Njengoba izihlungi, njenganoma yimuphi omunye umkhiqizo owenziwe ngumuntu, zingenakwenziwa ukuze zifane ncamashi nezincazelo zencwadi, amanye amanani avumelekile kumele ashiwo. Kuzihlungi ze-narrowband, amapharamitha ayinhloko okufanele kunikezwe ngawo ukubekezelelana yile: ubude be-peak, ukudluliselwa kwe-peak, kanye ne-bandwidth, ngoba cishe kuzo zonke izinhlelo zokusebenza lapho ukudluliselwa kwe-peak kuphakeme kungcono, futhi ngokuvamile kwanele ukusho umkhawulo wayo ophansi. Ngokubekezelela ubude be-peak kunezici ezimbili eziyinhloko. Esokuqala ukufana kobude be-peak phezu kobuso besihlungi. Kuyohlala kukhona ukuhlukahluka okuthile, noma kuncane kakhulu, kulo lonke ifilimu, kodwa umkhawulo kumele unikezwe. Okwesibili, iphutha ekulinganiseni ubude be-peak obumaphakathi endaweni yonke yesihlungi. Lesi sibonelelo sivame ukuba sihle, ukuze isihlungi sihlale sithambekele ukuze sivumelane nobude be-wavelength obufanele. Kubude be-bandwidth obunikeziwe, inani lokuthambekela elivunyelwe kunoma yiluphi uhlelo lokusebenza lizonqunywa ngezinga elikhulu ububanzi kanye nensimu yokubuka yesistimu, ngoba njengoba i-angle yokuthambekela iyanda, ububanzi obugcwele bama-engeli okwenzeka isihlungi esingawamukela buyancipha.
I-bandwidth yesihlungi nayo kufanele icaciswe futhi inikezwe imvume, kodwa ngenxa yobunzima bokulawula i-bandwidth ngokunembe kakhulu, ngokuvamile akunakwenzeka ukukhawulela i-bandwidth ngokuqinile, futhi imvume kufanele ibe banzi ngangokunokwenzeka, ngokuvamile kungabi ngaphansi kwenani elilinganisiwe izikhathi ezingu-0.2, ngaphandle kokuthi kunesidingo esikhethekile salo.
Enye ipharamitha ebalulekile ku-optical performance index yi-cutoff esifundeni se-cutoff, engachazwa ngezindlela eziningana ezahlukene, kungaba njengokudlulisa okumaphakathi kulo lonke ububanzi, noma njengokudlulisa okuphelele kulo lonke ububanzi kunoma yiliphi ubude be-wavelength, kokubili okunganikeza umkhawulo ophezulu. Eyokuqala ivame ukusetshenziswa lapho umthombo wokuphazamiseka kuyi-spectrum eqhubekayo, eyesibili ibe umthombo womugqa, lapho-ke ubude be-wavelength obusetshenzisiwe, uma buyaziwa, kufanele bushiwo.
Enye indlela ehluke kakhulu yokusho ukusebenza kwesihlungi ukuhlela ama-envelope aphezulu naphansi okushintshashintsha kokudluliselwa ngobude be-wavelength. Ukusebenza kwesihlungi akumele kuwele ngaphandle kwesifunda esimbozwe yi-envelope; kubalulekile ukuthi i-engeli yokwamukela yesihlungi nayo ishiwo. Lolu hlobo lwe-metric lucacile kakhulu kunelokuqala okukhulunywe ngalo ngenhla, nokho, iphutha elilodwa lale ncazelo ye-metric ukuthi indlela ichaza isixhumanisi ngasinye ngamagama aphelele, okungaba nzima kakhulu uma kusetshenziswa inani elimaphakathi lingase lifanele. Ngaphezu kwalokho, akunakwenzeka ukuklama isivivinyo sokunquma ukuthi isihlungi siyahlangabezana yini nalolu hlobo lwe-metric ephelele, futhi i-bandwidth elinganiselwe yethuluzi lokuhlola igcina inomphumela. Ngakho-ke, uma izihlungi zizochazwa ngale ndlela, kunconywa ukuthi kufakwe inothi lokuthi ukusebenza kwesihlungi okuchazwe kubude be-wavelength ngayinye kuyisilinganiso sokusebenza ngezikhathi ezithile. Ngokuvamile, izincazelo zezilinganiso zokusebenza kwe-optical zenziwe ngaphandle kwesidingo esikhulu se-subs ezengeziwe. Kunoma yikuphi ukusetshenziswa okukodwa lezi zinto zizobonisa amazinga ahlukahlukene okubaluleka, futhi icala ngalinye kumele licatshangelwe ngezinga elikhulu ngokwemigomo yalo. Kusobala ukuthi kulo mkhakha kubalulekile ukuthi umsebenzi womklami wesistimu uhlanganiswe eduze nowomklami wokuhlunga.
–Lesi sihloko sikhishwe yi-umenzi womshini wokumboza nge-vacuumI-Guangdong Zhenhua
Isikhathi sokuthunyelwe: Septhemba-28-2024