An audio signal s(t)generated by a loud speaker is reflected at two different walls with reflection coefficients r1 and r2. the signal x(t) recorded by amicrophone close to the loud speaker, after sampling is;
x(n)=s(n)+r1*s(n-k1)+r2*s(n-k2)
where k1 and k2 are the delays of the two echoes.
a) determine the autocorrelation rxx(l) of the signal
x(n)
b) what happens if r2=0?
c) can we obtain r1,r2,k1, and k2 by observing rxx(l)?