Digital Data and Line Coding Data and Computer Communication Suherman, PhD Reference: Wikipedia elearning.vtu.ac.in
Digital Data Dipresentasikan dengan nilai “0” dan “1” Pasangan “0” dan “1” disebut binary number (biner) Banyaknya nilai “0” dan “1” tiap detik disebut dengan “bit rate”. Dalam line/baseband coding dan broadband coding (modulasi), terkadang 1 digit diwakili 1 simbol, tapi juga terkadang 2, 4, 8 bit diwakili 1 simbol. Banyaknya simbol per detik disebut “Baud rate”.
Sumber Data Digital Digitalisasi suara: suara analog, disampling kemudian diubah menjadi data digital: PCM24, PCM30, ADPCM, CELP dan vocoder lainnya. Transducer: alat ukur yang mengubah karakteristik alam menjadi data biner. Video. Data.
Line Coding Line coding atau baseband coding adalah pengkodean nilai “0” dan “1” dalam tegangan listrik. Dibutuhkan agar simbol “0” dan “1” dapat ditransmisikan secara efective melalui kabel. Representasi “0” dan “1” bervariasi. Karena perubahan pulsa tegangan memiliki spektrum frekuensi, maka dibutuhkan representasi yang efektif, agar kecepatan transfer semakin tinggi.
Line Coding Dimana saja line coding dibutuhkan? Serial: Non-Return-to-Zero (NRZ), Polar NRZ, NRZ inverted, Bipolar encoding, Manchester encoding, Differential Manchester encoding, HDB3. Serial interfacing: RS-series (RS-232), TIA-series, EIA-series, MIL-series. Paralel interfacing: LPT-series, IEEE-1284, dll Connector: DE-9 (DB-9), DB25, RJ11, RJ45, DIN-8, dll
Line Coding Unipolar Coding:
Line Coding Polar Coding
Line Coding Non-Return to Zero (NRZ)
Line Coding Return to Zero (RZ)
Line Coding Manchester Coding
Line Coding Differential Manchester Coding
Line Coding AMI (Alternate Mark Inversion) atau BnZS (Bipolar n-Zero Substitution)
Line Coding 2B1Q (2-Binary 1-Quartenary) - Four voltage level
Line Coding MLT3 (Multi Line Transmission Three Leve)
Studi Lanjut Serial – Paralel Port Connectors Common line codes AMI Modified AMI codes: B8ZS, B6ZS, B3ZS, HDB3 2B1Q 4B5B 4B3T 6b/8b encoding Hamming Code 8b/10b encoding 64b/66b encoding 128b/130b encoding Coded mark inversion (CMI) Conditioned Diphase Eight-to-Fourteen Modulation (EFM) used in Compact Disc EFMPlus used in DVD RZ — Return-to-zero NRZ — Non-return-to-zero NRZI — Non-return-to-zero, inverted Manchester code (also variants Differential Manchester & Biphase mark code) pulse-position modulation (a generalization of Manchester code) Miller encoding (also known as Delay encoding or Modified Frequency Modulation, and has variant Modified Miller encoding) MLT-3 Encoding Hybrid Ternary Codes Surround by complement (SBC) TC-PAM Optical line codes: Carrier-Suppressed Return-to-Zero Alternate-Phase Return-to-Zero Serial – Paralel Port Connectors
Thesis?? - Analysis dan Simulasi Representasi Spektral Line Coding