1
涓�銆佸～绌洪
1
锛庡簭鍒?/p>
(
)
sin(3
/
5)
x
n
n
飦?/p>
飥?/p>
鐨勫懆鏈熶负
10
銆?/p>
2
锛庣嚎鎬ф椂涓嶅彉绯荤粺鐨勬�ц川鏈?/p>
浜ゆ崲寰嬪緥
缁撳悎寰?/p>
鍒嗛厤寰嬨�?/p>
3
锛庝粠濂堝鏂壒閲囨牱瀹氱悊寰楀嚭锛岃浣垮疄淇″彿閲囨牱鍚庤兘澶熶笉澶辩湡杩樺師锛岄噰鏍烽鐜?/p>
f
涓庝俊鍙锋渶楂橀鐜?/p>
fs
鍏崇郴涓猴細
f>=2fs
銆?/p>
4
锛庤嫢姝ｅ鸡搴忓垪
x(n)=sin(30n
蟺
/120)
鏄懆鏈熺殑锛屽垯鍛ㄦ湡鏄?/p>
N=
8
銆?/p>
5
锛庡簭鍒?/p>
(
)
sin(3
/
5)
x
n
n
飦?/p>
飥?/p>
鐨勫懆鏈熶负
10
銆?/p>
6
锛?/p>
璁?/p>
LTI
绯?/p>
缁?/p>
杈?/p>
鍏?/p>
涓?/p>
x(n)
锛?/p>
绯?/p>
缁?/p>
鍗?/p>
浣?/p>
搴?/p>
鍒?/p>
鍝?/p>
搴?/p>
涓?/p>
h(n)
锛?/p>
鍒?/p>
绯?/p>
缁?/p>
闆?/p>
鐘?/p>
鎬?/p>
杈?/p>
鍑?/p>
y(n)=
銆?/p>
7
锛庡洜鏋滃簭鍒?/p>
x(n)
锛屽湪
Z
鈫掆垶鏃讹紝
X(Z)=
x(0)
銆?/p>
浜屻�佸崟椤归�夋嫨棰?/p>
1
锛幬?/p>
(n)
鐨勫倕閲屽彾鍙樻崲鏄?/p>
(
A
)
A.1
B.
未
(
蠅
)
C.2
蟺未
(
蠅
)
D.2
蟺
2
锛庡簭鍒?/p>
x
1
锛?/p>
n
锛夌殑闀垮害涓?/p>
4
锛屽簭鍒?/p>
x
2
锛?/p>
n
锛夌殑闀垮害涓?/p>
3
锛屽垯瀹冧滑绾挎�у嵎绉殑闀垮害鏄?/p>
锛?/p>
C
锛?/p>
A. 3
B. 4
C. 6
D. 7
3
锛?/p>
LTI
绯荤粺锛岃緭鍏?/p>
x
锛?/p>
n
锛夋椂锛岃緭鍑?/p>
y
锛?/p>
n
锛?/p>
锛涜緭鍏ヤ负
3x
锛?/p>
n-2
锛?/p>
锛岃緭鍑轰负锛?/p>
B
锛?/p>
A. y
锛?/p>
n-2
锛?/p>
B.3y
锛?/p>
n-2
锛?/p>
C.3y
锛?/p>
n
锛?/p>
D.y
锛?/p>
n
锛?/p>
4
锛庝笅闈㈡弿杩颁腑鏈�閫傚悎绂绘暎鍌呯珛鍙跺彉鎹?/p>
DFT
鐨勬槸
锛?/p>
D
锛?/p>
A.
鏃跺煙涓虹鏁ｅ簭鍒楋紝棰戝煙涓鸿繛缁俊鍙?/p>
B.
鏃跺煙涓虹鏁ｅ懆鏈熷簭鍒楋紝棰戝煙涔熶负绂绘暎鍛ㄦ湡搴忓垪
C.
鏃跺煙涓虹鏁ｆ棤闄愰暱搴忓垪锛岄鍩熶负杩炵画鍛ㄦ湡淇″彿
D.
鏃跺煙涓虹鏁ｆ湁闄愰暱搴忓垪锛岄鍩熶篃涓虹鏁ｆ湁闄愰暱搴忓垪
5
锛?/p>
璁剧郴缁熺殑鍗曚綅鎶芥牱鍝嶅簲涓?/p>
h(n)
锛屽垯绯荤粺鍥犳灉鐨勫厖瑕佹潯浠朵负锛?/p>
C
锛?/p>
A
锛庡綋
n>0
鏃讹紝
h(n)=0
B
锛庡綋
n>0
鏃讹紝
h(n)鈮?
C
锛庡綋
n<0
鏃讹紝
h(n)=0
D
锛庡綋
n<0
鏃讹紝
h(n)鈮?
6
锛庝笅鍒楀摢涓�涓郴缁熸槸鍥犳灉绯荤粺锛?/p>
B
锛?/p>
A.y(n)=x (n+2)
B. y(n)= cos(n+1)x (n)
C. y(n)=x (2n)
D.y(n)=x (- n)
7
锛?/p>
x(n)=
未
(n-3)
鐨勫倕閲屽彾鍙樻崲涓猴紙
A
锛?/p>
A.
jw
3
e
飥?/p>
B.
jw
3
e
C.1
D.0
8
锛?/p>
1
0
),
(
)
(
飥?/p>
飥?/p>
飥?/p>
a
n
u
a
n
x
n
鐨勫倕閲屽彾鍙樻崲涓猴紙
C
锛?/p>
A.
jw
ae
飥?/p>
1
1
B.
jw
ae
-
1
1
C.
jw
ae
-
-
1
1
D.
jw
ae
-
1
1
飥?/p>
9
锛庤嫢搴忓垪鐨勯暱搴︿负
M
锛岃鑳藉鐢遍鍩熸娊鏍蜂俊鍙?/p>
X(k)
鎭㈠鍘熷簭鍒楋紝鑰屼笉鍙戠敓鏃跺煙娣峰彔鐜拌薄锛?/p>
鍒欓鍩熸娊鏍风偣鏁?/p>
N
闇�婊¤冻鐨勬潯浠舵槸
(
A
)