(1) ikhowudi ye-AMI
Ikhowudi ye-AMI(Alternative Mark Inversion) ligama elipheleleyo lenye ikhowudi yokuguqula uphawu, umgaqo wayo wokhowudo kukuguqula ngokutshintshanayo ikhowudi yomyalezo “1″ (uphawu) ukuya “+1″ kunye “-1″, ngelixa i-“0” ( uphawu olungenanto) luhlala lungatshintshanga. Umzekelo:
Ikhowudi yomyalezo: 0 1 1 0 0 0 0 0 0 0 0 0 1 1 0 0 1 1
AMI ikhowudi: 0-1 +1 0 0 0 0 0 0 0 0 0 0 0 0 1 +1 0 0 0 0 1 +1
I-waveform ehambelana nekhowudi ye-AMI nguloliwe we-pulse onamanqanaba amahle, angalunganga kunye ne-zero. Inokubonwa njengenguquko ye-unipolar waveform, oko kukuthi, "0" isahambelana nemigangatho engu-0, kwaye "1" ihambelana nemigangatho elungileyo kunye nengalunganga.
I-advanteji yekhowudi ye-AMI kukuba akukho nxalenye ye-DC, kwaye i-high and low frequency components incinci, kwaye amandla agxininiswe kwi-frequency ye-1/2 yeeyadi.
(Umfanekiso 6-4); Isekethe ye-codec ilula, kwaye impazamo yekhowudi inokubonwa ngokusebenzisa umgaqo we-alternating polarity yesiginali. Ukuba i-AMI-RZ i-waveform, emva kokuyifumana, nje ukuba ukulungiswa kwamaza okugcweleyo, kunokutshintshwa kwi-unipolar waveform ye-RZ, apho icandelo lexesha elincinci linokukhutshwa. Ngokujonga ezi zibonelelo zingentla, ikhowudi ye-AMI ibe yenye yeekhowudi zothumelo ezisetyenziswa ngokuqhelekileyo.
Ukungalungi kwekhowudi ye-AMI: Xa ikhowudi yoqobo inomtya "0" omde, inqanaba lophawu alitsibi ixesha elide, okukhokelela kubunzima bokukhupha uphawu lwexesha. Enye yeendlela ezisebenzayo zokusombulula ingxaki ye "0" ikhowudi kukusebenzisa ikhowudi ye-HDB3.
(2) ikhowudi ye-HDB3
Igama elipheleleyo lekhowudi ye-HDB3 yikhowudi yesithathu yoxinzelelo oluphezulu lwe-bipolar. Yinguqulelo ephuculweyo yekhowudi ye-AMI, injongo yokuphucula kukugcina inzuzo yekhowudi ye-AMI kwaye unqobe iintsilelo zayo, ukuze inani elithi "0" lingadluli ezintathu. Imigaqo yayo yokufaka iikhowudi imi ngolu hlobo lulandelayo:
Jonga inani looziro abaqhagamshelwe kwikhowudi yomyalezo. Xa inani lika "0" lingaphantsi okanye lilingana no-3, umgaqo wekhowudi uyafana naleyo yekhowudi ye-AMI. Xa inani leeqanda ezilandelelanayo lidlula kwisithathu, omnye kooziro abane abalandelelanayo ujikwa abe licandelwana kwaye endaweni yakhe kufakwe i-000V. I-V (ukuthatha ixabiso +1 okanye -1) kufuneka ibe ne-polarity efana neyangaphambili esecaleni engeyiyo-" 0 "i-pulse (kuba oku kwaphula umthetho wokutshintshwa kwe-polarity, i-V ibizwa ngokuba yi-pulse yokutshatyalaliswa). Iikhowudi ze-V ezimeleneyo kufuneka zitshintshwe. Xa ixabiso lekhowudi ye-V linokuhlangabezana neemfuno kwi-(2) kodwa lingenako ukuhlangabezana nale mfuneko, "0000" indawo yayo ithathwa ngu "B00V". Ixabiso lika-B liyafana nale ilandelayo ye-V pulse ukusombulula le ngxaki. Ngoko ke, u-B ubizwa ngokuba yi-pulse elawulayo. I-polarity yokuhanjiswa kwenombolo emva kwekhowudi engu-V kufuneka kwakhona itshintshe.
Ukongeza kwiinzuzo zekhowudi ye-AMI, ikhowudi ye-HDB3 ikwanciphisa inani "0" ikhowudi ukuya ku-3, ukuze ulwazi lwexesha lukhutshwe xa lufumana. Ngoko ke, ikhowudi ye-HDB3 yolona hlobo lwekhowudi lusetyenziswa kakhulu e-China naseYurophu nakwamanye amazwe, kunye nohlobo lwekhowudi yojongano lomthetho A PCM ngezantsi kwamaqela amane ikhowudi ye-HDB3.
Kwikhowudi ye-AMI engentla kunye nekhowudi ye-HDB3, ikhowudi nganye yesignali yokubini iguqulwa ibe yi-bit-bit yexabiso lenqanaba lesithathu (+1, 0,-1) ikhowudi, ngoko olu hlobo lwekhowudi lukwabizwa ngokuba yikhowudi ye-1B1T. Ukongeza, ikhowudi ye-HDBn inokuqulunqwa ukuze inani elithi "0" lingadluli n.
(3) ikhowudi ye-biphase
Ikhowudi yeBiphasic ikwabizwa ngokuba yikhowudi yaseManchester. Isebenzisa isikwere samaza esisikwere esilungileyo kunye esingalunganga sexesha elinye ukumela i-"0" kunye neform yayo yokuguqula imele "1". Omnye wemigaqo yekhowudi kukuba “0” ikhowudi imelwe yi “01” ikhowudi enamanani amabini, kwaye “ikhowudi engu-1” imelwe “yi-10” ikhowudi enamanani amabini, umzekelo:
Ikhowudi yomyalezo: 1 1 0 0 0 1 0 1
Ikhowudi yeBiphase: 10 10 01 01 10 01 10
I-bipolar code waveform yi-bipolar NRZ waveform enamanqanaba amabini kuphela epolarity echaseneyo. Inomphakamo wokutsiba kwindawo esembindini wesimboli ngasinye sokuphumla, ngoko iqulethe ulwazi olutyebileyo lwexesha, kwaye akukho candelo le-DC, kwaye inkqubo yokukhowuda ilula. Ukungalungi kukuba i-bandwidth ekhoyo iphindwe kabini, ukwenzela ukuba ukusetyenziswa kwebhendi ye-frequency kuncitshiswe. Ikhowudi ye-Biphase ilungele ukuhanjiswa koluhlu olufutshane lwezixhobo ze-terminal data, kwaye isoloko isetyenziswa njengohlobo lwekhowudi yothumelo kwinethiwekhi yendawo.
(4) Ikhowudi ye-biphase eyahlukileyo
Ukuze ucombulule iimpazamo zokubhaqa ezibangelwa ukuguqulwa kwe-polarity kwiikhowudi ze-biphasic, ingcamango yeekhowudi zokwahlula inokwamkelwa. Iikhowudi ze-Biphasic ziyangqamaniswa kwaye zimelwe kukutsiba kwenqanaba phakathi kobude bexesha lesimboli nganye (ukutsiba ukusuka ku-negative ukuya ku-positive kumele i-binary "0" kwaye ukutsiba ukusuka kwi-positive ukuya ku-negative kumele i-binary “1″). Kwi-coding ye-biphase eyahlukileyo, inqanaba lokutsiba embindini wento nganye lisetyenziselwa ungqamaniso, kwaye nokuba kukho ukutsiba okongezelelweyo ekuqaleni kwento nganye kusetyenziswa ukumisela ikhowudi yomqondiso. Ukuba kukho ukutsiba, kubonisa ibhinari "1", kwaye ukuba akukho tsiba, ibonisa ibhinary "0". Le khowudi isetyenziswa rhoqo kuthungelwano lwengingqi yendawo.
(5)ikhowudi yeCMI
Ikhowudi ye-CMI imfutshane kwikhowudi yokubuyisela uphawu, kwaye ifana nekhowudi ye-bipolar, ikwayikhowudi ye-bipolar flat. Imithetho yayo yokukhowuda yile: “1″ ikhowudi ngokunye imelwe ngu “11” kunye “00” neekhowudi ezinedijithi ezimbini; Ikhowudi ye-0 imelwe yi-01, kwaye i-waveform yayo iboniswe kwi-Figure 6-5 (c).
Ikhowudi ye-CMI kulula ukuyisebenzisa kwaye iqulethe ulwazi olutyebileyo lwexesha. Ukongeza, ekubeni i-10 liqela lekhowudi ekhubazekileyo, iikhowudi ezingaphezu kwezintathu aziyi kubonakala, kwaye lo mgaqo ungasetyenziselwa ukufumanisa impazamo enkulu. Le khowudi iye yanconywa yi-ITU-T njengohlobo lwekhowudi ye-PCM ye-quad-group code, kwaye ngamanye amaxesha isetyenziswe kwiinkqubo zokuhanjiswa kwentambo ye-optical kunye namazinga angaphantsi kwe-8.448Mb / s.
(6)Ikhowudi yokuvala ikhowudi
Ukuze kuphuculwe ukusebenza kwekhowudi yomgca, uhlobo oluthile lokuphindaphinda luyafuneka ukuze kuqinisekiswe ulungelelwaniso kunye nobuchule bokubona impazamo yeepatheni zekhowudi. Ukuqaliswa kwekhowudi yebhloko kunokufezekisa iinjongo zombini ukuya kwinqanaba elithile. Uhlobo lwekhowudi yebhloko inekhowudi ye-nBmB, ikhowudi ye-nBmT njalo njalo.
Ikhowudi ye-nBmB luhlobo lwekhowudi yebhloko, eyahlula ikhowudi yokubini ye-n-bit yomthombo wolwazi woqobo kwiqela, kwaye iyibuyisele kwiqela lekhowudi entsha ye-M-bit ikhowudi yokubini, apho m>n. Kuba m>n, ikhowudi entsha iseti inokuba ne-2^m indibaniselwano, ngoko ke kukho (2^m-2^n) ngaphezulu (2^m-2^n). Kwi-2 "indibaniselwano, iqela lekhowudi elikhethiweyo likhethwa njengeqela lekhowudi evumelekileyo ngandlela-thile, kwaye enye isetyenziswa njengeqela lekhowudi ekhubazekileyo ukufumana ukusebenza kakuhle kweekhowudi. Umzekelo, kwi-4B5B encoding, ibuyisela i-4-bit encoding nge-5-bit encoding, kukho kuphela 2^4=16 imidibaniso eyahlukeneyo ye-4-bit grouping, kunye ne-2^5=32 indibaniselwano eyahlukileyo ye-5- bit grouping. Ukuze sifezekise ungqamaniso, singakhetha amaqela ekhowudi ngendlela engekho ngaphezu kwesinye esikhokelayo "0" kunye nezimamva ezibini "0", kwaye amanye angasebenzi amaqela ekhowudi. Ngale ndlela, ukuba kukho ikhowudi ekhubazekileyo ebekwe ekupheleni kokufumana, kubonisa ukuba kukho impazamo yekhowudi kwinkqubo yokudlulisa, ngaloo ndlela iphucula ikhono lokubona impazamo yenkqubo. Iikhowudi ze-biphase kunye neekhowudi ze-CMI ezichazwe ngaphambili zinokuthathwa njengeekhowudi ze-1B2B.
Kwinkqubo yokunxibelelana kwe-fiber optical, m = n + 1 isoloko ikhethwa, kwaye ikhowudi ye-1B2B, ikhowudi ye-2B3B, ikhowudi ye-3B4B kunye nekhowudi ye-5B6B ithathwa. Phakathi kwabo, ikhowudi ye-5B6B isetyenziswe ekusebenzeni njengekhowudi yokuhambisa umgca kumaqela e-cubic kunye namaqela angaphezu kwe-quadruple.
Ikhowudi ye-nBmB ibonelela ngolungelelwaniso olulungileyo kunye nokufunyanwa kwempazamo, kodwa iza ngexabiso, oko kukuthi, ukunyuka kwe-bandwidth efunekayo.
Ingcamango yoyilo yekhowudi ye-nBmT kukuguqula iikhowudi zokubini kwiikhowudi ze-m ternary, kunye ne-m
Oku ngasentla Shenzhen HDV phoelectron Technology Ltd. ukukuzisela malunga "baseband transmission uhlobo ikhowudi eqhelekileyo" ulwazi, ithemba ukukunceda, Shenzhen HDV phoelectron Technology Ltd. ngaphezuI-ONUuthotho, uthotho lwe-transceiver,OLTseries, kodwa kwakhona ukuvelisa uthotho imodyuli, ezifana: Unxibelelwano imodyuli optical, imodyuli yonxibelelwano optical, network module optical, imodyuli yonxibelelwano optical, imodyuli ifayibha optical, Ethernet imodyuli ifayibha optical, njl., inokubonelela ngenkonzo ehambelanayo esemgangathweni kwiimfuno zabasebenzisi ezahlukeneyo ' , wamkele utyelelo lwakho.