涓�
.
濉┖棰?/p>
1
銆?/p>
涓�绾挎�ф椂涓嶅彉绯荤粺锛?/p>
杈撳叆涓?/p>
x
锛?/p>
n
锛?/p>
鏃讹紝
杈撳嚭涓?/p>
y
锛?/p>
n
锛?/p>
锛?/p>
鍒欒緭鍏ヤ负
2x
锛?/p>
n
锛?/p>
鏃讹紝
杈撳嚭涓?/p>
2y(n)
锛?/p>
杈撳叆涓?/p>
x
锛?/p>
n-3
锛夋椂锛岃緭鍑轰负
y(n-3)
銆?/p>
2
銆佷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>
fs
涓庝俊鍙锋渶楂橀鐜?/p>
f
max
鍏崇郴涓猴細
fs>=2f
max
銆?/p>
3
銆佸凡鐭ヤ竴涓暱搴︿负
N
鐨勫簭鍒?/p>
x(n)
锛屽畠鐨勭鏁ｆ椂闂村倕绔嬪彾鍙樻崲涓?/p>
X
锛?/p>
e
jw
锛?/p>
锛屽畠鐨?/p>
N
鐐圭鏁ｅ倕绔嬪彾鍙?/p>
鎹?/p>
X
锛?/p>
K
锛夋槸鍏充簬
X
锛?/p>
e
jw
锛夌殑
N
鐐圭瓑闂撮殧
閲囨牱
銆?/p>
4
銆佹湁闄愰暱搴忓垪
x(n)
鐨?/p>
8
鐐?/p>
DFT
涓?/p>
X
锛?/p>
K
锛?/p>
锛屽垯
X
锛?/p>
K
锛?/p>
=
銆?/p>
5
銆佺敤鑴夊啿鍝嶅簲涓嶅彉娉曡繘琛?/p>
IIR
鏁板瓧婊ゆ尝鍣ㄧ殑璁捐锛屽畠鐨勪富瑕佺己鐐规槸棰戣氨鐨?/p>
浜ゅ彔
鎵�浜х敓鐨?/p>
鐜拌薄銆?/p>
6
锛?/p>
鑻ユ暟瀛楁护娉㈠櫒鐨勫崟浣嶈剦鍐插搷搴?/p>
h
锛?/p>
n
锛?/p>
鏄瀵圭О鐨勶紝
闀垮害涓?/p>
N
锛?/p>
鍒欏畠鐨勫绉颁腑蹇冩槸
(N-1)/2
銆?/p>
7
銆佺敤绐楀嚱鏁版硶璁捐
FIR
鏁板瓧婊ゆ尝鍣ㄦ椂锛屽姞鐭╁舰绐楁瘮鍔犱笁瑙掔獥鏃讹紝鎵�璁捐鍑虹殑婊ゆ尝鍣ㄧ殑杩囨浮甯︽瘮杈?/p>
绐?/p>
锛岄樆甯﹁“鍑忔瘮杈?/p>
灏?/p>
銆?/p>
8
銆佹棤闄愰暱鍗曚綅鍐叉縺鍝嶅簲锛?/p>
IIR
锛夋护娉㈠櫒鐨勭粨鏋勪笂鏈夊弽棣堢幆璺紝鍥犳鏄?/p>
閫掑綊
鍨嬬粨鏋勩�?/p>
9
銆佽嫢姝ｅ鸡搴忓垪
x(n)=sin(30n
蟺
/120)
鏄懆鏈熺殑
,
鍒欏懆鏈熸槸
N= 8
銆?/p>
10
銆佺敤绐楀嚱鏁版硶璁捐
FIR
鏁板瓧婊ゆ尝鍣ㄦ椂锛岃繃娓″甫鐨勫搴︿笉浣嗕笌绐楃殑
绫诲瀷
鏈夊叧锛岃繕涓庣獥鐨?/p>
閲囨牱鐐?/p>
鏁?/p>
鏈夊叧
11
锛?/p>
DFT
涓?/p>
DFS
鏈夊瘑鍒囧叧绯伙紝
鍥犱负鏈夐檺闀垮簭鍒楀彲浠ョ湅鎴愬懆鏈熷簭鍒楃殑
涓诲�煎尯闂存埅鏂?/p>
锛?/p>
鑰屽懆鏈熷簭鍒楀彲
浠ョ湅鎴愭湁闄愰暱搴忓垪鐨?/p>
鍛ㄦ湡寤舵嫇
銆?/p>
12
锛庡闀垮害涓?/p>
N
鐨勫簭鍒?/p>
x(n)
鍦嗗懆绉讳綅
m
浣嶅緱鍒扮殑搴忓垪鐢?/p>
x
m
(n)
琛ㄧず锛屽叾鏁板琛ㄨ揪寮忎负
x
m
(n)=
x((n-m))
N
R
N
(n)
銆?/p>
13
锛庡鎸夋椂闂存娊鍙栫殑鍩?/p>
2-FFT
娴佸浘杩涜杞疆锛屽苟
灏嗚緭鍏ュ彉杈撳嚭锛岃緭鍑哄彉杈撳叆
鍗冲彲寰楀埌鎸夐鐜囨娊
鍙栫殑鍩?/p>
2-FFT
娴佸浘銆?/p>
14.
绾挎�хЩ涓嶅彉绯荤粺鐨勬�ц川鏈?/p>
浜ゆ崲鐜?/p>
銆?/p>
缁撳悎鐜?/p>
鍜屽垎閰嶅緥銆?/p>
15.
鐢?/p>
DFT
杩戜技鍒嗘瀽妯℃嫙淇″彿鐨勯璋辨椂锛?/p>
鍙兘鍑虹幇鐨勯棶棰樻湁娣峰彔澶辩湡銆?/p>
娉勬紡
銆?/p>
鏍呮爮鏁堝簲
鍜岄鐜?/p>
鍒嗚鲸鐜囥�?/p>
16.
鏃犻檺闀垮崟浣嶅啿婵�鍝嶅簲婊ゆ尝鍣ㄧ殑鍩烘湰缁撴瀯鏈夌洿鎺モ厾鍨嬶紝鐩存帴鈪″瀷锛?/p>
涓茶仈鍨?/p>
鍜?/p>
骞惰仈鍨?/p>
鍥涚銆?/p>
17.
濡傛灉閫氱敤璁＄畻鏈虹殑閫熷害涓哄钩鍧囨瘡娆″鏁颁箻闇�瑕?/p>
5渭s
锛?/p>
姣忔澶嶆暟鍔犻渶瑕?/p>
1渭s
锛?/p>
鍒欏湪姝よ绠楁満涓婅绠?/p>
2
10
鐐圭殑鍩?/p>
2 FFT
闇�瑕?/p>
10
绾ц澏褰㈣繍绠楋紝鎬荤殑杩愮畻鏃堕棿鏄?/p>
______渭s
銆?/p>
浜岋紟閫夋嫨濉┖棰?/p>
1
銆?/p>
未
(n)
鐨?/p>
z
鍙樻崲鏄?/p>
A
銆?/p>