6.02 Spring 2008
1 of 3
HW #9
M
ASSACHUSETTS
I
NSTITUTE OF
T
ECHNOLOGY
D
EPARTMENT OF
E
LECTRICAL
E
NGINEERING AND
C
OMPUTER
S
CIENCE
6.02 Introduction to EECS II
Spring 2008
Homework #9: Source Coding
Issued: April 11, 2008
Due: April 18, 2008
Problem 1.
Huffman and other coding schemes tend to devote more bits to the coding of
(choose one):
(A) symbols carrying the most information
(B) symbols carrying the least information
(C) symbols that are likely to be repeated consecutively
(D) symbols containing redundant information
Problem 2.
Consider the following two Huffman decoding tress for a variablelength
code involving 5 symbols: A, B, C, D and E.
(A) Using Tree #1, decode the following encoded message: "01000111101".
(B) S
uppose we were encoding messages with the following probabilities for each of the
5 symbols: p(A) = 0.5, p(B) = p(C) = p(D) = p(E) = 0.125.
Which of the two
encodings above (Tree #1 or Tree #2) would yield the shortest encoded messages
averaged over many messages?
(C) Using the probabilities for A, B, C, D and E given in part (B), construct a variable
length binary decoding tree using the simple greedy algorithm presented in lecture:
1.
Begin with the set S of symbols to be encoded as binary strings, together with the
probability P(x) for each symbol x. The probabilities sum to 1 and measure the
frequencies with which each symbol appears in the input stream. In this example,
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '08
 Terman
 Computer Science, Electrical Engineering, Coding theory, arithmetic coding, Variablelength code, 2bit values

Click to edit the document details