, ) = 0.
|cos0| < 1,
|(, )|
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4 .= % * . (1.2.14)
(>)= V 11 (1-2.15)[, / * .
|| 1 = 7 ^ ) = 1 , 0-2.16)
|| |2= (, > = - -2-17)
N 1 = J I h r (i-2^ )V =
(1.2.17) . (1.2.13)
{ }, -
. ,
{} {} {} ,
(X, ) = ( . * * ) = (1.2.19) = 0 = 0 = 0
( pw ),
:
S > A = Z X ( 1-2-20) = 0 = 0
.
:
I w h J l k - b . r (1-2-21)V = 0
, , ,
. . -
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, , , , , . 1.2.1. N
, /7= 1, 2, N.
N
{ },
.V
= Z = z = z (*> >. . . )-
=0 = 0 =0 =0
1.3.
L2
S
*(/), , .
, jt(f)
J|*(0|2dt< 0 0 .
, ,
*(/) - 1.
11
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L 2 .
.
L2 ,
d2(xt )
y{t) (/).
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X + = W O) + (0), 41 ) + (1), * (* ) + (\ ...],
= [(0), ax (l) , a(\ ...].
,
12,
(1.2.13) - (1.2.16). (;)
. * (0 L 2,
( )
12. L 2 12
,
N
x = [jc(0), (1), jc(2), (\ x (N -\ ) ]
12,
12. , 12 N
\|/. N
.
12
{\|/}
00
(1.3.8)
(1.3.10)
(1.3.9)
L 2 12 (1.2.18).
(1.3.11)
13
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(Y. V ) =
0,
2
m = n,
(1.3.12)
(1.3.13)
m^n.
1.3.1. 12
() (. . 1.7):
,
. , ,
(1.3.16) (1.3.17) (), 3. ,
N. () {)-
( N) . N- . , :
N ( , N , ). N.
, = 0,1, N \,. .
12.
() :
(1.3.15)
(1.3.16)
(1.3.17)
14
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1.4. .
*(/), ,
,
* (') = ('), (1.4.1)
{
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.
, (1.4.5).
|(/)}
. 1.4.1.
. 1.4.1.
. -
{(/)}, .
. 1.4.2.
/ t u T
. 1.4.2.
%(t)
hn(t)= ( -/ ). t = :
jx (T )h n(T -x )d x =|()()^ = , =1, 2,
16
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1.5. .
(1.4.1) , , . . .
1)
. ,
2) , 2(N )= 0. ?
(1.5.1) .
, .
, ,
, (1.5.2),
{ (0}- ,
N- (1.4.5)
* (/) N-
{ (0}- ,
(1.5.1) , , (1.5.2),
2{N). , N
.
,
2
(1.5.1)
(1.5.2)
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.
= ^ -5-3)
a = \x{t)V(t)dt. (1.5.4)
. (1.5.1)
( ) = 1 (/ )] [* ( - I * ; : (') ]}
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1.5.1.
. -N
= ^ , * I
II* - II2=
. , ,
, ,2-, , . 1.5.1.
, I , , 2-.
X , 2 . ,
. ,
:
-
1.6. L2
: .
. .
19
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J *( , ( =
,
/ sin 2/1 (/ :/) 1* ( = / ; - , , (1.6.1)
2nfe(t -k A t) 2/
At, (~,):
, * 1 ,| || 2 ^ 1 , , (1.6.2) ! =/ = 2 ^ = /
(. . 2.2). , ,
,
t = kAt:
(1.6.3,2nfe( t -k b t )
/ V" . s m 2 n f (t -k A t )
x ( t )= X * (* ')~ . ,- , (1-6.4)* = _ 2nfe(t -k A t)
. , .
- 00
J k(t) e -J2' f , dt= 2/ (f)e x p (- j2 n fk A t) (1.6.5)
- kAt.
2/ (/ )
(. 1.6.1). t - kAt
, 1.
20
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/= (//)/, /= 1, 2,
.
sin 2 f ( t ~ A t )
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.
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00
cwal (w,0 ) , (1.6.12)n=0
.n | ,t(Q)wal(w, 0 ) c/0. (1.6.13)0
x(0)
N= 2V v - ,
[25].
, wal(, 0 ) [0 ,1) .
wal(, 0).
, wal (, 0) ( -
), ( - ) ,
0 = 1/2. , -,
0 = 1/2 , -,
. - . :
ni= 0, .
, , wal(5, 0). . . - ,
0 = 1/2.
= (101). 2- 1,
0 = 1/8, 3/8, 5/8, 7/8. wal(5, 0) . 1.6.2.
wal(0, 0 ) = 1,
wal(>7, 0) = 1 .
V1
-^ rij2', nj =0, ni=1, =(wv_j... , 0)./= 0
. = 1,
23
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1/8 1/4 3/8 1/2 5/8/ 3/4 7/8 1
+1 1 1 1 1
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p = (p v_\
0)
Pi= , 0 ,
2. -
[2V_I, 2V-1).
. 1.6.4. - , .
)
. 1.6.4. :
- ; - [0, 1).
. , , 2:
wal(w, 0 )wal(w , 0 ) = wal(/7 /, 0) . (1.6.16 ) had( /7,0)
.
(
). 1.6.1.
25
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1.6.1 h h
. . . . . .
0 000 0 000 01 001 001 1 100 42 010 011 3 110 63 011 010 2 010 24 100 110 6 011 3
5 101 111 7 111 7
6 110 101 5 101 57 111 100 4 001 1
0
1.
-:
^ (9 )= cwal(, 0), (1.6.17)*
1
= J x(9)wai(, eye.
N =2V, v - , SN(Q) -
1/N, ,
(0):
) = 1 ^ ( 9 ) , (1.6.18)*=
3ct = NJ (0)^0 ,
fl, k / N < Q < ( k + l )/ N , ) = \
{0, 0.-
:
26
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e \ N ) = J[x (0)-5 W(0)]2^ -
[7]
N - 2 V\
'(0 ) - .
:wal w(0, ) = wal(, 0)wal(/w, ). (1.6.20)
, 0 ;
0 [0,1), [0,1), . 1.6.5. ,
. .
. 1 . 1
. 1.6.5.
27
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1.7. 1,
, N.
TV-
.
iV- N,. .
N x N .
, :
-1 0 |
1
2 I1(, *)=
0 1 2
1 0 0 0
0 1 0 0
0 0 1 0
1
1 (/?, ) = (1.7.1)1 - ,
[ * .
, 1:
g 1
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,
1". (1.6.8) (1.7.3),
t - A t , t -
. .1. .
2. || *|| .
3. N .4. :
(1.7.5) (1.7.6) (), 3.
5. :
I= ( + w )modJV, . . N.
6. :
7. - WNnk WNnk
N , ,
( N - n ) N N ,
N >() - 2nrtk /N .
- ,
.(1.7.4)
(1.7.5)=
(1.7.6)
(1.7.7)
(1.7.8)
w~nk w {N~n)kr v N - VV N
29
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.8. N
, . N
N ( - nn = N 12) (^" 0 "
- . N
( = 0 )
(N -\ )/2 - .
9. (. 1.7.1).
, ,
2nn/N .
N W k
2 , . . N .
-
* - 1
1 1**0k - N - l
(N-n)Jt
N - .
. 1.7.1
n/N W k
( N - n ) / N - WfjN~n)k
(1.6.8) .
10. :
An k+ mq)N (1.7.9)
-
. 1.6 0,
30
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[0,1). -
* + \ =0, 1, 2, N - I ; N = 2\
_N N
0
, . . wal(w, ) pal (/?, ).
N = 2V
W^. /-
/- ( ) . N= 8
. 1.7.2.
1-0-1.
-
-
-
= = = 1:-
-
d = G
_______T b R e
W8=
1 1 1-1-1-1-1
-1-1-1 1 1
1 _1_1 1 1-1-1
-1-111 -1-1 1
~1 -1 1-1 1 1-1
1-11 -1-1 1-1 1
1-1 1-1 1-1 1-1
-waico,*)
-*wal(l*)
-*wal(2, k)
-waK3. k)
4*wal(4.)
-wal^A)
-wal(6yk)
-*wal7,A:)
J L
1/4 3/4- L .11/2
a) 6)
. 1.7.2. , , N= 8: -; -
\ , . .
w ww ; = i , (1.7.10)
I - ,
. 1, ,
. -
-.
31
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, .
N =
2:
,1 1
1 -1, HL HL
HL -H L(1.7.11)
, (. 1.7.3).
hadft)
had&O)
had(2,0)
had(3.G)
bad(4,0)
had&O)
had(6,0)
had(7,G)
" U b i F b F
= t = F = b F = b
I___L.1/4
___I___t. l. ,.
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W- :
had(A, ) =had( h N , ) = had (, N).
{har(r, m, 0)} , Q = t/T -
t [, ), 1910
L 2[0, 1). . \.1
.
1 0
.)
1II-1
S'T1t 1111 } 1II
1U \'ir
=
1 1
1
S
1
V2
1
-V2
1
-7 2
-1
0
-1
0
-1
0
-1
0
0 0 0 0 V2 V2 - -V2
2 - 2 0 0 0 0 0 0
0 0 2 - 2 0 0 0 0
0 0 0 0 2 - 2 0 0
0 0 0 0 0 0 2 -2
)
. 1.7.4. N = $:
- ; -
, [29]:
har(0,0,0) = 1, 0 [0 ,1);
har(r, w, 0) =
m- 1 m -1/2 < 0 < -
v 2r
m -1 /2 m---------- < 0 < ;2 r 2r
0, 0 e [0 ,1),
'(1.7.14)
0 < r< log2N 1< m < 2r
. 1.7.46.
3 .
33
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,,, /?= log2N.
har(0,1, 0)
. - . , , . - (, ) -
, -. - . 1.14.
, . 1.1-1.7
1. , .
2. , .
3. .4. (1.14), (1.16).5. (1.17).
6. L 2(T). .
^ ). .7
. ?
8. { > t s T I
.
9. - |(, )| < ||||-||||,
, :
34
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10. :
= 1 | (/ ) (/ - ) .'
- |(, )| < ||||*||||,
,
|/( )|
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18. {; /?= 1 ,2 , . . . } -
2( ). 2( ) -
:
19. . .
( - 0 0 , ).
20. .21. . .
.22. -.23. .
- .24. ().
.25. 8x8
.26. ,
.
27. jc(0) = 0, 0 [0,1) . -.
28. jc(/)
2. y(t)
. y(t),
. (1.1), (1.2), (1.3).
29. : ) ; ) , ) .
30. 16 .31. , 16
.
36
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1.8.
1.8.1. .
:
'2d t< . (1.8.1)J M 2, x(t)- ( ),
, , , .
jc(f) - .
[16], :
) x(t) /(,-);
) jc(r) 0,- );
) jc(/) ,
.
: (/)-
, X ( f )
(/)
X ( f ) = l.i.m. \x(t)e~J2nfldl, (1.8.2)->
l.i.m. (limit in the mean):
2
lim J X ( f ) - j x ( t ) e - J2nf'dl d f = 0. (1.8.3)* 00 - T
, X ( f) -
, x ( t )
X ( f )
w
*( 0 = l.i.m. \ X ( f ) e i2' f 'd f (1.8.4)
:
37
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f|* (/)|2A = \\X( f )\2df (1.8.5)- -
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^(co) = R e [ A r ( c o ) ] = J* x(/) cos /dt^-00
00
( co ) = I m [ ^ ( c o ) ] = J x ( / ) s i n c o / < # ,-00
\X(a)\= ^ 2() + 2()
- - (),
, 5(co)() = -arctg -
()
- () .
2) A"(co). (
)
Z ( co ) = * * ( - cd ) .
, () |^()|-
, i?(co) () - .
*(/) - ,
Jf(co) = (-) = () =|()|,
. .
.3) . x{t)
() = ] '()ejal da= | JT(cd) | da=2n 2
1 ^= - j \ X (co)| COS [ f + ( )] rfco.
= 0 ^ (0 ) = J (/ ) - .-
1 00 /= 0 jc(0) = JX.() .
2 4) .
eJ{* ,
.
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\
- :
x(t) = [ " '] = cos / = + eia' ).
, - (. 1.8.1).
Rc , - -
, . -cos- ,
"+() > ,
^() )= 2\\X{ f )\2df. (1.8.13)
-a> 71 * (/ )- ( ),
,
V , (/ ) = | * (/ ) f = X { f ) - X \ f ) (1.8.14)
40
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. . /.
4)
] , (0 2(0 1 dt= ] x2(t) i - ] ejvl dv d t:
-y(co-v)rdt dv = = W V)
= - ) x i (v)Z 2(- v)rfv = Jf, () Jf2(),
(1.8.15)
. e. .5) . :
= ( 0 2(0 = J* l (T) * 2 ( f - T) rfT -00
:00 00
- ia,dt =
(1.8.16)
( )= | J, (x )x 2( f -T ) ^ T
00 00
1*1 ( ) | 2 dx.
$ = t - ,
( )= Jjc,(x)e^ Vx |jc2 (9) ~1,V S = X, (>)2(), (1.8.17)00 00
. . . .
, , * (/ )- ,
h ( t ) - (
-) jc(f) (), h(t)).
:
y ( t )= j x (T )h ( t - T )d t = x ( t )h ( t )
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, .
6) .
(/) :00
)= Jx(0 x{t + x)dt. (1.8.19)00
, .
. ( )- ,
.
(1.8.12), ,
jc (f ) Rx(t)
\|/() = | ()|2 :
Rx() ,(). (1.8.20)
1.8.2.
().
y(t) , . , -
,
. , .
1. ( ).2. ,
.3. ,
. 8-.
:
^)
*(/) ;
42
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# ( )
;
() = ( ) ()
;
{1)
() .
, , , ( ) ,
, t - q o t= . ,
, , , . . ().
, , ( ). :
- ;
- .
, , , .
.
1.8.3.
(. 1,8.2).
Jf(a>) = [ 1= -* \ % = -/2 '
t /2
tor2
( .8 .2 )
43
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(. 1.8.26).
)
- / 2 /2 t
)
. 1.8.2. - , - , -
|"()|
4/ . ,
-
2
. 1.8.3
(2 + 1)
-1, 2, 3,
. (. 1.8.2) .
. 1.8.3 ( ) = 1 = 1 .
. 1.8.3, . 1.8.36. .
44
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, /2,
X ( f ) = ExSm e~Jnf'/
e~jnfx ,
. 1.8.3.
1
) 21
45
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(. 1.8.5)
(0
, -( /)2,
(2/)5(/ + /2) (2/)8(/-/2).
,
, . . 1.8.56.
(1.8.22)
(. 1.8.4). .
- 6) t l A X C O ) '
2F.T/7
/ 5/ w- / 2 0 /2 t
. 1.8.5
-(/)2(> )+ ( /)('2 + e 'J2) = (/)2(),
(1.8.23)
46
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. )
fexp(-aO, t >, 1
[, t<
- - .
mc(t )
. 1.8.6
, a > 0 (. 1.8.6).
X ( f ) = \~'~ i2*f'dt=-----------------------1---------- |+/2' ' 1 - ( + /2/) +j l n f (1.8.24)
X { f ) = |(/)|[(/)],
( )
\(\ = -
y]a2+(2nf)2
( )
(/) = -arctg(2n//a),
. 1.8.66.
(1.8.25)
(1.8.26)
47
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X ( f )
Re [.Y(/ )] Im [Z (/ )] ,
. 1.8.6.
. | ()|
Re[J f(/)] , (/ )
1[(/ )] - .
x(t)= ',
. 1.8.7.
:,(/) :
x(t) = x ,(t) + x](-t) .
() = * , ( ) +* , () =
2= -------------1--------------;-----( + j) ( -j) +
(1.8.27) . 1.8.76.
. 1.8.7
- :
x {t ) = e m l (1.8.28)
(. 1.8.8). , ,
[~2(/2)2] = 0,1.
2 ^ - In 0,1 3,035
48
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X(a>)= \ e ^ ' 1+jM)dt .
. 1.8.8. a - , -
,
.
pV +ja t= V +j(at = (/+-=^)2+ -^ 7 ,4p 4p 2p 4p
A'(co) = e /4p!) j e dt.
4 = / dt = d^/
(>) = -
- )2 /42
i (1.8.29)
. . (. 1.8.8). .
*(/),
, = ,
49
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/2 /2
^() = J (/) dt = J x(t) dt= const = .-/2 -/2
, eJb}xl2 = 1.
, , , , .
, 7/2
/2
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x(t )
. , .
1.8.1 .
/,
1.8.2 0,9 5,1/ 0,81 / 0,73
1.8.4 0,541 5,3/ 0,84/ 0,46
1.8.5 0,596 4,57/ 0,73/ 0,43
1.8.6 1,15/ 6,16 0,98 1,13
1.8.8 0,83/(3 1,64(3 0,26 0,22
:
-/ > , (1.8.30)
- , /.
/,
.
00\ { t - Q 2x \t )d t
J x\t)dt-
00 / 00
t0= j t x 2(t)dt/ j x 2(t)dt - (- / -
), ^ - .
,
()2= - ^ J^-cO o)2!^ )!2^ ^ ^ J|A"(to)|2dc,
0= -!- | | ^ .2 J
51
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(1.8.31)
. . .
=1/2 .
. .
x(t ) t , 1//,
^ ( )- , 1/, . .
. , .
, , , . - , .
- . [5-7]. .
- , , - , . ,
, - , .
,
:
1.8.4. -
(1.8.32)
/0+
| 8 (t - t0)dt = \ > 0. (1.8.33)
5(/-/0) = 8(/0-0 , (1.8.34)
52
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} 5( t - t a ) d t = j 5( t - t 0)dt = , e> 0. (1.8.35)/0 -e
, -
(-, 0-
j 5 ( T - / 0 ) d T = y ( / - f 0 ), (1.8.36)
(t-/0) - :
0 t < tQ,= = ^0j (1.8.37)
1 t > tQ.
, -. :
= (1.8.38)
) )
^
~ 0
' / ()] ' '
. 1.8.9. --, -
(. 1.8.10), , .
I )
/-/2 2
. 1.8.10. , -,
:
(/) = 5(/);-+0
53
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1 t2lim exp(~ ) = 5(?);
/2T 2x
. n tsin
lim-----^ = 5(0-*->0 Tit
() . , - , ,
.
, ,
/0 x(t)
J x (t )5 ( t - t0)dt =x(t0)9 a < t0 b.
Jt(/) t = t0 ( ),
j x ( t )5( t - t 0)dt = ( l/ 2)[(/0+) + x(t0.) ], a < t 0 < b , (1.8.40)
a
(/0+) x(t0_) - (/) .
(1.8.39) ,
8(/ -/0)
(. 1.8.10), . - ,
:
\x {t )b{t -d )d t = x{a\ (1.8.41)
(/) 8(/-)= x ( t - a ) , (1.8.42)
(0 *8(^ -) = ()-8 (/-), (1.8.43)
S [( f- f0)/a] = |a|8(f-f0) 5(at- /0) = 7 8(/ - ). (1.8.44)
54
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(1.8.41) ,
00
J 5(t)e- j2nfdt = e=1, (1.8.45)
. . - . ( ):
00
6(0= \e n%f'd f (1.8.46)-
, , 1
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+ (/ = 0_) -
(/ = 0+). , t= 0
5 '(0 -1 It .
- :
J x ( t )V n)( t - t 0)dt = ( - l ) " x M ( t0). (1.8.52) () (! ) ( )
t = t,
j x ( t ) P \ t - t 0)d t = ^ [ jS '> (t0. ) + X**\t0_) ]. (1-8-53)-
- (1.8.52) |
I
= ()" ~/' (1.8.54)
, t0 =0, 8()(0 ^ 0 ' )" (1-8-55)
1.8.5.
|
(1.8.49), -!
(1.8.56)
A sm ln fy = - e ' W ) [ 5 ( / - / 0) - 5 (/ + /0)].
2 2j ,
/0
J 8(n)( t - t 0)e- ja dt =
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- !2, / 0.
= 2/ (1.8.56)
Acos 0/= ( ^ 0' + (0' ) [8( - 0) + 8( + 0)],
(1.8.57)
Asin 0/= ( '/- [8( - 0) - 8( + 0)].V j
(/) (1.8.36) - (1.8.38).
y(t)= e~at-(/), > 0
, , . .00
|| -/ -(0|
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. 1.8.10.
+1, t >0,sgn/ = ,6 1 -1, /
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1.8.2.
u(t) = J () - . : /, -
/:
( = J x(x)dx = ~ y(t -)].* t- L
(1.8.60) ,
(/) = - f x(x) dx U(v>) = (1 - eJmT) = ( ) ^ "/2 77 2
(1.8.61)
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sin(co - co0) /2 sin(co + co0) /2 T- (1.8.62)
( - co0)t/2 ( + co0)t/2
= 4/0 ( ) . 1.8.12
(-0) -( + 0)
|AXco)|.
. 1.8.12.
, , , ,
\()\ > 0 :
. , , .
1.8.4. . N (. 1.8.13).
] . (N-1)T
t
. 1.8.13
60
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^ ( ) .
N
* ( ) = ()[1 ++ e~J"2T+.. . +e iNT/2 - jcaNT12 -i
=x ,() - j - p s r =x , =
= X - " -] ),2)S*n /21 sin 77 2
, = 2/ NT, m -, () = 0.
,( (. 1.9.2).
.
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2/32/ 2/ i!X(u>6)
2/4 2/ 2 -/. 1.8.14. :
- , -
. .
______________________________________________ 1.8. 2
*(/) X ( f )
x{at )- -X\- \
X ( f + f 0)
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3 df 2 / ^ ( / )a t
4 1 < /)
^ ~ j2 n J f
5M - U o * - ^
i j2 n f 2
6/rt f l . ' > 0 1 5 ( / )ct(/) =
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13 * * 2 1 2 + ( 2 / )
14 - y'Sgn/nt
15 t e~al a (t ) 0
( + j2 n f)
162n
17 i [ 8 (/ + /0) - 5 ( / - / 0)] 7 s in 2 / / 0
18 x( / )cos2 /0/ o i [ l ( / + / 0) + I ( / - / 0)]
19 1 * . 8 ( / - ]k--co * n = o \ * ) V * /
20 Z * ( / - 7 ) = Z * ( W > y2" mk= -co 1 =oo \ * J k=-00
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1.9.
x(t ) = e Jaiot -
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- , .
x ( t )= J 7'' 2 { ( -). (1.9.5) = -
, -
-. 8-
, = 2/.
, .
,
^() ,
.
. (1.9.6)
. (0:
/2
- / 2
- :
= - J | * ( 0 | = - J x ( t )- x * W t = * - / - > * _/->-/2 1 -/2
X I ,- J e ^ ' - e - ^ d t = X 2 (1.9.6)00 00 1 /2 00
(0, -77 2 /772.
() = J xT(t )e- ja 'dt
= ).
66
(1.9.7)
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-
= - ) .= -
(1.9.8)
. - -
00 . 1 00
= - * -
(1.9.9)
1 - nt 1 = J 5(/ - /) 7 dt= .
-/2 ^
-
1 _ 00
- (0 = 8(/-) = 8(-) =- - * = 00* = -
= 8((- to) = ().
D^ (0 ^ () 00 00
^ 5(f - &)
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, - *(/)
= z 5( t - k T ) = -
jcT(f) -
- D T(t).
-
^(^ ^ ^ () 5(-) =
. = (1.9.11)
= ( ) 5( - ),= -00
= 2/, a . () - ,
.
, , . (1.9.11)
sin*- () = -^ -5 ( - ) (1.9.12) = - 2
. 1.9.2 = 3.
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. 1.81.9
-20. (1-20) 1.8.2. :
I. /= at .
- / .
4. / .
5. y(t) x(t ) a(t )
.6. (0 = lim e~at t> 0,
>0
0
. / = 0.
7. sgn(0 = o ( t ) -< j ( - t ) .
& .
910. , .
II. ,
=*(/) +*(-/).
15-16. /.
21. N ,
,
NT.
. .
22.
00
12. x(t ) = e ata(t),
69
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a) E
) X
i_ T
J D____ C LT IT
1 I i T 21
23.
x(/) = sin2it/0f; -
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) Re , =1 = ,
ImC = .[ \
26. -2 (
).
_*>
. .:
ReC =2 * /77 sin
= -
2
27.
/ =1
2/.2 / , (/-: .
28.
sm2nf ( { ( t - kAt ) 1
At =-2/.2n f(1(t - kA t) (-,).
. -
* (0 , (/),
.29. 2N+ 1
-, . , .
. (2N + 1)
( 2 ' +] \
IV )S(2 N + 1) = ^(1- )
, - , q- .
71
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:
, ( / ) =sin 7i/(2W+ 1)
/
j
in in
- NT - I t \ > N T
30. x(t ) X(/),
. . X ( f ) = 0 , , [ - / , /]
,
/ = 1/2/,,
* (0 = * (0 D{t ) = :(0 AtZ 8 (- =
= / x(kAt)d(t - kAt).
**-00
X ( f).
. .
31. ,
\ At
.
X h(t -kAt) .* -
32. ,
( - D* - 5 S* = 00 * -00
/ L 2
12
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33. 31 32, :
) { ) x { f ~ .- * = - V/
34* ,
(* ("\ x) = (y ,Z ) , Y ( f ) = ( j l n f ) " - X ( f) .
35t :
* > ) [ * $ > ] ( " ) *36. , ,
1 -2*1/1----- - ,
. 9 . . .
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1.10.
, , :
( 0 = - - ] ( < ) ' ,
. . ((). ,
x(t) =
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(1.10.2)p- j c o
, :
( / ) ( ) .
jc(/) , ( ) -
. -, = 0.
(1.10.2)
(p - , + )
. 1,10.1). -
{(3+jI
*(/) = - ! _ 4 ( ) ' dp = Y j Res-J 2k abca * " =A (1.10.3) -( . : .
75
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1.10.1. x ( t ) = exp(p0t) a (t \ 0=(30+j 0 -
. (/)
x(t)= 0 /< 0. (1.10.1)
( ) = je~ip~Po) dt = -r(P~P ) ' t -CO
/= 0P - P o
Re p= P > P0 t >.
ePoa(t) . -
= 0.
1
(10
^ ( / ) p+Pi
= -, (Pj > 0).
1.10.2. x(t)= ~ 2/cosco2/a(/) 2>0.
/
(1 1 >\ 1 &
i
/
1
\ ^ ' ( ej,,h' + ^ ' ) ' dt 0
\
1 , 2= - 2+ j a 2. - 2 ~
( )
. 1.10.3 = 2= - 2 +; 'w 2 = ' = - 2 -;'2.
. 1.10.3.
1.10.1.
( ) ,
. (
) ( ( ) ) ]
,
76
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X(p) = O n P + a ^ P + " + *
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= ) (/ > + 2)]..2 = - 4 ^(+1)
1
~-
= -1,
* = [ ( + 1)3]=., = + 2
= 1.1
1 2 1 1/>+ 1 + 2 ( + 1)2 ( + 1)3 ( + 1)3(/> + 2)
^ | ( + 1)2( + 2 ) - ( + 1) + ^ ( + 1)( + 2 ) + ( + 2)
( + 1)3( + 2)
,
0 } =1.
(22+ 1 2) - 3 2+2 2-0 2=-1.
( ) = 1 1 , 1 ______1 _(/> + 1)3(/> + 2) ( p + l f ( + 1)2 + 1 + 2
,
. x(t) ( ) .
t x ( t ) o - ^ - , (1.10.8dp
(1.10.1). ,
te~al - ---- = ---- ? , (1.10.9dp + ( + )
\( . 0. 0
( + ) " 1'
,
*(/) = ^ t 2e4 - te~l + ' ( - e~2t, t> 0. npi
, . !
/=
78
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-p lt o ii x .
, 1,10.2.
^
(!
(
w
9 iit)
vit):an-
* i'(,)n 1 Lu ir
a rr.
DOM.
*
- V0{t)
. 1.10.4
'('> ^ #0(
:
v(/)-v(l,a t
V(0 = R i ( t) \ i ( t) ~ C - ~ - v(/) - v(0) =
v (t ) = L ~ ^ - / ( / ) - 1(0) = j - J v ( t ) c / t ;
%{#) /(f) ; i0(t) v(t).
V(p ) = RI (p ), (1.10.11)
v(t)V(p) /(/)/(/?) - .
, .
79
1 V
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? - ^ ( ). (1..12)at
:
Ji ^ l e-pdt = x (t )e -p'\*+p\ x (t )e^d t= ( ) - (0). 0
, :
I ( p ) = CpV (p ) -Cv (0 ) (1.10.13)
F (p ) = -U (/ > )+ , (1.10.14)
V ( p) = p L I ( p ) - L i ( 0) (1.10.15)
) = - \ - ( )+ - (1.10.16)pL
(1.10.14) ,
Z (p ) = \l ,
v(0) /,
. , (1.10.16) ,
Z (p ) - pL /(0)/,
. . 1.10.5.
V(p^Rlip))
)
)
vw - ^-) + ^ v ( p ) s r
-------
) ' - 1) + ' L _ 0 _ 1
. 1.10.5
80
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(-)
, |^ . .
{ 1.10.5. , & (. 10.6). v(t)
I:
*{0)p
V'(p)
[fc) -ihM - V a ) 6 ). 1.10.6.
(. 1.10.65) - :
l s V(p)_
RV ( p ) -
v(0).
, /(0 .
[ V(p),
( ) = + .
p ip + d /R C )) '
Sfr* : { -0 -~ \ ! RC. -
It = 1R 2=v (0 ) - IR .
(1*10.6) (1.10.7),
v(/) = IR+ (v(0) - IR)e' t/RC, t >0.
. 1.10..
(1.10.17)
. 1.10.6. , . 1.10.6
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1.10.6. ,
/(/) (. 1.10.7). v(/).
/(/) /)L l
) V{p)r\ vL
. 1.10.7. () (
/(/) = /(/), 1()= / /*
:
- + + R pL t
( ) = IL
P\-R+TL+PCJ {-RP + X+ P2LC)R
- ( 1 ~ 0 = , +2/? + 0) LC 2L
V(p ) :
12= - + yja2-(ol = - jto, to = /2- 2
( ) = I *\L
{ P - P S K P - P i )
: . =_ _ _ oil /021
2 2 -27 2 (1.10.6) (1.10.7)
v(/) = .''+ ,= - ~>') = 1 2 2V 7
sin /.
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w 0,
v(/) = I*/~sin 0t= 1~sin 0 (1.10.18)
- .
. 1.10.8.
> 0
,
1.10.1
, () + 2(/) ( ) + 2{)
x ( t - T ) u ( t - T ) < * X ( p ) e pT, > 0
w fdX(p )
t x ( t ) < * -----dp
ie e-wx ( t ) ^ X ( p + )
x ( a t ) o - X , > 0 LaJ
* - ^ ( ) - ( 0)at
) 1
Jx, ( ) 2(t -) dzX, ( ) 2() 0
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______________________________________ 1.10.!
(0 X ( p )
8(0 1
IItT 1
p
-/ 1
p +a
sin co010
P 2+u>l
C O S CD0t P
2 2p + 0
e~a'cos co01 p + a
{p + a f + ^ l
. 1.10
1. 0 .
x(t), t >0
a) \ - e a' a , Re [p ]>0 ,p (p +a)
6)e+a,sin(o0/ 0 , R e [ p ] > a ,
( p -a) +a>0
) e cos (0/+ / 4 ) P 0 R e [p ]> a,V 2[ (p + a )2+(o2]
r)
- a / (P + a ) 2 - 0 r 1te cosoi0tr --------- :----- 4-, Re [p] > -a,[( p + a ) +co0J
)I 1 1 < f < 2 1< --p--------- =, /?,[0, -
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* 0
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3. (1
) h(t)
( )
( )= \h{t)e"'dt.
Re [p] > (3,,
, - , h(t).
. , , ,
, .
)h[t)
~'((t)
()1
+
R e [ P ] > - a
) h{t)= ~2cos 2/, 2 > 0, t >0.
) h(t) = ~2sin 2/, 2 > 0, t >0.
) h(t)= sin 3/, /> 0. ) h(t)= cos 3/, t >0.
4. R, L ,
, t= 0 !
.
.5.
RL-.
6. , , L J
, /(/).
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*: RL C t= 0 linn e(t)= sin ,/. i (t )
9 -0 > .taf&^tWpaamJibHO R L
( , R, /= 0
(1) = - *, > 0. / 0)*0. -
Inrtb /7-.
( RLC- t= 0
e(/) = cosco,/. /(/)
II> 0* .
, . - ^ -.
(*\ *
I tx - t= 0 > 0 . (0 )*0 , -
'
(.
; .
* ( / ) -
\
0 / 2/
. 1.11.1
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*(/)
At ,
x(t)
(. 1.11.1).
, . . *(/ ) = 0 t x(0)g(/) + (x t -x i4 )g(/-kA/).
At- 0, i
y(t) = x(0) g ( t ) + J x'(x)g(t - x ) d x . (1.11.2)0
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t
(0= g(O)x(0 + \g\i )x ( t - t ) dx, (1.11.3)0
y{t)= x(0)g (0 + Jx'[t- x )g (x) dx, (1.11.4)0
A t ) = g ( 0 ) x ( t ) + ) g \ t - x ) x ( x ) dx. (1.11.5)0
(1.11.2) - (1.11.5)
.
(0
(. 1.11.2). At,
(/).
. 1.11.2
x(kAt)[(/ - At) - o(t - At - /)].
:
*(/ )= ^ x{kAt)- [ ( j ( t - k A t ) - o ( t - A t - /)]/.- /
At
x ( t ) At^ (kAt)b(t- At). (1.11.6)
=- (1.11.6)
8- x(kAt)At,
t = kAt (. 1.11.3). (1.11.6) ,
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-
At >0.
/>, At->dz ,
.
(1.8.32), :
x( f)= J*(T )8( f- = (0 8(0- (1.11.7)
.
h(t). (1.11.7)
-:
= t :()
h(t) = 8(t). ,
. , .
h(t)
5(/-) (-), At^ x(kAt)h(t-kAt) y(t).* = -00 * = -00
At> 0,
00
y ( t ) = ^x (x )h ( t -x )dx = x ( t )h{t\ ( 1.11.8)
.
. h(t) =0 t
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, ,
Z (p\ t= 0
*(/) ( ) . , ,
i ( t ) o I ( p ) = X ( p )/ Z ( p )
: ( )
l/Z(p) . *(/) = 5(/) 1,
( )
, . ( 1 / , (1.11.9)
. . .(/)
.
// ( /)= | ( ) /- )* / . (1 .11 .10)
1.11.1. R L /= 0
x{t)= Ee~at t> 0.
1 -*/ . (/) = 1 (1.11.10)
L
Hf) = E \ e ' " e L dx =
R v r , ( R \I- 0 -1 _
dZ= L [a - (R/L )\ e
V J, t>0 .
>0,
* > - !( _R t \
1- 1 , /> 0.
&- Ea{t).
1.11.2. , , . 1.11.4 .
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, . M t),)
dt[
J
v(0)
X(p) 1 (/7)-
k K n
. 1.11.4
( ) = ~
, , ( ) h(t)= (/),
. 1.11.4 . (1.11.8)
x(t)\I i t
(/) = Jx(t )h{t - )dx -Jx(x)a(/ - x)dx= Jx(x)dx.o o o
y(t ) = Jx(T)rfx+^(0),0
. 1.11.3. - t -0
/(/) = ~
v(f) .
:
V(p ) = 1() Z {p )= 1() R l t ) .R + (l/pC )
(),) \1 .Up) P K U S C )
, (. . 1.10)
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a) 6)
. 1.11.5. () ()
h(t), , ,
-' = /( ).
(1.11.8),
v(0= Ji(t)fc(/-T)rfx= )( - ') \ e-{'- ')IRC\d i = vC )
- ( e- "R C t > 0.
RC
[-(1/)]
. 1.11.6.
. 1.11.6. , . 1.11.5
, >0,
Aa(t):
v (t ) = A R ( l -e ' " * c ) , t >0.
AR .
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1.11.4. . 1.11.7. t= 0
x(t) ,
. 1.11.7. i(t)
t > tr
. 1.11.7
. 1.1\.1.. . c ( t ) 1/ /?,
{ R i p ) _
pL + R ( + )
= R/L. 0 2= .
-\ 2 = - 1.
(1.10.7) R
g ( t ) = l - e - p = l - e ~ L> (1.11.11)
(1.11.5)
( 0= g (0) (0 + fg ' ( t~ (" dr.
R R
g(0 ) = 0, g \ t ) = j e L g X t -x ) = j e *
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/(/) =y ( t ) l R
i (0 = j - e ' L'"* U t dx+ j - e ' ^ U . e ' a,t"') ti
* - 1r - a L
. 1.11
1. R, -
I.
)
0~
, t =
*(/) = kt.
y{t).
. 0 = RC
.2. R
,
,
*(/)
. t > 2 T
3. L,
, t=
,
. t{ < t < t2 t > t2
95
f(t)!
111i t
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4. L,
, /= 0 ~/
r ! L a = r/L.
:. \
r - a L - -te
5. , te~
:
r - a L -te EL
( r - a L f - e
2 L- r e
6. )
g (0 ,
h(t) .
) ,
, h(t) = g'(t).
) - .
7. ](/) - ] (t) .
v
I 2
I 2 3 4 5 6
) .
) 2(t) 2(t).
8. u2(t) z/,(/) = k(t + T)
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1.12.
,
]/) [/0-/ /0+ / J , /0 2/ (. 1.12.1).
x(r) = A(t)cos[2nf01+ (0]> (1.12.1)
A(t) (/) -
. (
/0 0)
. , - .
- .
, :
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Acos[2nf0/+ 0] = R e ( ^ V 2n/o'),
As\n[2n/0/+ 0] = Im(Ae j(?0ej2i:fnt).
Aem
. (1.12.1)
,
/0 ,
.
. (1.12.1)
* (0 = (0cos 2n f 0 1- (0sin 2/01. (1.12.2)
(0 = A(t)cos (/) xs(t) = A(t) sin (/) (1.12.3)
x(t), (0 - , /) -
. .
2f ti.
.
cos2;rf j
s inlxf j
. 1.12.2.
,
(0 cos 2nf01= (1 /2)[(/) cos 22f 0t - x s(/) sin 22/0/] +1 /2( t).
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2/0
()
xc(t).
xs(/).
,
, 90 .
x{t) . (1.12.3)
Ait) = 4 * ( 0 +*,2(0.*,(/) (7) = arctg .*(0
, cp(f)
.
7(0 = * + > , ( ' ) = (1-12.5)
.
(0 = |(0|-
\ | / (0 = 2 / 0/ + ( / ) ,
:
/. /. 1 dy r 1 d xs 0 = / + = / + - r -a r c tg ^ -
2 dt 2 dt , . ( 12-6)1 X X - X X
-/ +2 I+ 2
, , , (. 1.12.3).
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:(/)
(/)
x(t ) = R e[y( t)e J2nfo']. (1.12.7)
*(0
. 1.12.3
,
.
*(/ ) (1.12.1)
,
X ( f ) = } x(t)e~J2nf,dt= \X(f)\ ej *A f ) ,
I*(/)| = \x (-/)| > * (" / ) = (/)>
. e. , - (. 1.12.1).
N
= ) W )e -j2nf'dt =|(/)| ej^ f )
2/.|/>
-
. 1.12.4
f (1.12.7)
* ( = ! / - / ) + ^ - ( / + /0)]. (1-12.8)
~
* +( = / - / ) ,
* ( = | - (/ + / ) ] -
(1.12.9)
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(/ ) ((/ )
(/) . 1.12.4.
[ - / , / ].
.
.
. . , . ,
, [Sign/] =j l n t , (1.12.11)
) = [ * ] = [ X ( / ) ] + [X(/)Sign / ] =
= () + 7[(0 (1/ 0].
*(/).
, (1.12.10)
101
xA(t) =Re [*,(/) ] + 7 Im f-].
Re [*, (/ )] = *(/)>
/> ,/ < ,
(. 2. 0)
X( / ) = X( / ) + X(/ ) Sign/, ( 1.12.11)
/ > 0,
/ < 0.
( 1.12.12)
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xA(t) = x{t ) + j x r {t), (1.12.13)
xr {t) = < X r ( f ) = -y ^( /)S ign/ . (1.12.14)
(/) (1.12.12), . .
:
/ - * W
. (1.12.12) (1.12.15) = ty
, . .
,
(1.12.12) (1.12.15). (1.12.12) :
I fnt ( - jSign/)
(. 1.12.5).
90.
(1.12.15)
x(t) = 1/7>
//(/) = - /Sign/
. 1.12.5.
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, , x(t) = coslnft
(0 = sin2/7, x(t) = sinln ft xr ( t ) = - cos ln f t .
,
cos ln fnt + sin 2 f n,
( = Z sin 1- cos 2 -
.
, . . .
/0, h(t) t = - t 0
t = t0 h(t) tQ. ,
,
. , t0
.
, -/1
. , , . .
/0 > 2/.
(1.12.2) (1.12.7)
*(0 = (t) cos ln fQt - xs(t ) sin 2 rc/01=Re[y(/)eJ2/' ].
(/) ej2nfo1 (/)
/0. (t )eJ2nfot
.
xr{t) =1[ (/)'2"' ] = xc(/)sin2n/01+ xs(t) co s2 nf at=
= xc(/)cos(2ttf Qt - n / l ) - x s(t )sin (l n f t - n i l ) .
x(t) xr {t\ ,
c o s l n f t sin2rc^/,
xc(t) ,(/) .
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= , ,
, :
, 1 const , xr ( t ) = -------d x -0.
71-1
: () -
- = t, x r ( t )
. ,
:
( = ( / + / 0). (1.12.16)
( = * ( ' ) ( -/ 2 /0,
*(/) :
,(/) = (/) (2 /0 (1.12.17)
x(t)= Re [( 0 '2/0/) ]. (1.12.18) /0 . ,
(1.12.1) /0
.
\xA(t )\ = jx 1(t) + x2r ( t )
A(t ) = Jx2c( t) + x2(t).
/0 ,
( / ) . /0
|J^(/)|2 /0
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- fo) 2\XA(f i [ df . 1.12.6 -
, .
. 1.12.6.
- ; - ;-
1.12.1.
x(t) X ( f \
.
' 2X+( f ) , / > ,
;
* , ( / ) =, / < 0,
/
/ , ( 0 = 2f eJ2nftdt = !L (e J2lzf -1).
oJ Jnt
x(t) =R e[^ (0] = x 02 f sin 2/// 2nfet,
xr ( t ) = lm [^(0] = X 02f, sin2(n fat) /(nfet).
. 1.12.7 ,
. , ,
.
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0.4
0.6
. 1.12.7.
. 1.12
1. , /) x,(t ) -
,
x(t),
.
2. x(t)
x(t) = cosoy + 2cosco2/.
, , , , .
4.
x(f) = Asin2nf0t, t> 0.
3. x(t)
^(),
.
0) . .
5.
xA{t\
, aw** -
/ < / < / 2 / > 0 .
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6. ,
;(/)
xA(t) -*(/) +jx r (t ) :
7. x'A{t\ (()
- 5. () ,
() f Q= (/ +/ 2)/2.8. xr( t ) - *(/).
, xr ( t ) * (0 , . .
.9. -
, ,
.11. (0 t 0
. t= 0
.
.12. xA(t)
x'A(t).
13. , (/ )
y(t) /0
X A( f ) xA(t\ . .
(/) = (0 cos 2nf0t+ (0 sin 2 /0/,
xs(t) = (/) cos 2nf0t- x(t)sin 2nf0t.
00
^x{t)x'r (t)dt= 0,
x ) = ------5-.sin (oet
.
10. x(t)= Asin 2nf0tSignt,
r ( f ) = X A( f + f 0).
107
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14. , ,
( )= \xA{t) xA{t + -z)dt,
. ?
15. .
16. .
17. - .
18. , .
19. :
) :() = cos ln fy ; - < /< , ) (/) = - < t
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p j */4() =-------- e~J(*'
cljay
x ( t ) , ,
0 .
23. ,
*(/) (/) * (/ ),
_ (t )e > = jy (t).24. :
)/ ( * ) = --. )/ ( , ) - ^ .1+ X
25. ,
() Q()
*( ) = () + ()
.
1.13.
.
, . , . . [33].
, j ,
. cas (cosine-and-sine).
109
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. x(f ) - ,
. :
(/ )= jx(f)ca s2n ffdtr (1.13.1)-tr
cas2nft= cos2rc/Y + sin 2nft. (1.13.2)
x(t)
: x ( t )= J K(/)cas2it/ tdf, (1.13.3)
-
(/ )
X(f )\
(/) = Re X ( f ) - ImX ( f ) . (1.13.4)
(/ ) = (/ ) +
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X ( f ) = Ax sin / __infz = ^ sin /
/ /
sinit/t .cosn/ x- --------- SinH/x =
n f*
_ ^ _ s i n 2 n / T ,4_sin2n ft - ' J A T
2 / /
(1.13.4)
^ sin2rc/ . sin2/ ( / ) = -f -- J
2 / /
(1.13.8)
(/ ) .
1.13.1, .
) .it )
. 1.13.1
(/ )
Q ( f).
[(-, t > 0 , a > 0 , *(/) = )( ~ c v i i
? = J| (co)|2|
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. (1.14.13):
^ o * m n ( a^ aWA o 9b) + W y(a9b). (1.14.16)
. 0
- 0:
Wx }(a,b) = Wx(a,b -b 0). (1.14.17)
. () () :
; ( - . - ) (1-14.18)0 0 0
:
W1.
,
x(t)
, . .
-
, - . . , , ,
( ) - . , , ( )
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. ( , ..) -
, . , , .
- ?
L2(R) /.
:
(1.14.13)
x(t)
.
() - - Y|/(r).
, - ()
. ,,. ,
- | , ^.
(, \|/) = (X , ) /2,
(1.14.23) (1.14.24) (1.14.13)
(1.14.20)
(1.14.21)
(1.14.22)
|() = ( + .), (1.14.24)
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W,(a,b) = - j = } * (/ )V
- ) d t = - J 2nJ\a\
jX {o > )e Ja% J,(o>)da =
1 = f ()' {aa)d(a= ^ = f X {(o)e ^ r\ [a(.) = 0* ) -
, - /.
2
eJM , (1.14.25)
()
]=
(1.14.26)
. 1.14.7. - ,
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(1.14.30)
Wx(a, b):
=wx(2\ k 2 ") . (1.14.31)
(1.14.30) , x(t)
.
(1.14.30) ,
, . , ,
v (0 = M,oo(0 (* 1.14.8).
/oi(01 2. *
'V07(
1
0.5
7 V i b ( 0 V n ( 0 V i2 W p i n
\ Ji l .\ I
!____!
1 J 4 4 1n
v 2o(0 v 2i (0
0 1 2 3 4 * 6 7 * 9
0.5 * (0
* 6 1 2 J 4 5 6 7 9 9
. 1.14.8.
127
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, , . .
- , - . ,
- .
, , . ( ), . 2.3.
N =2V ( v - ),
:
, = 0 (. . = 1)
2V-1 = N -1 .
/(1, 2,3 ,. .. ) \|fmk(t ) , . / = v
= 0, . . \\tm 0(t )
(. 1.14.8; N=8).
. 1.14.9 .
- (. 1.14.2). -
Wx(, ).
(, )
1, - - q\
, .
-
w = 0,1, 2 ,... , v; : = 0,1, 2 , 2V~W-1.
I 2
128
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-. Wx(a,b )
(. 1.14.9 ). . 1.14.10
Wx(a,b) (, ) ;
, - ( ).
. 1.14.9.
129
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0
10 20 30 40
. 1.14.10.
, -
Wx(ayb);
Wx (, ).
(
) . (
Wx(, ))
, .
130
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A 2.
, - *(/) - - . () . ( ), . 1.7
, .
. 2.1.1.
. 2.1.1. -
2.1. .
t
* ( 0 = * ( 0 \ 0
1111kAt t-------- ^
131
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.
At.
y(t) (. 2.1.1)
(. . 1.9):
71S i n w - - - . 2
At ,
, , ( A r - A t ) T 0,
lim [M ')] = A v (0 = S ^ ' = 30
-, /, . .
D^ {t) = At S( t -kAt ) . (2.1.1)=-
.
Da,{()
x(t ) :
(/) = (0-> =
^ (2.1.2)= / x(k/\t)S(! - At),
. 2.1.2.
(2.1.2) . .
(/)
-:
k\i t
-'(') = A r ^ x ( h \ r ) S ( r - k M )
/
- -, N
1 \
/ I \I
\ / V
. 2.1.2
At I* ' > = * I
132
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(/) = J *(/) 5(/ = ^x(t)b(kAt-t)dt. (2.1.3)
. , ,
x(kAt), ()
. ,
x(kAt) ,
. (2.1.2) ; .,(
. (. 1.11):
= /
( = 0, 1, 2, ...), (2.1.4)
, a dr /,
, , . .
(/) xA(t) '(/)
:
-, At, .
(2.1.2) (2.1.5) At-x(kAt).
tk = kAt, = 0, 1, 2, 3 ......
. 2.1.2.
(2.1.4)
'(/) = / ^ x ( k A t ) - S { t - k A t ) k=-
= *(/)! ( t - k A t ) = x ( t ) D f (t ) .(2.1.5)
133
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x\(t)
(2.1.2) . .
(/),
, . - .
2.2.
(2,1.1).
- :
>*(/) = / 5(/ - At ) = At - - - -
/
2
b { t - k b ) e - j ^ d t = -
2
.
2 /
>/ ( /) = / X 8 (/- * /)= X * 'it = = -
(2.2.1)
(1.9.10)
(2.2.2)
/ = / = 1// . ,
-, .
/) ( (/)
f i t .
/-1
) ) (1)
111-\/ / / V V. 2.2.1.
134
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(0 = At 8(/ - / ) > ( / ) = X 5 ( / - n fA) (2.2.3)= - = -
. 2.2.1.
*(/).
X(/ ) - x(t).
(2.1.5) - ,
( = ( X 5 ( / - / )= J X ( J - v ) b ( y - n f J d v .= -0 0 = _*
-
* , (/ ) = Z X ( f- n f > ) = X ( f ) + ' X ( f nf i ). (2.2.4) - = I
, At
, /= A f = 1/ At.
. 2.2.2 ,
, .
J.IVJI
/
Df m* (U
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, , (, /7 = 0),
. .
1933 .. , [18].
*(/) , . .
, ,
1 (/)1 (- , ),
[ - / , f e] (. 2.3.1). *(/)
At= 1/2/.
- kAt.
2 (/ )
.
2.3.
X ( f ) -
* (1.6.1):
. 2.3.1
(2.3.1)
( * , < 1 "f , .m s in 2 n f ' 0 - )
* (*,*) A / i 2 - )z(2.3.2)
J
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(2.3.3)
* = ] ( 2/ ( f ) e J2*fkAldf.
( 2/(/) = = X ( f) M ,/
= x(kAt). (2.3.4)
: ,
[- / , /] / = 1/2/, /
* (/)
x{kAt) *(/)
:
(2.3.5) :
X ( * (0 = Yj : ( * |(? -)5(- :^ =
(2.3.6)
(2,3.6)
(2.3.5)
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Atx (kAt ) . (2.3.6)
-
2/.2 ( )* . (/) = 2/.2/# (/ ) , X ( f ~ ) = (- = - *
, , (2.3.5). ,
x(t)
.
. , (2.3.5) .
. , ,
(/) ,
:
(/), = , 1, 2 , 3,
;
&tx(k&t)\
[-/ , /]
, .
, . . (. 2.3,2).
/
. At = \l2 fe
(2.2.2) (/), . 2.3.26.
, , , (aliasing)
" -
138
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At ( A t).
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(/). ,
(2.3.7) (2.3.3),
* = ?) (/ ) {/) /
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*| *
;
;
;
5-;
. .
2.4.
A ] j( f)
00 00x{kAt) = Jx(t)5(f- kAt)dt- Jx(/)-8(kAt - t)dt,
-OO -0
. e. x(t)
8(/)
, h(t)
0< /(. 2.4.1). . 2.4.1
kAt x(kAt)= J x(t)h(kAt - t)dt= J x(t)h(kAt- t)dt= [jt(f) h( t)]t_ ,
kAt- -o o
. e. / = kAt.
141
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(2.1.2)
(/) = At^ x(/:Af) 5(~ )= = -
= [(/ ) (/ )]- * 5(/-;/)
(2.4.1)
(2.4.1) , ( f)
(/) = [(/) (/ )] h(t).
(2.4.1) ,
( / ) = / ) - ( / ) ] ( / ) (2.4.2)
D f (/ ) = 5 (/ ~ n fa) - , - -
X (/ ) = [(0 ] , (/ ) = [/*(/)] -
. (2.4.2) . , (2.4.2)
. 2.4.2
\(
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|#(/)| const, .
0(/ ) = 2/, 2 (/ ) = 1
(/).
,
0( {( =
/ ). 2.4.3
, 1(/ )
,
h(t) (. 2.4.3).
.
h( t )=0 ^
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.
. 2.4.46
= ( ; - 0 / 2 ) / ) = ^ . ^ 8 (2.4.3)n jv
1 */ 1
(&/) = J x ( t )dt = f x ( t )h (kAt - t )d t =9 - 9 -
, ,
(/) = At x(A:Af)5(/-/:A/) = - -
= i [ x ( f ) (/)] /J 8 ( / - ) .
-,
Xa = [ X ( f ) - H ( f ) ] D /t( f ) =
^ 1( / ) = ^ ( / ) 7 ^ e - jn/e7l/0
(2.4.4)
(2-4.5)
(2.4.6)
, 0
sin 71/ 0it0
(/) = -7/0.
0 = /; < 1; At = \/2 f e. ,
1% /,
/
S i n T i a -2/.
7ia:
'2/.
> 0.99. a < 0,15, . .
15% At. / =f a
= -13,5.
144
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2.4.2. ,
. 2.4.5.
*(/ ).
;
At = \!2fe. . 2.4.5
- ().
. 2.4.5.
At x(t)
!.
At = /t.
< 1. , X ( f ) |/|^ /-
,
x(t).
145
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.
At x(kAt)b(t -k A t) -k= ->
h( t) ,
= (0 =
(/) = / (*/) ':
y(t) = At x(kAt)IIz(t-kAt),
fl 0 < /< I,
t.
j2nfkAt ^ Tl f g-jnf _
/
X i f - n f J - x sm nfx e-Jnfi
/
(2.4.7)
(2.4.8)
(2.4.9)
. 2.4.6 X ( f ) Y( / ).
; '( .
/, i t ,
. 2.4.6.
,
X { f - n f a) -
~ ^ sin / ---------- .
/
Y { f ) = ( / At ) = 1/4. ,
sin / / / -.
146
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, 00
(/) =/ ^ x(kAt)b{t - kAt) (2.4.10)= -
.
Z * (/ - / * )= -
.
(2.4.7) .
Y { f ) / > .
(2.4.7) (2.4.10)
(2.4.8), . 2.4.7. , -
*(0
b(t )
. 2.4.7
, (/ ) -
,
sin /
n f x
.
x(t) -00
At ^ ITx(t kAt) = -
147
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(/) =
(1.9.12)
s(t) = x(t)- X I l ^ t - k A t ) ,* = -00
1 - /2 < /< /2,
(2.4.11)
(2.4.12)[
-
sin(rcwc/ At)At fla, ( / At)
6 ( f - n / A t ) . (2.4.13)
(2.4.11)
S ( f ) = X ( f ) P ( f ) =
sin(rcwx/At)= Z
A t . t U
T 00A ( nnz/At)
sin(nnt/ At)
\ X ( f - f , ) b ( f , - n l A t ) d f , = (2.4.14)oo
X ( f - n / A t ) .At a, (nnz/At)
, S ( f )
X ( f ) ,
f A 1/At
sin(rc/7x/A/)(nnz/At)
(. 2.4.8).
. . 2.4.8 S ( f )
= ( /At)= 1/4.
. 2.4.8.
148
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2.5.
(2.3.5) ,
x(t)
{At) -
sin 2// - , . 2.5.1.
2nf,t
sin 2 f J
7\ '" -- "/' - /^ _/0 /t
. 2.5.1.
. 2.3,
x(t)
()
At 2 nfe t
(. 2.5.2).
At ^ x(kAt) 6(t - At) = -
5- Atx(kAt) (. 2.5.2).
(2.3.5)
* (/ ') = ' } X x (kAt )8 ( t-kAt )h0( t ' - l)d t .- =-
-,
149
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)
(*08((-*/)*
VO.0
. 2.5.2. - ; -
* ( 0 = / ^ x(kAt)h0(t ' -k At ) = jT x(kAt) = -0
sin2nfa(tr-kAt)
2nfe(t ' -kAt) '
/0(/) * t< 0, ,
.
. tQ9
hQ( t - t 0) t< ,
H ML/=1/2/ '\
y n m r v
.
*/] :
150
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, , () . - , . -,
, h(t)
,
*f ln|tf(/)|
J .~7^
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/ ,= (2+5)/ . .
const
|(/)|='
!/|s/e,
/, / , - /
X(/ ), x(Y),
. -
(2.5.2) , . . |#(/)|^0
\f\> f R~/- f a - f e
. ,
|#(/)|
g # (/ ) [- / e, /]
(. 2.5.5). ,
NX 2
/
, . . (/ ) # (/ ) * X(/ ),
x{t). . 2.5.5
1, 2.
2.5.1. (. 2.5.6).
. 2.5.6.
152
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h { t ) hQ(t)
2
/ < , ,
, . 2.5.6.
,
//(/) h ( t ) ,
,
. 2.5.66.
/ = + f e .
, . 2.5.7,
, 0 < t < 2 9 (2.5.3)
, t.
00
( / ) = (2.5.4)
H0(f ] )
"(>
(2.5.5)
.
h(t), ,
,
. . 2.5.7.
153
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2.5.2.
* ( 0 =
\ \ ~ \
sin 2nfe ( t - ) 0< t
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.
/ 11
/ /. 2.5.10
155
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f c .
(. 2.5.11).
1 1
1+ 21+
/
\2J2
1+
X2
= 2
2
J 'S
J e j
= 2-1.
(2.5.9) , 2f \2
J \
\ f l J
,
lg
2- 1
-
(2.5.9)
(2.5.10)
(2.5.11)
V 2-1
l8( f (2.5.9)
/ = - ^ ~ - f ~ a
, |i/(/)|2
1 1----- "~1+ 2 2
[/[, /2].
156
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:
f = f c , ,
10 lg 0,5 = - \
|#(/)|2 /
, , / = 0;
(2-\ ) |#(/)|2
/ = 0;
;
9
(. 2.5.10);/
v = 1 fc
|(|2 * v -2"
, , 10 lg( v '2w) = -20lg v .
, -2 00,3 = -6 ;
,
---------------------- = 6 /7.
= 10 / -60 /.
. , .
v = ^~ J
|tf(v)|2 =----- - ---- . (2.5.12)1 1+ (v )
8 < 1- , , (v ) - - ,
157
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f cos( arccos v), Ivl < 1,() = \ (2.5.13)
[cosh( arccos hv), |v|> 1.
r(v) = 2v7;.l(v)-r.2(v), >2, (2.5.14) 0(v ) = 1 7] (v ) = v.
. 2.5.12 -1 < v < 1. v > 1
(v). v l ( v ) 2~]v
,
(v)
-1 < v < 1 . v = l
v = l ( f = f j ( 1) = 1
.
(v )
. 2.5.13
8.
. 2.5.13
158
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-
.
2.5.3. 3-
f c .
, 3fc.
v = 1 (1) = 1 .
|//(V)|2=-----1 _ = ,51 ' 1+22(1)
6 = 1. 3- (2.5.14)
3(v) = 2v2(v ) - 7J(v) = 2v[2v7J (v ) - 0(v )] - 7J (v ) = 4v3- 3v.
, v = 1,
10 lg[l /(1+992) ] -40 .
-, .
. . .
, . , , . . . . .
,
(/) = / x(kAt) 5( t -kAt) . (2.5.15)*=-
. ,
159
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\ (0 = * ]C x(kAt )q( t -kAt )= (2.5.16)Jt= -oo
00 = ^ x(A/)J 8(x kAt)q(t - x)d =
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(2.5.2),
, (/ ) = -0 sin /0
, / 0 1, ,
----------- 1 + \\ 1, - /31 6 11
sin
(. 2.5.15).
'(| g(t) i
i .O f , / /
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, x{t) kAt
( + 1)/
x(t) = x(kAt)+ x'(kAt)(t- kAt)+ X ^ ^ ^ ~ + (2.6.1)
dx(t)x"(kAl)= 'd 2x(0~
dt t= / dt2
* (/ )-
, :
x(kAt)= [jc(ArAr) - jc((At -1 ) /) ];At
x"(kAt)= [x (kAt) - ' (( -1 ) ] =At
- !-r [ x ( k A t ) - 2 x ( ( k - 1)A t )+ x ( (k - 2 ) A t ) ] .At2
, , . , ,
x[n)(kAt), . , , , .
. , , . , . (2.6.1).
(2.6.1). At (. 2.6.1).
162
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, , (. 2.4.5). At
, (. 2.6.1).
. 2.6.1.
(2.6.1):
(t) = x(kAt) , At < t< (k + 1)
h{t)
(). ,
,
( f ) = l t sinnf At - ' = _ L . sin(Jt/ /A ) .
*///
. 2.6.26, . , . -
/ = /
, / = //2.
//(/) .
,, -
RC = At/.
163
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.
*
)
>*
|
1
\t t
|(|
. 2.6.2.
-
164
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, //(/) :
At, (1/ '2/ ) - .
, At,
, . 2.6.3.
(. 2.6.4). (2.6.1):
, ,
. x(kAt)
, . () , 2t (. 2.6.4).
At. h(t) # (/ )
. 2.6.46, .
j2nfdkt-
(0=/ *>-
At
. 2.6.3. -
k(t )= x(kAt)+ x\kAt){t - At) -
= ( ) + [jc(*A/) - (( - l )Af ) ]( f - kAt).
165
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a*co
/ 2/ -1/At 1
. 2.6.4.
, :
. 2.6.5. - ,
. , , , .
[4],
x(t) =sin 2nfQt
/ > / 0( 2,2//7), (2.6.2)
8 =1*(0-*(0|
K o L, , = 0,01, / > 22/0,
10 , . 2.6.1. , ()
, f c -
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f A, . . f c= // 2. ,
,
V= (/ /f c) >1 (. . 2.5)
20 . (2 .6 .2 )
f c f e=10f c
, f e 10^..
2.7.
, , [-, ]. , (0
.
*(/ ) 2( ) :
\()\ * -2
f A> 0, \fe(2 ,2 //). = 0,01, f a >2 ,2 fei. .
X ( f ) = jx( t )e -J2p/,dt.-
Af = \12
= (1/2) |^ )~ ]2^ 1dt= A f X ( n A f ) .-
X ( f ) = | ] / ( / )2,"^ ' e~j2p f'dt =
= / * ( / ) \ e j2n(n&f~f ) , dt. -
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1( c i2itlnbf-f)tjt 1 c i2x(nbf-f)tI7' _ 2 sin 2nT{nAf - f )
i j2 n(n bf - f ) l-r 2rr(nAf - f )
X(/ )
* (/ ) = Z Af = l/2T (2.7.1)2 n T ( f - n A f )
( ) . X ( f ) /
,
/ - 2
/ = 1/27
2
, . , , t [- , ],
X ( f \ [(/)].
, ,
, :00 00
J>(0|2
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(/) 2 ,
(/)(-/) 4
\X ( f ) \2 /
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: , , , .
, , (. 3.3).
2.8.
, -
|/| [/0 /0+/], /0 2/ (. 2.8.1).
)( .
V "
j > o
----------------- 1-1-1
- j;>
)
m
0
X
'
-**
)
T 1
f
0
, :
L /
T i
- /i y y
( f. 2.8.1
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* (0 = cos[2 /0/+ (/)], (2.8.1)
A(t) (0 -
. . (
/0 0)
. ,
. - .
= 2 (/ + )
( - ).
At =1/2/ , . . +(/)
_(/ ) / = 2/
,
.
2/,
, . , . 1.12.
.
X _ ( f ) .
(/) = jt(/) + yjtr (/), ( / )- ,
* (/ )
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( (/ ) = -y sig n/).
. 1.12, ,
[/ - /, / + /]. ,
X (/ ) = 2+( / )
.
(f)
At= 1/ 2fe
2+(/ ) / =2/ (. 2.8.1).
2+(/ nfA) ,
(/) ^ ( kAt).
. 2.8.2
. , (^)
. . (), .
. 2.8.2.
(/) ( kAt)
( 2 .8 .2 )
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h (t ) = Sm27lfet e J2nfl>' (2.8.3)' nt
, , . .
^ (/ ) . 2.8.1
. , /0/2/ - , - . /0,
().
(t )= (/) +jxs(/) = A(t)eJ n ,
.
, + (/ ) ,
*(/) = x ( t ) ~ j x r (/).
\ ( t) At= 1/2/
2_(/ )
/ =2/ (. 2.8.1 ). \ (/)
\ [At)
V_8in2ltf et e-j2nf0, } nt
jc(/) = ,4(/)cos[2rc/01+ (0] = (,(08 2// - xs(t)sin2/01 (2.8.4)
(/) = ,4(/)cosq>(0 xs(/) = A(t)sin (/)
,
2/, -
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| (&/)} {5(&/)}, At = \/2fe (. . 1.12).
. 2.8.25.
) /0
, . . .
( f )
xs (/) -
. ,
.
f f l= 2 f e (4 /
).
/ = 2(/0 + /), .
Jt(f)
|jcc (/ )} {&/)},
(/) uxs(/), * (/ ),
cos2xfj , -
* |*/| '
,
sin2Jtfj
jA'A/j At= 1/2fe
(. 2.8.26).
(0= cos2nf0t -
sin2 n f 0t.
( 2 . 8 . 5 )
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, 100 , ,
.
(/) .
(/)
/= 2 + 1 (2.8.6)
4/0
/0 , ,
, . . = 2, 4, 6,... ( ).
(2.8.6) (/) -
/0.
(2.8.4)
x ( k A t ) = ( kAt)co$2nf0k A t -x s(kAt)sir\2nf0kAt =
=jcc (A/)cosrc(w + l/2)-j ts (A/)simt (w + l/2).
x(2kA t) = (2/)*(1)^ :[(2/ + 1) ] = xs[(2 + l) A /]*(-l)*+
( 2kAt) = jc(2A;A/)-(-1)*
xs [( 2 * +1) /] = [(2 * +1) /] (-1 )* + (2.8.7)
,
:(/)
(. 2.8.3). , /,
, . .
t = kAt
(kAt ) xs[kAt).
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( , .2.8.3 ) ().
, , . 2.8.4.
| (~\" \ 1 1
\*,[(2'+1)/j
>(2)
f
| | 1
I , ()(-
. 2.8.4.
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:(/) * -
- () (. 2.4.5). :(/)
- () . (). , .
. ,
, (/) = (2/), -
, ,
(*) + *5 (5/). (4/) = -
' 2
/. .
, . .
* (/ ),
At :
0 1 2 3 4 5 6 7 8 9
( ) 0 , *2 *3 *4 *5 *6 *7 *i *9
>() *0 0 ~* 0 *4 0 - * * 0 1 0
( * ) 0 X, 0 - X j 0 *5 0 *7 0 *9
. . jc(:/)
.
>>,(&) 2{)
= {k )+ jy2 (* ) (2-8-8)
,
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y( k) = xc (2k) + jx s (2k+ 1).
y { t) x ( f ) ,
() ( ) ,
y ( t ) = x ( t ) e x p j 2 n ^ - t ,