Raws li peb txhua tus paub, walkie-talkie yog cov cuab yeej tseem ceeb hauv wireless intercom system.Lub walkie-talkie ua raws li qhov txuas ntawm lub suab xa mus rau hauv kev sib txuas lus wireless.Cov digital walkie-talkie tuaj yeem muab faib ua zaus faib ntau qhov nkag (FDMA) thiab sijhawm faib ntau yam nkag (TDMA) raws.Yog li ntawm no peb pib nrog qhov zoo thiab qhov tsis zoo ntawm ob tus qauv thiab qhov sib txawv ntawm cov digital thiab analog walkie-talkies:
1.Ob-channel ua hom ntawm digital walkie-talkie
A.TDMA (Lub Sijhawm Division Multiple Access): lub dual-slot TDMA hom yog saws los faib cov 12.5KHz channel rau hauv ob lub qhov, thiab txhua lub sijhawm qhov yuav xa tau lub suab lossis cov ntaub ntawv.
Qhov zoo:
1. Muab ob npaug rau channel peev xwm ntawm ib qho analog system los ntawm ib tug repeater
2. Ib qho repeater ua haujlwm ntawm ob lub repeaters thiab txo cov peev txheej ntawm cov khoom siv kho vajtse.
3. Siv TDMA thev naus laus zis tso cai rau cov roj teeb walkie-talkie ua haujlwm ntev txog 40% ntev dua yam tsis tas yuav kis tau tus mob.
Qhov tsis zoo:
1. Lub suab thiab cov ntaub ntawv tsis tuaj yeem xa mus rau tib lub sijhawm.
2. Thaum lub repeater hauv lub kaw lus tsis ua haujlwm, FDMA system tsuas yog poob ib channel, thaum TDMA system yuav plam ob txoj kev.Yog li, qhov tsis ua haujlwm tsis muaj peev xwm ua rau tsis zoo dua li FDMA.
B.FDMA(Frequency Division Multiple Access):FDMA hom tau txais yuav, thiab cov channel bandwidth yog 6.25KHz, uas txhim kho kev siv ntau zaus.
Qhov zoo:
1. Siv lub 6.25KHz ultra-narrow band channel, qhov kev siv spectrum tuaj yeem raug muab faib ua ob npaug piv rau cov tshuaj analog 12.5KHz tsis muaj qhov rov ua dua.
2. Hauv 6.25KHz channel, cov ntaub ntawv suab thiab GPS cov ntaub ntawv tuaj yeem xa mus rau tib lub sijhawm.
3. Vim hais tias ntawm qhov nqaim nqaim sharpening yam ntxwv ntawm qhov tau txais lim, qhov tau txais rhiab heev ntawm kev sib txuas lus id tau zoo tuaj hauv 6.25KHz channel.Thiab cov txiaj ntsig ntawm kev kho qhov yuam kev, kev sib txuas lus nyob deb li ntawm 25% loj dua li cov xov tooj cua analog FM.Yog li ntawd, rau kev sib txuas lus ncaj qha ntawm thaj chaw loj thiab cov khoom siv hauv xov tooj cua, FDMA txoj kev muaj qhov zoo dua.
Qhov txawv ntawm ib qho digital walkie-talkie thiab analog walkie-talkie
1.Kev ua haujlwm ntawm lub suab teeb liab
Digital walkie-talkie: cov ntaub ntawv-raws li kev sib txuas lus hom optimized los ntawm cov teeb liab processor processor nrog ib tug tshwj xeeb digital encoding thiab baseband modulation.
Analog walkie-talkie: hom kev sib txuas lus uas hloov lub suab, teeb liab, thiab nruam-yoj mus rau tus neeg nqa khoom zaus ntawm walkie-talkie thiab ua kom zoo dua los ntawm kev nthuav dav.
2.Kev siv cov peev txheej spectrum
Digital walkie-talkie: zoo ib yam li xov tooj ntawm tes digital thev naus laus zis, digital walkie-talkie tuaj yeem thauj cov neeg siv ntau dua ntawm cov channel muab, txhim kho kev siv spectrum, thiab siv cov peev txheej zoo dua.
Analog walkie-talkie: muaj teeb meem xws li kev siv tsawg ntawm cov peev txheej zaus, kev hu tsis zoo, thiab ib hom kev lag luam, uas tsis tuaj yeem ua tau raws li kev xav tau ntawm kev lag luam cov neeg siv khoom.
3. Hu tau zoo
Vim hais tias kev sib txuas lus digital thev naus laus zis muaj peev xwm kho qhov yuam kev hauv qhov system, thiab piv rau analog walkie-talkie, nws tuaj yeem ua tiav lub suab zoo thiab lub suab zoo hauv ntau qhov chaw teeb liab thiab tau txais suab nrov tsawg dua li analog walkie-talkie.Tsis tas li ntawd, cov txheej txheem digital muaj kev tiv thaiv zoo ntawm ib puag ncig lub suab nrov thiab tuaj yeem mloog cov suab nrov hauv qhov chaw muaj kev kub ntxhov.
Post lub sij hawm: Aug-06-2021