Optical Multiplexing rau High Speed Communication Systems
Kev taw qhia
Optical kis tau siv pulses ntawm lub teeb mus kis cov ntaub ntawv los ntawm ib qho chaw mus rau lwm tus los ntawm kev siv fais fab. Lub teeb yog hloov dua siab rau electromagnetic carrier yoj, uas yog hloov los nqa cov ntaub ntawv raws li lub teeb propagates los ntawm ib kawg mus rau lwm. Txoj kev loj hlob ntawm fiber ntau qhov muag tau revolutionized cov kev lag luam hauv telecommunications. Optical fiber tau hloov lwm yam kev kis kab mob xws li tooj liab hlau txij thaum inception, thiab yog siv los xaim cov tub ntxhais lub ntsiab. Niaj hnub no, qhov muag fais fab tau siv los tsim cov kev sib txuas lus tshiab kev sib txuas lus uas xa tawm cov ntaub ntawv ua lub suab pulses, piv txwv yog multiplexers / demultiplexers siv lub tshuab ua kom qhov muag zoo tshaj.
Dab tsi yog Multiplexing?
Multiplexer (Mux) yog ib qho khoom siv sib txuas ua ke uas muab ntau yam analog los sis digital cov kev tawm tswv yim rau hauv ib txoj kab sib txuas. Thiab ntawm lub receiver kawg, tus multiplexer hu ua DeMultiplexer (DeMux) -performing kev ua haujlwm ntawm multiplexers. Kev sib txuam ntau yog vim li no cov txheej txheem ntawm kev sib txuas ob los yog ntau lub tswv yim rau hauv kev sib kis. Ntawm tus txais lub txiaj ntsim, qhov kev teeb tsa ua ke tau muab cais tawm rau hauv cov teeb meem sib txawv. Multiplexing ua rau kev siv kev siv cov bandwidth. Ntawm no yog ib daim duab uas qhia tau hais tias txoj ntsiab cai ntawm kev tshaj tawm qhov siab / kev sib tw siab.
Optical Mux thiab DeMux yuav tsum muaj kev sib txuas lus thiab kev sib tw rau ntau qhov txuas mus rau ib qho txuas tib si. Txhua tus I / O tshwj xeeb yuav raug siv rau ib lub tsho ntev. Ib qho kev lim kho qhov muag yuav ua tau raws li Mux thiab DeMux. Optical Mux thiab DeMux yog cov khoom siv fais fab kis tau yooj yim, uas npaj kom ua tiav cov kab txuas rau hauv thiab tawm ntawm kev thauj (feem ntau optical fiber). Cov txheej txheem kev lim lub wavelengths tuaj yeem ua tau siv Prisms , Thin Film Filter (TFF) , thiab Dichroic cov ntxaij lim dej lossis kev cuam tshuam kev cuam tshuam . Cov ntaub ntawv lim dej yog siv los xaiv kev ywj siab ntawm lub teeb ntawm lub teeb tiam sis dhau tag nrho lwm tus neeg. Txhua lub lim tau tig rau ib qho kev txheeb ze.
Cheebtsam ntawm Optical Multiplexer
Feem ntau, ib qho kev tshaj lij tau muaj Combiner , Kais Couplers (Ntxiv / Tee), Lim (Prisms, Nyias zaj duab xis, lossis Dichroic), Splitter , thiab Optical Fiber . Ntawm no yog ib daim duab uas qhia tau hais tias cov qauv ntawm ib qho kev tshaj lij qhov muag.
Optical Multiplexing Techniques
Muaj ntau yam peb hom kev sib txuam hauv ntau lub teeb pom kev zoo rau cov kev sib txuas ntawm fiber ntau: Optical Time Division Multiplexing (OTDM), Wavelength Division Multiplexing (WDM), thiab Code Division Multiplexing (CDM).
OTDM : Separating wavelengths nyob rau lub sijhawm.
WDM : Txhua channel tau txais ib qho kev sib tw tshwj xeeb; Channel yauv ntawm txog 50 GHz; Xws li WDM (CWDM) thiab ntom WDM (DWDM).
CWDM : Yam ntxwv los ntawm kev sib tshuam channel dua li DWDM.
DWDM : Siv ib txoj hlua sib tshuam ntau heev, yog li ntawd, ntau ntau wavelengths tau txais kev pab.
CDM : Kuj siv cov tshuaj microwave; Spectrum ntawm txhua lub wavelength raug muab tso rau txoj kev sib kis yooj yim; Cov Cheebtsam ob leeg nyob rau hauv lub sijhawm thiab kev muaj zog ntau tiam sis txoj kev qhia txog txhua lub wavelength.
Daim ntaub ntawv
Qhov kev pabcuam loj hauv kev sib txuas lus hauv kev sib txuas lus yog bandwidth-cov neeg siv xav xa tawm ntawm ntau tus nqi thiab cov neeg muab kev pabcuam xav muab ntau cov kev pabcuam, qhov no, qhov xav tau rau kev ceev dua thiab kev txhim khu kev kub ceev.
Txo cov nqi kho vajtse, ib qho kev siv ntau lub voj voos yuav siv tau los ua ke thiab xa tawm ntau qhov chaw ntawm Chaw Nyob mus rau Qhov chaw B.
Txhua lub wavelength, λ, tuaj yeem nqa tau ntau lub teeb meem.
Mux / DeMux pab kho qhov muag pib ntawm kev sib txuas lus hauv kev sib txuas lus thiab lwm yam ntawm kev teeb liab thiab kev sib kis.
Yav tom ntej tom ntej no internet.
Zoo Tshaj Plaws
Cov ntaub ntawv tawm tswv yim thiab cov ntaub ntawv dhau los: Cov ntaub ntawv muaj peev xwm ua tau rau kev sib kis tau yooj yim yog nyob rau hauv Gbps ntawm txhua lub sijhawm; Kev sib txuas ntawm ntau lub wavelengths txhais tau ntau dua kev nkag mus hauv ib qho kev sib txuas lus nruab.
Tsawg kawg ua rau me nyuam yaus: Kev sib txuas lus tsis zoo yog qhov sib piv tsawg dua rau lwm qhov kev sib txuas lus.
Tsawg tsawg kawg hais tawm qeeb.
Muaj kev pabcuam ntxiv.
Ua Ntej Rov Qab Mus Txog Nyiaj Txiag (ROI)
Qes tsawg ntsis yuam kev (BER)
Tsis paub lus
Fiber Tawm Zog thiab Kev Tshawb Fawb: Lub teeb liab los ntawm kev poob qab ploj thiab cuam tshuam los ntawm qhov sib txawv ntawm qhov sib txawv, ces tus neeg tsim nyog yuav tsum rov qab kho kom huv.
Tsis muaj peev xwm ntawm cov khoom siv niaj hnub siv tam sim no (CPE) kom tau txais tib lub sij hawm sib kis ntawm qhov kho tshuab xa mus (ua tiav tagnrho-optical networks).
Optical-to-Electrical Conversion Overhead: Cov teeb meem kev kos tau hloov mus rau hauv hluav taws xob teeb liab siv cov yees duab-detectors, hloov thiab hloov mus rau qhov kho qhov muag. Optical / hluav taws xob / kho qhov muag pom cov sij hawm qeeb thiab tsis muaj zog. End-to-kawg optical kis las yuav zoo dua.
Lub neej tom ntej
Kev tshawb fawb hauv cov khoom siv kho qhov kawg: Cov xov tooj ntawm tes, PC, thiab lwm yam cuab yeej siv tau txais thiab xa mus kho qhov muag.
Tsav ceev ntawm cov suab sib npaug.
Tsawg distortion los ntawm fiber ntau dispersion.
End-to-kawg kho qhov muag Cheebtsam: Tshem tawm qhov xav tau Optical-to-Electrical converter thiab visa piv.
Xaus
Thaum optical kis tau zoo dua piv rau lwm yam kev kis kab mob vim nws txoj kev txo qis thiab qhov kev sib tham ntev ntev, kev kho qhov muag pom tau zoo nyob rau hauv qhov teeb meem kev sib tw thiab kis tau los ntawm kev xa tawm ntau hom kev siv tib txuas. Raws li txoj kev loj hlob ntawm internet yuav tsum muaj fiber ntau kis kab mob kis tau los ntawm ntau dua kev nkag mus, optical multiplexing kuj tseem ceeb nyob rau hauv cov duab ua thiab xa daim ntawv thov.