hw2_501_Au11

hw2_501_Au11 - ECE-501 Introduction to Analog and Digital...

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

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

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

Unformatted text preview: ECE-501 Introduction to Analog and Digital Communications Autumn 2011 Homework #2 Sep. 30, 2011 HOMEWORK ASSIGNMENT #2 Due Mon. Oct. 10, 2011 (in class) Reading: 1. Ch. 2.10-2.12 (the sections on Fast Fourier Transform Algorithms and Computation of the IDFT are optional). 2. Ch. 3.1–3.5. Problems: 1. In this problem you will use MATLAB to study causal linear-phase LPFs. (a) One way to design a causal linear-phase LPF is to truncate the t o-shifted sinc impulse response h ( t ) = 2 B sinc(2 B ( t − t o )) so that h ( t ) = 0 for t < 0 and t > 2 t o . For a single-sided bandwidth of B = 20 Hz and an impulse response length of 2 t o = 0 . 5 seconds, generate a T s = 0 . 001-sampled version of this impulse response in MATLAB and use plottf.m to plot the impulse and frequency magnitude responses. Comment on the non-ideality of the magnitude response of this filter. (b) Another way to generate a causal linear-phase LPF is to use MATLAB’s built-in filter design routines. Here you will use firls.m to repeat the filter design task in part (a). As described in the lecture, firls is used as follows: h = firls(Lf, [0,fp,fs,1], [G,G,0,0])/Ts; fp fs 1 G f 1 / (2 T s ) Lf +1 = impulse response length { 0, fp } , { fs , 1 } = normalized freq pairs { G , G } , { 0, 0 } = corresp. magnitude pairs For a fair comparison with the truncated-sinc design of part (a), use the same values of t o , T s , and passband gain, and set the passband and stopband cutoffs to be 0 . 9 B and 1 . 1 B Hz, respectively, for the same B . ( Hint: This implies Lf = 2 t o /T s and G = 1. Also, don’t forget to normalize the cutoff frequencies by 1 2 T s when setting fp and fs !) 2. In this problem you will experiment with the effects of filtering in MATLAB. Use a sampling rate of 1 T s = 1000 Hz throughout....
View Full Document

Page1 / 4

hw2_501_Au11 - ECE-501 Introduction to Analog and Digital...

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

View Full Document Right Arrow Icon
Ask a homework question - tutors are online