Mgbama baseband dijitalụ bụ ụdị ọkụ eletrik na-anọchi anya ozi dijitalụ, nke enwere ike ịnọchite anya ọkwa dị iche iche ma ọ bụ usu. Enwere ọtụtụ ụdị akara ngosi baseband dijitalụ (nke a na-akpọ akara ngosi baseband). Onyonyo 6-1 na-egosi ụdị mgbama mgbaama baseband ole na ole, anyị ga-ejikwa usu akụkụ anọ dịka ọmụmaatụ.
1. Unipolar ebili mmiri
Dịka egosiri na eserese 6-1(a), nke a bụ ụdị mgbama mgbama baseband kacha mfe. Ọ na-eji ọkwa dị mma na ọkwa efu na-anọchi anya ọnụọgụ ọnụọgụ abụọ "1" na "0," ma ọ bụ ọ na-eji ọnụnọ ma ọ bụ enweghị pulses na-anọchi anya "1" na "0" na oge akara. bụ na ọ dịghị etiti oge n'etiti ọkụ eletrik, polarity bụ otu, na ọ na-adị mfe site na TTL na CMOS sekit. Enwere ike izipu ya n'ime kọmputa ma ọ bụ n'etiti ihe dị ezigbo nso, dị ka bọọdụ sekit e biri ebi na chassis.
2. Bipolar waveform
Ọ na-eji nti na-adịghị mma larịị pulses na-anọchi anya ọnụọgụ abụọ digits "1" na "0," dị ka e gosiri na Figure 6-1 (b) .N'ihi na nti na-adịghị mma etoju nwere hà amplitudes na-emegide polarities, ọ dịghị DC akụrụngwa mgbe. ihe gbasara nke puru omume nke "1" na "0" na-egosi, nke na-eme ka mgbasa ozi na ọwa, na ọkwa mkpebi maka iweghachi mgbaàmà na njedebe na-enweta bụ efu, Ya mere, ọ dịghị emetụta mgbanwe nke àgwà ọwa, na ikike mgbochi nnyonye anya dịkwa ike. ITU-T's V.24 interface standard na American Electrotechnical Association's (EIA) RS-232C interface standard ma na-eji ụdị ebili mmiri bipolar.
3. Unipolar nloghachi-na-efu ebili mmiri
Ogologo usu na-arụ ọrụ nke nlọghachi-na-efu (RZ) waveform bụ ihe na-erughị akara obosara T, nke pụtara na voltaji mgbaama na-alaghachi na efu mgbe niile tupu oge nkwụsị nke akara, dị ka egosiri na Figure 6-1(c). ).gosi. Na-emekarị, nlọghachi-na-efu waveform na-eji koodu ọkara ọrụ, ya bụ, ọrụ okirikiri (T/TB) bụ 50%, na ozi oge nwere ike wepụta ozugbo site na unipolar RZ waveform. mgbanwe ebili mmiri.
kwekọrọ n'ụdị ebili mmiri na-alaghachi-na-efu. Unipolar na bipolar waveforms dị n'elu bụ nke na-adịghị alaghachi na efu (NRZ) ebili mmiri nwere okirikiri ọrụ nke.
4.Bipolar nloghachi-na-efu waveform
Ọ bụ nlọghachi-na-efu ụdị nke bipolar waveform, dị ka e gosiri na Figure 6-1(d). Ọ na-ejikọta njirimara nke bipolar na nlọghachi-na-efu. N'ihi na enwere ohere ohere efu n'etiti mkpụrụ akụ dị n'akụkụ, onye nnata nwere ike ịchọpụta oge mmalite na njedebe nke akara ọ bụla, ka onye na-ezipụ na onye nnata wee nwee ike jikwaa mmekọrịta ntakịrị. Uru a na-eme ka ebili mmiri bipolar nulling bara uru.
5. Ụdị ebili mmiri dị iche iche
Ụdị ebili mmiri a na-egosipụta ozi ahụ na mgbanwe na mgbanwe nke ọkwa nke akara dị n'akụkụ, n'agbanyeghị ike ma ọ bụ polarity nke akara ahụ n'onwe ya, dị ka egosiri na Figure 6-1 (e). N'ọnụọgụ a, "1" na-anọchi anya ya site n'ịwụ elu larịị, na "0" na-anọchi anya ọkwa agbanweghị. N'ezie, ihe ndị a dị n'elu nwekwara ike gbanwee. Ebe ọ bụ na ụdị ebili mmiri dị iche na-anọchi anya ozi site na mgbanwe mgbanwe nke ọkwa pulse dị n'akụkụ, a na-akpọkwa ya koodu ebili mmiri n'otu aka ahụ, nke bu unipolar ma ọ bụ bipolar waveform ka a na-akpọ koodu waveform zuru oke. Iji ụdị ebili mmiri dị iche iche na-ebuga ozi nwere ike iwepụ mmetụta nke ọnọdụ mmalite nke ngwaọrụ ahụ, karịsịa na usoro mgbanwe nke oge. Enwere ike iji ya dozie nsogbu nke ambiguity nke ụgbọelu.
6. Multi-larịị ebili mmiri
Enwere naanị ọkwa abụọ nke ụdị ebili mmiri dị n'elu, ya bụ, otu akara ọnụọgụ abụọ dabara na otu usu. Iji meziwanye ojiji nke bandwit ugboro ugboro, enwere ike iji ụdị ebili mmiri dị n'ọkwa dị iche iche ma ọ bụ ọtụtụ uru. Ọgụgụ 6-1 (f) na-egosi ọkwa 2B1Q nwere ọkwa anọ (bit abụọ na-anọchi anya otu n'ime ọkwa anọ), ebe 11 na-anọchi anya + 3E, 10 na-anọchi anya + E, 00 na-anọchi anya -E, na 01 na-anọchi anya -3E. A na-eji ụdị ebili mmiri dị iche iche na sistemụ nnyefe data dị elu nwere eriri ugboro ole na ole. Ebe ọ bụ na otu pulse nke multi-level waveform kwekọrọ na ọtụtụ koodu ọnụọgụ abụọ, ọnụọgụ bit na-abawanye n'okpuru ọnọdụ nke otu baud ọnụego (otu bandwidth nnyefe). Ejila ya mee ihe n'ọtụtụ ebe.
Ekwesiri ighota na udiri ebili mmiri nke otu usu nke na-anọchite anya akara ozi abughi ihe anọ. Dị ka ezigbo mkpa na ọwa ọnọdụ, ndị ọzọ ụdị dị ka Gaussian pulse, zụlitere cosine pulse, wdg nwekwara ike iji. Mana n'agbanyeghị ụdị nke a na-eji ebili mmiri, enwere ike ịnọchite anya mgbama baseband dijitalụ na mgbakọ na mwepụ. Ọ bụrụ na ụdị ebili mmiri na-anọchi anya akara ndị ahụ bụ otu mana ụkpụrụ ọkwa dị iche.
Nke a bụ "Okwu mmalite nke Digital Baseband Signal Waveforms" nke Shenzhen HDV Phoelectron Technology Co., Ltd. wetara gị, enwere m olileanya na isiokwu a nwere ike inyere gị aka ịbawanye ihe ọmụma gị. E wezụga nke a isiokwu ma ọ bụrụ na ị na-achọ ezigbo ngwa anya eriri nkwurịta okwu akụrụngwa emeputa ụlọ ọrụ ị nwere ike tụleegbasara anyị.
Shenzhen HDV photoelectric Technology Co., Ltd bụ tumadi a emeputa nke nkwurịta okwu ngwaahịa. Ka ọ dị ugbu a, akụrụngwa a na-emepụta na-ekpuchiUsoro ONU, ngwa anya modul usoro, Usoro OLT, nausoro transceiver. Anyị nwere ike ịnye ọrụ ahaziri maka ọnọdụ dị iche iche. A na-anabata gịndụmọdụ.
