Data Encoding with Modulation Techniques for AFCAT 2020

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Complete Video at - Data Encoding: Manchester Encoding and Differential Encoding (Computer Science)


  1. Manchester Encoding

  2. Differential Encoding

Encoder and decoder

Encoder and Decoder

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Complete notes and preparation module at

Manchester Encoding

  • There is different type of Conversions or encoding techniques.

    • It can be analog to digital

    • It can be digital to analog

    • Or it can also be digital to digital

  • Manchester Encoding is done in digital to digital conversion. It shows us the transitions in the signals.

  • It can be done according to two formats:

  • IEEE Format

  • Dr. Thomas’s Format

Manchester Encoding

  • At Physical Layer data need to be encoded for security concerns. It is done at the middle of the bit interval. Here

  • High to Low: 1

  • Low to High: 0

Image of Manchester Encoding

Image of Manchester Encoding

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Differential Encoding

  • It is also done at the middle of the bit interval. But here in this differential encoding technique there will be an edge on negative signal and no edge with continuing line is present in case of 1.

Image of Differential Encoding

Image of Differential Encoding

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Q1. Machester Encoding technique is based upon the:


  1. Digital to Analog Conversion of Data

  2. Digital to Digital Conversion of Data

  3. Analog to Digital Conversion of Data

  4. None of these

Ans: 2.

Q2. Encoding of data normally happens at which layer of transmission protocol?


  1. Internet Layer

  2. Physical Layer

  3. Data Link Layer

  4. Application Layer

Ans: 2.

  • Topics Covered are:-

  • Different types of encoding requirements.

  • Manchester Encoding

  • Differential Encoding

  • Comparison between Manchester and Differential technique.