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Asked by Passband Modulation on 21 Sep 2012

i am just a matlab beginner.

x[n]=2cos(0.2*pi*n) with a length of N =100 , that is, ,0<N<99 plotted

clear all n=[0:99]; x=2*cos(0.2*pi*n); stem(n,x); legend('x[n]'); title('Sequence of 2*cos(0.2*pi*n)'); xlabel('n'); ylabel('x[n]'); axis([0 99 -2 2]);

how to use MATLAB to compute the mean, and energy and power of x[n]given mean=x, energy=Ex and power=Px.

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Answer by Wayne King on 21 Sep 2012

Edited by Wayne King on 21 Sep 2012

Accepted answer

You can just do:

mean(x) Ex = norm(x,2)^2 % the energy Px = 1/numel(x)*norm(x,2)^2 % power

If you don't want to use norm(), you just use sum()

Ex = sum(abs(x).^2) Px = 1/numel(x)*sum(abs(x).^2)

Note that the RMS of the signal is

sqrt(Px)

The Signal Processing Toolbox implements this as rms()

Walter Roberson on 18 Dec 2013

pinak parida commented,

power ,energy of a signal how norm works to be check?

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