Question

Consider the following codes:
A. Hamming Code,
B. Huffman Code,
C. Shannon-Fano Code,
D. Convolution Code. Which of these are source codes?

• A. A, B and D only
• B. B and C only
• C. A and D only
• D. B, C and D only

Hint:

If the purpose of the code is to make the file smaller (compression), it's a source code. If its purpose is to make the transmission more robust against errors, it's a channel code.

Answer 1

The Correct Option is B

Step 1: Differentiate between Source Coding and Channel Coding.

• Source Coding (Data Compression): The goal is to remove redundancy from the source information to represent it more efficiently (using fewer bits). Examples include Huffman coding and Shannon-Fano coding.
• Channel Coding (Error Control Coding): The goal is to add controlled redundancy to the data in order to detect and/or correct errors that may occur during transmission over a noisy channel. Examples include Hamming codes, convolutional codes, and block codes.

Step 2: Classify the given codes.

• (A) Hamming Code: This is a classic block code used for error detection and correction. It is a channel code.
• (B) Huffman Code: This is a variable-length coding algorithm used for lossless data compression. It is a source code.
• (C) Shannon-Fano Code: This is another variable-length coding technique for data compression. It is a source code.
• (D) Convolution Code: This is a type of error-correcting code that generates parity symbols via the sliding application of a Boolean polynomial function to a data stream. It is a channel code.

Step 3: Identify the source codes.

The source codes from the list are:

• Huffman Code (B)
• Shannon-Fano Code (C)