EEET 3028 Introduction to Communication Systems University of South Australia School of Engineering Assignment 2 (2013 SP6) General information This assignment covers sampling and principles of digital communication systems, and their simulation in MATLAB. Your report should include written answers, block diagrams, sketches of signals, plots produced by MATLAB and the corresponding MATLAB code. Explain how you came to your answers and conclusions, and provide concise answers. Hand-written answers, mathematical derivations, sketches, and block diagrams are ne if done neatly and clearly. You may scan them and include them in your document. The report is to be submitted online and on time. Late submissions may not be considered. Make sure that you have added the cover page. The deadline for submission is given on the course webpage. Problems Sampling 1. Consider the sinusoidal signal x(t) = 8 sin(6t + ‘0): Assume ‘0 = =4 for this question and ‘0 = 0 for the following two questions. Compute analytically the spectrum. Sketch the magnitude and phase spectrum. What is the meaning of Nyquist rate”, and what is the Nyquist rate for this signal? (Consider the signal to be a low-pass signal.) 2. The sampling function s(t) = X+1 i=??1 (t ?? iTs); Ts = 1=4, is used to obtain the sampled signal y(t) = x(t) s(t). Sketch y(t) alongside x(t) (at least 3 periods). Sketch the magnitude spectrum of y(t). Hint: Explicit computation of the spectrum Y (f) is not required. 3. Assume now Ts = 1=16. The signal x(t) is reconstructed from the sampled signal y(t) using at-top sampling, giving the reconstructed signal z(t). Sketch z(t) alongside x(t) (at least three periods). Discuss if the original signal x(t) can be perfectly reconstructed from z(t). Assignment 2 (2013 SP6) Page 1
EEET 3028 Introduction to Communication Systems University of South Australia School of Engineering Digital transmitter 4. Draw the block diagram of a digital transmitter. Explain how the transmit signal is…