EVM: khutsufatso ea Error Vector Magnitude, e bolelang hore phoso ea vector amplitude.
Phatlalatso ea sehlopha sa maqhubu a dijithale ke ho hlophisa lets'oao la baseband qetellong ea ho romella, ho e romella moleng bakeng sa phetiso, ebe o e theola pheletsong ea ho amohela ho khutlisa lets'oao la mantlha la baseband.Ts'ebetsong ena, phoso ea modulation e hlahisoang ke modulator, boleng ba lisebelisoa tsa RF, lerata la phase-locked loop (PLL), phello ea ho sotha PA, lerata la mocheso, le moralo oa modulator kaofela li tla hlahisa li-vector tsa liphoso (EVM).EVM e tla ba le tšusumetso e kholo boleng ba matšoao a fetotsoeng, kahoo projeke ea tlhahlobo ea boleng ba modulation ke e 'ngoe ea likarolo tsa bohlokoa tsa tlhahlobo ea RF.
EVM e bua ka ho hlaka ho ba haufi pakeng tsa karolo ea IQ e hlahisoang ha transmitter e theola lets'oao le karolo e nepahetseng ea lets'oao.Ke sesupo sa boleng ba lets'oao le fetotsoeng.Boholo ba nako, vector ea phoso e amana le merero ea ho feto-fetoha ha M-ary I / Q joalo ka QPSK, 'me hangata e bontšoa ke setšoantšo sa "naleli" sa I / Q sa matšoao a demodulation.
Bothata ba vector amplitude [EVM] e hlalosoa e le karo-karolelano ea motso oa boleng ba lisekoere tsa matla a mahareng a lets'oao la vector ea phoso ho motso o bolelang boleng ba lisekoere tsa matla a mahareng a lets'oao le loketseng 'me le hlahisoa e le peresente.Ha EVM e nyane, e ntlafatsa boleng ba matšoao.
Bothata ba vector amplitude ke ho kheloha lipakeng tsa waveform e lekantsoeng le waveform e fetotsoeng ka khopolo.Mefuta ena ka bobeli e na le bandwidth ea 1.28 MHz le coefficient ea roll-off ea 0.22.Li-waveform tse peli li fetoloa hape ka ho khetha frequency, mohato o felletseng, amplitude e felletseng, le nako ea nako ea chip ho fokotsa vector ea phoso.Nako ea ho lekanya ke nako ea nako e le 'ngoe.Boholo ba vector ea liphoso ha boa lokela ho feta 17.5%.
Sepheo sa teko ke ho bona hore na waveform e entsoeng ke transmitter e nepahetse ka ho lekaneng hore moamoheli a fumane ts'ebetso ea kamohelo e boletsoeng.
Ena ke kenyelletso ea EVM e tsoang ho Shenzhen HDV Optoelectronic Technology Co., Ltd., k'hamphani ea puisano ea optical e etsang lihlahisoa tsa puisano.Rea u amohela horerisana