Question

A source generates four independent symbols with probabilities 0.50, 0.25, 0.15. 0.10 at a rate of 20000 symbols per second. The symbols are encoded into binary format using Huffman coding scheme. The average bit rate at the output of the source encoder will be____ kbps.

• A. 35

Answer 1

The correct option is A 35
Huffman Coding

Symbol probability	0.50	0.25	0.15	0.10
Code word	0	10	110	111

Average length of code word is,

$\overline{L}{\sum }_{i=1}^4{P}_1{l}_1=(0.50\times 1)+(0.25\times 2)+(0.15\times 3)+(0.10\times 3)$

=1.75 bits/symbol

Average bit rate at the output of encoder,

$R_b=\overline{L}{r}_s=1.75\times 20000=35\text{kbps}$