Mtunda wolankhulana womwe njira yolumikizirana yopanda zingwe imatha kutsimikiziridwa ndi zinthu zosiyanasiyana monga zida zosiyanasiyana zomwe zimapanga dongosolo komanso malo olumikizirana. Ubale pakati pawo ukhoza kuwonetsedwa ndi njira zotsatirazi zolumikizirana mtunda.
Ngati mphamvu yotumizira ya chipangizo choyankhulirana ndi PT, phindu la mlongoti wotumizira ndi GT, ndipo kutalika kwa mawonekedwe ndi λ. Kukhudzika kwa wolandila chipangizocho ndi PR, kupindula kwa mlongoti ndi GR, ndipo mtunda pakati pa tinyanga zolandira ndi kutumiza ndi R, mkati mwa mtunda wowonekera komanso m'malo popanda kusokonezedwa ndi ma elekitiroma, ubale wotsatirawu ulipo:
PT(dBm)-PR(dBm)+GT(dBi)+GR(dBi)=20log4pr(m)/l(m)+Lc(dB)+ L0(dB) Mu fomula, Lc ndiye kutayika kwa ma feed a siteshoni yotumizira mlongoti; L0 ndi kutayika kwa mafunde a wailesi panthawi yofalitsa.
Popanga dongosolo, malire okwanira ayenera kusiyidwa kwa chinthu chomaliza, kutayika kwa mafunde a wailesi L0.
Nthawi zambiri, malire a 10 mpaka 15 dB amafunikira podutsa m'nkhalango ndi nyumba za anthu; malire a 30 mpaka 35 dB amafunikira podutsa nyumba zolimba za konkriti.
Kwa 800MH, 900ZMHz CDMA ndi GSM ma frequency band, amakhulupirira kuti mulingo wolandila mafoni am'manja ndi pafupifupi -104dBm, ndipo chizindikiro chomwe chidalandilidwa chiyenera kukhala osachepera 10dB apamwamba kuwonetsetsa kuti chiwongola dzanja chaphokoso chikufunika. Ndipotu, kuti mupitirize kulankhulana bwino, mphamvu yolandiridwa nthawi zambiri imawerengedwa ngati -70 dBm. Tangoganizani kuti base station ili ndi magawo awa:
Mphamvu yotumizira ndi PT = 20W = 43dBm; mphamvu yolandira ndi PR = -70dBm;
Kutayika kwa feeder ndi 2.4dB (pafupifupi 60m feeder)
Foni yam'manja yolandila mlongoti phindu GR = 1.5dBi;
Kutalika kwa mafunde λ = 33.333cm (kufanana ndi pafupipafupi f0 = 900MHz);
Equation yolumikizana pamwambapa ikhala:
43dBm-(-70dBm)+ GT(dBi)+1.5dBi=32dB+ 20logger(m) dB +2.4dB + kufalitsa kutaya L0
114.5dB+ GT(dBi) -34.4dB = 20logger(m)+ kufalitsa kutaya L0
80.1dB+ GT(dBi) = 20logger(m)+ kufalitsa kutaya L0
Pamene mtengo kumanzere kwa fomula ili pamwambayi ndi yaikulu kuposa mtengo wa kumanja, ndiko kuti:
GT(dBi)> 20logor(m)-80.1dB+kutaya kufalitsa L0. Pamene kusalingana kumagwira, zikhoza kuganiziridwa kuti dongosololi likhoza kusunga kulankhulana kwabwino.
Ngati siteshoni yoyambira imagwiritsa ntchito mlongoti wotumizira omnidirectional ndi phindu la GT = 11dBi ndipo mtunda pakati pa tinyanga zotumizira ndi kulandira ndi R = 1000m, kulumikizana kwa equation kumakhala 11dB> 60-80.1dB + kutayika kwa kufalitsa L0, ndiko kuti, pamene kutaya kwa kufalitsa L0B <31 km kungasungidwe bwino.
Pansi pamikhalidwe yotayika yofananira yomwe ili pamwambapa, ngati mlongoti wotumizira akupeza GT = 17dBi, ndiye kuti, kuwonjezeka kwa 6dBi, mtunda wolumikizana ukhoza kuwirikiza kawiri, ndiko kuti, r = 2 makilomita. Ena angaganizidwe mofananamo. Komabe, ziyenera kudziwidwa kuti mlongoti wapansi wokhala ndi phindu la GT la 17dBi ukhoza kukhala ndi chithunzithunzi cha mtengo wofanana ndi fani ndi m'lifupi mwake 30 °, 65 ° kapena 90 °, ndi zina zotero.
Kuonjezera apo, ngati mlongoti wotumizira akupeza GT = 11dBi sikunasinthidwe m'mawerengedwe omwe ali pamwambawa, koma malo ofalitsa amasintha, kutaya kwa kufalitsa L0 = 31.1dB-20dB = 11.1dB, ndiye kuchepetsa kutayika kwa 20dB kudzakulitsa mtunda wolankhulana kakhumi, ndiko kuti, r = makilomita 10. Nthawi yotayika yofalitsa imakhudzana ndi malo ozungulira ma elekitiroma. M'madera akumidzi, pali nyumba zambiri zazitali ndipo kutayika kwa kufalitsa kumakhala kwakukulu. M'madera akumidzi akumidzi, nyumba zapafamu ndizochepa komanso zochepa, ndipo kutayika kwa kufalitsa kumakhala kochepa. Choncho, ngakhale makonzedwe a machitidwe oyankhulana ali ofanana ndendende, njira yowonetsera bwino idzakhala yosiyana chifukwa cha kusiyana kwa malo ogwiritsira ntchito.
Chifukwa chake, posankha ma amnidirectional, ma antenna olunjika ndi mafomu opeza bwino kwambiri kapena otsika mtengo, ndikofunikira kulingalira kugwiritsa ntchito tinyanga toyambira tamitundu yosiyanasiyana komanso mawonekedwe malinga ndi momwe ma network amalumikizirana ndi mafoni ndi malo ogwiritsira ntchito.
Kuti mudziwe zambiri za antennas, chonde pitani:
Nthawi yotumiza: Jul-25-2025
