MER: Qhov kev hloov pauv yuam kev, uas yog qhov sib piv ntawm tus nqi zoo ntawm vector magnitude rau qhov zoo ntawm qhov yuam kev loj ntawm daim duab hnub qub (qhov piv ntawm lub square ntawm qhov zoo tagnrho vector magnitude rau square ntawm qhov yuam kev vector magnitude) . Nws yog ib qho ntawm cov cim tseem ceeb los ntsuas qhov zoo ntawm cov teeb liab TV digital. Nws yog ib qho tseem ceeb heev rau qhov kev ntsuas logarithmic ntawm qhov tsis sib haum xeeb superimposed ntawm lub teeb liab digital modulation. Nws zoo ib yam li lub teeb liab-rau-nruab piv lossis cov cab kuj-rau-nruj piv siv nyob rau hauv analog system. Nws yog qhov kev txiav txim siab qhov tseem ceeb ntawm kev ua siab ntev. Lwm cov kev ntsuas zoo sib xws xws li BER me ntsis yuam kev tus nqi, C / N cab kuj-rau-nruab piv, lub zog theem nruab nrab lub zog, daim duab hnub qub, thiab lwm yam.
Tus nqi ntawm MER yog qhia hauv dB, thiab qhov loj dua tus nqi ntawm MER, qhov teeb meem zoo dua. Qhov zoo dua lub teeb liab, qhov ze ntawm cov cim modulated yog mus rau qhov zoo tagnrho txoj hauj lwm, thiab vice versa. Cov txiaj ntsig ntawm MER qhia txog lub peev xwm ntawm tus txais digital los kho tus lej binary, thiab muaj lub hom phiaj teeb liab-rau-nruab nrab piv (S / N) zoo ib yam li cov teeb liab baseband. QAM-modulated teeb liab yog tso tawm los ntawm pem hauv ntej kawg thiab nkag mus rau hauv tsev los ntawm kev nkag mus network. Qhov taw qhia MER yuav maj mam deteriorate. Nyob rau hauv cov ntaub ntawv ntawm constellation daim duab 64QAM, tus nqi pib ntawm MER yog 23.5dB, thiab nyob rau hauv 256QAM nws yog 28.5dB (qhov tso zis pem hauv ntej-kawg yuav tsum yog hais tias nws siab tshaj 34dB, nws muaj peev xwm xyuas kom meej tias lub teeb liab nkag mus rau hauv lub tsev ib txwm. , tab sis nws tsis txiav txim siab qhov txawv txav tshwm sim los ntawm qhov zoo ntawm kev sib kis kab mob los yog lub hauv ntej kawg). Yog tias nws qis dua tus nqi no, daim duab hnub qub yuav tsis raug kaw. MER qhov taw qhia pem hauv ntej-kawg modulation tso zis yuav tsum: Rau 64/256QAM, pem hauv ntej-kawg> 38dB, sub-pem hauv ntej-kawg> 36dB, optical node> 34dB, amplifier> 34dB (secondary yog 33dB), cov neeg siv kawg> 31dB (secondary yog 33dB ), saum toj no 5 Lub ntsiab lus tseem ceeb MER kuj tseem siv tau los nrhiav cov teeb meem cable TV kab.
Qhov tseem ceeb ntawm MER MER yog suav tias yog ib hom kev ntsuas SNR, thiab lub ntsiab lus ntawm MER yog:
①. Nws suav nrog ntau hom kev puas tsuaj rau lub teeb liab: suab nrov, cov cab cab xau, IQ amplitude imbalance, thiab theem suab nrov.
②. Nws qhia txog lub peev xwm ntawm cov haujlwm digital los kho cov lej binary; nws qhia txog qhov kev puas tsuaj rau cov teeb liab TV digital tom qab kis tau los ntawm lub network.
③. SNR yog ib qho piv txwv hauv qab, thiab MER yog lub xov tooj cua zaus.
Thaum lub teeb liab zoo degrades mus rau ib theem, cov cim yuav nws thiaj li raug txiav txim tsis raug. Lub sijhawm no, qhov tseeb me ntsis yuam kev tus nqi BER nce. BER (Bit Error Rate): Me ntsis yuam kev tus nqi, txhais raws li qhov piv ntawm tus naj npawb ntawm cov khoom yuam kev rau tag nrho cov khoom. Rau binary digital signals, txij li thaum binary khoom kis tau tus mob, tus nqi me ntsis yuam kev yog hu ua qhov yuam kev me ntsis (BER).
BER = Yuam me ntsis tus nqi / Tag nrho tus nqi me ntsis.
BER feem ntau yog qhia nyob rau hauv scientific notation, thiab qhov qis BER, qhov zoo dua. Thaum lub teeb liab zoo heev, BER qhov tseem ceeb ua ntej thiab tom qab kho qhov yuam kev yog tib yam; tab sis nyob rau hauv cov ntaub ntawv ntawm qee qhov cuam tshuam, BER qhov tseem ceeb ua ntej thiab tom qab kev kho qhov yuam kev yog qhov sib txawv, thiab tom qab kev kho qhov yuam kev Tus nqi qis dua. Thaum qhov yuam kev me ntsis yog 2 × 10-4, ib nrab mosaic tshwm sim qee zaus, tab sis nws tseem tuaj yeem pom; BER qhov tseem ceeb yog 1 × 10-4, ntau tus mosaics tshwm sim, thiab cov duab rov qab zoo li tsis sib xws; BER ntau dua 1 × 10-3 tsis tuaj yeem saib tag nrho. saib. BER Performance index tsuas yog siv tus nqi thiab tsis qhia tag nrho cov xwm txheej ntawm tag nrho cov khoom siv network. Qee lub sij hawm nws tsuas yog tshwm sim los ntawm kev nce siab vim muaj kev cuam tshuam tam sim ntawd, thaum MER yog qhov sib txawv kiag li. Tag nrho cov txheej txheem tuaj yeem siv los ua cov ntaub ntawv yuam kev. Yog li, MER tuaj yeem muab kev ceeb toom ntxov rau cov teeb liab. Thaum lub teeb liab tsis zoo, MER yuav txo. Nrog rau kev nce suab nrov thiab cuam tshuam rau qee qhov, MER yuav maj mam txo qis, thaum BER tseem tsis hloov pauv. Tsuas yog thaum cuam tshuam nce mus rau qee qhov, MER Lub BER pib deteriorate thaum MER poob tas li. Thaum MER poob mus rau theem pib, BER yuav poob qis heev.
Post lub sij hawm: Feb-23-2023