Nyquist Aragtida - aasaas u teori macluumaadka teknoolajiyada casriga ah

guulaha yar oo si xoog leh u saameeyay horumarinta isgaarsiinta iyo macluumaadka tiknolojiyada, sida Aragtida Nyquist ah. By waaweyn iyo, saynisyahan this ayaa ammaanay dalka aan ka yarayn SP ah Queens, ama AS Popov. Waxaa macquul ah in Kotelnikov yaqaan baxsan Russia ka sii badan in Fatherland ah.

warkiisiina wuxuu leeyahay ay sharaxaad. Nyquist Aragtida noqday saldhig u teori waayo, dhammaan qalabka casriga ah digital loo isticmaalo isgaarsiinta. Waxay ku salaysan tahay mabda'a digitizing signal kasta ama image. Waxaa abuuraa xaalad for xisaabinta isgaarsiinta multi-channel ee labo signal a. Sababo la Aragtida Nyquist ah, aad u soo celin kartaa buuq iyo "sinna" signal, abuurista difaac ah. farsamada cryptographic waxaa sidoo kale inta badan ku salaysan Aragtida this. Waxaa laga yaabaa in iyadu ka heli kartaa codsiyada kale oo faa'iido leh.

Qoraaga of muhiimadda sida ee horumarka ah ee radio shaqada teori waxa uu ku dhashay 1908 in Kazan. Aabbihiisna wuxuu ahaa professor Jaamacadda a, Injineer caan ah iyo xisaab Aleksandr Petrovich Kotelnikov, si marka ay timaado hiddo, sayniska ee Victor Alexandrovich ahaa "in dhiigga". Ka dib ka qalin Moscow Energy machadka, ninkii dhallinyarada ahaa oo u tegey si ay u qalin iskuulka. Halkan ka dibna ay xiiseyneyso in uu awoodda topic link bandwidth. Si fudud u gelin, waxa uu ahaa cajiib ah sida dad badan oo ka dhinac walba la hadli kartaa silig telefoon isku mid ah (oo aan waxba loo dhimayn is faham wadaaga iyo intelligibility).

Fikrado ku saabsan horeba, iyo xataa, sida ay uga leexatay, arrin sax ah. Tusaale ahaan, Nyquist ee 1928 soo jeediyay in haddii wareegga waajib of signal farqiga waa loo siman yahay si muddada inta jeer ee ugu badan kala bar, ka dibna waxaa la soo celin karin.

D = 1 / 2f,

halkaas oo:

D - signal markii la ogolaan baaba'aa,

inta jeer ee ugu badan F ku jira spectrum signalka.

Nyquist macquul maleeyey in signalka audio telefoonka isagoo a kala duwan oo soo noq of 3 Khz, waxaa suurtagal ah in Nal at inta jeer ah 6000 jeer labaad la waayi maayo macluumaad waxtar leh.

fikradaha geesi iyo dareen leh noocan oo kale ah u ogolaan taariikhyahanadu casriga ah ee sayniska ka yimi dalalka reer galbeedka si ay ugu bedesho fikrada ah "Nyquist Aragtida" magaca qoraaga. Nyquist Aragtida - in magaca Aragtida Nyquist ee buugaagta badan oo Yurub iyo Maraykanka. Si kastaba ha ahaatee, waa mid ka mid wax soo jeedinaya, xitaa haddii ay tahay mid aad u dhiirran oo xaqiijiyay by dhaqanka, iyo wax kale - si ay u caddeeyaan. Aragtida ka duwan axioms ama la xiqiijiyay in, in by qeexidda u baahan cadeyn.

Halkan waxaa lagama maarmaan ah in ay bixiyaan cashuur saaxiibadeena reer galbeedka. Mudnaanta Nyquist in cadeyn ah "Nyquist Aragtida" jirin wax muran ah ka mid ah.

Aan heer ku filan sare ee aqoonta xisaabta ka sarreeya waa wax aan macquul aheyn in la fahmo sida exquisitely diyaariyey Aragtida Nyquist. caddayn wuxuu ku salaysan yahay waveform ku dhaw in qeexan yihiin tirada Kotel'nikova ah (ay "dhagar" by karsado gaaban).

Noocan oo kale ah ku salaysan teori ah muddada ugu yar ee signal wadnaha na siinaysaa fursad ay ku isticmaalaan telefoonada gacanta maanta, iyo sidoo kale si digital ah oo sakhiray in processing image, music iyo noocyo badan oo kale oo content.