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chapter 3

Module by: Phuong Nguyen

CH Ư ƠNG 3

Đ ẠI C Ư ƠNG V Ề T ÍN HI ỆU NHI ỄU V À S Ố

C ác lo ại t ín hi ệu bi ểu th ị tin (hay th ông tin) g ồm ti ếng n ói , âm thanh , d ữ li ệu , h ình ảnh , video (h ình ảnh đ ộng). T ín hi ệu đ ư ợc ph ân lo ại theo nhi ều c ách m à m ột c ách l à ph ân ra th ành t ín hi ệu t ư ơng t ự (hay li ên t ục th ời gian) v à t ín hi ệu s ố (hay r ời r ạc th ời gian). X ử l ý t ín hi ệu l à d úng c ác m ạch đi ện t ử v à m áy t ính (ph ần c ứng v à ph ần m ềm) đ ể t ạo m ột t ác đ ộng n ào đ ó l ên t ín hi ệu khi ến t ín hi ệu ra kh ác t ín hi ệu v ào theo c ách m à ta mu ốn .

1.1 T ÍN HI ỆU V À PH ÂN LO ẠI T ÍN HI ỆU

T ín hi ệu (signal) l à s ự bi ến thi ên c ủa bi ên đ ộ theo th ời gian . Bi ên đ ộ c ó th ể l à đi ện áp , d òng đi ện , c ông su ất , vv… , nh ưng th ư ờng đ ư ợc hi ểu l à đi ện áp . Ở đ ây c ó y ếu t ố bi ên đ ộ v à y ếu t ố th ời

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