OFDM yaperekedwa mu IEEE802.11a.Kutengera njira yosinthira iyi, tiyenera kudziwa kuti OFDM ndi chiyani kuti timvetsetse ma protocol osiyanasiyana.
Kodi OFDM ndi chiyani?
OFDM ndi ukadaulo wapadera wosinthira zinthu zambiri.Tekinoloje iyi ikufuna kugawa tchanelo kukhala njira zingapo za orthogonal, ndikusinthira ma data othamanga kwambiri kukhala mitsinje yapang'onopang'ono yolumikizirana yofananira, yomwe imasinthidwa ndikutumizidwa panjira iliyonse.Chingwe chilichonse chimakhala cha orthogonal kwa chimzake, ndipo mayendedwe afupipafupi pambuyo pa kufalikira kwa ma spectrum modulation amatha kulumikizana, kuchepetsa kusokoneza pakati pa subcarriers ndikuwongolera ma spectrum magwiritsidwe.
Momwe mungamvetsetse orthogonal palibe kusokoneza: pamene subcarrier imodzi ifika pachimake, matalikidwe a subcarrier wina ndi 0. Ndiko kuti, ma subcarriers awiri ndi orthogonal popanda kusokoneza.Monga momwe tawonetsera pachithunzichi, pamene matalikidwe a buluu akufika ali apamwamba kwambiri, chonyamulira china ndi 0.
Komanso, OFDM imatha kugwiritsa ntchito ma subcarriers omwe amalumikizana chifukwa ma subcarriers amafotokozedwa m'njira yomwe imawapangitsa kukhala osavuta kuwasiyanitsa.
Chizindikirocho chimagawidwa m'magulu atatu, kuchokera kumanzere kupita kumanja.Chiwongola dzanja chilichonse chimagwiritsidwa ntchito polemba ma data, monga momwe tawonetsera padontho lofiira pachithunzichi, lomwe limafanana ndi mzere wa 0 pansipa.Mmodzi amafika pachimake, ndipo ena onse amafika 0. Ma subcarriers awa amapangidwa mwadala kuti azikhala ndi ubale wa orthogonal wina ndi mnzake.Pachimake cha chonyamulira chilichonse Pakali pano, matalikidwe a ma subcarriers enawo ndi 0.
5GHz OFDM njira:
Njira ya 5GHz ili ndi 52 subcarriers, ndipo subcarrier iliyonse ili ndi 312.5 kHz.Pali njira 48 zotumizira deta, ndipo mayendedwe 4 amagwiritsidwa ntchito pofotokozera gawo.
Tekinoloje ya OFDM subchannel modulation imagwiritsa ntchito QAM (QAM ndiye chidule cha quadrature amplitude modulation, chomwe chimatanthauziridwa kuti "quadrature amplitude modulation" mu Chitchaina).QAM imagwiritsa ntchito matalikidwe ndi gawo la mafunde onyamula kuti atumize zambiri.
Zomwe zili pamwambazi ndikulongosola kwachidziwitso cha protocol ya OFDM-802.11 yobweretsedwa kwa inuMalingaliro a kampani Shenzhen HDV Phoelectron Technology Co., Ltd.ndikukhulupirira kuti nkhaniyi ingakuthandizeni kukulitsa chidziwitso chanu.Kupatula nkhaniyi ngati mukuyang'ana kampani yabwino yopanga zida zoyankhulirana zama fiber zomwe mungaganizirezambiri zaife.
Zinthu zoyankhulirana zopangidwa ndi kampaniyi zikuphimba:
Module: Optical fiber modules, Ethernet modules, Optical fiber transceiver modules, optical fiber access modules, SSFP Optical modules,ndiSFP kuwala ulusi, ndi zina.
Gulu la ONU: EPON ONU, AC ONU, Optical fiber ONU, CATV ONU, GPON ONU, XPON PA, ndi zina.
kalasi ya OLT: Kusintha kwa mtengo wa OLT, Mtengo wa GPON OLT, EPON OLT, kulankhulana OLT, etc.
Zomwe zili pamwambazi zimatha kuthandizira zochitika zosiyanasiyana zapaintaneti.Pazinthu zomwe zili pamwambazi, gulu la akatswiri komanso lamphamvu la R & D limaphatikizidwa kuti lipereke chithandizo chaukadaulo kwa makasitomala, ndipo gulu loganiza bwino komanso laukadaulo litha kupereka chithandizo chapamwamba kwambiri kwa makasitomala oyambirira.kukambilanandipo kenako ntchito.