20092ee132A_1_ca2sol

# 20092ee132A_1_ca2sol - EE132A, Spring 2009 Prof. John...

This preview shows pages 1–2. Sign up to view the full content.

EE132A, Spring 2009 Communication Systems Prof. John Villasenor Handout# 17 TAs: Pooya Monajemi and Erica Han Computer Assignment #2 Solution (a) QPSK System: The probability of bit error in a coherent QPSK system is approximately given by = 0 erfc 2 1 N E P b B Let x = 0 N E b in dB. So, the argument of ( ) erfc should be replaced by 10^(x/10). See the plot and MATLAB code that follows. (b) One-dimensional constellation: This one-dimensional constellation has the following properties: - The average symbol energy is E - The probability of occurrence of each symbol is equal. i.e., ( ) ( ) ( ) ( ) 4 1 = = = = D P C P B P A P The probability of symbol error is given by: ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) [ ] D E P C E P B E P A E P D P D E P C P C E P B P B E P A P A E P P E | | | | 4 1 | | | | + + + = + + + = By symmetry: ( ) ( ) ( ) ( ) C E P B E P D E P A E P | | and | | = = Thus, ( ) ( ) [ ] B E P A E P P E | | 2 1 + = Since ( ) A E P | and ( ) B

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.

## This note was uploaded on 02/05/2012 for the course EE 132B taught by Professor Izhakrubin during the Spring '09 term at UCLA.

### Page1 / 4

20092ee132A_1_ca2sol - EE132A, Spring 2009 Prof. John...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online