Kahor inta aan la fahmin tiknoolajiyada PAM4, waa maxay tiknoolajiyadda wax-ka-beddelka? Tiknoolajiyadda wax-ka-beddelka waa farsamada lagu beddelo calaamadaha baseband (calaamadaha korontada ceeriin) calaamadaha gudbinta. Si loo hubiyo waxtarka isgaarsiinta loona xalliyo dhibaatooyinka gudbinta calaamadaha masaafada dheer, waxaa lagama maarmaan ah in loo wareejiyo muuqaalka calaamadaha kanaalka soo noqnoqda sare iyada oo loo marayo habaynta gudbinta.
PAM4 waa farsamo wax ka beddelka wareegga garaaca afaraad (PAM) ee nidaamka.
Calaamadda PAM waa tignoolajiyad gudbin calaamado oo caan ah ka dib NRZ (Aan ku soo noqon Eber).
Calaamadda NRZ waxay isticmaashaa laba heer oo calaamad ah, sare iyo hoose, si ay u matasho 1 iyo 0 ee calaamadda macquulka dijitaalka ah, waxayna gudbin kartaa 1 bit oo macluumaad macquul ah wareeg kasta oo saacad ah.
Calaamadda PAM4 waxay isticmaashaa 4 heer oo kala duwan oo calaamad ah si loo gudbiyo calaamadda, wareegga saacad kastana wuxuu gudbin karaa 2 bits oo macluumaad macquul ah, kuwaas oo kala ah 00, 01, 10, iyo 11.
Sidaa darteed, xaaladaha heerka baud-ka oo kale, heerka bit-ka ee calaamadda PAM4 waa labanlaab ka badan calaamadda NRZ, taas oo labanlaabaysa waxtarka gudbinta isla markaana si wax ku ool ah u yareysa kharashyada.
Tiknoolajiyadda PAM4 si weyn ayaa loogu isticmaalay dhinaca isku xirka calaamadaha xawaaraha sare leh. Waqtigan xaadirka ah, waxaa jira module gudbiye optical ah oo 400G ah oo ku salaysan tignoolajiyadda wax ka beddelka PAM4 ee xarunta xogta iyo module gudbiye optical ah oo 50G ah oo ku salaysan tignoolajiyadda wax ka beddelka PAM4 ee shabakadda isku xirka 5G.
Habka hirgelinta ee module-ka gudbiyaha indhaha ee 400G DML ee ku salaysan habaynta PAM4 waa sidan soo socota: marka la gudbinayo calaamadaha cutubka, 16-ka kanaal ee la helay ee calaamadaha korontada ee 25G NRZ waxaa laga soo gelinayaa cutubka is-dhexgalka korontada, oo uu hore u farsameeyay processor-ka DSP, PAM4 la habeeyey, oo soo saaray 8 kanaal oo calaamadaha korontada ee 25G PAM4 ah, kuwaas oo lagu shubay jajabka darawalka. Calaamadaha korontada ee xawaaraha sare leh waxaa loo beddelaa 8 kanaal oo calaamadaha indhaha ee xawaaraha sare leh ee 50Gbps iyada oo loo marayo 8 kanaal oo laysar ah, oo ay weheliso multiplexer qaybeed mowjad ah, waxaana loo soo saaray 1 kanaal oo ah wax soo saarka calaamadaha indhaha ee xawaaraha sare leh ee 400G. Marka la helayo calaamadaha cutubka, calaamadda indhaha ee xawaaraha sare leh ee 1-kanaal 400G waxaa la soo gelinayaa iyada oo loo marayo cutubka is-dhexgalka indhaha, oo loo beddelay calaamadda indhaha ee xawaaraha sare leh ee 8-kanaal 50Gbps iyada oo loo marayo demultiplexer, oo uu helay qaataha indhaha, oo loo beddelay calaamad koronto. Ka dib soo kabashada saacadda, kordhinta, sinaanta, iyo jajabinta PAM4 iyadoo la adeegsanayo jajab farsameed oo DSP ah, calaamadda korontada waxaa loo beddelaa 16 kanaal oo calaamadda korontada 25G NRZ ah.
Ku dabaq tignoolajiyada wax-ka-beddelka PAM4 modules-ka indhaha ee 400Gb/s. Module-ka indhaha ee 400Gb/s ee ku salaysan wax-ka-beddelka PAM4 wuxuu yarayn karaa tirada laysarka loo baahan yahay ee dhammaadka gudbinta wuxuuna si la mid ah u yarayn karaa tirada qaataha loo baahan yahay ee dhammaadka helitaanka sababtoo ah isticmaalka farsamooyinka wax-ka-beddelka heerka sare ah marka loo eego NRZ. Wax-ka-beddelka PAM4 wuxuu yareeyaa tirada qaybaha indhaha ee ku jira module-ka indhaha, kaas oo keeni kara faa'iidooyin sida kharashyada isu-geynta oo hooseeya, isticmaalka korontada oo yaraada, iyo cabbirka baakadaha oo yar.
Waxaa jira baahi loo qabo modules-ka indhaha ee 50Gbit/s ee shabakadaha gudbinta iyo dib-u-hagaajinta 5G, xal ku salaysan aaladaha indhaha ee 25G oo lagu kabay qaabka wax-ka-beddelka garaaca wadnaha ee PAM4 ayaa la qaataa si loo gaaro shuruudaha xawaaraha sare iyo qiimaha jaban.
Marka la sharraxayo calaamadaha PAM-4, waxaa muhiim ah in fiiro gaar ah loo yeesho farqiga u dhexeeya heerka baud iyo heerka bit-ka. Calaamadaha NRZ ee dhaqameed, maadaama hal calaamad ay gudbiso hal qayb oo xog ah, heerka bit-ka iyo heerka baud-ka waa isku mid. Tusaale ahaan, 100G Ethernet, iyadoo la isticmaalayo afar calaamadood oo 25.78125GBaud ah oo loogu talagalay gudbinta, heerka bit-ka ee calaamad kasta sidoo kale waa 25.78125Gbps, afarta calaamadoodna waxay gaaraan gudbinta calaamadda 100Gbps; Calaamadaha PAM-4, maadaama hal calaamad ay gudbiso 2 bit oo xog ah, heerka bit-ka ee la gudbin karo waa labanlaab heerka baud. Tusaale ahaan, iyadoo la isticmaalayo 4 kanaal oo calaamado ah oo 26.5625GBaud ah si loogu gudbiyo 200G Ethernet, heerka bit-ka ee kanaal kasta waa 53.125Gbps, 4 kanaal oo calaamado ahna waxay gaari karaan gudbinta calaamadda 200Gbps. 400G Ethernet, waxaa lagu gaari karaa 8 kanaal oo calaamado ah oo 26.5625GBaud ah.
Waqtiga boostada: Jan-02-2025