EVM: impfunyapfunyo ya Error Vector Magnitude, bivuze amakosa ya vector amplitude.
Ikimenyetso cya digitale yumurongo wa bande ni uguhindura ibimenyetso bya baseband kumpera yoherejwe, kubyohereza kumurongo wohereza, hanyuma ukabimanura kumpera yakira kugirango ugarure ikimenyetso cyambere cya baseband. Muri ubu buryo, ikosa rya modulation ryakozwe na modulator, ubwiza bwibikoresho bya RF, urusaku rufunze feri (PLL) urusaku, ingaruka zo kugoreka PA, urusaku rwumuriro, hamwe nubushakashatsi bwa modulator byose bizabyara amakosa (EVM). EVM izagira ingaruka zikomeye kumiterere yibimenyetso byahinduwe, bityo umushinga wogupima ubuziranenge ni kimwe mubice byingenzi bigize ibizamini bya RF.
EVM yerekeza cyane cyane hafi yikintu cya IQ cyakozwe mugihe itumanaho ryerekana ibimenyetso nibimenyetso byiza. Nicyerekana ubuziranenge bwibimenyetso byahinduwe. Igihe kinini, ikosa ryikosa rifitanye isano na M-ary I / Q gahunda yo guhindura nka QPSK, kandi mubisanzwe byerekanwa nigishushanyo cya I / Q “inyenyeri” yerekana ibimenyetso bya demodulation.
Ikosa rya vector amplitude [EVM] risobanurwa nkikigereranyo cyumuzi bivuze kwaduka kwagaciro kwimpuzandengo yimbaraga zikigereranyo cyikimenyetso cyerekana imizi bivuze kwaduka kwaduka kwimbaraga zingana zimpuzandengo yikimenyetso cyiza kandi kigaragazwa nkijanisha. Gitoya ya EVM, nibyiza byerekana ibimenyetso.
Ikosa rya vector amplitude ni ugutandukana hagati yumurongo wapimwe wapimwe na teoretiki yahinduwe. Imiyoboro yombi ifite umurongo wa 1.28 MHz hamwe na coefficient ya 0.22. Imirongo ibiri yumurongo irahindurwa muguhitamo inshuro, icyiciro cyuzuye, amplitude yuzuye, hamwe na chip isaha yo kugabanya amakosa ya vector. Intera yo gupima ni umwanya umwe. Ikosa ntarengwa rya vector amplitude ntigomba kurenza 17.5%.
Intego yikizamini ni ukureba niba umurongo wakozwe na transmitter ari ukuri bihagije kugirango uwakiriye abone imikorere yo kwakira yakiriwe.
Nibimenyekanisha kuri EVM kuva muri Shenzhen HDV Optoelectronic Technology Co., Ltd., isosiyete itumanaho optique ikora ibicuruzwa byitumanaho. Murakaza neza kuribaza