MER: Chiŵerengero cha zolakwika zosintha, chomwe ndi chiŵerengero cha mtengo wogwira ntchito wa kukula kwa vekitala ku mtengo wogwira mtima wa kukula kwa zolakwika pa chithunzi cha kuwundana kwa nyenyezi (chiŵerengero cha sikweya ya kukula kwa vekitala yabwino kwa sikweya ya kukula kwa vekitala yolakwika) . Ndi chimodzi mwa zizindikiro zazikulu zoyezera khalidwe la zizindikiro za digito za TV. Ndizofunikira kwambiri pazotsatira za kuyeza kwa logarithmic za kusokonekera komwe kumayikidwa pa siginecha yosinthira digito. Ndizofanana ndi chiŵerengero cha chizindikiro-ku-phokoso kapena chiŵerengero cha chonyamulira-ku-phokoso chomwe chimagwiritsidwa ntchito mu dongosolo la analogi. Ndi dongosolo la chiweruzo Mbali yofunika kwambiri ya kulephera kulolerana. Zizindikiro zina zofananira monga BER bit error rate, C/N carrier-to-noise ratio, power level average mphamvu, chojambula cha kuwundana, etc.
Mtengo wa MER umasonyezedwa mu dB, ndipo kukulira kwa mtengo wa MER kumapangitsa kuti chizindikirocho chikhale bwino. Pamene chizindikirocho chili bwino, zizindikiro zosinthidwa zimakhala pafupi ndi malo abwino, ndi mosemphanitsa. Zotsatira zoyeserera za MER zikuwonetsa kuthekera kwa wolandila digito kuti abwezeretse nambala ya binary, ndipo pali chiyerekezo cha cholinga cha signal-to-noise (S/N) chofanana ndi chizindikiro cha baseband. Chizindikiro cha QAM-modulated chimachokera kutsogolo ndikulowa m'nyumba kudzera pa intaneti. Chizindikiro cha MER chidzawonongeka pang'onopang'ono. Pankhani ya chithunzi cha kuwundana 64QAM, mphamvu ya MER ndi 23.5dB, ndipo mu 256QAM ndi 28.5dB (zotulutsa zakutsogolo ziyenera kukhala Ngati ndizokwera kuposa 34dB, zitha kuwonetsetsa kuti chizindikirocho chimalowa mnyumba mwanthawi zonse. , koma sizikutsutsa zolakwika zomwe zimachitika chifukwa cha khalidwe la chingwe chotumizira kapena kutsogolo kutsogolo). Ngati ili yotsika kuposa mtengo uwu, chithunzi cha nyenyezi sichidzatsekedwa. MER chizindikiro chakumapeto kotulutsa zotulutsa: Kwa 64/256QAM, kutsogolo> 38dB, sub-end> 36dB, Optical node> 34dB, amplifier> 34dB (yachiwiri ndi 33dB), kumapeto kwa ogwiritsa> 31dB (yachiwiri ndi 33dB ), pamwamba pa 5 A key MER point amagwiritsidwanso ntchito nthawi zambiri kupeza mavuto a chingwe cha TV.
Kufunika kwa MER MER kumatengedwa ngati muyeso wa SNR, ndipo tanthauzo la MER ndi:
①. Zimaphatikizapo mitundu yosiyanasiyana ya kuwonongeka kwa siginecha: phokoso, kutayikira kwa chonyamulira, IQ amplitude kusalinganika, ndi phokoso lagawo.
②. Imawonetsa kuthekera kwa ntchito za digito kubwezeretsa manambala a binary; imawonetsa kuchuluka kwa kuwonongeka kwa ma siginecha a digito pa TV pambuyo pofalitsidwa kudzera pa netiweki.
③. SNR ndi gawo la baseband, ndipo MER ndi gawo la ma radio frequency parameter.
Pamene khalidwe la siginecha likutsika mpaka pamlingo wina, zizindikirozo pamapeto pake zidzasinthidwa molakwika. Panthawiyi, kulakwitsa kwenikweni kwa BER kumawonjezeka. BER (Bit Error Rate): Chiwerengero cha zolakwika pang'ono, chomwe chimatanthauzidwa ngati chiŵerengero cha chiwerengero cha ma bits olakwika ku chiwerengero chonse cha ma bits. Kwa ma siginecha a digito, popeza mabizinesi amapatsirana, kuchuluka kwa zolakwika pang'ono kumatchedwa bit error rate (BER).
BER = Zolakwika Pang'ono Rate/Total Bit Rate.
BER nthawi zambiri imafotokozedwa muzolemba zasayansi, ndipo kutsika kwa BER, kumakhala bwinoko. Pamene khalidwe la chizindikiro liri labwino kwambiri, ma BER amayenera kuwongolera kusanachitike komanso pambuyo pake; koma pankhani ya kusokoneza kwina, ma BER amayenera kuwongolera pambuyo ndi pambuyo pake ndi zosiyana, ndipo pambuyo pa kuwongolera zolakwika Mlingo wolakwika pang'ono ndi wotsika. Pamene cholakwika pang'ono ndi 2 × 10-4, zojambula pang'ono zimawonekera nthawi zina, koma zimatha kuwonedwabe; BER yovuta kwambiri ndi 1 × 10-4, zojambulajambula zambiri zimawonekera, ndipo kusewera kwazithunzi kumawoneka kwapakatikati; BER wamkulu kuposa 1 × 10-3 sangathe kuwonedwa konse. penyani. Mlozera wa BER ndi wamtengo wapatali chabe ndipo suwonetsa bwino momwe zida zonse zapaintaneti zilili. Nthawi zina zimangoyamba chifukwa cha kuchuluka kwadzidzidzi chifukwa cha kusokoneza nthawi yomweyo, pomwe MER imatsutsana kwathunthu. Njira yonseyi ingagwiritsidwe ntchito ngati kusanthula zolakwika za data. Chifukwa chake, MER imatha kupereka chenjezo loyambirira lazizindikiro. Pamene khalidwe la chizindikiro likuchepa, MER idzachepa. Ndi kuwonjezeka kwa phokoso ndi kusokoneza pamlingo wina, MER idzachepa pang'onopang'ono, pamene BER imakhalabe yosasinthika. Pokhapokha kusokonezedwa kumachulukirachulukira, MER The BER imayamba kuwonongeka pomwe MER imatsika mosalekeza. Pamene MER imatsikira pamtunda, BER idzatsika kwambiri.
Nthawi yotumiza: Feb-23-2023