Kulumikizana kwa digito popanda zingwe: Mfundo yogwira ntchito ya IQ modulation

Kulumikizana kwa digito popanda zingwe: Mfundo yogwirira ntchito yaKusintha kwa mtengo wa IQ
IQ modulation ndiyo maziko a njira zosiyanasiyana zosinthira machitidwe apamwamba omwe amagwiritsidwa ntchito kwambiri m'madera a LTE ndi WiFi, monga BPSK, QPSK, QAM16, QAM64, QAM256, ndi zina zotero. Chifukwa njira zosinthira zomwe zimagwiritsidwa ntchito pamtundu uliwonse wa OFDM zikadali njira zingapo zosinthira za QAM kutengera kusinthika kwa IQ, ndipo makamaka, kukhazikitsidwa kwa OFDM ndikuwongolera kwa IQ modulation pazambiri za orthogonal subcarriers.
Malingaliro a I ndi Q mu IQ modulation amafanana ndi chidule cha mawu awiri achingerezi: Mu Phase ndi Quadrature, motsatana. Kungolankhula kuchokera ku tanthauzo lenileni, mayina a ma I ndi Q ma sign alibe tanthauzo. Kodi mu-phase ndi chiyani? Kodi orthogonality ndi chiyani? Ndi chizindikiro chanji chomwe chimagwiritsidwa ntchito ngati chizindikiritso cha-gawondi quadrature? Pakukhazikitsa koyenera, mafunde a cosine ndi sine a ma frequency omwewo amagwiritsidwa ntchito ngati ma I ndi Q ma sign. Chifukwa chake, chizindikiro cha cosine chomwe chimagwiritsidwa ntchito ngati chizindikiro cha I ndicho chizindikiro, chomwe ndi chizindikiro cha In Phase. Chizindikiro cha cosine chomwe chili ndi madigiri a 90 kunja kwa gawo ndi chizindikiro cha I mwachibadwa ndi chizindikiro chake cha Quadrature. Chifukwa chake kumvetsetsa kosavuta kwa ma IQ kusinthira ma sign ndikuwona chizindikiro cha I ngati chonyamulira cha cosine, ndi chizindikiro cha Q ngati siginecha yonyamula sine yokhala ndi kusiyana pafupipafupi kwa madigiri a 90 kuchokera pa chizindikiro cha I.

Zomwe zimatchedwa IQ modulation ndikugwiritsa ntchito ma sign a I, omwe ndi ma sign a cosine, ndi ma sign a Q, omwe ndi ma siginecha a sine (omwe ali ndi kusiyana kwa magawo 90 ndi orthogonal kwa wina ndi mnzake) pafupipafupi monga zonyamulira, kusinthira nthawi imodzi ma sign a baseband kwa onyamula awiriwo, kenako ndikuwongolera ma siginecha awiriwo ndikuwamasulira mozungulira ma RF. Pambuyo polandira chizindikiro cha mawayilesi, malekezero olandirira amachitaKusintha kwa IQ. Pa nthawi ya IQ demodulation, chifukwa zonyamulira ziwirizi ndi orthogonal kwa wina ndi mzake, zizindikiro ziwiri za baseband zikhoza kupatulidwa kuchokera ku chizindikiro chosakanikirana kutengera chizindikiro cha I ndi Q chonyamulira chomwe chimagwiritsidwa ntchito mumayendedwe am'mbuyomu ndikusinthidwa padera. Pazidziwitso zonse za I ndi Q zosinthidwa ndi IQ, kukulitsa matalikidwe achibale a mbali imodzi sikumangowonjezera matalikidwe a siginecha yosinthidwa, komanso kumapangitsa kuti gawo la siginecha yosinthidwayo lisunthike kumbali ndi kuchuluka kwa matalikidwe. Chifukwa chake, kusinthasintha kwa IQ ndikusinthasintha kwa matalikidwe komwe kumachitika pa chizindikiro cha I ndi chizindikiro cha Q, koma zotsatira zake sizimangokhudza matalikidwe a siginecha yosinthidwa, komanso kusintha kwake. Ili ndiye mfundo yoyambira yosinthira IQ ndikutsitsa.