i understand that you are trying to add harmonics (fundamental upto third ) by computing harmonics at some instants of time and trying to get plot of it
M = 64; %Number of subcarriers
K = 4; %overlapping factor
y=[1 0.97195983 sqrt(2)/2 0.23514695 ]
T= M;
l=K*T; % simplify the equation instead of typing it every time
for k=1:3
for t=0:100
h(k,t+1)=((y(1)^2)*cos((2*k*pi*t)/l))+((y(2)^2)*cos((2*k*pi*t)/l))+((y(3)^2)*cos((2*k*pi*t)/l))+((y(4)^2)*cos((2*k*pi*t)/l))
%here im using t+1 because t=0 cannot be used since indexing must be a positve non zero interger i could use logic(t) but im too lazy
end
end
a=1+(2*sum(h))
plot(a)
xlabel('h(t)')
ylabel('t')
is this the graph you are expecting?
even code can be improved
