(1) AMI code
Lambar AMI (Madaidaicin Alamar Inversion) ita ce cikakken sunan madadin lambar juyar da alamar, ƙa'idar sa ta ɓoye ita ce ta canza lambar saƙon a madadin "1" (alama) zuwa "+1" da "-1", yayin da "0" ( alamar komai) ya kasance ba canzawa. Misali:
Lambar saƙo: 0 1 1 0 0 0 0 0 0 0 0 0 1 1 0 0 1 1
Lambar AMI: 0-1 +1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 +1 0 0 0 0 0 1 +1
Siffar igiyar igiyar igiyar ruwa wacce ke daidai da lambar AMI jirgin ƙasan bugun jini ne mai inganci, mara kyau da matakan sifili. Ana iya ganinsa azaman nakasar igiyar igiyar ruwa ta unipolar, wato, “0″ har yanzu yayi daidai da matakan sifili, kuma “1″ a madadin ya dace da matakan inganci da mara kyau.
Amfanin lambar AMI shine cewa babu wani abu na DC, kuma ƙananan ƙananan ƙananan ƙananan ƙananan ƙananan ƙananan ƙananan ƙananan, kuma makamashi yana mayar da hankali a mitar 1/2 yadi gudun.
(Hoto na 6-4); Da'irar codec abu ne mai sauƙi, kuma ana iya lura da kuskuren lambar ta amfani da ƙa'idar musanya polarity na sigina. Idan nau'in igiyar igiyar ruwa ce ta AMI-RZ, bayan an karɓi ta, idan dai an daidaita cikakkiyar igiyar igiyar ruwa, za a iya canza shi zuwa wani nau'in igiyar igiyar ruwa ta RZ, wanda daga ciki za a iya fitar da ɓangaren lokaci na bit. Dangane da fa'idodin da ke sama, lambar AMI ta zama ɗaya daga cikin lambobin watsawa da aka fi amfani da su.
Lalacewar lambar AMI: Lokacin da lambar asali tana da dogon “0″ kirtani, matakin siginar baya tsalle na dogon lokaci, yana haifar da wahala wajen fitar da siginar lokaci. Ɗaya daga cikin ingantattun hanyoyin magance matsalar “0″ code shine amfani da lambar HDB3.
(2) HDB3 code
Cikakken sunan lambar HDB3 shine lambar bipolar mai girma mai girma ta uku. Yana da ingantacciyar sigar lambar AMI, manufar haɓakawa ita ce kiyaye fa'idodin lambar AMI da shawo kan gazawarsa, ta yadda adadin “0″ bai wuce uku ba. Ka'idojin shigar da shi sune kamar haka:
Duba adadin sifili da aka haɗa zuwa lambar saƙon. Lokacin da adadin “0″ ya yi ƙasa da ko daidai da 3, ƙa'idar coding iri ɗaya ce da ta lambar AMI. Lokacin da adadin sifilai a jere ya wuce uku, kowane ɗayan sifili huɗu na jere ana juya shi zuwa ƙaramin yanki kuma a maye gurbinsu da 000V. V (ɗaukar darajar +1 ko -1) yakamata ya kasance yana da polarity iri ɗaya kamar na baya kusa da waɗanda ba” 0 “ bugun jini (saboda wannan ya karya ka'idar canjin polarity, V ana kiransa bugun bugun jini). Matsakaicin lambobi V-code dole ne su canza. Lokacin da ƙimar lambar V zata iya biyan buƙatun a cikin (2) amma ba zata iya cika wannan buƙatun ba, “0000″ ana maye gurbinsu da “B00V”. Darajar B iri ɗaya ce da bugun bugun V mai zuwa don magance wannan matsalar. Saboda haka, B ana kiranta bugun bugun jini. Matsakaicin watsa lambar bayan lambar V shima yakamata ya canza.
Baya ga fa'idodin lambar AMI, lambar HDB3 kuma tana iyakance adadin ko da “0″ code zuwa 3, ta yadda za a iya fitar da bayanin lokacin lokacin karɓa. Saboda haka, lambar HDB3 ita ce nau'in lambar da aka fi amfani da ita a China da Turai da sauran ƙasashe, kuma nau'in lambar doka ta PCM da ke ƙasa da ƙungiyoyi huɗu sune lambar HDB3.
A cikin lambar AMI da ke sama da lambar HDB3, kowace lambar siginar binaryar tana jujjuya zuwa lambar darajar matakin mataki-1-bit guda uku (+1, 0,-1), don haka irin wannan lambar kuma ana kiranta lambar 1B1T. Bugu da kari, ana iya tsara lambar HDBn ta yadda adadin “0″ bai wuce n.
(3) lambar biphase
Lambar Biphasic kuma ana kiranta da lambar Manchester. Yana amfani da raƙuman murabba'i masu inganci da mara kyau na lokaci ɗaya don wakiltar "0" da jujjuyawar raƙuman sa don wakiltar "1". Ɗaya daga cikin ƙa'idodin codeing shine cewa "0" lambar tana wakiltar "01" lambar lambobi biyu, kuma "1" lambar tana wakilta ta "10" lambar lambobi biyu, misali:
Lambar saƙo: 1 1 0 0 0 1 0 1
Lambar Biphase: 10 10 01 01 10 01 10
A bipolar code waveform ne mai bipolar NRZ waveform tare da matakai biyu kawai na kishiyar polarity. Yana da matakin tsalle a tsakiyar kowane tazara ta alama, don haka yana ƙunshe da wadataccen bayanan lokaci, kuma babu wani ɓangaren DC, kuma tsarin coding yana da sauƙi. Rashin hasara shi ne cewa bandwidth da aka mamaye yana ninka sau biyu, don haka an rage yawan amfani da band ɗin. Lambar Biphase ya dace don watsa gajeriyar hanya ta kayan aikin tashar bayanai, kuma galibi ana amfani dashi azaman nau'in lambar watsawa a cibiyar sadarwar yanki.
(4) Bambancin lambar biphase
Domin warware kurakuran yanke hukunci sakamakon juyewar polarity a cikin lambobin biphasic, ana iya ɗaukar ra'ayin lambobi daban-daban. Lambobin biphasic suna aiki tare kuma suna wakilta ta hanyar tsalle tsalle a tsakiyar kowace alama (tsalle daga korau zuwa tabbatacce yana wakiltar binary “0″ kuma tsalle daga tabbatacce zuwa korau yana wakiltar binary “1″). A cikin bambance-bambancen biphase codeing, matakin tsalle a tsakiyar kowane kashi ana amfani dashi don aiki tare, kuma ko akwai ƙarin tsalle a farkon kowane kashi ana amfani dashi don tantance lambar siginar. Idan akwai tsalle, yana nuna binary “1″, idan kuma babu tsalle, yana nuna binary “0″. Ana yawan amfani da wannan lambar a cibiyoyin sadarwar yanki.
(5) CMI code
Lambar CMI gajere ce don lambar juyar da alamar, kuma kama da lambar bipolar, ita ma lambar lebur mai bipolar ce. Dokokin coding ɗinta sune: “1″ code ana wakilta ta hanyar “11″ da “00″ lambobin lambobi biyu; Lambar 0 tana wakilta ta 01, kuma ana nuna sifarta a hoto 6-5(c).
Lambar CMI yana da sauƙin aiwatarwa kuma yana ƙunshe da bayanan lokaci mai albarka. Bugu da ƙari, tun da 10 ƙungiya ce ta nakasassu, fiye da lambobi uku ba za su bayyana ba, kuma ana iya amfani da wannan doka don gano kuskuren macro. ITU-T ce ta ba da shawarar wannan lambar a matsayin nau'in lambar mu'amala ta PCM quad-group, kuma wani lokaci ana amfani da ita a tsarin watsa kebul na gani tare da ƙimar ƙasa 8.448Mb/s.
(6)Block codeing
Domin inganta aikin coding na layi, ana buƙatar wasu nau'in sakewa don tabbatar da aiki tare da iya gano kuskuren ƙirar lambobin. Gabatarwar toshe codeing na iya cimma dalilai biyu zuwa wani lokaci. Sigar block codeing yana da lambar nBmB, lambar nBmT da sauransu.
nBmB code wani nau'i ne na block codeing, wanda ke raba n-bit binary code na asalin bayanan rafi zuwa rukuni, kuma ya maye gurbinsa zuwa sabon code group na M-bit binary code, inda m>n. Saboda m>n, sabon saitin lambar zai iya samun haɗin 2^m, don haka akwai ƙarin (2^m-2^n). A cikin 2 "haɗin, an zaɓi ƙungiyar lambar da ta dace azaman rukunin lambar da aka ba da izini ta wata hanya, sauran kuma ana amfani da su azaman rukunin lambar nakasassu don samun kyakkyawan aikin coding. Misali, a cikin 4B5B encoding, maye gurbin 4-bit encoding tare da 5-bit encoding, akwai kawai 2 ^ 4 = 16 haɗuwa daban-daban don rukunin 4-bit, da 2 ^ 5 = 32 haɗuwa daban-daban don 5- rukuni-rukuni. Domin samun aiki tare, za mu iya zaɓar ƙungiyoyin lamba ta hanyar da ba ta wuce ɗaya jagorar “0″ da ƙari biyu “0″, sauran kuma ƙungiyoyin lambar nakasassu ne. Ta wannan hanyar, idan akwai naƙasasshiyar lambar da aka saita a ƙarshen karɓa, yana nuna cewa akwai kuskuren lambar a cikin tsarin watsawa, don haka inganta ikon gano kuskuren tsarin. Lambobin biphase da lambobin CMI da aka kwatanta a baya ana iya ɗaukar su azaman lambobin 1B2B.
A tsarin sadarwar fiber na gani, ana yawan zaɓar m=n+1, kuma ana ɗaukar lambar 1B2B, lambar 2B3B, lambar 3B4B da lambar 5B6B. Daga cikin su, an yi amfani da lambar 5B6B a aikace a matsayin lambar watsa layin don ƙungiyoyi masu cubic da fiye da ƙungiyoyi huɗu.
Lambar nBmB tana ba da aiki tare mai kyau da gano kuskure, amma yana zuwa akan farashi, wato, bandwidth da ake buƙata yana ƙaruwa.
Tunanin ƙirar lambar nBmT shine canza n lambobin binary zuwa lambobin m, da m
Na sama shi ne Shenzhen HDV phoelectron Technology Ltd. don kawo muku game da "baseband watsa na kowa code type" ilmi, da fatan ya taimake ka, Shenzhen HDV phoelectron Technology Ltd. ban daONUjerin, transceiver jerin,OLTjerin, amma kuma samar da module jerin, kamar: Communication Optical module, Tantancewar sadarwa module, cibiyar sadarwa Tantancewar module, sadarwa Tantancewar module, Tantancewar fiber module, Ethernet Tantancewar fiber module, da dai sauransu, na iya samar da daidai ingancin sabis don daban-daban masu amfani 'bukatun. , barka da zuwan ku.