Question regarding interpolation and decimation
4 views (last 30 days)
Show older comments
Hi, I was tasked with the following question:
Construct a DT signal given by
- Sketch the signal using the stem function.
- Transform the signal x[k] based on the operation y[k] = x[k/5] followed by the operation z[k] = y[5k]. What is the relationship between x[k] and z[k]?
- Repeat (ii) with the order of interpolation and decimation reversed.
So far I've solved (i) and (ii) (code and result attached). Is what I'm doing correct? I also need help understanding the (iii) as I simply do not get what is being asked. Please let me know if what I have solved is correct and that what is being asked in (iii).
clc;
close all;
clear all;
% Variables
k = [0:1:120];
x = (1 - exp(-0.003 * k) .* cos((pi * k) / 20));
N = length(x);
n = 0:N-1;
% Question I
subplot(3,1,1)
stem(n, x);
xlabel('Samples');
ylabel('Amplitude');
title('Input Sequence');
% Question II
y = x(1:5:120);
n1 = 0:length(y)-1;
subplot(3,1,2)
stem(n1, y);
xlabel('Samples');
ylabel('Amplitude');
title('Decimated Sequence');
z = zeros(1,5*N);
n2 = 1:1:5*N;
j = 1:5:5*N;
z(j) = x;
subplot(3,1,3)
stem(n2, z);
xlabel('Samples');
ylabel('Amplitude');
title('Interpolated Sequence');
0 Comments
Answers (1)
Ananya Tewari
on 23 Sep 2021
Hi,
You can refer to the documentation of interpolation and decimation to understand about them. Here is the link to another answer which may help you in getting a better understanding of interpolation, decimation and their implementation.
0 Comments
See Also
Categories
Find more on Multirate Signal Processing in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!