Sampling vs Quantization
Hauv kev ua cov teeb liab digital thiab cov haujlwm muaj feem cuam tshuam, piv txwv thiab quantization yog ob txoj hauv kev, theej cov kauj ruam, siv hauv kev txiav txim siab ntawm lub teeb liab analog hauv kev hloov nws mus rau lub teeb liab digital. Nrog rau kev tshwm sim ntawm hluav taws xob thiab khoos phis tawj, yuav luag txhua txoj haujlwm thev naus laus zis yog digitized yog li lawv tuaj yeem tswj hwm los ntawm khoos phis tawj lossis lwm lub tshuab digital. Ob qho no yog cov tswv yim tseem ceeb hauv kev hloov pauv mus rau digital.
Kev Sampling yog dab tsi?
Hauv kev ua cov teeb liab digital, kev ua piv txwv yog cov txheej txheem ntawm kev rhuav tshem cov teeb liab txuas ntxiv mus rau qhov tsis sib xws. Ib qho kev siv ntawm cov txheej txheem yog analog rau digital hloov dua siab tshiab ntawm lub suab teeb liab. Cov txheej txheem rhuav tshem lub suab nthwv dej mus rau hauv ntu raws lub sijhawm axis los tsim cov kab ke ntawm cov cim. Yog li ntawd, qhov tseem ceeb nyob rau hauv lub sij hawm axis yog hloov dua siab tshiab los ntawm nruam, mus rau discrete qhov tseem ceeb nrog sib xws magnitudes. Cov teeb liab coj mus kuaj yog hu ua Pulse Amplitude Modulated Signal.
Thaum tus txheej txheem, tsis pub dhau lub sijhawm teem sijhawm T, ib qhov siab tshaj plaws (ib qho qauv) raug xaiv los sawv cev rau tag nrho lub sijhawm. Yog li, theej muaj lub teeb liab txuas ntxiv, cov txheej txheem tsim lub teeb liab nrog ib qho amplitude sawv cev rau lub sijhawm tag nrho. Txawm li cas los xij, tseem qhov loj ntawm qhov amplitude yog tas li. Cov khoom siv ntawm lub kaw lus uas ua tiav cov txheej txheem no yog hu ua tus qauv.
Txawm hais tias lub teeb liab muaj qhov tseem ceeb hauv x axis tam sim no, lub teeb liab yog ib nrab txuas ntxiv thiab tsis tuaj yeem sawv cev kom raug digitally. Yuav kom ua tiav qhov teeb meem tsis sib haum xeeb, ib kauj ruam thib ob ntawm kev txiav txim siab tau ua tiav.
Quantization yog dab tsi?
Hauv kev ua cov teeb liab digital, quantization yog cov txheej txheem ntawm kev kos cov txheej txheem loj dua rau cov teeb me me. Qhov piv txwv zoo tshaj yog muab cov lej sib npaug kom lawv tswj tau. Xav txog qhov hnyav ntawm ib pawg ntawm cov pob chocolate. Lawv hnyav qhov nruab nrab ntawm 4.99 grams thiab 5.20 grams. Tsis yog hais rau lawv tus kheej nws yog qhov sawv cev zoo yog tias peb hais cov khoom qab zib uas hnyav 5.00 grams. Txhawm rau ua qhov no, qhov hnyav ntawm cov khoom yuav tsum tau sib npaug los yog qis. Tib qhov kev sib cav siv thaum hais tias khau yog $ 15.00, txawm tias tus nqi yog $ 14.99.
Siv qhov no rau cov teeb liab, cov teeb liab ib nrab discretized twb muaj ib qho txiaj ntsig txuas ntxiv uas sawv cev rau txhua lub sijhawm ntawm lub sijhawm pulse amplitude modulated teeb liab. Nyob rau hauv tus txheej txheem quantization, qhov amplitude qhov tseem ceeb yog sib npaug los yog nqes mus rau qhov ze tshaj plaws predetermined tus nqi. Qhov tshwm sim yog tias, es tsis yog qhov amplitude ntawm cov teeb liab muaj ntau qhov tseem ceeb, lawv tau nqaim mus rau ntau qhov me me ntawm qhov tseem ceeb. Hom teeb liab no hu ua Pulse Code Modulated Signal.
Qhov txawv ntawm Sampling thiab Quantization yog dab tsi?
• Hauv kev piv txwv, lub sij hawm axis yog discretized thaum, nyob rau hauv quantization, y axis los yog lub amplitude yog discretized.
• Nyob rau hauv tus txheej txheem sampling, ib qho amplitude tus nqi raug xaiv los ntawm lub sij hawm luv luv los sawv cev rau nws thaum, nyob rau hauv quantization, qhov tseem ceeb uas sawv cev rau lub sij hawm intervals yog sib npaug, los tsim ib tug finite set ntawm qhov ua tau amplitude qhov tseem ceeb.
• Sampling yog ua tiav ua ntej txheej txheem quantization.
