Vazhinji vatengi vanobvunza pakusarudza ayakakosha vhidhiyo transmitter- chii chakasiyanaCOFDM isina waya vhidhiyo transmitteruye OFDM vhidhiyo transmitter?
COFDM ine Coded OFDM, Mune ino blog tichaikurukura kuti ikubatsire kuziva kuti ndeipi sarudzo ingave nani application yako.
1. OFDM
OFDM tekinoroji inokamura chiteshi chakapihwa mune akawanda orthogonal sub-channel mune frequency domain.Imwe subcarrier inoshandiswa kumodulation pane imwe neimwe subchannel, uye imwe neimwe subcarrier inofambiswa nenzira yakafanana.Nenzira iyi, kunyangwe iyo chiteshi chese chisiri-flat uye inosarudza frequency.Asi imwe neimwe subchannel yakati sandara.Narrowband transmission inoitwa pane imwe neimwe sub-channel, uye chiratidzo bandwidth idiki pane inoenderana bandwidth yechiteshi.Naizvozvo, kupindira pakati pechiratidzo waveforms kunogona kubviswa zvakanyanya.
Sezvo vatakuri veimwe sub-chiteshi vari orthogonal kune mumwe nemumwe muOFDM system.Mavara avo anopindirana.Izvi hazvingodzikisi kupindirana pakati pevatakuri, asi zvakare inovandudza spectrum kushandiswa.
2. COFDM
COFDMis Coded Orthogonal Frequency Division Multiplexing, zvinoreva kuti
pamberi peOFDM modulation, iyo yedhijitari kodhi rwizi inoiswa encoded.
Ko Coded iyi inoita sei?Iyo chiteshi coding (sosi coding ndeyekugadzirisa dambudziko rekuita, uye chiteshi coding ndeyekuona kuvimbika kwekutapurirana).
Iyo chaiyo nzira ndeye:
2.1.Forward Error Correction (FEC)
Semuenzaniso, 100 bits yedata inoda kugadziridzwanokutitransmitting.Kutanga shandura iyo ku200 bits,.Kana chiratidzo chikagamuchirwa, kunyangwe paine dambudziko nekufambiswa kwe100 bits, iyo data chaiyo inogona kuramba ichideredzwa.Muchidimbu, ndeye kuwedzera redundancy pamberi pemodulation kuvandudza kuvimbika kwekutapurirana.Izvi zvinodaidzwa kuti Internal Error Correction (FEC) muCOFDM masisitimu.Uye it yakakosha parameter yeCOFDM system.
2.2.Guard Interval
Fkana chinangwa solvingiyo yakawanda-dambudziko renzirandizvochiratidzo chinotapurirwa chinosvika kumagumo ekugamuchira kuburikidza neakawanda nzira dzekutumira. Anguva yevarindi inopinzwa pakati peiyo transmitted data bits.
3. Mhedziso
Musiyano uripo pakati peCOFDM neOFDM ndewekuti makodhi ekugadzirisa kukanganisa uye nguva dzevarindi dzinowedzerwa pamberi pe orthogonal modulation kuti kufambisa kwemasaini kushande.
OFDM inogadzirisa inosarudza chiteshi kupera muhuwandu-nzira nharaunda zvakanaka, asi haisati yakunda chiteshi flat fading.
COFDM inogonesa kupera kweiyo yega yeyuniti kodhi chiratidzo panguva yekufambisa kuti ionekwe seyakazvimiririra yakazvimirira kuburikidza nekodha, nekudaro kubvisa pesvedzero yeflat fading uye Doppler frequency shift.
4.Kushandiswa kweOFDM uye COFDM
COFDM yakanyatsokodzera kutapurirana isina waya panguvahigh speedkufamba.Zvakaita se Hd wirelesstransmittervehiclemkunze, zvikepemesh kutaurirana, zvikopokopoCofdm Hd Transmitter uyelongrangedronevideotransmitter.
COFDM zvakare ine yakasimba nlos kugona.Yakakodzera kushandiswa munzvimbo dzisingatarisirwi uye dzakavharidzirwa senge nzvimbo dzemadhorobha, masabhabhu, uye zvivakwa, uye inoratidza yakanakisa "diffraction" uye "kupinza" kugona.
OFDM inogonesa kushandiswa kwakanyanya kwakanaka kweiyo spectrum uye inokwanisa kuramba kune frequency yakasarudzwa kupera, iyo inogara ichishandiswa muLTE uye wifi network.
Nguva yekutumira: Jun-12-2023
