Kamaʻilio kikohoʻe uea ʻole: Kumu hana o ka modulation IQ

Kamaʻilio kikohoʻe uea ʻole: Kumu hana oHoʻololi IQ
ʻO ka modulation IQ ke kumu o nā ʻano modulation kiʻekiʻe like ʻole i hoʻohana nui ʻia ma nā kahua LTE a me WiFi, e like me BPSK, QPSK, QAM16, QAM64, QAM256, a pēlā aku. ʻO ka hoʻomaopopo ʻana i ke kumumanaʻo hana o ka modulation IQ he mea nui ia no ka hoʻomaopopo maikaʻi ʻana i ke ʻano hoʻokō OFDM ma LTE a me WiFi. No ka mea, ʻo nā ʻano modulation i hoʻohana ʻia ma kēlā me kēia subcarrier o OFDM he mau ʻano hana modulation QAM like ʻole e pili ana i ka modulation IQ, a ʻo ke kumu, ʻo ka hoʻokō ʻana o OFDM ka superposition o ka modulation IQ ma nā subcarriers orthogonal he nui.
ʻO nā manaʻo o I a me Q i ka modulation IQ e pili ana i nā pōkole o ʻelua mau huaʻōlelo Pelekania: In Phase a me Quadrature, kēlā me kēia. Ma ka ʻōlelo wale ʻana mai ka manaʻo maoli, ʻaʻohe manaʻo o nā inoa o nā hōʻailona I a me Q. He aha ka in-phase? He aha ka orthogonality? He aha ka hōʻailona i hoʻohana ʻia ma ke ʻano he kuhikuhi e hoʻoholo ai i ka in-paea me ka quadrature? I ka hoʻokō pono ʻana, hoʻohana pinepine ʻia kahi hoʻonohonoho o nā nalu cosine a me sine o ka alapine like e like me nā hōʻailona I a me Q. No laila, ʻo ka hōʻailona cosine i hoʻohana ʻia ma ke ʻano he hōʻailona I ʻo ia ka hōʻailona kuhikuhi, ʻo ia hoʻi he hōʻailona In Phase. ʻO ka hōʻailona cosine he 90 degere ma waho o ka pae me ka hōʻailona I ʻo ia kona hōʻailona Quadrature. No laila, ʻo ka hoʻomaopopo maʻalahi loa o nā hōʻailona modulation IQ ʻo ia ka noʻonoʻo ʻana i ka hōʻailona I ma ke ʻano he hōʻailona lawe cosine, a ʻo ka hōʻailona Q ma ke ʻano he hōʻailona lawe sine me ka ʻokoʻa alapine o 90 degere mai ka hōʻailona I.

ʻO ka mea i kapa ʻia ʻo IQ modulation, ʻo ia ka hoʻohana ʻana i kahi hoʻonohonoho o nā hōʻailona I, ʻo ia hoʻi nā hōʻailona cosine, a me nā hōʻailona Q, ʻo ia hoʻi nā hōʻailona sine (me ka ʻokoʻa pae o 90 degere a orthogonal kekahi i kekahi) o ka alapine like me nā mea lawe, e hoʻololi i ʻelua mau hōʻailona baseband i nā mea lawe ʻelua, a laila e hoʻopili i nā hōʻailona modulated ʻelua a hoʻouna iā lākou ma o kahi kaapuni RF. Ma hope o ka loaʻa ʻana o ka hōʻailona alapine lekiō, hana ka hopena loaʻaKa demodulation IQ. I ka wā o ka demodulation IQ, no ka mea, he orthogonal kekahi i kekahi nā mea lawe ʻelua, hiki ke hoʻokaʻawale ʻia nā hōʻailona baseband ʻelua mai ka hōʻailona hui ʻia ma muli o nā hōʻailona lawe I a me Q i hoʻohana ʻia i ke kaʻina hana modulation ma mua a demodulation ʻokoʻa. No nā hōʻailona I a me Q i hoʻololi ʻia e IQ, ʻo ka hoʻonui ʻana i ka amplitude pili o kekahi ʻaoʻao ʻaʻole wale e hoʻonui i ka amplitude o ka hōʻailona modulated, akā e hoʻoulu pū i ka pae o ka hōʻailona modulated e neʻe i ka ʻaoʻao me ka hoʻonui ʻia o ka amplitude. No laila, ʻo ka modulation IQ ka modulation amplitude i hana ʻia ma ka hōʻailona I a me ka hōʻailona Q, akā ʻaʻole wale ka hopena modulation e hoʻopilikia i ka amplitude o ka hōʻailona modulated, akā ʻo kona loli pae. ʻO kēia ke kumu hana kumu o ka modulation IQ a me ka demodulation.