Hauv kev sib txuas lus digital, qhov uas tus neeg txais tau txais yog qhov sib npaug ntawm cov teeb liab xa mus thiab cov suab nrov channel.
Kev txais tos zoo tshaj plaws ntawm cov teeb liab digital yog nyob ntawm qhov ua yuam kev tsawg kawg nkaus raws li qhov "zoo tshaj plaws". Qhov yuam kev uas tau txiav txim siab hauv tshooj no feem ntau yog tshwm sim los ntawm band-limited Gaussian dawb suab nrov. Raws li qhov kev xav no, binary digital modulated teeb liab tau muab faib ua peb hom: lub teeb liab kom ntseeg tau, teeb liab kev ntseeg siab thiab cov teeb liab hloov pauv, thiab qhov ua yuam kev tsawg kawg yog qhov ntsuas ntau ntawm ib qho los ntawm ib qho. Tsis tas li ntawd, qhov yuam kev tshwm sim tau txais ntau lub hauv paus band teeb liab raug tshuaj xyuas.
Lub hauv paus ntsiab lus ntawm kev tsom xam yog coj tag nrho tus nqi piv txwv ntawm qhov tau txais cov teeb liab raws li vector nyob rau hauv K-dimensional txais vector qhov chaw, thiab faib qhov chaw txais vector rau hauv ob cheeb tsam. Txiav txim siab seb puas muaj qhov yuam kev tau tshwm sim raws li thaj tsam uas tau txais vector poob rau hauv. Daim duab thaiv ntawm qhov zoo tshaj plaws receiver tuaj yeem tau txais thiab qhov yuam kev me ntsis tuaj yeem xam los ntawm qhov kev txiav txim siab. Qhov kev ua yuam kev me ntsis no yog qhov ua tau zoo tshaj plaws, uas yog, theoretically qhov tsawg tshaj plaws tau.
Qhov zoo tshaj plaws me ntsis yuam kev tus nqi ntawm binary txiav txim lub teeb liab yog txiav txim siab los ntawm kev sib raug zoo coefficient p thiab lub teeb liab-rau-nrov piv E / n., tab sis tsis muaj kev sib raug zoo nrog lub teeb liab waveform. Qhov me dua qhov sib txheeb coefficient p, qhov tsawg dua qhov yuam kev me ntsis. 2PSK teeb liab muaj qhov tsawg tshaj plaws kev sib txheeb coefficient (p=-1) thiab tus nqi qis tshaj qhov yuam kev. Lub teeb liab 2FSK tuaj yeem suav tias yog lub teeb liab orthogonal nrog kev sib raug zoo coefficient p = 0.
Rau cov teeb liab nrog cov teeb liab thiab kev hloov pauv, tsuas yog FSK teeb liab yog siv los ua tus sawv cev kev tsom xam, vim hais tias nyob rau hauv cov channel no, lub amplitude thiab theem ntawm lub teeb liab raug hloov pauv vim muaj suab nrov, yog li FSK teeb liab feem ntau haum rau daim ntawv thov. Incoherent demodulation yog txoj kev tau txais txiaj ntsig zoo tshaj plaws vim yog qhov hloov pauv ntawm cov teeb liab theem tshwm sim los ntawm cov channel.
Los ntawm kev sib piv me ntsis yuam kev tus nqi ntawm qhov tiag receiver thiab qhov zoo tshaj plaws receiver, nws yuav pom tau hais tias yog lub teeb liab-rau-suab nrov zog piv r nyob rau hauv lub tiag tiag receiver yog sib npaug rau tus piv E / n ntawm lub code zog thiab suab nrov zog spectral. ceev nyob rau hauv qhov zoo tshaj plaws receiver, me ntsis yuam kev tus nqi ntawm ob yog tib yam. Txawm li cas los xij, vim tias tus txais tiag tiag yeej ib txwm tsis tuaj yeem ua tiav qhov no. Yog li ntawd, qhov kev ua tau zoo ntawm tus txais tiag tiag yog ib txwm qis dua rau qhov zoo tshaj plaws receiver.
Qhov no yog ShenzhenHDV Phohluav taws xob Technology Ltd. los coj koj txog "kev txais tos zoo tshaj plaws ntawm cov teeb liab digital", vam tias yuav pab tau koj, thiab ShenzhenHDV Phohluav taws xob Technology Ltd. ntxiv rauONUseries, transceiver series,OLTseries, tab sis kuj tsim module series, xws li: Kev sib txuas lus kho qhov muag module, optical kev sib txuas lus module, network kho qhov muag module, kev sib txuas lus optical module, optical fiber module, Ethernet optical fiber module, thiab lwm yam., tuaj yeem muab cov kev pabcuam zoo sib xws rau cov neeg siv khoom sib txawv. , txais tos koj tuaj xyuas.
