Nyquist Theorem - the yokungotaura hwaro kwemichina yekufambisa mashoko yechizvino

kubudirira shoma vanofurirwa zvakasimba saka kukura pakukurukurirana uye mashoko michina, sezvo Nyquist theorem no. Kazhinji, musayendisiti ichi wakudza nyika yedu hapana muduku kupfuura SP Queens, kana AS Popov. Zvinogoneka kuti Kotelnikov anozivikanwa kunze Russia kunyange kupfuura muna Yababa.

mukurumbira ichi chine tsanangudzo yacho. Nyquist theorem no akava yokungotaura hwaro zvose ano digitaalinen michina inoshandiswa yokukurukura. Zvinonzi inobva pana digitizing chero chiratidzo kana mufananidzo. It anosika zvinhu nokuda kukarukureta ose multi-gwara kudyidzana chiratidzo peya. Nokuda Nyquist theorem no, unogona kudzorera ruzha uye "kwakandionza" chiratidzo, ndinosika kutapata ose. Cryptographic chidobi chiri zvikurukuru yakavakirwa theorem no ichi. Zvichida iye anogona kuwana zvimwe mafomu.

Munyori kwakadaro zvainoreva kukura redhiyo yokungotaura basa akaberekwa muna 1908 muKazan. baba vake aiva muzvinadzidzo yunivhesiti, yakakurumbira injiniya uye nyanzvi yemasvomhu Aleksandr Petrovich Kotelnikov, saka kana totaura majini, aiva sainzi mu Victor Alexandrovich "muropa". Ndapedza kubva Moscow Energy Institute, jaya akaenda kupedza chikoro. Pano zvino dzinofarira ake nyaya bandwidth linked chinzvimbo. Zvichitaurwa zviri nyore, akanga kuziva sei vanhu vakawanda kubva kumativi anogona kutaura zvakafanana runhare waya (pasina rusaruro kune tinzwisisane uye intelligibility).

Zvekungofungira nezvazvo kare, uye kunyange, sezvo zvikazooneka, zvikuru yakarurama. Somuenzaniso, Nyquist muna 1928 kwakaratidza kuti kana basa kutenderera pakakoromoka mureza akaenzana hafu nguva chemhando kakawanda, saka inogona kudzorerwa.

D = 1 / 2F,

apo:

D - bvumidzwa nguva chiratidzo nokupera;

F- kunonyanyisa maitikiro huri chiratidzo chakarondedzera.

Nyquist musoro vaifungidzira kuti foni Audio Mureza ane kakawanda-siyana 3 kHz, zvinokwanisika kuti strobe panguva kakawanda 6000 nguva por wechipiri pasina kurasikirwa anobatsira mashoko.

zvekungofungira kwakadaro vakashinga uye nzwisisa kubvumira ano venhoroondo nemasayendisiti kubva kunyika dzokuMadokero kutsiva pfungwa "Nyquist Theorem" zita romunyori. Nyquist theorem no - ndicho zita Nyquist raMwari theorem no mu mabhuku akawanda dzeEurope uye American. Zvisinei, chinhu chimwe chinhu chinoratidza, kunyange kana chiri ushingi uye kwechokwadi tsika, uye chimwe chinhu - kuzviratidza. Theorem kwakasiyana axioms kana pfungwa, kuti kubudikidza tsanangudzo zvinoda uchapupu.

Pano zvakafanira kubhadhara mutero shamwari dzedu Western. Pokutanga Nyquist ari uchapupu "Nyquist Theorem" hapana kukakavadzana.

Pasina zvakakwana yakakwirira azvipire ruzivo pamusoro dzakakwirira masvomhu hazvibviri kunzwisisa sei hwakaisvonaka akagadzira Nyquist theorem no. Chinoratidza anobva pakuva rakada waveform kuti kutaura nhamba Kotel'nikova ( "Plotting" yaro pfupi pulses).

yokungotaura hwaro kwakadaro shoma nguva yacho kupomba chiratidzo kunotipa mukana kushandisa maserura nhasi, uyewo digitized uye pasi mufananidzo kubudiswa, mumhanzi uye dzimwe mhando kugutsikana zhinji.