7/30/2019 Tng quan h thng thng tin

1/5

TNG QUAN V H THNGTHNG TIN IN T PGS.TS HONG NH CHIN

1 Nguyn Hng Phc 40801594Phan Nht V 50802678

IN THC TN S V TUYN

TNG QUAN V H THNG

THNG TIN IN T

GVHD: PGS.TS HONG NH CHIN

THC HIN: NGUYN HNG PHC 40801594

PHAN NHT V 50802678

7/30/2019 Tng quan h thng thng tin

2/5

TNG QUAN V H THNGTHNG TIN IN T PGS.TS HONG NH CHIN

2 Nguyn Hng Phc 40801594Phan Nht V 50802678

TNG QUAN V H THNG THNG TIN IN T

H thng thng tin c nh ngha l h thng chuyn ti tin tc t ngun pht n ni nhn tinmt khong cch no . H thng thng tin c th thc hin gia mt hay nhiu ngun phttin ng thi n mt hay nhiu ni nhn tin, do ta c kiu thng tin mt ng, a ng,phuong thc thng tin mt chiu, hai chiu hay nhiu chiu. Mi trng thng tin c thdnghu tuyn hoc v tuyn, nh dng dy truyn sng, cable truyn tin hoc sng in t v tuyn.

S khi tng qut ca mt h thng thng tin

Khi pht c chc nng x l tn hiu tin tc v cung cp vo mi trng thng tin mt tn hiuc dng ph hp vi c tnh ca mi trng, vi iu kin ni dung ca tin tc truyn i khngthay i. Khi pht c th bao gm cc phn m ha, iu ch v khuch i pht.

Mi trng truyn cho php truyn ti thng tin tni pht n ni thu. Mi trng thng tinc th dng hu tuyn (dy dn in song hnh, dy cable tn hiu, si quang,) hoc v

tuyn ( khng gian tu do, chn khng, mi trng cht lng,). Mi trng thng tin c thgy suy hao cng sut tn hiu v gy tr pha tn hiu khi truyn tin.

Khi thu c chc nng thu nhn tn hiu tin tc tmi trng thng tin, ti to li tn hiu tintc cung cp n ni nhn. Khi thu c th bao gm cc phn khuch i tn hiu in ( bssuy hao trn mi trng thng tin), gii iu ch v gii m, khi chn lc knh thng tin.

Nhiu: tn hiu ngu nhin khng mong mun, xut hin trong mi trng truyn tin hay t ccphn t, linh kin ca thit b, lm si dng cc tn hiu. Nhiu cng c thc loi b hocgim thiu nh hng nhcc b chn lc tn s, cc b xl ngng ti ni thu. i vi nhiu

nhn, qu trnh x l thng phc tp, s dng cc thut ton th v sai (thut ton logic m,mng neural, chui Markov,i vi can nhiu gy mo dng tn hiu c thuc khc phcbi cc b cn bng equalizer.

Khi phtIn ut

Nhiu

Mi trngtruyn Khi thu

Output

Voice, data, nh

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TNG QUAN V H THNGTHNG TIN IN T PGS.TS HONG NH CHIN

3 Nguyn Hng Phc 40801594Phan Nht V 50802678

S khi my pht:

S khi my thu

My thu thanh va fthu truyn hnh dn dng i tn mt ln.

My thu thng tin chuyn dng i tn hai ln tng chn lc v loi nhiu tn snh.

iu ch: qu trnh bin i mt trong cc thng s sng mang cao tn thnh hnh sin (bin ,tn s, pha) t l vi tn hiu iu chbng gc.

i tn: qu trnh dch chuyn ph tn s ca tn hiu iu ch ln cao (my pht Tx hayxung thp (my thu Rx) m khng thay i cu trc ph (dng tn hiu) ca n thun tin

x l tn hiu.

Tng hp tn s: b to nhiu tn s chun c n nh cao t mt hoc vi tn s chun cadao ng thch anh.

Khuch i cng sut cao tn: Khuch i tn hiu iu ch tn sno n mc cngsut cn thit, lc, phi hp trkhng vi anten pht ATX

iu chIn ut

Tng hptn s

i tnKhuch icng sut

cao tn

Digiatal

Control

m(t)

ATX ,fc

RF Amp

(LNA)

Tng hptn s

itn 1

Khuchi

Digiatal

Control

fc

AR

itn 2IF1 IF2

Giiiuch

AGC

Output

m(t)

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TNG QUAN V H THNGTHNG TIN IN T PGS.TS HONG NH CHIN

4 Nguyn Hng Phc 40801594Phan Nht V 50802678

Anten pht ATX: phn t bin i nng lng in cao tn thnh sng in t bc x vo khnggian.

Anten thu ARX: phn t bin i nng lng sng in t thnh tn hiu cao tn ng vo my thu.Anten c tnh thun nghch.

B khuch i cao tn tn hiu nh: thng l b khuch i nhiu thp LNA. N khuch i tinchn lc tn hiu thu tanten thu n mc cn thit i tn xung trung tn (IF).

B khuch i trung tn: b khuch i c chn lc cao, khuch i ln tn hiu nh saui tn tn s trung tn n mc cn thit gii iu ch.

Gii iu ch: qu trnh khi phc li tn hiu ban u t tn hiu cao tn biu ch.

Cc di tn thng tin

7/30/2019 Tng quan h thng thng tin

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TNG QUAN V H THNGTHNG TIN IN T PGS.TS HONG NH CHIN

5 Nguyn Hng Phc 40801594Phan Nht V 50802678