(1) AMI kodhi
AMI(Alternative Mark Inversion) kodhi ndiro zita rizere reimwe maki inversion kodhi, mutemo wayo weencoding ndeyekushandura meseji kodhi "1" (maka) kuita "+1" uye "-1", nepo "0" ( isina chinhu) inoramba isina kuchinjika. Semuyenzaniso:
Kodhi yemeseji: 0 1 1 0 0 0 0 0 0 0 0 1 1 0 0 1 1
AMI kodhi: 0-1 +1 0 0 0 0 0 0 0 0 0 0 0 1 +1 0 0 0 0 1 +1
Iyo waveform inoenderana neAMI kodhi chitima chinopuruzira chine zvakanaka, zvisina kunaka uye zero mazinga. Inogona kuonekwa seunipolar waveform deformation, kureva kuti, "0" ichiri kuenderana nemazinga e-zero, uye "1" inopindirana nemazinga akanaka uye asina kunaka.
Kubatsira kwe AMI kodhi ndeyekuti hapana DC chikamu, uye iyo yakakwira uye yakaderera frequency zvikamu zvidiki, uye simba rinoiswa pane frequency ye1/2 yadhi kumhanya.
(Mufananidzo 6-4); Iyo codec yedunhu iri nyore, uye kukanganisa kwekodhi kunogona kucherechedzwa nekushandisa mutemo wealternating polarity yechiratidzo. Kana iri AMI-RZ waveform, mushure mekuigamuchira, sekureba iyo yakazara wave rectification, inogona kuchinjwa kuita unipolar RZ waveform, kubva iyo iyo bit time chikamu chinogona kubviswa. Tichifunga nezvezvakanakira zviri pamusoro, AMI kodhi yave imwe yeanonyanya kushandiswa ekutumira makodhi.
Zvakaipa zve AMI kodhi: Kana iyo yekutanga kodhi ine refu "0" tambo, iyo nhanho yechiratidzo haisvetuke kwenguva yakareba, zvichikonzera kuomerwa mukuburitsa chiratidzo chenguva. Imwe yenzira dzinoshanda dzekugadzirisa dambudziko re "0" kodhi kushandisa HDB3 kodhi.
(2) HDB3 kodhi
Zita rizere reHDB3 kodhi ndeyechitatu-odha yepamusoro-density bipolar kodhi. Iyo yakagadziridzwa vhezheni yeAMI kodhi, chinangwa chekuvandudza ndechekuchengetedza zvakanakira AMI kodhi uye kukunda kukanganisa kwayo, kuitira kuti nhamba ye "0" isapfuure matatu. Mitemo yayo yekukodha ndeyotevera:
Tarisa huwandu hwemaziro akabatana nekodhi meseji. Kana iyo nhamba ye "0" iri pasi kana kuenzana ne3, mutemo wekukodha wakafanana neiyo AMI kodhi. Kana huwandu hwemazero akatevedzana huchipfuura matatu, imwe neimwe yechina yakatevedzana zero inoshandurwa kuita chidimbu uye inotsiviwa ne000V. V(kutora kukosha +1 kana -1) kunofanirwa kuve neiyo polarity yakafanana neyakare yakatarisana isiri-” 0 “kupuruzira (nekuti izvi zvinotyora mutemo wepolarity alternation, V inonzi the destroying pulse). Pedyo neV-code polarities inofanira kuchinjana. Kana kukosha kweV kodhi kuchikwanisa kuzadzisa zvinodiwa mu (2) asi isingakwanise kuita izvi, "0000" inotsiviwa ne "B00V". Kukosha kweB kwakafanana neinotevera V pulse kugadzirisa dambudziko iri. Nokudaro, B inonzi regulating pulse. Iyo polarity yekufambiswa kwenhamba mushure meiyo V kodhi inofanirawo kuchinjika.
Pamusoro pezvakanakira AMI kodhi, HDB3 kodhi zvakare inodzika nhamba ye "0" kodhi kusvika 3, kuitira kuti ruzivo rwenguva rugone kutorwa kana uchigamuchira. Naizvozvo, HDB3 kodhi ndiyo inonyanya kushandiswa kodhi mhando muChina neEurope nedzimwe nyika, uye iyo interface kodhi mhando yemutemo A PCM pazasi mapoka mana HDB3 kodhi.
Mune iyo iri pamusoro AMI kodhi uye HDB3 kodhi, yega yebhinari chiratidzo kodhi inoshandurwa kuita imwechete-bit matatu-nhanho kukosha (+1, 0,-1) kodhi, saka iyi mhando yekodhi inonzi zvakare 1B1T kodhi. Mukuwedzera, iyo HDBn kodhi inogona kugadzirwa kuitira kuti nhamba ye "0" isapfuure n.
(3) biphase code
Biphasic code inozivikanwawo seManchester kodhi. Inoshandisa iyo yakanaka uye isina kunaka symmetric square mafungu enguva imwe kumiririra "0" uye yayo inverting waveform kumiririra "1". Imwe yemitemo yekukodha ndeyekuti "0" kodhi inomiririrwa ne"01" kodhi ine manhamba maviri, uye "1" kodhi inomiririrwa ne"10" kodhi ine manhamba maviri, semuenzaniso:
Kodhi yemeseji: 1 1 0 0 0 1 0 1
Biphase code: 10 10 01 01 10 01 10
A bipolar code waveform is bipolar NRZ waveform ine mazinga maviri chete akatarisana polarity. Iyo ine nhanho yekusvetuka pakati pepakati pechiratidzo chega chega, saka ine yakapfuma ruzivo rwenguva, uye hapana DC chikamu, uye iyo coding process iri nyore. Izvo zvisingabatsiri ndezvekuti bandwidth inogarwa yakapetwa kaviri, kuitira kuti frequency band kushandiswa kuderedzwa. Biphase kodhi inokodzera kupfupi-renji kufambisa kwedhata terminal michina, uye inowanzoshandiswa seyekufambisa kodhi mhando munharaunda yenzvimbo network.
(4) Differential biphase code
Kuti ugadzirise zvikanganiso zve decoding zvakakonzerwa nekudzoserwa kwepolar mu biphasic codes, pfungwa yekusiyanisa macode inogona kugamuchirwa. Biphasic codes anowiriraniswa uye anomiririrwa nekusvetuka nhanho pakati penguva yechiratidzo chega chega (kusvetuka kubva kunegative kuenda kune yakanaka kunomiririra bhinari "0" uye kusvetuka kubva kune yakanaka kuenda kune yakaipa kunomiririra bhinari "1″). Mukusiyanisa biphase coding, nhanho yekusvetuka pakati pechinhu chimwe nechimwe inoshandiswa kuwiriranisa, uye kana paine kumwe kusvetuka kwekutanga kwechinhu chimwe nechimwe kunoshandiswa kuona kodhi yechiratidzo. Kana paine kusvetuka, zvinoratidza bhinari "1", uye kana pasina kusvetuka, inoratidza bhinary "0". Iyi kodhi inowanzo shandiswa mumambure emunharaunda.
(5)CMI kodhi
CMI kodhi ipfupi kune maki yekudzosera kodhi, uye yakafanana neiyo bipolar kodhi, iri zvakare bipolar bipolar flat kodhi. Mitemo yayo yekukodha ndeiyi: "1" kodhi inomiririrwa neimwe "11" uye "00" macode ane manhamba maviri; Iyo 0 kodhi inomiririrwa ne01, uye waveform yayo inoratidzwa muMufananidzo 6-5 (c).
CMI kodhi iri nyore kuita uye ine ruzivo rwakapfuma rwenguva. Mukuwedzera, sezvo 10 iboka rekodhi rakaremara, anopfuura matatu makodhi haazoonekwi, uye mutemo uyu unogona kushandiswa pakuona kukanganisa kukuru. Iyi kodhi yakakurudzirwa neITU-T sePCM quad-group interface code type, uye dzimwe nguva inoshandiswa mune optical cable transmission systems ine mazinga ari pasi pe8.448Mb / s.
(6)Vhara kukodha
Kuti uvandudze mashandiro emutsara wekukodha, imwe mhando yekudzokorora inodiwa kuti ive nechokwadi chekuwiriranisa uye kukanganisa kwekuona kugona kwekodhi mapatani. Kuunzwa kweblock coding kunogona kuzadzisa zvinangwa zvese kusvika pamwero wakati. Iyo fomu yeblock coding ine nBmB kodhi, nBmT kodhi uye zvichingodaro.
nBmB kodhi imhando yeblock coding, iyo inokamura n-bit bhinari kodhi yeyekutanga ruzivo rukova muboka, uye inoitsiva muboka idzva rekodhi reM-bit binary kodhi, uko m> n. Nekuti m>n, iyo nyowani kodhi seti inogona kunge iine 2^m misanganiswa, saka kune akawanda (2^m-2^n) misanganiswa. Mune 2 "musanganiswa, boka rekodhi rakanaka rinosarudzwa seboka rekodhi rakabvumirwa neimwe nzira, uye mamwe anoshandiswa seboka rekodhi rakaremara kuti riwane kushanda kwakanaka kwekodha. Semuenzaniso, mu4B5B encoding, kutsiva 4-bit encoding ne5-bit encoding, pane chete 2^4=16 misanganiswa yakasiyana ye4-bit grouping, uye 2^5=32 akasiyana misanganiswa ye5- bit grouping. Kuti tikwanise kuwiriranisa, tinogona kusarudza mapoka emakodhi nenzira isingapfuuri imwe inotungamira "0" uye maviri suffixes "0", uye mamwe ese akaremara macode mapoka. Nenzira iyi, kana pane kodhi yakaremara yakagadzwa pamagumo ekugamuchira, inoratidza kuti pane chikanganiso chekodhi muhutano hwekutumira, nokudaro kuvandudza kukwanisa kwekuona kukanganisa kwegadziriro. Iwo biphase makodhi uye CMI makodhi akatsanangurwa kare anogona kutorwa semakodhi e1B2B.
Mune optical fiber communication system, m = n + 1 inowanzosarudzwa, uye 1B2B code, 2B3B code, 3B4B code uye 5B6B code inotorwa. Pakati pavo, iyo 5B6B kodhi yakashandiswa mukuita senge mutsara wekutumira kodhi kumapoka ecubic uye anopfuura mapoka mana.
Iyo nBmB kodhi inopa kuwiriranisa kwakanaka uye kuona kukanganisa, asi inouya nemutengo, ndiko kuti, inodiwa bandwidth inowedzera.
Pfungwa yekugadzira yenBmT kodhi ndeyekushandura n mabhinari macode kuita m ternary codes, uye m
Zviri pamusoro iShenzhen HDV phoelectron Technology Ltd. kuti ikuunze nezve "baseband transmission common code type" ruzivo, tariro yekukubatsira, Shenzhen HDV phoelectron Technology Ltd.ONUseries, transceiver series,OLTdzakatevedzana, asiwo dzinogadzira module dzakatevedzana, dzakadai se: Kukurukurirana optical module, optical communication module, network optical module, communication optical module, optical fiber module, Ethernet optical fiber module, nezvimwewo, inogona kupa iyo inoenderana mhando sevhisi kune akasiyana vashandisi 'zvido , gamuchirai kushanya kwenyu.