CHNG II M PHNG TUYN THNG TIN QUANG WDM BNG PHN MM OPTISYSTEM 2.1. Tng quan v phn mm Optisystem Cng vi s bng n v nhu cu thng tin, cc h thng thng tin quang ngy cng tr nn phc tp. phn tich, thit k cc h thng ny bt buc phi s dng cc cng c m phng OptiSystem l phn mm m phng h thng thng tin quang. Phn mm ny c kh nng thit k, o kim tra v thc hin ti u ha rt nhiu loi tuyn thng tin quang, da trn kh nng m hnh ha cc h thng thng tin quang trong thc t. Bn cnh , phn mm ny cng c th d dng m rng do ngi s dng c th a thm cc phn t t nh ngha vo. Phn mm c giao din thn thin, kh nng hin th trc quan. OptiSystem c th gim thiu cc yu cu thi gian v gim chi ph lin quan n thit k ca cc h thng quang hc, lin kt, v cc thnh phn. Phn mm OptiSystem l mt sng to, pht trin nhanh chng, cng c thit k hu hiu cho php ngi dng lp k hoch, kim tra, v m phng gn nh tt c cc loi lin kt quang hc trong lp truyn dn ca mt quang ph rng ca cc mng quang hc t mng LAN, SAN, MAN ti mng ultra-long-haul. N cung cp lp truyn dn,thit k v quy hoch h thng thng tin quang t cc thnh phn ti mc h thng.Hi nhp ca n vi cc sn phm Optiwave khc v cc cng c thit k ca ngnh cng nghip in t hng u phn mm thit k t ng gp phn vo OptiSystem y nhanh tin sn phm ra th trng v rt ngn thi gian hon vn. 2.1.1. Li ch - Cung cp ci nhn ton cu vo hiu nng h thng - nh gi s nhy cm tham s gip vic thit k chi tit k thut - Trc quan trnh by cc ty chn thit k v d n khch hng tim nng - Cung cp truy cp n gin tp hp rng ri cc h thng c tnh d liu - Cung cp cc tham s t ng qut v ti u ha - Tch hp vi h cc sn phm Optiwave

2.1.2. ng dng To ra p ng nhu cu ca cc nh khoa hc nghin cu, k s vin thng quang hc, tch hp h thng, sinh vin v mt lot cc ngi dng khc, OptiSystem p ng cc nhu cu ca th trng lng t nh sng pht trin mnh m nhng vn d s dng cng c thit k h thng quang hc. OptiSystem cho php ngi dng lp k hoch, kim tra, v m phng: - Thit k mng WDM / TDM hoc CATV - Thit k mng vng SONET / SDH - Thit k b pht, knh, b khuch i, v b thu thit k bn phn tn - nh gi BER v penalty ca h thng vi cc m hnh b thu khc nhau - Tnh ton BER v qu cng sut tuyn ca cc h thng c sng dng khuch i quang. - Thay i h thng tham s BER v tnh ton kh nng lin kt Khi h thng quang hc tr nn nhiu hn v phc tp hn, cc nh khoa hc v k s ngy cng phi p dng cc phn mm k thut m phng tin tin, quan trng h tr cho vic thit k. Ngun OptiSystem v linh hot to iu kin thun li hiu qu v hiu qu trong vic thit k ngun sng. "

2.2. c im v chc nng 2.2.1. Cu to th vin (Component Library) Th vin OptiSytem bao gm hng trm cc thnh phn cho php bn c th nhp cc thng s c o t cc thit b thc s. N tch hp vi cc th nghim v thit b o lng t cc nh cung cp khc nhau. Ngi s dng c th kt hp cc thnh phn mi da trn h thng con v ngi s dng v nh ngha l th vin, hoc s dng m phng cng vi mt cng c ca bn th ba chng hn nh MATLAB hoc SPICE. C th bao gm: Th vin ngun quang Th vin cc b thu quang Th vin si quang Th vin cc b khuch i (quang, in) Th vin cc b MUX, DEMUX Th vin cc b lc (quang, in) Th vin cc phn t FSO

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Th vin cc phn t truy nhp Th vin cc phn t th ng (quang, in) Th vin cc phn t x l tn hiu (quang, in) Th vin cc phn t mng quang Th vin cc thit b o quang, o in

2.2.2. Tch hp vi cc cng c phn mm Optiwave Optisystem cho php ngi dng s dng kt hp vi cc cng c phn mm khc ca Optiwave nh OptiAmplifier, OptiBPM, OptiGrating, WDM_Phasar v OptiFiber thit k mc phn t. Miu t c tn hiu pha trn OptiSystem x l cc nh dng tn hiu hn hp cho tn hiu quang v in trong Hp phn Th vin. OptiSystem tnh ton cc tn hiu ang s dng thch hp cc thut ton c lin quan n cc yu cu m phng chnh xc v hiu qu. Cht lng v thc hin cc thut ton d on hiu sut h thng, OptiSystem tnh ton cc thng s chng hn nh BER v Q-Factor bng cch s dng phn tch s hoc bn phn tch k thut ca h thng gii hn bi biu tng nhiu v ting n. Cc cng c trc quan nng cao Cc cng c trc quan tin tin to ra ph OSA ,xung tn hiu,biu mt,phn cc trng thi,cc s hp thnh v nhiu hn na.Ngoi ra,bao gm cc cng c nghin cu WDM cc danh sch tn hiu ngun,hnh nh ting n v OSNR cho mi knh. Theo di, gim st d liu Bn c th chn cc cng thnh phn lu d liu v gn mn hnh sau khi m phng kt thc. iu ny cho php bn x l d liu sau khi m phng m khng cn tnh ton li , Bn c th ty nh km mt s hin hnh ti mn hnh ti cng mt cng.

2.2.3. Cc cng c hin th Optisystem c y cc thit b o quang, o in. Cho php hin th tham s, dng, cht lng tn hiu ti mi im trn h thng.

Thit b o quang: Phn tch ph (Spectrum Analyzer) Thit b o cng sut (Optical Power Meter) Thit b o min thi gian quang (Optical Time Domain Visualizer) Thit b phn tch WDM (WDM Analyzer) Thit b phn tch phn cc (Polarization Analyzer) Thit b o phn cc (Polarization Meter)...

Thit b o in: Oscilloscope Thit b phn tch ph RF (RF Spectrum Analyzer) Thit b phn tch biu hnh mt (Eye Diagram Analyzer) Thit b phn tch li bit (BER Analyzer) Thit b o cng sut (Electrical Power Meter) Thit b phn tch sng mang in (Electrical Carrier Analyzer)...

2.3. Tm tt hng dn s dng phn mm optisystem 2.3.1. Yu cu chung Trc khi ci t Optisystem, chc chn rng cc yu cu i vi h thng l ph hp vi cc m t di y. Yu cu phn cng v phn mm Optisystem yu cu cu hnh h thng thp nht l: PC b vi x l pentium 3 hoc tng ng. H iu hnh microsoft windows XP hoc Vista,32 hoc 64 bit. 400MB cng cn trng . phn gii ha 1024x768,nh nht 65536 mu. Ram 128MB( gi ). Internet explorer 5.5 hoc cao hn. DirectX 8.1 hoc cao hn.

Key bo v: Mt key bo v phn cng c cung cp km theo phn mm Ch : Xin hy chc rng key bo v phn cng khng c kt ni trong sut qu trnh ci t Optisystem.

chc chn Optisystem vn hnh mt cch ng n, kim chng li theo cc bc sau: - Key bo v kt ni ng vo cng song song /USB ca my tnh. - Nu bn s dng nhiu hn mt key bo v, chc rng khng c s xung t gia key bo v Optisystem v cc key kia. Ch : Dng mt hp chuyn i ngn chn s xung t key bo v. Chc rng cp gia hp chuyn i v my tnh l ln nht ca dng c o. Th mc Optisystem Thng thng, b ci Optisystem s to ra mt th mc Optisystem trong cng ca bn. Th mc Optisystem gm mt s th mc con sau: - \bin cc tp thc thi c,th vin ng dn ng, v tp tr gip. - \components tham s cc phn t ca Optisystem t nh cung cp. - \doc ti liu h tr Optisystem. - \libraries th vin phn t Optisystem. - \samples tp v d Optisystem. - \toolbox tp lin h MATLAB. Ci t Optisystem c th c ci t trn Windows XP hoc Vista. Nn thot ht cc chng trnh Windows trc khi ci t chng trnh.

Bng 1: Cc bc ci t Bc 1 Thc hin ng nhp vo vi vai tr ngi qun tr hoc ng nhp vo ti khon vi c quyn qun tr.

2 3

Cho CD Optisystem vo CD ROM. Trn thanh cng c,vo Start v chn Run. Hp thoi Run hin ra. Trong hp thoi Run, g F:\setup.exe, F y l CD ROM ca bn. Bm OK v theo cc hng dn v du nhc trn mn hnh Khi ci t xong, khi ng li my tnh.

4

5 6

Trnh din Optisystem bao gm nhiu nht l 15 kch bn. Vi cng mt tp trnh din nh nhau bn c th c nhiu kch bn vi cc phn t khc nhau v ty chn cc phn t. Khu qut Mi kch bn c th c cc tham s c gn sn trong ch qut. Bn c th t gn s ln qut bng cch thay i tham s la chn. Gi tr tham s thay i theo mi ln qut lp; to ln mt lot cc kt qu tnh ton khc nhau cn c trn s thay i gi tr tham s. Qut tham s ph thuc vo yu t ca mt kch bn: tham s v kt qu. Ti u ha Mi kch bn c s ti u ha. S dng ti u ha thay i gi tr ca cc tham s bit trong sut qu trnh tnh ton v vy h thng ca bn cn t c nhiu iu kin yu cu. Qu trnh ti u ha l c lp vi cc ln qut tham s, nhng c th c s dng cho mi ln qut lp tham s ring bit.

Hnh 2.1: Thnh phn trnh din 2.3.2 Hng dn s dng phn mm optisystem Th vin cc phn t ( component library ) : Ngi dng truy cp vo ly cc phn t thit k (Hnh 1)

Hnh 2.2: Th vin cc phn t Th vin cc phn t:

- Th vin ngun quang - ( optical sources library ) - Th vin cc b thu quang - (receivers library) - Th vin si quang - (optical fiber library) - Th vin cc b khuch i (quang, in) - (amplifier library) - Th vin cc b MUX, DEMUX - Th vin cc b lc (quang, in) - (filter library) - Th vin cc phn t FSO - ( free space optics library) - Th vin cc phn t truy nhp - ( access library) - Th vin cc phn t th ng (quang, in) - (passiver library) - Th vin cc phn t x l tn hiu (quang, in) -( signal processing library) - Th vin cc phn t mng quang (network library) - Th vin cc thit b o quang, o in Ngoi ra cc phn t c nh ngha sn, Optisystem cn c - Cc phn t Measured components. Vi cc phn t ny, Optisystem cho php nhp cc tham s c o t cc thit b thc ca cc nh cung cp khc nhau. - Cc phn t do ngi s dng t nh ngha ( User-defined Components)

Hnh 2.3: Giao din th vin Giao din ngi s dng ( GUI ) - Project layout : phn m ngi s dng thit k

Hnh 2.4. Giao din ngi s dng - Dockers : bao gm

+ Project Browser : truy nhp n cc tham s v kt qu ca thit k (Hnh 3)

Hnh 2.5: Project Browser + Description : a ra cc thng tin m t tm tt v thit k

Hnh 2.6: Description

+ Status bar : hin th nhng gi v vic s dng Optisystem

Hnh 2.7: Status bar + Menu bar : cha cc menu c sn trong Optisystem

Hnh 2.8: Menu bar + Pan window

Hnh 2.9: Pan window + Tool bars : cc thanh cng c c sn trn ca s

Hnh 2.10: Tool bars

2.3.3 To mt d n mi - Vo File menu, la chn New, ca s Project layout xut hin

Hnh2.11. Ca s Project layout - Vo Component Library, dng chut ko phn t cn s dng v th vo Main Layout (Hnh 10)

Hnh 2.12. t phn t vo Main layout

- Vic kt ni gia cc phn t trong thit k c th c thc hin mt cch t ng hoc bng tay nh vic s dng cc nt chc nng trong Layout Operations

Hnh 2.13: Kch hot kt ni t ng

Hnh 2.14:Hy b ch kt ni t ng

2.3.4. Hin th v thay i tham s ca cc phn t trong d n Khi to mt thit k mi trn Optisystem, phi thit lp cc tham s ton cc. Cc tham s ny s lin quan n tc , chnh xc v yu cu v b nh cho vic thc hin m phng thit k. Cc tham s ny c gi l tham s ton cc v n nh hng n tt c cc thnh phn trong thit k c s dng cc tham s ny. Trong Optisystem, cc tham s ny bao gm: - Tc bit (bit rate) - Chiu di chui bit (Bit sequence length) - S mu trn mt bit (Number of samples per bit). thit lp thng s ton cc ta thc hin nh sau: - Cch 1: Kch p vo mn hnh Layout. - Cch 2: Layout -> Parameters t cng c Menu. Khi mn hnh Parameters xut hin:

Hnh 2.15 :mn hnh Parameters * Thay i cc tham s ca cc phn t trong bi ton m phng: - Thc hin kch p vo phn t cn thay i tham s hp thoi v cc tham s ca phn t xut hin . - Di chuyn con tr n cc gi tr thch hp. - Nhp gi tr tham s mong mun. Ch : C ba ch ca tham s l Norman, Script v Sweep: - Trong ch Scrip c thc hin khi tham s ny l tham s ton cc, n c lin quan n tt c cc phn t khc trong h thng. - Ch Sweep c s dng khi thc hin qut tham s. - Ti mc Power cho php ta nhp cng sut pht quang c gi tr ph hp vi tng knh. Tip theo tin hnh thay i tc bit (Bit rate): Ti mc value chn Set bit rate.

Hnh 2.16 :Chn trng thay i tc bt

Tin hnh nhp tc bit 10Gbit/s= 10000000000 (bt/s).

Hnh 2.17 : Nhp tc bt mun thay i

+ Tin hnh thit lp ca s thi gian: ti Value chn Set Time Window v nhp gi tr

Hnh2.18 : Thit lp ca s thi gian thc

Hnh 2.19 : Thay i cng sut pht quang

+ Kt thc ci t tham s ton cc bng cch click OK cc thng s ton cc c hin th nh sau:

* Xa cc tham s mi khi d n: thc hin qua cc bc: - Trong hp thoi Layout Parameter, kch vo ct Value bn cnh tham s bn mun thay i. - Kch Remove Par: Tham s c xa. Ch : Bn khng th chnh sa hoc xa cc tham s h thng.

2.3.5. Chy m phng a. Chy m phng n t hp (Ctrl F5), hoc click Colculatol trn thanh cng c. Mn hnh hin th:

Hnh 2.20: Giao din mn hnh chy m phng + Tip theo click vo nt Run chy chng trnh:

Hnh 2.21 : Chy chng trnh + Sau khi chng trnh chy xong, hin th gi tr ca BER ta kch p vo thit b o BER ca knh u tin (CH1).

Hnh 2.22: o t s BER ca knh + Thc hin tng t nh vy vi cc knh cn li tm cc gii gi tr ph hp. b. Hin th kt qu m phng - Kch p chut vo cc phn t hin th trong thit k hin th th v cc kt qu m qu trnh m phng to ra.

Hnh 2.23 : Kt qu m phng c. tin hnh thit lp tham s qut ta thc hin nh sau: + Cch 1: n t hp phm Ctrl +Home + Cch 2: Thc hin 3 bc sau: Bc 1: Kch chut vo nt Set Total Sweep Iterarion trn Layout Bar hp thoi Total Parameter Sweep Iterations trn Layout Tool Bar xut hin trn hnh: Bc 2: Nhp gi tr s ln qut . Bc 3: Click chut OK

Hnh 2.24: Thit lp tham s quyt d. Thay i s ln qut: Sau khi tnh ton, thay i s ln qut hin th trn bn thit k (layout), thc hin cc bc sau: - Bc 1: La chn Layout > Set Current Sweep Interation trn Menu toolbar. Hp thoi Set Current Sweep Iterarion xut hin nh trn hnh 20 - Bc 2: Nhp vo s ln qut mun hin th trn bn thit k - Bc 3: Kch chut vo nt OK Hoc s dng Previous Sweep Interarion hoc Next Interation trn Layout Toolbal chuyn i s ln qut.

Hnh 2.25: Chuyn i s ln qut. e. Thay i gi tr tham s qut: Sau khi chn s ln qut th chng ta thc hin nhp gi tr cn qut ca tham s. Trc khi nhp tham s cn qut phi chuyn sang ch qut Sweep Mode. f. chuyn sang ch qut cho tham s thc hin nh sau: + La chn Layout -> Parameter Sweep trn Menu Toolbar . Hp thoi v cc tham s ca cc phn t nh hnh v. Ch yu thit lp qut tham s cho ngun lazer. + Kch p vo ngun CW lazer Properies hp thoi xut hin:

Hnh 2.26: Hp thoi chuyn sang ch qut cho tham s + Ti Mode kch chut chn Sweep. Kt thc bng OK.

Hnh 2.27: Chn ch ca tham s + Sau tin hnh in tham s qut bng cch click chut vo Parameter Sweep trong ct Value. Kt thc bng OK. + Sau khi thay i xong cc tham s qut tin hnh bc tip theo.

g. Hin th kt qu m qu m phng qut tham s Sau khi chng trnh chy xong, hin th gi tr ca BER ta kch p vo thit b o BER ca knh u tin (CH1). hin th kt qu m phng qut tham s (i vi thit k h thng, thng hin th s thay i BER theo gi tr ca tham s qut), thc hin cc bc sau: o Bc 1: La chn Report tab trong ca s Project Layout o Bc 2: Kch chut vo nt Opti2Dgraph trn Report toolbar o Bc 3: Trong Project Browser, la chn tham s Sweep Mode, ko tham s ny v th vo trc X ca th 2D o Bc 4: Trong Project Browser, la chn tham s Min. Log of BER ca thit b phn tch li bit, ko tham s ny v th vo trc Y ca th 2D Kt qu thay i BER theo tham s qut s hin th trn th 2D.

Hnh 2.28:. Cc bc hin th kt qu m phng qut tham s 2.4. M hnh m phng 2.4.1 Yu cu thit k 1) Bi ton: Xy dng phng n thit k h thng thng tin quang WDM c s dng khuch i quang EDFA vi cc yu cu thit k nh sau: Tc bit: 10 Gbit/s

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C ly truyn dn:

300 km

S lng knh bc sng: 4 knh Si quang n mode chun (G.652)

Mt s gi khi thit k: Loi si:

Ngun pht: - Loi ngun: Laser. - Phng thc iu ch: iu ch ngoi

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B thu: S dng PIN kt hp vi b lc thng thp Bessel

2) Yu cu: a) S dng phn mm Optisystem xy dng m hnh m phng h thng thng tin quang WDM theo phng n thit k. Lu : cc tham s ton cc (global parameters m phng) c thit lp nh sau Tc bit: Chiu di chui: S mu trong 1 bit: 10 Gbit/s 128 bits 64

b) a cc thit b o vo m hnh m phng. Cc thit b o trn tuyn c t ti cc v tr ph hp xc nh c cht lng v dng tn hiu ti cc im cn thit trn tuyn. Cc thit b o c bn: Thit b o cng sut quang Thit b phn tch ph quang Thit b o BER

c) Chy m phng d) Hin th kt qu m phng bng cc thit b o t trn tuyn e) Thay i cc tham s ca cc phn t trn tuyn t c BER = 10-12 3) Bo co kt qu thc hnh M hnh m phng Cc tham s m phng chi tit Kt qu m phng

o Kt qu m phng theo phng n thit k ban u h thng ban u o S thay i ca cc tham s thit k t c BER = 10-12 Nhn xt, phn tch kt qu m phng .

2.4.2 M phng theo phng n thit k 2.4.2.1 Tuyn pht quang: chn ca s truyn 1550nm EDFA bng C Mi knh quang bao gm ngun pht quang lazer CW lazer, b pht xung RZ pulse genarator, b pht bit in pseudom-Radom Bit sequence Genarator, b iu ch Machzehnder. Tuyn pht quang gm 4 knh quang c tch hp thng quang b ghp knh quang MUX. Thit lp tham s ton cc Tc bt: Chiu di chui: 10GBps 128bits

S mu trong mt bt: 64 S mu =Chiu di chuiS mu trong mt trong mt bit=12864=8192

Hnh 2.29: Thit lp tham s ton cc Ngun pht: S dng ngun CW Laser ( continous Wave Laser ) : nhm gim nh hng ca tn sc si.

Hnh 2.30: Ngun Laser pht CW Laser B to xung RZ

Hnh 2.31: B to xung RZ B to chui bit

Hnh 2.32. B to chui bt

B iu ch ngoi

Hnh 2.33: B iu ch Mach-Zehnder

B ghp knh quang (ghp 4 knh)

Hnh 2.34: B ghp knh MUX 41 Ton tuyn pht 4 knh quang

Hnh 2.35: Tuyn pht quang

2.4.2.2 Tuyn truyn dn quang

Hnh 2.36. Tuyn truyn dn quang

Si quang s dng G.652 c cc tham s: ti ca s truyn 1550nm th: Suy hao si: 0.2dB tn sc: 0.335 ps/nmkm dc tn sc (0.092ps/nm^2/k): 0.075ps/nm^2/k. Do khong cch ng truyn ln thun tin cho vic m phng chng ta s dng b Sloop ng vai tr nh mt b nhn cc vng lp. Chn chiu di si G.652 l 60km, s b lp l: 300km60km=5 b.

Hnh 2.37. B lp Do si quang c suy hao tn sc nn trong tuyn truyn dn s s dng b b tn sc DCF. Thng s ca b b tn sc: Gi s si G652 c chiu di l L1=50km. tn sc l : D1= 16.75 ps/nm.km. dc tn sc : 0.075ps/nm^2.km. Chiu di si b tn sc ( DCF) l L2=60km-50km=10km Th b tn sc D2= -D1L1/L2.= -5016.75/10= -83 ps/nm.km. dc tn sc : 0.375ps/nm^2.km.

Hnh 2.38. Thng s si b tn sc DCF Khuch i quang EDFA: Do suy hao si quang nn cn s dng b khuch i EDFA b suy hao si. + L1=50km th suy hao si l: 500.2=10dB li ca b khuch i EDFA l 10dB + L2=10km th suy hao si l: 100.2=5dB li ca b khuch i EDFA l 5dB

2.4.4.3 Tuyn thu ca h thng WDM

Hnh 2.39. Tuyn thu WDM

Thit b o BER

Hnh 2.40. Thit b o BER

2.4.3 Kt qu m phng theo yu cu thit k Tuyn WDM theo yu cu

Hnh 2.41. Tuyn WDM thit k theo yu cu

Quang ph tn hiu pht

Hnh 2.42. Quang ph tn hiu pht Quang ph tn hiu thu

Hnh 2.43. Quang ph tn hiu u thu knh th 3 Cng sut tn hiu pht

Hnh 2.44. Tng cng sut pht

Cng sut tn hiu thu

Hnh 2.45. Cng sut thu ca knh 4

T l li bit BER Mt quang

Hnh 2.46. Hin th mt quang BER ca mt knh

Hnh 2.47. BER ca knh th nht l 10-13 2.4.4. Kt qu m phng thay i cc tham s t BER=10-12 Khi thay i mt trong cc tham s h thng th t s li bt BER se thay i theo. Thay i cng sut Laser pht

Hnh 2.48. Thay i cng sut Laser pht Hoc thay i h s suy hao si quang ln thnh 0.2025dB

Hnh 2.49. H s suy hao si quang thay i

BER thay i + BER ca knh th nht thay i

Hnh 2.50. BER ca knh th nht t 10-12 + Mt quang:

Hnh 2.51. BER t 10-12 khi thay i mt s tham s