MER: Ikigereranyo cya modulation ikigereranyo, nicyo kigereranyo cyagaciro keza k'ubunini bwa vector nigiciro cyiza cyubunini bwikosa ku gishushanyo mbonera cy’inyenyeri (ikigereranyo cya kare ya kwadiri yubunini bwiza bwa vectori na kare ya kare yikosa rya vector) . Nibimwe mubipimo byingenzi bipima ubuziranenge bwibimenyetso bya TV. Nibisobanuro byingenzi kubipimo byo gupima logarithmic yo kugoreka hejuru yikimenyetso cya modulasiyo. Irasa nikigereranyo cyerekana-urusaku cyangwa igipimo cyabatwara-urusaku rukoreshwa muri sisitemu yo kugereranya. Nuburyo bwo guca imanza Igice cyingenzi cyo kwihanganira gutsindwa. Ibindi bipimo bisa nkibipimo bya BER biti, igipimo cya C / N itwara-urusaku, urwego rwimbaraga zingana, igishushanyo mbonera, nibindi.
Agaciro ka MER kagaragarira muri dB, kandi nini agaciro ka MER, nibyiza byerekana ibimenyetso. Ibyiza nibimenyetso, niko ibimenyetso byahinduwe byegeranye kumwanya mwiza, naho ubundi. Ibisubizo byikizamini cya MER byerekana ubushobozi bwabakiriya ba digitale kugirango bagarure umubare wibiri, kandi hariho igipimo cyerekana ibimenyetso-by-urusaku (S / N) bisa nkibimenyetso bya baseband. Ikimenyetso cya QAM cyahinduwe gisohoka kuva imbere kandi cyinjira murugo binyuze mumurongo winjira. Ibipimo bya MER bizagenda byangirika buhoro buhoro. Kubijyanye nigishushanyo mbonera cy’inyenyeri 64QAM, agaciro kangana na MER ni 23.5dB, naho muri 256QAM ni 28.5dB (ibisohoka imbere-bigomba kuba Niba birenze 34dB, birashobora kwemeza ko ibimenyetso byinjira murugo bisanzwe , ariko ntibibuza ko bidasanzwe biterwa nubwiza bwumugozi wohereza cyangwa impera yimbere). Niba ari munsi yiyi gaciro, igishushanyo cyinyenyeri ntikizafungwa. Icyerekezo cya MER cyerekana imbere-iherezo ryibisabwa bisabwa: Kuri 64 / 256QAM, imbere-impera> 38dB, sub-imbere-impera> 36dB, optique node> 34dB, amplifier> 34dB (icya kabiri ni 33dB), impera yumukoresha> 31dB (icya kabiri ni 33dB ), hejuru ya 5 Ingingo y'ingenzi MER nayo ikoreshwa kenshi mugushakisha ibibazo byumurongo wa tereviziyo.
Akamaro ka MER MER ifatwa nkuburyo bwo gupima SNR, kandi ibisobanuro bya MER ni:
①. Harimo ubwoko butandukanye bwangirika kubimenyetso: urusaku, gutwarwa kwabatwara, IQ amplitude imbalance, n urusaku rwicyiciro.
②. Irerekana ubushobozi bwimikorere ya digitale yo kugarura imibare ibiri; iragaragaza urugero rwibyangiritse kubimenyetso bya TV nyuma yo koherezwa kumurongo.
③. SNR ni baseband ibipimo, na MER nikintu cya radiyo yumurongo.
Iyo ubuziranenge bwibimenyetso bugabanutse kurwego runaka, ibimenyetso amaherezo bizacibwa nabi. Muri iki gihe, igipimo nyacyo cyo kwibeshya BER iriyongera. BER. Kubimenyetso bibiri bya digitale, kuva binary bits yoherejwe, igipimo cyamakosa bita biti ikosa (BER).
BER = Ikosa Bit Igipimo / Igipimo Cyuzuye.
BER isanzwe igaragarira mubumenyi bwa siyansi, kandi hepfo ya BER, nibyiza. Iyo ibimenyetso byubwiza nibyiza cyane, BER indangagaciro mbere na nyuma yo gukosora amakosa ni kimwe; ariko mugihe cyo kwivanga runaka, BER indangagaciro mbere na nyuma yo gukosora amakosa iratandukanye, na nyuma yo gukosora amakosa Ikosa rya bito ni rito. Iyo ikosa rya bito ari 2 × 10-4, mozayike igice igaragara rimwe na rimwe, ariko irashobora kuboneka; bikomeye BER ni 1 × 10-4, umubare munini wa mosaika ugaragara, kandi gukina amashusho kugaragara rimwe na rimwe; BER irenze 1 × 10-3 ntishobora kurebwa na gato. reba. Indangantego ya BER ni iyagaciro gusa kandi ntigaragaza neza uko ibikoresho byose byumuyoboro bihagaze. Rimwe na rimwe, biterwa gusa no kwiyongera gutunguranye bitewe no kwivanga ako kanya, mugihe MER ihabanye rwose. Inzira yose irashobora gukoreshwa nkisesengura ryamakosa. Kubwibyo, MER irashobora gutanga imburi hakiri kare kubimenyetso. Iyo ubwiza bwibimenyetso bugabanutse, MER izagabanuka. Hamwe no kwiyongera kw urusaku no kwivanga kurwego runaka, MER izagabanuka buhoro buhoro, mugihe BER idahindutse. Gusa iyo kwivanga kwiyongera kurwego runaka, MER BER itangira kwangirika iyo MER igabanutse bikomeje. Iyo MER igabanutse kurwego, BER izagabanuka cyane.
Igihe cyo kohereza: Gashyantare-23-2023