Ngaphambi kokuqonda itekhnoloji yePAM4, yintoni itekhnoloji yokumodareyitha? Itekhnoloji yokumodareyitha bubuchule bokuguqula imiqondiso ye-baseband (imiqondiso yombane ekrwada) ibe ziimpawu zothumelo. Ukuze kuqinisekiswe unxibelelwano olusebenzayo kunye nokunqoba iingxaki kwi-transmission yesignali yomgama omde, kuyimfuneko ukudlulisa i-spectrum yesignali kwishaneli ephezulu-frequency ngokumodareyitha ukuhanjiswa.
I-PAM4 yindlela yesine yokumodareyitha i-pulse amplitude (PAM) yokumodareyitha.
Isignali ye-PAM iteknoloji yokudlulisa uphawu oludumileyo emva kwe-NRZ (Ukungabuyi kwi-Zero).
Isignali ye-NRZ isebenzisa amanqanaba amabini omqondiso, aphezulu naphantsi, ukumela i-1 kunye ne-0 yesiginali ye-digital logic, kwaye inokudlulisa i-1 bit of logic information clock cycle.
Isignali ye-PAM4 isebenzisa amanqanaba ama-4 ahlukeneyo omqondiso wokuhanjiswa kwesignali, kwaye umjikelo ngamnye wewotshi unokuhambisa ii-bits ze-2 zolwazi lwelogic, ezizezi 00, 01, 10, kunye ne-11.
Ngoko ke, phantsi kweemeko ezifanayo ze-baud, i-bit rate ye-PAM4 yesiginali iphindwe kabini kwisignali ye-NRZ, ephinda kabini ukusebenza kakuhle kokuhanjiswa kunye nokunciphisa ngempumelelo iindleko.
I-teknoloji ye-PAM4 isetyenziswe ngokubanzi kwintsimi ye-high-speed signal interconnection. Okwangoku, kukho imodyuli ye-400G ye-transceiver optical esekelwe kwi-PAM4 iteknoloji yokumodareyitha kwiziko ledatha kunye ne-50G imodyuli ye-transceiver optical esekelwe kwi-PAM4 iteknoloji yokumodareyitha ye-5G inethiwekhi yoqhagamshelwano.
Inkqubo yokuphunyezwa kwemodyuli ye-400G DML ye-transceiver optical transceiver esekelwe kwi-PAM4 modulation ngolu hlobo lulandelayo: xa uhambisa izibonakaliso zeyunithi, iziteshi ezifunyenweyo ze-16 ze-25G NRZ iimpawu zombane zingena kwiyunithi yombane yombane, iqhutywe ngaphambili yiprosesa ye-DSP, i-PAM4 imodulated, kwaye imveliso ye-8 iziteshi ze-25G PAM4 iimpawu zombane, ezilayishwe kwi-chip yomqhubi. Iimpawu zombane ezikhawulezayo ziguqulwa zibe yi-8 ye-50Gbps ye-high-speed optical signals ngokusebenzisa i-8 channels ye-laser, idibaniswe yi-multiplexer ye-wavelength division, kwaye idibaniswe kwi-1 ye-channel ye-400G ye-speed-speed optical signal output. Xa ufumana iimpawu zeyunithi, i-1-channel 400G i-high-speed optical signal ifakwe kwiyunithi ye-optical interface, iguqulelwe kwi-8-channel 50Gbps i-high-speed optical signal ngokusebenzisa i-demultiplexer, efunyenwe ngummkeli optical, kwaye iguqulwe ibe ngumbane. uphawu. Emva kokubuyiswa kwewashi, ukukhulisa, ukulinganisa, kunye nokuchithwa kwe-PAM4 nge-chip ye-DSP yokucubungula, isignali yombane iguqulwa ibe yi-16 iziteshi ze-25G NRZ zombane.
Faka iteknoloji ye-PAM4 yokumodareyitha kwiimodyuli ze-400Gb / s ezibonakalayo. I-400Gb / s imodyuli ye-optical esekelwe kwi-PAM4 yokumodareyitha inokunciphisa inani le-laser ezifunekayo ekupheleni kokudlulisa kwaye ngokuhambelanayo inciphise inani labamkeli abafunekayo ekupheleni kokufumana ngenxa yokusetyenziswa kweendlela eziphezulu zokumodareyitha ngokuthelekiswa ne-NRZ. Ukumodareyitha kwe-PAM4 kunciphisa inani lamacandelo optical kwimodyuli ye-optical, enokuzisa inzuzo efana neendleko zendibano eziphantsi, ukunciphisa ukusetyenziswa kwamandla, kunye nobukhulu obuncinane bokupakisha.
Kukho imfuno ye-50Gbit / s iimodyuli ze-optical kwi-5G yokuhanjiswa kunye ne-backhaul networks, kunye nesisombululo esisekelwe kwi-25G yezixhobo ezibonakalayo kunye nokuxhaswa nge-PAM4 ifomathi ye-pulse amplitude modulation yamkelwa ukufezekisa iimfuno eziphantsi kunye ne-bandwidth ephezulu.
Xa uchaza iimpawu ze-PAM-4, kubalulekile ukunikela ingqalelo kumahluko phakathi kwesantya se-baud kunye ne-bit rate. Kwimiqondiso yesiqhelo ye-NRZ, kuba isimboli esinye sihambisa isuntswana ledatha, isantya se-bit kunye ne-baud ziyafana. Ngokomzekelo, kwi-100G Ethernet, usebenzisa izibonakaliso ezine ze-25.78125GBaud zokudluliselwa, isantya se-bit kwi-signal nganye nayo i-25.78125Gbps, kwaye iimpawu ezine zifezekisa ukuhanjiswa kwe-100Gbps; Kwiimpawu ze-PAM-4, ekubeni isimboli esinye sihambisa ii-bits zedatha, i-bit rate enokuthi idluliselwe kabini i-baud rate. Ngokomzekelo, ukusebenzisa iziteshi ze-4 ze-26.5625GBaud izibonakaliso zokudluliselwa kwi-200G Ethernet, isantya se-bit kwisitishi ngasinye yi-53.125Gbps, kunye ne-4 iziteshi zeempawu zinokufikelela kwi-200Gbps yokudluliselwa kwesignali. Kwi-400G Ethernet, inokufezekiswa ngeziteshi ze-8 zeempawu ze-26.5625GBaud.
Ixesha lokuposa: Jan-02-2025