I-OFDM iphakanyiswe ku-IEEE802.11a. Ngokusekelwe kule ndlela yokushintshashintsha, sidinga ukwazi ukuthi iyini i-OFDM ukuze siqonde izimiso ezihlukene.
Yini i-OFDM?
I-OFDM iwubuchwepheshe obukhethekile bokushintshwa kwezinkampani eziningi. Lobu buchwepheshe buhlose ukuhlukanisa ishaneli ibe amashaneli amancane e-orthogonal, bese iguqula amasiginali wedatha enesivinini esikhulu abe imifudlana yedatha engaphansi enesivinini esincane ukuze idluliselwe ngokufanayo, eshintshwayo futhi idluliselwe kusiteshi esincane ngasinye. I-subcarrier ngayinye ine-orthogonal kwenye, futhi iziteshi zemvamisa ngemuva kokushintshwa kwe-spectrum yokusabalalisa zingadlulana, kunciphise ukugxambukela phakathi kwama-subcarriers nokuthuthukisa ukusetshenziswa kwe-spectrum.
Indlela yokuqonda i-orthogonal akukho ukuphazamiseka: lapho inkampani yenethiwekhi eyodwa ifinyelela phezulu, i-amplitude yesinye isithwali esingaphansi ngu-0. Okusho ukuthi, ama-subcarriers amabili ane-orthogonal ngaphandle kokuphazanyiswa. Njengoba kuboniswe esithombeni esingezansi, lapho i-amplitude yokufika eluhlaza okwesibhakabhaka iphakeme kakhulu, enye inkampani yenethiwekhi ingu-0.
Futhi, i-OFDM ingasebenzisa abathwali abangaphansi abagqagqana ngoba abathwali abancane bachazwa ngendlela eyenza kube lula ukuwahlukanisa.
Isignali ihlukaniswe yaba abathwali abathathu abangaphansi, ukusuka kwesobunxele kuye kwesokudla. Inani eliphakeme lenkampani yenethiwekhi engaphansi ngalinye lisetshenziselwa ukufaka ikhodi yedatha, njengoba kuboniswe ichashazi elibomvu emfanekisweni, elihambisana nomugqa wesikali ongu-0 ngezansi. Enye ifinyelela esiqongweni, kanti enye ifinyelela ku-0. Lezi zithwali ezingaphansi zenzelwe ngamabomu ukugcina ubudlelwano be-orthogonal nomunye nomunye. Ukuphakama kwenkampani yenethiwekhi ngayinye Ngalesi sikhathi, i-amplitude yezinye izithwali ezingaphansi ezimbili ngu-0.
5GHz OFDM isiteshi:
Isiteshi esingu-5GHz sinabathwali abangaphansi abangu-52, futhi inkampani yenethiwekhi ngayinye ino-312.5 kHz. Kuneziteshi ezingama-48 zokudlulisa idatha, kanti iziteshi ezi-4 zisetshenziselwa ireferensi yesigaba.
Ubuchwepheshe bokushintshwa kwesiteshi esincane se-OFDM busebenzisa i-QAM (i-QAM isifinyezo se-quadrature amplitude modulation, ehunyushwa ngokuthi “quadrature amplitude modulation” ngesiShayina). I-QAM isebenzisa i-amplitude nesigaba segagasi lesithwali ukuze idlulise ulwazi.
Okungenhla yincazelo yolwazi yephrothokholi ye-OFDM-802.11 olethelwe yonaI-Shenzhen HDV Phoelectron Technology Co., Ltd. ngethemba ukuthi lesi sihloko singakusiza ukukhulisa ulwazi lwakho. Ngaphandle kwalesi sihloko uma ufuna inkampani enhle yabakhiqizi bemishini yokuxhumana ye-fiber ongase uyicabangeleMayelana NATHI.
Imikhiqizo yokuxhumana ekhiqizwe yikhava yenkampani:
Imojuli: amamojula we-fiber optical, Amamojula we-Ethernet, amamojula we-fiber optical transceiver, amamojula okufinyelela kwefiber optical, Amamojula we-SSFP optical, futhiImicu ye-Optical SFP, njll.
I-ONUisigaba: EPON ONU, AC ONU, i-fiber optical ONU, I-CATV ONU, I-GPON ONU, XPON ONU, njll.
OLTisigaba: Ukushintsha kwe-OLT, I-GPON OLT, I-EPON OLT, ukuxhumanaOLT, njll.
Imikhiqizo engenhla ingasekela izimo zenethiwekhi ezahlukahlukene. Kule mikhiqizo engenhla, ithimba le-R & D eliqeqeshiwe nelinamandla limataniswe ukuze linikeze amakhasimende ukwesekwa kobuchwepheshe, futhi ithimba lebhizinisi elicabangayo nelichwepheshile linganikeza izinsizakalo zekhwalithi ephezulu kumakhasimende kusenesikhathi.ukubonisanafuthi kamuva umsebenzi.