(1) code AMI
ʻO ke code AMI (Alternative Mark Inversion) ka inoa piha o ke code inversion mark ʻokoʻa, ʻo kāna lula hoʻopāpā e hoʻololi i ke code memo "1" (mark) i "+1" a me "-1", aʻo ka "0" ( ʻaʻole hoʻololi ʻia ka hōʻailona hakahaka). ʻo kahi laʻana:
Ka helu memo: 0 1 1 0 0 0 0 0 0 0 0 0 1 1 0 0 1 1
AMI code: 0-1 +1 0 0 0 0 0 0 0 0 0 0 0 0 1 +1 0 0 0 0 1 +1
ʻO ka nalu e pili ana i ka code AMI he kaʻaahi pulse me nā pae maikaʻi, ʻino a me ka ʻole. Hiki ke ʻike ʻia ma ke ʻano he unipolar waveform deformation, ʻo ia hoʻi, “0″ i pili i nā pae ʻaʻohe, a ʻo “1″ pili i nā pae maikaʻi a me nā pae maikaʻi ʻole.
ʻO ka pōmaikaʻi o ka code AMI ʻaʻohe mea DC, a he liʻiliʻi nā ʻāpana kiʻekiʻe a haʻahaʻa, a paʻa ka ikehu ma ke alapine o 1/2 iwilei wikiwiki.
(Kiʻi 6-4); He maʻalahi ke kaʻapuni codec, a hiki ke ʻike ʻia ka hewa o ke code ma ka hoʻohana ʻana i ke kānāwai o ka polarity o ka hōʻailona. Inā he ʻano hawewe AMI-RZ, ma hope o ka loaʻa ʻana, ʻoiai ka lōʻihi o ka hoʻoponopono ʻana i ka nalu piha, hiki ke hoʻololi ʻia i kahi unipolar RZ waveform, kahi e hiki ai ke unuhi ʻia ka ʻāpana manawa bit. I ka nānā ʻana i nā pono i luna, ua lilo ka code AMI i hoʻokahi o nā code hoʻouna maʻamau.
Nā pōʻino o ke code AMI: Ke loaʻa i ke code kumu ke kaula lōʻihi "0", ʻaʻole e lele ka pae o ka hōʻailona no ka manawa lōʻihi, e hopena i ka paʻakikī i ka unuhi ʻana i ka hōʻailona manawa. ʻO kekahi o nā ala maikaʻi e hoʻoponopono ai i ka pilikia o ka "0″ code ʻo ia ka hoʻohana ʻana i ka code HDB3.
(2) code HDB3
ʻO ka inoa piha o ka code HDB3 ʻo ke kolu o ka helu bipolar kiʻekiʻe kiʻekiʻe. He mana hoʻomaikaʻi ia o ka code AMI, ʻo ke kumu o ka hoʻomaikaʻi ʻana ʻo ia ka mālama ʻana i nā pono o ka code AMI a lanakila i kona mau hemahema, i ʻole ka nui o ka "0" ma mua o ʻekolu. ʻO kāna mau lula hoʻopāpā penei:
E nānā i ka helu o nā zeros i pili i ke code memo. Ke emi ka helu o “0″ ma mua o ka 3, ua like ka lula coding me ka helu AMI. Ke oi aku ka heluna o na zeros hope i ekolu, e hooliloia kela a me keia o na zero hope eha i mahele a hoololiia e 000V. V(lawe i ka waiwai +1 a i ʻole -1) pono e loaʻa i ka polarity like me ka puʻupuʻu pili ʻole ma mua (no ka mea, ua haki kēia i ka lula o ka hoʻololi polarity, kapa ʻia ʻo V ka pulse luku). Pono nā polarities V-code pili. Ke hiki i ka waiwai o ke code V ke hoʻokō i nā koi ma (2) akā ʻaʻole hiki ke hoʻokō i kēia koi, ua pani ʻia ʻo "0000″ e "B00V". Ua like ka waiwai o B me ka V pulse e hoopau i keia pilikia. No laila, kapa ʻia ʻo B ka pulse hoʻoponopono. ʻO ka polarity o ka hoʻoili helu ma hope o ke code V pono e hoʻololi.
Ma waho aʻe o nā pōmaikaʻi o ka code AMI, ua kaupalena ʻia ka code HDB3 i ka helu o ke code "0" i ka 3, i hiki ke unuhi ʻia ka ʻike manawa i ka wā e loaʻa ai. No laila, ʻo ka code HDB3 ka mea i hoʻohana nui ʻia ma Kina a me ʻEulopa a me nā ʻāina ʻē aʻe, a ʻo ke ʻano code interface o ke kānāwai A PCM ma lalo o nā pūʻulu ʻehā he code HDB3.
Ma ka helu AMI a me ka code HDB3 ma luna, ua hoʻololi ʻia kēlā me kēia code hōʻailona binary i kahi helu helu ʻekolu pae (+1, 0,-1), no laila ua kapa ʻia kēia ʻano code 1B1T code. Eia hou, hiki ke hoʻolālā ʻia ke code HDBn i ʻole ka nui o ka helu "0" ma mua o n.
(3) code biphase
ʻIke ʻia ʻo Biphasic code ʻo Manchester code. Hoʻohana ʻo ia i nā hawewe huinahā kūpono a maikaʻi ʻole o ka manawa hoʻokahi e hōʻike i ka "0" a me kāna ʻano nalu hoʻohuli e hōʻike i "1". ʻO kekahi o nā lula coding ʻo ia ka "0" code e hōʻike ʻia e ka "01" helu helu ʻelua, a ʻo ka "1" code e hōʻike ʻia e ka "10" helu helu ʻelua, no ka laʻana:
Helu memo: 1 1 0 0 0 1 0 1
Ka helu helu ʻelua: 10 10 01 01 10 01 10
ʻO ka nalu helu bipolar he ʻano nalu NRZ bipolar me ʻelua wale nō pae o ka polarity kūʻē. Loaʻa iā ia kahi lele pae ma ke kiko waena o kēlā me kēia manawa hōʻailona, no laila, loaʻa i ka ʻike kiko manawa waiwai, a ʻaʻohe mea DC, a maʻalahi ke kaʻina hana coding. ʻO ka hemahema ʻo ia ka pālua ʻana o ka bandwidth i noho ʻia, no laila e hoʻemi ʻia ka hoʻohana ʻana i ka band frequency. He kūpono ke code Biphase no ka hoʻouna pōkole ʻana i nā lako kikowaena data, a hoʻohana pinepine ʻia ʻo ia e like me ke ʻano o ka hoʻouna ʻana i ke code ma ka pūnaewele wahi kūloko.
(4) Pākuʻi biphase ʻokoʻa
I mea e hoʻoponopono ai i nā hewa decoding i hoʻohuli ʻia e ka polarity reversal i nā code biphasic, hiki ke ʻae ʻia ka manaʻo o nā code differential. Hoʻonohonoho ʻia nā code Biphasic a hōʻike ʻia e ka lele pae ma waena o ka lōʻihi o kēlā me kēia hōʻailona (ʻo ka lele ʻana mai ka ʻino a i ka maikaʻi e hōʻike ana i kahi binary “0″ a me kahi lele mai ka maikaʻi a i ka maikaʻi ʻole e hōʻike ana i kahi binary “1″). Ma ka coding biphase ʻokoʻa, hoʻohana ʻia ka lele pae ma waena o kēlā me kēia mea no ka hoʻonohonoho ʻana, a inā he lele hou i ka hoʻomaka o kēlā me kēia mea e hoʻohana ʻia e hoʻoholo i ke code hōʻailona. Inā he lele, hōʻike ia i kahi binary “1″, a inā ʻaʻohe lele, hōʻike ia i kahi binary “0″. Hoʻohana pinepine ʻia kēia code ma nā pūnaewele wahi kūloko.
(5)CMI code
He pōkole ka CMI code no mark reversal code, a e like me ka bipolar code, he bipolar bipolar flat code. ʻO kāna mau lula paʻi: “1″ code ua hōʻike ʻia e “11″ a me “00″ mau helu helu ʻelua; Hōʻike ʻia ke code 0 e 01, a hōʻike ʻia kona ʻano nalu ma ke Kiʻi 6-5(c).
He mea maʻalahi ka CMI code e hoʻokō a loaʻa i ka ʻike manawa waiwai. Eia kekahi, no ka mea he hui code disabled ʻo 10, ʻaʻole e ʻike ʻia ma mua o ʻekolu mau code, a hiki ke hoʻohana ʻia kēia lula no ka ʻike hewa macro. Ua ʻōlelo ʻia kēia code e ITU-T ma ke ʻano he ʻano code interface PCM quad-group, a hoʻohana ʻia i kekahi manawa i nā ʻōnaehana hoʻouna uwea optical me nā uku ma lalo o 8.448Mb/s.
(6) Hoʻopaʻa paʻa
I mea e hoʻomaikaʻi ai i ka hana o ka laina coding, pono kekahi ʻano redundancy e hōʻoia i ka hoʻonohonoho ʻana a me ka hiki ke ʻike hewa o nā kumu code. Hiki i ka hoʻokomo ʻana i ka coding block ke hoʻokō i nā kumu ʻelua i kekahi ʻano. ʻO ke ʻano o ka coding block he code nBmB, code nBmT a pēlā aku.
ʻO ke code nBmB kekahi ʻano o ka poloka coding, e hoʻokaʻawale ana i ka code binary n-bit o ke kahawai ʻike kumu i loko o kahi hui, a hoʻololi iā ia i kahi pūʻulu code hou o M-bit binary code, kahi m>n. Ma muli o ka m>n, he 2^m ka hui pū ʻana o ke code hou, no laila ua nui aʻe nā hui (2^m-2^n). Ma ka hui 2 ", koho ʻia ka pūʻulu code maikaʻi e like me ka pūʻulu code i ʻae ʻia ma kekahi ʻano, a hoʻohana ʻia ke koena e like me ka hui code disabled e loaʻa ai ka hana coding maikaʻi. No ka laʻana, i loko o kahi hoʻopili 4B5B, e hoʻololi ana i kahi hoʻopili 4-bit me kahi encoding 5-bit, aia wale nō 2^4=16 hui like ʻole no kahi hui 4-bit, a me 2^5=32 mau hui like ʻole no kahi 5- hui puʻupuʻu. I mea e hoʻokō ai i ka hoʻonohonoho like ʻana, hiki iā mākou ke koho i nā pūʻulu code ma ke ʻano o ke alakaʻi ʻana i "0" a me ʻelua suffixes "0", a ʻo ke koena he mau pūʻulu code disable. Ma kēia ala, inā loaʻa kahi code kīnā i hoʻonohonoho ʻia ma ka hopena e loaʻa ai, e hōʻike ana aia kahi hewa code i ke kaʻina hoʻouna, no laila e hoʻomaikaʻi ai i ka hiki ke ʻike hewa o ka ʻōnaehana. Hiki ke manaʻo ʻia nā code biphase a me nā code CMI i hōʻike mua ʻia me nā code 1B2B.
Ma ka ʻōnaehana kamaʻilio fiber optical, koho pinepine ʻia ka m=n+1, a lawe ʻia ke code 1B2B, 2B3B code, 3B4B code a me 5B6B code. Ma waena o lākou, ua hoʻohana ʻia ka code 5B6B i ka hoʻomaʻamaʻa ma ke ʻano he code hoʻouna laina no nā hui cubic a ʻoi aku ma mua o nā hui quadruple.
Hāʻawi ka code nBmB i ka synchronization maikaʻi a me ka ʻike hewa, akā hele mai ia ma ke kumukūʻai, ʻo ia hoʻi, piʻi ka bandwidth i koi ʻia.
ʻO ka manaʻo hoʻolālā o ke code nBmT e hoʻohuli i nā code binary i m code ternary, a me m
ʻO ka mea i luna ʻo Shenzhen HDV phoelectron Technology Ltd. e lawe iā ʻoe e pili ana i ka ʻike "baseband transmission common code type", manaʻolana e kōkua iā ʻoe, Shenzhen HDV phoelectron Technology Ltd.ONUmoʻo, moʻo transceiver,OLTmoʻo, akā hana pū kekahi moʻo module, e like me: Communication optical module, optical communication module, network optical module, communication optical module, optical fiber module, Ethernet optical fiber module, etc., hiki ke hāʻawi i ka lawelawe kūpono kūpono no nā mea hoʻohana like ʻole. , hoʻokipa i kou kipa ʻana.