Kulankhulana kwa digito kopanda zingwe: Mfundo yogwirira ntchito yosinthira IQ

Kulankhulana kwa digito kopanda zingwe: Mfundo yogwirira ntchitoKusintha kwa IQ
Kusinthasintha kwa IQ ndiye maziko a njira zosiyanasiyana zosinthira zamagetsi zomwe zimagwiritsidwa ntchito kwambiri m'magawo a LTE ndi WiFi, monga BPSK, QPSK, QAM16, QAM64, QAM256, ndi zina zotero. Kumvetsetsa mfundo yogwirira ntchito ya kusintha kwa IQ ndikofunikira kuti mumvetsetse bwino njira yoyambira yogwiritsira ntchito OFDM mu LTE ndi WiFi. Chifukwa njira zosinthira zamagetsi zomwe zimagwiritsidwa ntchito pa subcarrier iliyonse ya OFDM akadali njira zosiyanasiyana zosinthira za QAM kutengera kusintha kwa IQ, ndipo kwenikweni, kukhazikitsa kwa OFDM ndiko kuyika kwa kusintha kwa IQ pa subcarriers zingapo zozungulira.
Malingaliro a I ndi Q mu IQ modulation akugwirizana ndi chidule cha mawu awiri a Chingerezi: Mu Phase ndi Quadrature, motsatana. Kungotengera tanthauzo lenileni, mayina a zizindikiro za I ndi Q alibe tanthauzo. Kodi in-phase ndi chiyani? Kodi orthogonality ndi chiyani? Ndi chizindikiro chiti chomwe chimagwiritsidwa ntchito ngati chizindikiro chodziwira in-gawondi quadrature? Pochita zinthu mwanzeru, mafunde a cosine ndi sine okhala ndi ma frequency ofanana nthawi zambiri amagwiritsidwa ntchito ngati zizindikiro za I ndi Q. Chifukwa chake, chizindikiro cha cosine chomwe chimagwiritsidwa ntchito ngati chizindikiro cha I kwenikweni ndi chizindikiro chofotokozera, chomwe ndi chizindikiro cha In Phase. Chizindikiro cha cosine chomwe chili ndi madigiri 90 kunja kwa gawo ndi chizindikiro cha I mwachibadwa ndi chizindikiro chake cha Quadrature. Chifukwa chake kumvetsetsa kosavuta kwa zizindikiro za IQ modulation ndikuganizira chizindikiro cha I ngati chizindikiro chonyamulira cosine, ndi chizindikiro cha Q ngati chizindikiro chonyamulira sine chokhala ndi kusiyana kwa ma frequency a madigiri 90 kuchokera ku chizindikiro cha I.

Chomwe chimatchedwa IQ modulation ndikugwiritsa ntchito seti ya zizindikiro za I, zomwe ndi zizindikiro za cosine, ndi zizindikiro za Q, zomwe ndi zizindikiro za sine (zokhala ndi kusiyana kwa gawo la madigiri 90 ndi orthogonal kwa wina ndi mnzake) za pafupipafupi yofanana ndi zonyamula, kuti nthawi imodzi musinthe zizindikiro ziwiri za baseband ku zonyamula ziwirizo, kenako muwonjezere zizindikiro ziwiri zosinthidwa pamodzi ndikuzitumiza kudzera mu RF circuit. Pambuyo polandira chizindikiro cha pafupipafupi cha wailesi, gawo lolandira limagwira ntchito.Kuchepetsa IQ. Pa nthawi yochotsa IQ, chifukwa zonyamulira ziwirizi zimakhala zofanana, zizindikiro ziwiri za baseband zimatha kulekanitsidwa ndi chizindikiro chosakanikirana kutengera zizindikiro za I ndi Q zomwe zidagwiritsidwa ntchito kale mu njira yosinthira ndikusinthidwa padera. Pa zizindikiro zonse za I ndi Q zomwe zimasinthidwa ndi IQ, kuwonjezera kutalika kwa mbali imodzi sikungowonjezera kukula kwa chizindikiro chosinthidwa, komanso kumapangitsa gawo la chizindikiro chosinthidwa kusunthira kumbali ndi kukula kwa kukula. Chifukwa chake, kwenikweni, kusintha kwa IQ ndi kusintha kwa amplitude komwe kumachitika pa chizindikiro cha I ndi chizindikiro cha Q, koma zotsatira zake sizimangokhudza kukula kwa chizindikiro chosinthidwa, komanso kusintha kwake kwa gawo. Iyi ndiye mfundo yoyambira yogwirira ntchito yosinthira ndi kuchepetsa kwa IQ.