Problem declaring a signal.

I am a beginner in MATLAB and I'm studying for a test in Signal Processing and don't know how to tackle this some parts of this problem: "Using Matlab, convolve the two discrete-time signals: x1=(1/3)*(δ[n−1]+δ[n]+δ[n+1]) and x2 given by signal2.mat. Store the convolution (x1∗x2) in the variable x."

signal2.mat only contain the variable n which is an interval from -10 to 10 with a step of 1 and x2 which contain 21 random values.

I don't know what delta represents in x1 and how to implement/declare it in MATLAB. Any help is appreciated! I know what to do after I've declared x1, so further help than that is not needed!

[Star Strider]

The reference to is most likely the Dirac delta function, described in the Symbolic Math Toolbox dirac function.

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Answer 1

[Sahil Jain]

The "δ[n]" generally refers to the Dirac delta function. The following code will help you generate the required signal.

n=-10:1:10; 
x1=(1/3)*(dirac(n-1)+dirac(n)+dirac(n+1)); 

More information about the Dirac delta function can be found on its documentation page.

Answer 2

[Mattias Eek]

For anyone wondering how I solved this, here's my solution:

load = 'signal2.mat';
L = 21;
f = zeros(1,L);
mid = ceil(L/2);

for i=mid-1:mid+1
    f(i)=1/3;
end

x1=f;
x = conv(x1,x2);

You can probably solve it using dirac, like @Sahil Jain mentioned above, but this worked for me.