1 Sinewave with Random Phase and Amplitude (12 marks)
Let X(t) be a random process defined as
X(t) = A cos(wot + Θ) (1)
The frequency wo is constant, while the amplitude A and Θ are independent random variables. The amplitude distribution has a mean ̄μ_A and a variance σ_A^2. The phase has a uniform probability density function (pdf) given by
f_Θ(θ) = 1/(2π) for θ ∈ [0, 2π) (2)
a) Find the autocorrelation function R_XX(t_1, t_2) for X(t). [7]
b) A wide sense stationary (WSS) random process must satisfy two conditions. What are they? [2]
c) Is X(t) a WSS random process? [1]
d) Using the autocorrelation, write an expression for the power of the random signal X(t). [2]