Umgama wonxibelelwano onokufikelelwa yinkqubo yonxibelelwano engenazingcingo umiselwa yimiba eyahlukeneyo efana nezixhobo ezahlukeneyo ezenza inkqubo kunye nemeko yonxibelelwano. Ubudlelwane phakathi kwabo bunokubonakaliswa ngolu hlobo lulandelayo lomgama wonxibelelwano.
Ukuba amandla othumelo esixhobo sothumelo senkqubo yonxibelelwano yi-PT, inzuzo ye-eriyali yothumelo yi-GT, kunye ne-wavelength yokusebenza ngu-λ. Ubuntununtunu bomamkeli wesixhobo esifumanayo yi-PR, inzuzo yokufumana i-eriyali yi-GR, kwaye umgama phakathi kwe-eriyali yokufumana kunye nokuhambisa ngu-R, kumgama obonakalayo kunye nokusingqongileyo ngaphandle kokuphazamiseka kombane, obu budlelwane bulandelayo bukhona:
PT(dBm)-PR(dBm)+GT(dBi)+GR(dBi)=20log4pr(m)/l(m)+Lc(dB)+ L0(dB) Kwifomula, i-Lc yilahleko yokufakwa kwe-feeder ye-eriyali esisiseko ehambisa isikhululo; I-L0 yilahleko yamaza erediyo ngexesha lokusasaza.
Xa uyilwa inkqubo, umda owaneleyo kufuneka ushiywe kwinto yokugqibela, ilahleko yokusasazwa kwamaza erediyo L0.
Ngokubanzi, umda we-10 ukuya kwi-15 dB uyafuneka xa udlula emahlathini nakwizakhiwo zokuhlala; Umda wama-30 ukuya kuma-35 dB uyafuneka xa udlula kwizakhiwo eziqinisiweyo zekonkrithi.
Kwi-800MH, i-900ZMHz i-CDMA kunye ne-GSM frequency bands, ngokuqhelekileyo kukholelwa ukuba inqanaba lokufumana iifowuni eziphathwayo malunga ne-104dBm, kwaye isignali efunyenweyo ngokwenene kufuneka ibe ubuncinane i-10dB ephezulu ukuze kuqinisekiswe umlinganiselo ofunekayo we-signal-to-noise. Enyanisweni, ukwenzela ukugcina unxibelelwano oluhle, amandla afunyenweyo ahlala ebalwa njenge -70 dBm. Cinga ukuba isikhululo esisisiseko sinezi pharamitha zilandelayo:
Amandla okuthumela i-PT = 20W = 43dBm; amandla okufumana i-PR = -70dBm;
Ilahleko ye-feeder yi-2.4dB (malunga ne-60m feeder)
Ifowuni ephathwayo ifumana inzuzo ye-eriyali GR = 1.5dBi;
Ubude bobude obusebenzayo λ = 33.333cm (ilingana namaxesha f0 = 900MHz);
Le equation yonxibelelwano ingentla iya kuba:
43dBm-(-70dBm)+ GT(dBi)+1.5dBi=32dB+ 20loger(m) dB +2.4dB + ilahleko yokusasaza L0
114.5dB+ GT(dBi) -34.4dB = 20logger(m)+ ilahleko yokusasaza L0
80.1dB+ GT(dBi) = 20log(m)+ ilahleko yokusasaza L0
Xa ixabiso kwicala lasekhohlo lefomula ingentla likhulu kunexabiso kwicala lasekunene, oko kukuthi:
GT(dBi) > 20log(m)-80.1dB+propagation loss L0. Xa ukungalingani kubambe, kunokuqwalaselwa ukuba inkqubo inokugcina unxibelelwano oluhle.
Ukuba isikhululo sesiseko sisebenzisa i-antenna yokuhambisa i-omnidirectional kunye nenzuzo ye-GT = 11dBi kunye nomgama phakathi kwe-eriyali yokudlulisa kunye nokufumana ngu-R = 1000m, i-equation yonxibelelwano ngakumbi ibe yi-11dB> 60-80.1dB + ilahleko yokusabalalisa L0, oko kukuthi, xa ilahleko yokusabalalisa i-L0 <31 km inokugcinwa kakuhle kwi-1 km yonxibelelwano.
Ngaphantsi kweemeko zokulahlekelwa kwe-propagation efanayo nalapha ngasentla, ukuba i-antenna yokudlulisa izuza i-GT = 17dBi, oko kukuthi, ukwanda kwe-6dBi, umgama wonxibelelwano unokuphindwa kabini, oko kukuthi, r = 2 iikhilomitha. Abanye banokuchazwa ngendlela efanayo. Nangona kunjalo, kufuneka kuqatshelwe ukuba i-antenna yesitishi esisisiseko esine-GT ye-17dBi inokuthi ibe ne-fan-shaped beam coverage kunye nobubanzi be-beam ye-30 °, i-65 ° okanye i-90 °, njl., kwaye ayikwazi ukugcina i-omnidirectional coverage.
Ukongeza, ukuba i-eriyali yokudlulisela i-GT = 11dBi ihlala ingatshintshi kubalo olungentla, kodwa indawo yokusabalalisa iyatshintsha, ilahleko yokusabalalisa L0 = 31.1dB-20dB = 11.1dB, ngoko ilahleko yokusabalalisa i-20dB iya kwandisa umgama wonxibelelwano ngokuphindwe kashumi, oko kukuthi, r = 10 km. Ixesha lelahleko losasazo linxulumene nendawo engqongileyo ye-electromagnetic. Kwiindawo zasezidolophini, zininzi izakhiwo eziphakamileyo kwaye ilahleko yokusasaza inkulu. Kwiindawo ezisemaphandleni, izindlu zasefama ziphantsi kwaye zincinci, kwaye ilahleko yokwandisa incinci. Ngoko ke, nokuba iisetingi zenkqubo yonxibelelwano zifana ncakasana, uluhlu olusebenzayo lokugubungela luya kwahluka ngenxa yokumahluko kwimeko yokusetyenziswa.
Ke ngoko, xa ukhetha i-omnidirectional, i-eriyali yolwalathiso kunye neefom ze-antenna eziphezulu okanye eziphantsi, kuyimfuneko ukuqwalasela ukusebenzisa i-eriyali zesikhululo sesiseko seentlobo ezahlukeneyo kunye neenkcukacha ngokwemiqathango ethile yonxibelelwano lweselula kunye nokusingqongileyo kwesicelo.
Ukuze ufunde ngakumbi ngee-eriyali, nceda undwendwele:
Ixesha lokuposa: Jul-25-2025
