Let xn be a stationary random process with zero mean and

Question

Let x(n) be a stationary random process with zero mean and autocorrelation r_x(k). We form the process, y(n), as follows:

y(n) = x(n) + f(n)

where f(n) is a known deterministic sequence. Find the mean my (n) and the autocorrelation r_y(k, l) of the process y(n).