adaptive filter with more than two coefficients

The original question has been removed by the user.

Answer 1

[Honglei Chen]

You need to change the loop to

j = 3:N

and then the signal to

x(j-2:j)

Otherwise, your x(j-1:j) is only 2 samples long while your filter has 3 coefficients, dimension mismatch.

[Tom]

Thank you so much!!!!!