Ngaphambi kokuba uqonde iteknoloji ye-PAM4, yintoni iteknoloji yokuguqula? Iteknoloji yokuguqula yindlela yokuguqula imiqondiso ye-baseband (imiqondiso yombane eluhlaza) ibe yimiqondiso yokudlulisa. Ukuze kuqinisekiswe ukusebenza kakuhle konxibelelwano kunye nokoyisa iingxaki zokudlulisa imiqondiso kumgama omde, kuyimfuneko ukudlulisela i-spectrum yesignali kwitshaneli ye-high-frequency ngokusebenzisa i-modulation yokudlulisa.
I-PAM4 yindlela yokuguqula i-pulse amplitude modulation (PAM) ye-fourth order.
Isignali yePAM yiteknoloji yokudlulisa isignali edumileyo emva kwe-NRZ (Non Return to Zero).
Isignali ye-NRZ isebenzisa amanqanaba amabini esignali, aphezulu naphantsi, ukumela u-1 no-0 wesignali ye-logic yedijithali, kwaye inokudlulisa ulwazi lwe-logic oluncinci ngomjikelo wewotshi.
Isignali ye-PAM4 isebenzisa amanqanaba ama-4 ahlukeneyo esignali yokudlulisa isignali, kwaye umjikelo ngamnye wewotshi unokudlulisa ulwazi lwe-logic oluziibhithi ezi-2, ezizezi: 00, 01, 10, kunye ne-11.
Ngoko ke, phantsi kweemeko ezifanayo zesantya sebhawudi, izinga lebhithi lesignali ye-PAM4 liphindwe kabini kunesignali ye-NRZ, nto leyo ephinda kabini ukusebenza kakuhle kothumelo kwaye inciphisa ngokufanelekileyo iindleko.
Itekhnoloji ye-PAM4 isetyenziswa kakhulu kwicandelo lokunxibelelana kwesignali ngesantya esiphezulu. Okwangoku, kukho imodyuli ye-transceiver ye-optical ye-400G esekwe kwitekhnoloji ye-modulation ye-PAM4 kwiziko ledatha kunye nemodyuli ye-transceiver ye-optical ye-50G esekwe kwitekhnoloji ye-modulation ye-PAM4 kwinethiwekhi yokunxibelelana ye-5G.
Inkqubo yokusetyenziswa kwemodyuli ye-400G DML optical transceiver esekelwe kwi-PAM4 modulation yile ilandelayo: xa kuthunyelwa imiqondiso yeyunithi, iziteshi ezili-16 ezifunyenweyo zemiqondiso yombane ye-25G NRZ zifakwa kwiyunithi yojongano lombane, zicutshungulwe kwangaphambili yiprosesa ye-DSP, zilungiswe yi-PAM4, kwaye ziphume iziteshi ezi-8 zemiqondiso yombane ye-25G PAM4, ezifakwa kwitshiphu yomqhubi. Izibonakaliso zombane ezikhawulezayo ziguqulwa zibe ziziteshi ezi-8 zemiqondiso yojongano oluphezulu ye-50Gbps ngokusebenzisa iziteshi ezi-8 ze-laser, zidityaniswe yi-multiplexer yokwahlula ubude, kwaye zenziwe zibe yitshaneli enye ye-400G high-speed optical signal output. Xa zifumana imiqondiso yeyunithi, itshaneli enye ye-400G high-speed optical signal efunyenweyo ifakwa ngeyunithi yojongano oluphezulu, iguqulwe ibe yi-8-channel 50Gbps high-speed optical signal nge-demultiplexer, ifunyenwe yi-optical receiver, kwaye iguqulwe ibe yisignali yombane. Emva kokubuyiselwa kwewotshi, ukwandiswa, ukulinganiswa, kunye nokususwa kwePAM4 yitshiphu yokucubungula i-DSP, isignali yombane iguqulwa ibe ziitshaneli ezili-16 zesignali yombane ye-25G NRZ.
Sebenzisa itekhnoloji yokuguqula i-PAM4 kwiimodyuli ze-optical ze-400Gb/s. Imodyuli ye-optical ye-400Gb/s esekwe kwi-PAM4 modulation inokunciphisa inani leeleser ezifunekayo kwisiphelo sokudlulisa kwaye inciphise ngokufanayo inani leereceivers ezifunekayo kwisiphelo sokwamkela ngenxa yokusebenzisa iindlela zokuguqula eziphezulu xa kuthelekiswa ne-NRZ. I-PAM4 modulation inciphisa inani leenxalenye ze-optical kwimodyuli ye-optical, enokuzisa iingenelo ezifana neendleko eziphantsi zokuhlanganisa, ukusetyenziswa kwamandla okuncitshisiweyo, kunye nobungakanani obuncinci bokupakisha.
Kukho imfuneko yeemodyuli ze-optical ze-50Gbit/s kwiinethiwekhi zothumelo lwe-5G kunye ne-backhaul, kwaye isisombululo esisekelwe kwizixhobo ze-optical ze-25G kwaye esongezelelwe yifomathi ye-PAM4 pulse amplitude modulation siyasetyenziswa ukufezekisa iimfuno ze-bandwidth ezingabizi kakhulu neziphezulu.
Xa uchaza imiqondiso ye-PAM-4, kubalulekile ukuba uqwalasele umahluko phakathi kwesantya se-baud kunye nesantya se-bit. Kwiimpawu ze-NRZ zemveli, ekubeni uphawu olunye ludlulisela idatha encinci, izinga le-bit kunye nezinga le-baud ziyafana. Umzekelo, kwi-100G Ethernet, kusetyenziswa imiqondiso emine ye-25.78125GBaud yokudlulisela, izinga le-bit kwisignali nganye likwayi-25.78125Gbps, kwaye imiqondiso emine ifumana ukudluliselwa kwesignali ye-100Gbps; Kwiimpawu ze-PAM-4, ekubeni uphawu olunye ludlulisela idatha ye-bits ezi-2, izinga le-bit elinokudluliselwa liphindwe kabini kunezinga le-baud. Umzekelo, kusetyenziswa iziteshi ezi-4 zezibonakaliso ze-26.5625GBaud zokudlulisela kwi-200G Ethernet, izinga le-bit kwitshaneli nganye yi-53.125Gbps, kwaye iziteshi ezi-4 zezibonakaliso zinokufikelela kukudluliselwa kwesignali ye-200Gbps. Kwi-400G Ethernet, inokufezekiswa ngeziteshi ezi-8 zezibonakaliso ze-26.5625GBaud.
Ixesha leposi: Jan-02-2025