{"id":2561,"date":"2024-05-24T02:15:24","date_gmt":"2024-05-24T02:15:24","guid":{"rendered":"https:\/\/nfc-readers.com\/?p=2561"},"modified":"2024-05-24T02:15:24","modified_gmt":"2024-05-24T02:15:24","slug":"nfc-signal-processing-non-return-to-zero-encoding","status":"publish","type":"post","link":"https:\/\/nfc-readers.com\/pt\/nfc-signal-processing-non-return-to-zero-encoding\/","title":{"rendered":"Processamento de sinal NFC: codifica\u00e7\u00e3o sem retorno a zero"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_73 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">\u00cdndice<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Alternar \u00edndice de conte\u00fado\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Alternar<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/nfc-readers.com\/pt\/nfc-signal-processing-non-return-to-zero-encoding\/#Overview_of_NFC_Data_Transmission\" title=\"Vis\u00e3o geral da transmiss\u00e3o de dados NFC\">Vis\u00e3o geral da transmiss\u00e3o de dados NFC<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/nfc-readers.com\/pt\/nfc-signal-processing-non-return-to-zero-encoding\/#Standards_Communication_Protocols_in_NFC\" title=\"Padr\u00f5es e protocolos de comunica\u00e7\u00e3o em NFC\">Padr\u00f5es e protocolos de comunica\u00e7\u00e3o em NFC<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/nfc-readers.com\/pt\/nfc-signal-processing-non-return-to-zero-encoding\/#NFC_Non-Return-to-Zero_Level_NRZ-L_Encoding\" title=\"Codifica\u00e7\u00e3o NFC de n\u00edvel sem retorno a zero (NRZ-L)\">Codifica\u00e7\u00e3o NFC de n\u00edvel sem retorno a zero (NRZ-L)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/nfc-readers.com\/pt\/nfc-signal-processing-non-return-to-zero-encoding\/#NFC_Manchester_Encoding\" title=\"Codifica\u00e7\u00e3o NFC Manchester\">Codifica\u00e7\u00e3o NFC Manchester<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/nfc-readers.com\/pt\/nfc-signal-processing-non-return-to-zero-encoding\/#NFC_Modified_Miller_Encoding\" title=\"Codifica\u00e7\u00e3o Miller modificada NFC\">Codifica\u00e7\u00e3o Miller modificada NFC<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/nfc-readers.com\/pt\/nfc-signal-processing-non-return-to-zero-encoding\/#Types_of_Modulation_in_NFC\" title=\"Tipos de modula\u00e7\u00e3o em NFC\">Tipos de modula\u00e7\u00e3o em NFC<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/nfc-readers.com\/pt\/nfc-signal-processing-non-return-to-zero-encoding\/#In_Summary\" title=\"Resumindo\">Resumindo<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"auto-hide-last-sibling-br paragraph_c9271 paragraph-element\"><span class=\"ez-toc-section\" id=\"Overview_of_NFC_Data_Transmission\"><\/span><strong>Vis\u00e3o geral da transmiss\u00e3o de dados NFC<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"auto-hide-last-sibling-br paragraph_c9271 paragraph-element\"><br class=\"container_a4d0b wrapper_d536d undefined\" \/><a href=\"https:\/\/nfc-readers.com\/pt\/Wholesale\/rfid-nfc-reader\/\">NFC<\/a>, uma tecnologia de comunica\u00e7\u00e3o sem fio de baixa taxa de dados e curto alcance, opera por meio de uma sinergia de dois dispositivos \u2014 denominados iniciador e alvo. Comumente reconhecidos como tag e leitor, essas entidades se envolvem em troca de dados por meio de uma frequ\u00eancia portadora de RF de 13,56 MHz, contando com indu\u00e7\u00e3o eletromagn\u00e9tica sem contato. A proximidade necess\u00e1ria para tais intera\u00e7\u00f5es \u00e9 tipicamente menor que 10 cm.<\/div>\n<p>&nbsp;<\/p>\n<h2 class=\"auto-hide-last-sibling-br paragraph_c9271 paragraph-element\"><span class=\"ez-toc-section\" id=\"Standards_Communication_Protocols_in_NFC\"><\/span><strong>Padr\u00f5es e protocolos de comunica\u00e7\u00e3o em NFC<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"auto-hide-last-sibling-br paragraph_c9271 paragraph-element\"><br class=\"container_a4d0b wrapper_d536d undefined\" \/>Com base em taxas de dados vari\u00e1veis, juntamente com requisitos distintos de modula\u00e7\u00e3o e codifica\u00e7\u00e3o, a tecnologia NFC se manifesta por meio de tr\u00eas padr\u00f5es principais: NFC-A, NFC-B e NFC-F. Esses padr\u00f5es s\u00e3o associados a diferentes tipos de modula\u00e7\u00e3o e codifica\u00e7\u00e3o, conforme ilustrado na Tabela 1.<\/div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-2562\" src=\"https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/NFC-NRZ-L-Coding11-300x125.png\" alt=\"\" width=\"564\" height=\"235\" srcset=\"https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/NFC-NRZ-L-Coding11-300x125.png 300w, https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/NFC-NRZ-L-Coding11-1024x427.png 1024w, https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/NFC-NRZ-L-Coding11-768x320.png 768w, https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/NFC-NRZ-L-Coding11-18x8.png 18w, https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/NFC-NRZ-L-Coding11-600x250.png 600w, https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/NFC-NRZ-L-Coding11.png 1275w\" sizes=\"auto, (max-width: 564px) 100vw, 564px\" \/><\/p>\n<h2 class=\"auto-hide-last-sibling-br paragraph_c9271 paragraph-element\"><span class=\"ez-toc-section\" id=\"NFC_Non-Return-to-Zero_Level_NRZ-L_Encoding\"><\/span><strong>Codifica\u00e7\u00e3o NFC de n\u00edvel sem retorno a zero (NRZ-L)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"image-wrapper_dd1b3 clickable_dd1b3\" data-testid=\"mdbox_image\"><img decoding=\"async\" src=\"data:;base64,<svg xmlns='http:\/\/www.w3.org\/2000\/svg' version='1.1' width='400' height='256'\/>&#8221; alt=&#8221;&#8221; aria-hidden=&#8221;true&#8221; \/><img loading=\"lazy\" class=\"alignnone  wp-image-2563\" alt=\"\" width=\"559\" height=\"311\" srcset=\"https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/NRZ-L-coding-300x167.webp 300w, https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/NRZ-L-coding-18x10.webp 18w, https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/NRZ-L-coding.webp 596w\" sizes=\"auto, (max-width: 559px) 100vw, 559px\" \/><\/div>\n<p>&nbsp;<\/p>\n<ul class=\"auto-hide-last-sibling-br\">\n<li><em>Representa\u00e7\u00e3o<\/em>:O esquema de codifica\u00e7\u00e3o NRZ-L \u00e9 mostrado na Figura 1, onde um bin\u00e1rio &#039;1&#039; \u00e9 representado por uma alta voltagem (+V) e um bin\u00e1rio &#039;0&#039; \u00e9 denotado por uma baixa voltagem (0 volts).<\/li>\n<li><em>Caracter\u00edstica<\/em>:Tamb\u00e9m chamada de codifica\u00e7\u00e3o NRZ unipolar, essa representa\u00e7\u00e3o \u00e9 direta, marcando cada valor de bit com um n\u00edvel de voltagem distinto.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h2 class=\"auto-hide-last-sibling-br paragraph_c9271 paragraph-element\"><span class=\"ez-toc-section\" id=\"NFC_Manchester_Encoding\"><\/span><strong>Codifica\u00e7\u00e3o NFC Manchester<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"image-wrapper_dd1b3 clickable_dd1b3\" data-testid=\"mdbox_image\"><img decoding=\"async\" src=\"data:;base64,<svg xmlns='http:\/\/www.w3.org\/2000\/svg' version='1.1' width='400' height='256'\/>&#8221; alt=&#8221;&#8221; aria-hidden=&#8221;true&#8221; \/><\/div><p><img loading=\"lazy\" class=\"alignnone  wp-image-2564\" alt=\"\" width=\"520\" height=\"414\" srcset=\"https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/Manchester-coding-300x239.webp 300w, https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/Manchester-coding-15x12.webp 15w, https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/Manchester-coding-600x478.webp 600w, https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/Manchester-coding.webp 639w\" sizes=\"auto, (max-width: 520px) 100vw, 520px\" \/><\/p>\n<ul class=\"auto-hide-last-sibling-br\">\n<li><em>Varia\u00e7\u00e3o<\/em>:Existem duas variantes de c\u00f3digos Manchester: tipos CA (bipolar) e CC (unipolar).<\/li>\n<li><em>Significado da transi\u00e7\u00e3o<\/em>:Tanto o bin\u00e1rio &#039;1&#039; quanto o &#039;0&#039; s\u00e3o caracterizados por transi\u00e7\u00f5es de tens\u00e3o dentro do mesmo per\u00edodo de bits \u2014 de alto para baixo significa um bin\u00e1rio &#039;1&#039;, enquanto de baixo para alto implica um bin\u00e1rio &#039;0&#039;.<\/li>\n<li><em>Precis\u00e3o de transi\u00e7\u00e3o<\/em>:Essas transi\u00e7\u00f5es s\u00e3o meticulosamente colocadas no ponto m\u00e9dio do per\u00edodo de bits, refor\u00e7ando a clareza dos sinais de dados.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h2 class=\"auto-hide-last-sibling-br paragraph_c9271 paragraph-element\"><span class=\"ez-toc-section\" id=\"NFC_Modified_Miller_Encoding\"><\/span><strong>Codifica\u00e7\u00e3o Miller modificada NFC<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"image-wrapper_dd1b3 clickable_dd1b3\" data-testid=\"mdbox_image\"><img decoding=\"async\" src=\"data:;base64,<svg xmlns='http:\/\/www.w3.org\/2000\/svg' version='1.1' width='400' height='256'\/>&#8221; alt=&#8221;&#8221; aria-hidden=&#8221;true&#8221; \/><img loading=\"lazy\" class=\"alignnone  wp-image-2565\" alt=\"\" width=\"496\" height=\"276\" srcset=\"https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/Modified-Miller-coding-300x167.webp 300w, https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/Modified-Miller-coding-18x10.webp 18w, https:\/\/nfc-readers.com\/wp-content\/uploads\/2024\/05\/Modified-Miller-coding.webp 565w\" sizes=\"auto, (max-width: 496px) 100vw, 496px\" \/><\/div>\n<p>&nbsp;<\/p>\n<ul class=\"auto-hide-last-sibling-br\">\n<li><em>Mapeamento bin\u00e1rio &#039;1&#039;<\/em>: A l\u00f3gica bin\u00e1ria &#039;1&#039; \u00e9 invariavelmente indicada por uma transi\u00e7\u00e3o de alto para baixo e depois de volta para alto dentro do per\u00edodo de bits, independentemente do estado do bit anterior.<\/li>\n<li><em>Mapeamento bin\u00e1rio &#039;0&#039;<\/em>:A representa\u00e7\u00e3o do bin\u00e1rio &#039;0&#039; depende da condi\u00e7\u00e3o do bit anterior: se o bit anterior for um &#039;1&#039;, o zero atual segue um padr\u00e3o de transi\u00e7\u00e3o reversa e, se for um &#039;0&#039;, o mapeamento ecoa o de um bin\u00e1rio &#039;1&#039;.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h2 class=\"auto-hide-last-sibling-br paragraph_c9271 paragraph-element\"><span class=\"ez-toc-section\" id=\"Types_of_Modulation_in_NFC\"><\/span><strong>Tipos de modula\u00e7\u00e3o em NFC<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"auto-hide-last-sibling-br paragraph_c9271 paragraph-element\"><br class=\"container_a4d0b wrapper_d536d undefined\" \/>NFC abrange uma gama de tipos de modula\u00e7\u00e3o, como Amplitude Shift Keying (ASK) em ambas as variantes 10% e 100% e emprega t\u00e9cnicas de modula\u00e7\u00e3o de carga. Esses m\u00e9todos de modula\u00e7\u00e3o s\u00e3o integrais \u00e0 precis\u00e3o e efici\u00eancia dos protocolos de comunica\u00e7\u00e3o NFC.<\/div>\n<p>&nbsp;<\/p>\n<h2 class=\"auto-hide-last-sibling-br paragraph_c9271 paragraph-element\"><span class=\"ez-toc-section\" id=\"In_Summary\"><\/span><strong>Resumindo<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"auto-hide-last-sibling-br paragraph_c9271 paragraph-element\"><br class=\"container_a4d0b wrapper_d536d undefined\" \/>A arquitetura do NFC \u00e9 baseada em protocolos sofisticados de modula\u00e7\u00e3o e codifica\u00e7\u00e3o, com cada padr\u00e3o empregando mecanismos exclusivos para garantir comunica\u00e7\u00e3o segura e eficaz entre dispositivos de proximidade. Seja por meio dos n\u00edveis de voltagem do NRZ-L, das indica\u00e7\u00f5es bin\u00e1rias baseadas em transi\u00e7\u00e3o do Manchester ou dos mapeamentos dependentes de contexto do Modified Miller, a tecnologia NFC demonstra adaptabilidade a uma infinidade de ambientes e necessidades operacionais.<\/div>","protected":false},"excerpt":{"rendered":"<p>Vis\u00e3o geral da transmiss\u00e3o de dados NFC NFC, uma tecnologia de comunica\u00e7\u00e3o sem fio de baixa taxa de dados e curto alcance, opera por meio de uma sinergia de dois dispositivos \u2014 denominados iniciador e alvo. Comumente reconhecidos como tag e leitor, essas entidades se envolvem na troca de dados por meio de uma frequ\u00eancia portadora de RF de 13,56 MHz, contando com indu\u00e7\u00e3o eletromagn\u00e9tica sem contato. O [\u2026]","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2561","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/nfc-readers.com\/pt\/wp-json\/wp\/v2\/posts\/2561","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nfc-readers.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nfc-readers.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nfc-readers.com\/pt\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/nfc-readers.com\/pt\/wp-json\/wp\/v2\/comments?post=2561"}],"version-history":[{"count":1,"href":"https:\/\/nfc-readers.com\/pt\/wp-json\/wp\/v2\/posts\/2561\/revisions"}],"predecessor-version":[{"id":2566,"href":"https:\/\/nfc-readers.com\/pt\/wp-json\/wp\/v2\/posts\/2561\/revisions\/2566"}],"wp:attachment":[{"href":"https:\/\/nfc-readers.com\/pt\/wp-json\/wp\/v2\/media?parent=2561"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nfc-readers.com\/pt\/wp-json\/wp\/v2\/categories?post=2561"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nfc-readers.com\/pt\/wp-json\/wp\/v2\/tags?post=2561"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}