(1) Koodu AMI
Koodu AMI (Akara Mgbanwe ọzọ) bụ aha zuru oke nke koodu ntụgharị akara ọzọ, iwu ngbanwe ya bụ ịgbanwe koodu ozi “1″ (akara) ọzọ ka “+1″ na “-1″, ebe “0″ akara efu) na-agbanwe agbanwe. Ọmụmaatụ:
Koodu ozi: 0 1 1 0 0 0 0 0 0 0 0 1 1 0 0 1 1
Koodu AMI: 0-1 +1 0 0 0 0 0 0 0 0 0 0 0 1 +1 0 0 0 0 0 1 +1
Ụdị ebili mmiri kwekọrọ na koodu AMI bụ ụgbọ oloko pulse nwere ọkwa dị mma, adịghị mma na efu. Enwere ike ịhụ ya dị ka nrụrụ unipolar waveform, ya bụ, "0" ka dabara na ọkwa efu, yana "1" ọzọ kwekọrọ na ọkwa dị mma na nke na-adịghị mma.
Uru nke koodu AMI bụ na ọ nweghị akụrụngwa DC, na ihe ndị dị elu na nke dị ala dị ntakịrị, na ike na-etinye uche na ugboro nke 1/2 yard ọsọ.
(Foto nke 6-4); Sekit codec dị mfe, enwere ike ịhụ njehie nke koodu site na iji iwu nke ngbanwe polarity nke mgbaàmà. Ọ bụrụ na ọ bụ AMI-RZ waveform, mgbe ọ natachara ya, ọ bụrụhaala na mmezigharị ebili mmiri zuru ezu, enwere ike gbanwee ya ka ọ bụrụ ihe na-eme ka ọ bụrụ ihe na-adịghị mma nke RZ, nke nwere ike isi na ya wepụta akụkụ oge bit. N'ihi uru ndị a dị n'elu, koodu AMI aghọwo otu n'ime koodu nnyefe a na-ejikarị eme ihe.
Ọdịmma nke koodu AMI: Mgbe koodu izizi nwere ogologo “0″ eriri, ọkwa nke mgbaama anaghị awụlikwa elu ogologo oge, na-ebute ihe isi ike n'iwepụta akara oge. Otu n'ime ụzọ dị irè isi dozie nsogbu nke "0" koodu bụ iji HDB3 koodu.
(2) Koodu HDB3
Aha zuru oke nke koodu HDB3 bụ koodu bipolar nwere njupụta dị elu nke atọ. Ọ bụ ụdị koodu AMI emelitere nke ọma, ebumnuche nkwalite bụ ịnọgide na-enwe uru nke koodu AMI wee merie adịghị ike ya, nke mere na ọnụ ọgụgụ “0″ agaghị agafe atọ. Iwu itinye koodu ya bụ ndị a:
Lelee ọnụọgụ efu ejikọrọ na koodu ozi. Mgbe ọnụọgụ "0" erughị ma ọ bụ ha nhata na 3, iwu nzuzo bụ otu nke koodu AMI. Mgbe ọnụ ọgụgụ nke efu efu karịrị atọ, nke ọ bụla n'ime zeros anọ na-esochi na-atụgharị ka ọ bụrụ nkebi ma dochie 000V. V (na-ewere uru +1 ma ọ bụ -1) kwesịrị inwe otu polarity dị ka nke gara aga n'akụkụ na-abụghị " 0 "pulse (n'ihi na nke a na-emebi iwu nke polarity alternation, V na-akpọ mbibi usu). Oghere koodu V n'akụkụ ga-agbanwerịrị. Mgbe uru nke koodu V nwere ike imezu ihe achọrọ na (2) mana enweghị ike iru ihe a chọrọ, "0000" na-anọchi "B00V". Uru nke B bụ otu ihe na-esonụ V pulse iji dozie nsogbu a. Ya mere, B ka a na-akpọ pulse na-achịkwa. Polarity nke nnyefe nọmba ka koodu V ga-agbanwekwa ọzọ.
Na mgbakwunye na uru nke koodu AMI, koodu HDB3 na-amachikwa ọnụ ọgụgụ nke ọbụna "0" koodu na 3, ka e wee wepụta ozi oge mgbe ị na-enweta. Ya mere, koodu HDB3 bụ ụdị koodu a na-ejikarị eme ihe na China na Europe na mba ndị ọzọ, yana ụdị koodu interface nke PCM n'okpuru otu anọ bụ koodu HDB3.
N'ime koodu AMI dị n'elu na koodu HDB3, a na-atụgharị koodu mgbaama ọnụọgụ abụọ ọ bụla ka ọ bụrụ koodu uru otu-bit atọ (+1, 0,-1), ya mere a na-akpọkwa ụdị koodu a 1B1T koodu. Na mgbakwunye, enwere ike ịhazi koodu HDBn ka ọnụ ọgụgụ “0″ ghara agafe n.
(3) koodu biphase
A na-akpọkwa koodu biphasic dị ka koodu Manchester. Ọ na-eji ebili mmiri square symmetric dị mma na nke na-adịghị mma nke otu oge iji nọchite anya “0″ na ntụgharị ntụgharị ya ka ọ nọchite anya “1″. Otu n'ime iwu nzuzo bụ na koodu "0" nọchiri anya ya bụ "01" koodu ọnụọgụ abụọ, yana koodu "10" na-anọchi anya koodu ọnụọgụ abụọ, dịka ọmụmaatụ:
Koodu ozi: 1 1 0 0 0 1 0 1
Koodu nzipu ozi: 10 10 01 01 10 01 10
Usoro ebili mmiri bipolar bụ ụdị ebili mmiri NRZ bipolar nwere naanị ọkwa abụọ nke polarity na-emegide ya. Ọ nwere mmụba dị larịị n'etiti etiti akara akara ọ bụla, yabụ na ọ nwere ozi oge bara ụba, ọ nweghị akụrụngwa DC, yana usoro nzuzo dị mfe. Mwepu bụ na bandwit ejiri dị okpukpu abụọ, nke mere na ejiri eriri ugboro ugboro belata. Koodu biphase dabara adaba maka nnyefe ngwa ngwa data ọdụ data, a na-ejikarị ya dị ka ụdị koodu nnyefe na netwọk mpaghara.
(4) Koodu biphase dị iche
Iji dozie mpe mpe mpe mpe mpe mpe mpe akwa kpatara na koodu biphasic, enwere ike ịnakwere echiche nke koodu dị iche. A na-emekọrịta koodu biphasic ma na-anọchi anya ya site na mwụli elu n'etiti oge akara ọ bụla (ịwụli elu site na njọ gaa na nke ọma na-anọchi anya ọnụọgụ abụọ "0" na mwụli elu site na nke ọma gaa na-adịghị mma na-anọchi anya ọnụọgụ abụọ "1"). N'ime koodu biphase dị iche, a na-eji ọkwa elu n'etiti etiti nke ọ bụla emekọrịta ihe, yana ma enwere mwụli elu na mbido nke ọ bụla, a na-eji iji chọpụta koodu mgbama. Ọ bụrụ na enwere mwụli elu, ọ na-egosi ọnụọgụ abụọ “1″, ma ọ bụrụ na enweghị mwụli elu, ọ na-egosi ọnụọgụ abụọ “0″. A na-ejikarị koodu a na netwọk mpaghara.
(5) Koodu CMI
Koodu CMI dị mkpụmkpụ maka koodu ngbanwe akara, yana dị ka koodu bipolar, ọ bụkwa koodu flat bipolar bipolar. Iwu nzuzo ya bụ: “1″ koodu na-anọchi anya ọzọ site na “11″ na “00″ koodu ọnụọgụ abụọ; A na-anọchi anya koodu 0 site na 01, a na-egosikwa ụdị ifegharị ya na eserese 6-5(c).
Koodu CMI dị mfe iji mejuputa ma nwee ozi oge bara ụba. Na mgbakwunye, ebe 10 bụ otu koodu nkwarụ nwere nkwarụ, ihe karịrị koodu atọ agaghị apụta, enwere ike iji iwu a mee nchọpụta njehie nnukwu. ITU-T akwadoro koodu a dị ka ụdị koodu interface quad-group PCM, a na-ejikwa ya mgbe ụfọdụ na sistemụ nnyefe ngwa anya yana ọnụego n'okpuru 8.448Mb/s.
(6)Mgbochi koodu
Iji kwalite arụmọrụ nke koodu ntinye ahịrị, ọ dị mkpa ka ọ bụrụ ụdị nkwụghachi ụgwọ iji hụ na mmekọrịta na ike ịchọpụta njehie nke ụkpụrụ koodu. Iwebata koodu nzuzo nwere ike mezuo ebumnuche abụọ ahụ ruo n'ókè ụfọdụ. Ụdị nzuzo nzuzo nwere koodu nBmB, koodu nBmT na ndị ọzọ.
koodu nBmB bụ ụdị ngọngọ koodu, nke na-ekewa n-bit ọnụọgụ abụọ nke ozi izizi n'ime otu, ma dochie ya ka ọ bụrụ koodu koodu ọhụrụ nke koodu ọnụọgụ M-bit, ebe m>n. N'ihi na m>n, koodu ọhụrụ setịpụrụ nwere ike inwe nchikota 2^m, ya mere enwere ọtụtụ (2^m-2^n). Na 2 "nchịkọta, a na-ahọrọ otu koodu dị mma dị ka otu koodu ekwenyere n'ụzọ ụfọdụ, ma ndị ọzọ na-eji ya dị ka koodu nkwarụ nwere nkwarụ iji nweta ọrụ nzuzo dị mma. Dịka ọmụmaatụ, na ntinye 4B5B, dochie 4-bit encoding na ntinye 5-bit, enwere naanị 2^ 4 = 16 nchikota dị iche iche maka nchịkọta 4-bit, yana 2^ 5 = 32 nchikota dị iche iche maka 5- nchikota nke ntakiri. Iji nweta mmekọrịta, anyị nwere ike họrọ koodu otu n'ụzọ na-enweghị ihe karịrị otu na-eduga "0" na abụọ suffixes "0", na ndị ọzọ bụ nkwarụ koodu otu. N'ụzọ dị otú a, ọ bụrụ na enwere koodu nkwarụ setịpụrụ na njedebe nnata, ọ na-egosi na e nwere njehie koodu na usoro nnyefe, si otú a na-emeziwanye ikike nchọpụta njehie nke usoro ahụ. Koodu biphase na koodu CMI akọwara na mbụ nwere ike were ha abụọ dị ka koodu 1B2B.
N'ime sistemụ nkwurịta okwu fiber optic, a na-ahọrọkarị m = n+1, na-ewerekwa koodu 1B2B, koodu 2B3B, koodu 3B4B na koodu 5B6B. N'ime ha, ejirila koodu 5B6B mee ihe dị ka koodu nnyefe akara maka otu cubic na karịa otu anọ.
Koodu nBmB na-enye ezigbo mmekọrịta na nchọpụta njehie, mana ọ na-abịa na ọnụ ahịa, ya bụ, bandwidth achọrọ na-abawanye.
Echiche imewe nke koodu nBmT bụ ịtụgharị koodu ọnụọgụ abụọ n'ime koodu m ternary, yana m.
The n'elu bụ Shenzhen HDV phoelectron Technology Ltd. na-ewetara gị banyere "baseband nnyefe nkịtị koodu ụdị" ihe ọmụma, na-atụ anya inyere gị aka, Shenzhen HDV phoelectron Technology Ltd. na mgbakwunye naONUusoro, usoro transceiver,OLTusoro, ma na-emepụta modul usoro, dị ka: Communication ngwa anya modul, ngwa anya nkwurịta okwu modul, netwọk ngwa anya modul, nkwurịta okwu ngwa anya modul, ngwa anya eriri modul, Ethernet ngwa anya eriri modul, wdg, nwere ike inye kwekọrọ ekwekọ àgwà ọrụ maka dị iche iche ọrụ 'mkpa. , nabata nleta gị.