FDD thiab TDD, hais lus, tsuas yog sawv cev rau ob hom duplex sib txawv: TDD (Time Division Duplexing) FDD (Frequency Division Duplexing) "duplex" yog dab tsi? nws yog simplex; Ib yam li walkie-talkie, tib lub sijhawm, tsuas yog ib tog tuaj yeem hais lus, thiab lwm tus neeg mloog, uas txhais tau tias ib nrab-duplex; Yog tias ob tog tuaj yeem hais thiab mloog tib lub sijhawm, nws yog duplex.
Piv txwv li, lawv zoo li ob txoj kab thiab ib txoj kab.FDD: Ob txoj kab, ib txoj kab tsuas tuaj yeem mus rau hauv ib qho kev taw qhia, thiab ob txoj kev tsis cuam tshuam rau ib leeg.TDD: Ib txoj kab kev sib txawv, cov lus qhia sib txawv tau tso cai rau lub sijhawm sib txawv. Yog li ntawd, kev faib cov zaus bands rau FDD feem ntau yog nyob rau hauv khub-ib zaus band raug xa thiab lwm zaus band tau txais. Thiab TDD Tsuas yog ib qho zaus yuav muab.
Txawm hais tias nws zoo li TDD thiab FDD sib txawv heev, qhov sib txawv ntawm FDD LTE thiab TDD LTE yog qhov tsawg heev los ntawm tag nrho cov system.Lub core network yog tib yam, thiab cov wireless interface raws tu qauv feem ntau yog tib yam:
TDD thiab FDD, qhov sib txawv nyob hauv PHYsical txheej (phy).
Yooj yim to taub, lub thav duab kuj yog lub chaw nqa khoom ntawm cov ntaub ntawv xa mus,
Ib lub xov tooj cua, suav nrog 10 subframes. Txhua subframe suav nrog 2 lub sijhawm slots.1 qhov=0.5ms.1 subframe=1 ms1 ncej=10ms
TDD Qhov Zoo yog raws li hauv qab no:
Muaj peev xwm hloov kho qhov zaus, thiab siv cov kab hluav taws xob tawg tawg uas FDD tsis yooj yim rau siv; Nws tuaj yeem hloov kho cov kev pabcuam asymmetric los ntawm kev hloov pauv cov ntsiab lus ntawm uplink thiab downlink lub sij hawm slots; Nrog rau qhov sib xws ntawm uplink thiab downlink channels, tau txais thiab xa cov chaw nres tsheb hauv paus tuaj yeem faib qee lub xov tooj cua zaus, uas txo cov nqi khoom siv; Thaum tau txais cov ntaub ntawv uplink thiab downlink, tsuas yog xav tau ib qho kev hloov pauv yam tsis muaj transceiver cais, uas txo qhov nyuaj ntawm cov khoom siv.
Qhov tsis zoo ntawm TDD:
Lub sijhawm sib kis ntawm TDD lub sijhawm luv dua li ntawm FDD, yog li qhov kev pabcuam ntawm TDD lub hauv paus chaw nres tsheb yog pom tseeb me dua li ntawm FDD lub hauv paus chaw nres tsheb.TDD system muaj tib lub channel zaus, yog li nws tsis tuaj yeem cais kev cuam tshuam, thiab muaj. Kev cuam tshuam hauv thiab nruab nrab ntawm cov tshuab; Txhawm rau kom tsis txhob cuam tshuam nrog lwm lub tshuab wireless, TDD yuav tsum tau tshwj tseg ib pawg neeg saib xyuas loj, uas cuam tshuam rau tag nrho cov kev siv spectrum efficiency.Vim tias cov channel hloov pauv sai hauv kev kub ceev, TDD lub sijhawm sib koom ua haujlwm ua rau cov channel xov xwm qhia los ntawm lub xov tooj ntawm tes yuav tsum tau ncua, yog li TDD system yog inferior rau FDD nyob rau hauv high-ceev scene.
Cov txiaj ntsig zoo yog raws li hauv qab no: Muaj peev xwm hloov kho qhov zaus, thiab siv cov kab hluav taws xob tawg tawg uas FDD tsis yooj yim rau siv; Nws tuaj yeem hloov kho cov kev pabcuam asymmetric los ntawm kev kho cov ntsiab lus hloov ntawm uplink thiab downlink lub sij hawm slots; Nrog rau qhov sib xws ntawm uplink thiab downlink raws, kev txais thiab xa ntawm lub hauv paus chaw nres tsheb tuaj yeem faib qee lub xov tooj cua zaus, uas txo cov nqi khoom siv; Thaum tau txais cov ntaub ntawv uplink thiab downlink, tsuas yog xav tau hloov pauv yam tsis muaj transceiver cais tawm, uas txo qhov nyuaj ntawm cov khoom siv.
