Prob4 - ECE 1520 Data Communications Fall 2011 Problem Set...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ECE 1520 Data Communications Fall 2011 Problem Set 4 Due in class, Wednesday, Oct. 26th, 2011. 1. Consider the carrier given by c ( t ) = radicalbig (2 /T ) cos (2 πf c t + φ ) , ≤ t < T . A joint ASK-PSK signal set is defined using two indices p and q : s p,q ( t ) = q radicalbig (2 E/T ) cos parenleftBig 2 πf c t + p π 4 parenrightBig , ≤ t < T, where p = 0 , 1 , . . . , 7; q = 1 , 2 Plot the signal constellation of this scheme using the low-pass equivalent. 2. (Related to Q3.10 of Proakis and Salehi (5th ed.)) A speech signal is sampled at a sampling rate of 8kHz and then quantized to 8 levels. The probabilities of the 8 levels are (The probabilities are the same as in Prob set 2.): p 1 = 0 . 25 , p 2 = 0 . 20 , p 3 = 0 . 15 , p 4 = 0 . 12 , p 5 = 0 . 10 p 6 = 0 . 08 , p 7 = 0 . 05 , p 8 = 0 . 05 Determine a binary Huffman code for this source. If the transmission uses QPSK, what is the signalling interval for his source? What would the interval have been if we did not use Huffman coding?if we did not use Huffman coding?...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online