Noiseless coding: yadda shi duka ya fara?

Yana wani asiri ne da cewa da canja wurin da bayanai na wani sakon da za a iya gurbata, watau a abin da aka aiko iya sa erroneous karatu. Karkatacciyar fassara iya faruwa a ƙarƙashin rinjayar da wani m tsararru dalilai, amma ya fi kowa ne da wadannan:

- abin da ya faru na aika, da samun na'urar ko watsawa matsaloli tare da hardware ko software part;

- gaban amo a cikin a haɗa sadarwar tashar, wanda zai iya zama saboda ko dai su yi nasara ba saboda lalacewa, da kuma tare da matsaloli saboda gaban na waje tsoma (niyya ko bazuwar).

Domin tabbatar da mutuncin data sako watsa a kan daban-daban sadarwa tashoshi, da daban-daban fasahar amfani a yau, amma ya fi kowa, m, sauki da kuma dace wajen tabbatar da bayanan da kariya a kan wani noiseless coding.

Tarihi tsari bayanai a lokacin watsa fara a 1948, a lokacin da aka buga a shahara aiki na Shannon ta "Ilmin Lissafi Ka'idar Sadarwa." Yana da wannan labarin shi ne na asali manufa domin samuwar irin wannan abu a matsayin noiseless coding, wanda yana nufin coding cewa samar da iko ga kurakurai da kuma, idan ya cancanta, a gyara su.

Daga wani labarin da Shannon haka wani mai ban mamaki ƙarshe: tafiyar da gina sadarwa tashoshi da cewa rage girman da samuwar kuskure sakon, shi ne wuya da kuma tattalin arziki unfeasible. Yana da yawa sauki da kuma araha don amfani da hanyoyi dabam dabam na shigar da bayanai. A lokaci guda Shannon bai nuna wani takamaiman lambobin, da kuma kawai ya tabbatar da su zama.

Nau'in na coding bayanai da aka baje karatu a cikin hamsin hamsin na karshe karni, amma sakamakon bai kawo wani m sakamako. A shekaru goma da aka alama ta binciken wata hanya da cewa zai ba da damar don ƙirƙirar wani fanni na fasahar sadarwa, don rage da alama na samuwar wani watsa kuskure sako.

A farko fasahar da aka kira block lambobin, da kuma ya yafi ilmin lissafi a yanayi. Noiseless coding karo na farko a cikin wannan tsari da aka gabatar a cikin 1950s, a lokacin da block lambobin iya gyara daya kawai kuskure. Hakika, waɗannan lambobin ne m, amma saboda na dogon lokaci da aka gudanar da dama na gudanar da bincike da kuma ci gaba. A sakamakon haka ne dukan ajin na lambobin zuwa waƙa kuma daidai mahara kurakurai.

Wani fasahar da cewa characterizes kuskure iko coding, - ƙoƙari ya fahimtar tsarinsa da kuma dikodi mai, da bayyanar da kurakurai cikin sharuddan da ka'idar yiwuwa. A sakamakon haka, na tsawon lokaci da karatu aji Nonblock code da aka halitta, a cikin abin da ya fi yadu amfani convolutional lambobin.

A cikin seventies na karshe karni, wadannan biyu dabaru da aka gani a cikin wannan jijiya, tare da sakamakon cewa daga karshe gudanar ya samu daidai da wadanda lambobin, wanda ya jagoranci shi a cikin labarin, Shannon. A sakamakon da jam'i na aikin biyu haihuwarka cewa kafa iyali lambobin da aka samarwa da kuma bayar da high matakan tabbatar da sakon kirki a lokacin da baza ta hanyar sadarwa tashoshi.

Irin wannan shi ne tarihin samuwar kuskure gyara coding. Hakika, a yau samarwa a fadi da dama haihuwarka da Concepts kiyayewa bayanai watsa wadda ne daban-daban functionals, redundancy, AMINCI na tsari, yadda ya dace da kuma sauran key sigogi.