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(ELEC4140)[2009](f)midterm~dli^_25423.pdf
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Midterm (of ELEC331), 22nd of October, 2009


Remarks: This is an open-note exam. Duration: 9:00am C 10:20 am.



1. (10 pts) Given a memory-less source model of 5 symbols with the probability distribution shown as follows:


Symbol
Probability

a

e

i

o

u

0.2
0.3
0.2
0.2
0.1


i) Design a codebook (table) for the Huffman coding of this symbol set. Generate the bit-stream after the Huffman coding of the block of symbols {e,a,u,i,e} and find how many bits have been used.

ii) Design the codebook (table) with the minimum variance for the Huffman coding of the same symbol set. Generate the bit-stream after the Huffman coding of the same block of symbols {e,a,u,i,e} and find how many bits have been used.

iii) Find the small interval (both bounding values) for the arithmetic coding of the same block of symbols {e,a,u,i,e} and then find the shortest binary code for this block of symbols.














2. (10 pts) Fill in all entries in the table for the feed-forward and feed-back prediction structures (referring to Pages 4 and 5 of Chapter 4), under the following assumptions: (1) use the previous element for prediction, and (2) use x+ to do quantization at any discontinuity.



Input
Feeb-forward prediction
Feed-back prediction

m
xm
.mx

em
.me

.mx.

mx.


em




0
1
2
3
4
5
6
7
8
9
100
104
122
122
124
124
120
120
118
118
-
-
-
-
100
-
-
-
-
100



Output

Input

.8


8



.4

4

2

.2