CODEWITHSUNDEEP
matlabsignal-processinggaussian
ITA
ITA

Reputation: 3870

Symmetric shifted gaussian pulse

Consider this short code:

fc=2e9;
fs = 100e9;
for n=1:2
  tc = gmonopuls('cutoff',fc);
  t{n}  = -2*tc:1/fs:2*tc;
  y{n} = gmonopuls(t{n}+n*5e-11,fc);
  fc=fc+5e3;
end
plot(t{1},y{1},'r',t{2},y{2},'k')

It generates a two Gaussian mono-pulses shifted by a slight amount:

shifted gaussian pulse

My problem is this: How do I make this symmetric? Note how the tails match up...they are zero for both the red and black pulse. I am new to the signal processing toolbox in matlab and want to modify the code below to have matched heads too.

Upvotes: 1

Views: 162

Answers (1)

SleuthEye
SleuthEye

Reputation: 14577

gmonopuls computes a Gaussian pulse which is centered at 0:

t = -2*tc:1/fs:2*tc;
y = gmonopuls(t,fc);
plot(t, y, 'k');

enter image description here

Evaluating this function at different time instants does not change the fundamental shape of the curve. It would only change which part of the curve you are sampling:

K = 2*tc;
for n=1:3
  t{n} = -2*tc:1/fs:2*tc + (n-2)*K;
  y{n} = gmonopuls(t{n},fc);
end
plot(t{1},y{1},'rx', t{2},y{2},'k', t{3},y{3},'bs');
legend('t-K','t','t+K');

enter image description here

To obtain a curve shifted along the time axis you simply need to add a time offset after you have computed your function:

for n=1:2
  tc = gmonopuls('cutoff',fc);
  t{n} = -2*tc:1/fs:2*tc;
  y{n} = gmonopuls(t{n},fc);
  t{n} = t{n} - n*5e-11;
  fc=fc+5e3;
end
plot(t{1},y{1},'r',t{2},y{2},'k')

enter image description here

Upvotes: 2

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