MERKo te ōwehenga hapa whakarerekētanga, ko te ōwehenga o te uara whai hua o te rahi o te whārite ki te uara whai hua o te rahi o te hapa i runga i te hoahoa whetū (te ōwehenga o te tapawhā o te rahi o te whārite pai ki te tapawhā o te rahi o te whārite hapa). Ko tētahi o ngā tohu matua hei ine i te kounga o ngā tohu pouaka whakaata mamati. He mea nui ki ngā hua ine logarithmic o te whakapohehe i whakatakotoria ki runga i te tohu whakarerekētanga mamati. He rite ki te ōwehenga tohu-ki-haruru, te ōwehenga kawe-ki-haruru rānei e whakamahia ana i roto i te pūnaha anaro. He pūnaha whakatau he wāhanga nui o te manawanui rahunga. Ko ētahi atu tohu rite pēnei i te tere hapa moka BER, te ōwehenga kawe-ki-haruru C/N, te mana toharite taumata mana, te hoahoa whetū, me ētahi atu.
Ko te uara o te MER e whakaatuhia ana i roto i te dB, ā, ko te nui ake o te uara o te MER, ko te pai ake o te kounga o te tohu. Ko te pai ake o te tohu, ko te tata atu o ngā tohu kua whakarerekētia ki te tūranga pai, me te ritenga kē. Ko te hua whakamātautau o te MER e whakaata ana i te kaha o te kaiwhiwhi mamati ki te whakahoki mai i te tau rua, ā, he ōwehenga tohu-ki-haruru whāinga (S/N) e rite ana ki te tohu turanga. Ka tukuna te tohu kua whakarerekētia e te QAM mai i te pito o mua ka tomo ki te kāinga mā te whatunga urunga. Ka heke haere te tohu MER. Mō te hoahoa whetū 64QAM, ko te uara paepae empirika o te MER ko te 23.5dB, ā, i te 256QAM ko te 28.5dB (me 2 te putanga o mua. Mena he teitei ake i te 34dB, ka taea te whakarite kia tomo noa te tohu ki te kāinga, engari kāore e whakakore i te rerekētanga i puta mai i te kounga o te taura tuku, te pito o raro rānei). Mena he iti iho i tēnei uara, kāore te hoahoa whetū e raka. Ngā whakaritenga putanga whakarerekētanga o mua o te tohu MER: Mō te 64/256QAM, mua > 38dB, raro > 36dB, pūnga whatu > 34dB, whakakaha > 34dB (tuarua ko 33dB), pito kaiwhakamahi > 31dB (tuarua ko 33dB), neke atu i te 5. He maha ngā wā ka whakamahia he pūwāhi MER matua hei kimi i ngā raruraru raina pouaka whakaata taura.
Te Hiranga o te MER E kiia ana te MER hei momo ine SNR, ā, ko te tikanga o te MER ko:
①. Kei roto ko ngā momo kino ki te tohu: te haruru, te turuturu o te kaikawe, te kore taurite o te kaha o te IQ, me te haruru ā-wāhanga.
2. E whakaata ana i te kaha o ngā mahi matihiko ki te whakahoki mai i ngā tau rua; e whakaata ana hoki i te nui o te kino ki ngā tohu pouaka whakaata matihiko i muri i te tukunga mā te whatunga.
3. He tawhā turanga te SNR, ā, he tawhā auau reo irirangi te MER.
Ina heke te kounga o te tohu ki tētahi taumata, ka hē te wetewete i ngā tohu. I tēnei wā, ka piki ake te tere hapa moka tuturu BER. BER (Te Tere Hapa Moka): Te tere hapa moka, e tautuhia ana ko te ōwehenga o te maha o ngā moka hapa ki te tapeke o ngā moka. Mō ngā tohu matihiko rua, nā te mea ka tukuna ngā moka rua, ka kiia te tere hapa moka ko te tere hapa moka (BER).
BER = Tere Moka Hapa/Tere Moka Katoa.
Ko te BER e whakaatuhia ana i roto i ngā tohu pūtaiao, ā, ko te iti iho o te BER, ko te pai ake. Ina tino pai te kounga o te tohu, he rite tonu ngā uara BER i mua atu, i muri mai hoki i te whakatikatika hapa; engari i roto i te take o tētahi pokanoa, he rerekē ngā uara BER i mua atu, i muri mai hoki i te whakatikatika hapa, ā, i muri i te whakatikatika hapa, he iti ake te tere hapa moka. Ina 2×10-4 te hapa moka, ka puta he moka wāhanga i ētahi wā, engari ka taea tonu te tiro; ko te BER tino nui ko 1×10-4, ka puta he maha o ngā moka, ā, ka puta te purei whakaahua i te wā poto; kāore e taea te tiro i te BER nui atu i te 1×10-3. Mātakihia. Ko te tohu BER he uara tohutoro anake, ā, kāore e tino tohu i te tūnga o te taputapu whatunga katoa. I ētahi wā ka puta noa mai i te pikinga ohorere nā te pokanoa ohorere, ko te MER he tino rerekē. Ka taea te whakamahi i te tukanga katoa hei tātari hapa raraunga. Nō reira, ka taea e te MER te whakarato whakatūpato wawe mō ngā tohu. Ina heke te kounga o te tohu, ka heke te MER. Mēnā ka piki ake te haruru me te pokanoa ki tētahi taumata, ka heke haere te MER, engari ka noho tonu te BER. Ina piki ake te pokanoa ki tētahi taumata, ka tīmata te heke o te MER ina heke tonu te MER. Ina heke te MER ki te taumata paepae, ka tino heke te BER.
Te wā tuku: 23-Pepuere-2023