MER: Matsakaicin kuskuren gyare-gyare, wanda shine rabo na ingantaccen ƙimar girman vector zuwa ƙimar ingancin girman kuskuren akan zanen taurari (rabo na murabba'in ma'aunin ma'auni mai ma'ana zuwa murabba'in girman girman kuskuren kuskure). . Yana ɗaya daga cikin manyan alamomi don auna ingancin siginar TV na dijital. Yana da mahimmanci ga sakamakon ma'aunin logarithmic na murdiya da aka mamaye kan siginar daidaitawa na dijital. Yana kama da rabon sigina-zuwa-amo ko rabon mai ɗauka-zuwa amo da aka yi amfani da shi a cikin tsarin analog. Tsarin shari'a ne Muhimmin sashi na juriyar rashin nasara. Sauran alamomi masu kama da irin su BER bit kuskure, rabon C/N mai ɗaukar nauyi, matsakaicin ƙarfin matakin ƙarfin, zanen taurari, da sauransu.
An bayyana ƙimar MER a cikin dB, kuma mafi girman ƙimar MER, mafi kyawun ingancin siginar. Mafi kyawun siginar, mafi kusancin alamomin gyare-gyare suna zuwa matsayi mai kyau, kuma akasin haka. Sakamakon gwajin MER yana nuna ikon mai karɓar dijital don mayar da lambar binary, kuma akwai maƙasudin siginar-zuwa-amo rabo (S/N) mai kama da na siginar baseband. Ana fitar da siginar da aka daidaita QAM daga ƙarshen gaba kuma yana shiga gida ta hanyar hanyar sadarwa. Alamar MER za ta tabarbare a hankali. A cikin yanayin zane na 64QAM na ƙungiyar taurari, ƙimar ƙima na MER shine 23.5dB, kuma a cikin 256QAM shine 28.5dB (fitarwa na gaba ya kamata ya zama idan ya fi 34dB, yana iya tabbatar da cewa siginar ta shiga gida kullum. , amma ba ya kawar da rashin daidaituwa da ingancin kebul na watsawa ko ƙananan gaba). Idan ya yi ƙasa da wannan ƙima, ba za a kulle zanen ƙungiyar taurari ba. MER nuna alama gaban-karshen samfurin fitarwa bukatun: Don 64/256QAM, gaban-karshen> 38dB, sub-gaba-gaba> 36dB, Tantancewar kumburi> 34dB, amplifier> 34dB (na biyu shine 33dB), ƙarshen mai amfani> 31dB (na biyu shine 33dB ), sama da 5 Hakanan ana amfani da maɓalli na MER don nemo matsalolin layin TV na USB.
Ana ɗaukar mahimmancin MER MER azaman nau'i na ma'aunin SNR, kuma ma'anar MER shine:
①. Ya haɗa da nau'ikan lalacewa iri-iri ga siginar: amo, leka mai ɗaukar kaya, rashin daidaituwar girman IQ, da hayaniyar lokaci.
②. Yana nuna ikon ayyukan dijital don mayar da lambobin binary; yana nuna girman lalacewar siginar TV na dijital bayan an watsa ta hanyar hanyar sadarwa.
③. SNR siga ce ta tushe, kuma MER siga ce ta mitar rediyo.
Lokacin da ingancin siginar ya ragu zuwa wani matakin, a ƙarshe za a canza alamomin ba daidai ba. A wannan lokacin, ainihin ƙimar kuskuren BER yana ƙaruwa. BER (Bit Kuskuren Rate): Ƙimar Kuskuren Bit, wanda aka ayyana azaman rabon adadin ragowar kuskure zuwa jimlar adadin ragowa. Don siginar dijital na binary, tun da ana watsa raƙuman binaryar, ƙimar kuskuren bit ana kiranta ƙimar kuskuren bit (BER).
BER = Kuskuren Ƙimar Bit/Total Bit.
Gabaɗaya ana bayyana BER a cikin bayanin kimiyya, kuma ƙananan BER, mafi kyau. Lokacin da siginar siginar yayi kyau sosai, ƙimar BER kafin da bayan gyara kuskure iri ɗaya ne; amma game da wasu tsangwama, ƙimar BER kafin da kuma bayan gyaran kuskure sun bambanta, kuma bayan gyaran kuskuren kuskuren bit yana da ƙasa. Lokacin da kuskuren bit ya kasance 2 × 10-4, mosaic na ɓangaren yana bayyana lokaci-lokaci, amma har yanzu ana iya duba shi; BER mai mahimmanci shine 1 × 10-4, adadi mai yawa na mosaics sun bayyana, kuma sake kunnawa hoton ya bayyana tsaka-tsaki; BER fiye da 1×10-3 ba za a iya duba shi kwata-kwata. kallo. Fihirisar BER tana da ƙimar tunani kawai kuma baya nuna cikakken matsayin duk kayan aikin cibiyar sadarwa. Wani lokaci yana faruwa ne kawai ta hanyar haɓaka kwatsam saboda tsangwama nan take, yayin da MER gaba ɗaya akasin haka. Za a iya amfani da dukkan tsarin azaman bincike na kuskuren bayanai. Saboda haka, MER na iya ba da gargaɗin farko don sigina. Lokacin da ingancin siginar ya ragu, MER zai ragu. Tare da karuwar hayaniya da tsangwama zuwa wani ɗan lokaci, MER zai ragu a hankali, yayin da BER ya kasance baya canzawa. Sai kawai lokacin da tsangwama ya ƙaru zuwa wani ɗan lokaci, MER BER yana fara lalacewa lokacin da MER ke faɗuwa akai-akai. Lokacin da MER ya faɗi zuwa matakin ƙofa, BER zai ragu sosai.
Lokacin aikawa: Fabrairu-23-2023