ʻO ka Constellation kahi manaʻo kumu i ka modulation kikohoʻe. Ke hoʻouna mākou i nā hōʻailona kikohoʻe, ʻaʻole mākou e hoʻouna pololei i ka 0 a i ʻole 1, akā e hana mua i kahi hui o 0 a me 1 hōʻailona (bits) e like me hoʻokahi a i ʻole. Eia kekahi laʻana, hoʻokumu nā ʻāpana ʻelua i hui, ʻo ia hoʻi, 00, 01, 10, a me 11. ʻEhā mokuʻāina ka huina (inā ʻaʻohe ʻekolu mau ʻāpana, ʻewalu mau mokuʻāina, a pēlā aku). I kēia manawa, hiki iā mākou ke koho i ka QPSK (ʻehā-phase modulation, e pili ana i nā mokuʻāina ʻehā ma mua o 00, 01, 10, a me 11), ʻO nā helu QPSK ʻehā i hana i ka constellation QPSK. He 90 degere ka mamao o kēlā me kēia kiko mai nā kiko pili (he like ka amplitude). ʻO kahi helu constellation e pili ana i kahi hōʻailona modulation. Ma kēia ala, ʻo kēlā me kēia hōʻailona modulation i hoʻouna ʻia he pālua ka nui o ka ʻike ma mua o ka hoʻouna ʻana.
QPSK modulation constellation
ʻO ke kiʻikuhi hoku o ka hōʻailona i loaʻa
I ka loaʻa ʻana a me ka demodulating i ka hōʻailona QPSK, e hoʻoholo i ka hōʻailona i hoʻouna ʻia e like me ka mamao ma waena o ka hōʻailona i loaʻa a me nā helu ʻehā o ka constellation (maʻamau i kapa ʻia ʻo ka mamao ʻEulopa), a e hoʻoholo i kahi kikoʻī e pili kokoke ana i kahi wahi no ka demodulation.
No laila, hoʻohana nui ʻia ke kiʻikuhi constellation no ka paʻi ʻana i ka wā modulation (e like me QPSK, 16QAM, 64QAM, etc.) a no ka ʻike ʻana i kahi kiko i hoʻouna ʻia i ka wā hoʻokipa i hiki ke hoʻoemi pololei ʻia ka ʻikepili.
ʻO ka mea i luna aʻe ka wehewehe ʻike o ka Constellation Chart i lawe ʻia e Shenzhen Haidiwei Optoelectronics Technology Co., Ltd., he mea hana kamaʻilio optical a hana i ka kamaʻilio.huahana.
