Problem 1: Let $X(t)$ and $Y(t)$ are zero-mean jointly WSS processes with autocorrelation $R_{XX}(\tau) = E[X(t + \tau), X(t)]$ and $R_{YY}(\tau)$ and cross-correlation $R_{XY}(\tau)$. Consider the process $Z(t) = \sqrt{2} X(t) \cos(2\pi f_0 t) - \sqrt{2} Y(t) \sin(2\pi f_0 t)$ for some constant $f_0 > 0$. Determine under what condition(s) the process $Z(t)$ is also WSS.
Added by Julie L.
Close
Step 1
Step 1: A process is WSS if its mean is constant and its autocorrelation function depends only on the time difference. Show more…
Show all steps
Your feedback will help us improve your experience
Sri K and 54 other Intro Stats / AP Statistics educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Let Xt be a time series in which we are interested. However, because the measurement process itself is not perfect, we actually observe Yt = Xt + ̄̄̄t, where Xt is the signal and ̄̄̄t is the measurement noise or error process. We assume that Xt and ̄̄̄t are independent processes. Xt is stationary with autocorrelation function ̄X(k). Show that Yt is also stationary with autocorrelation function ̄Y(k) = ̄X(k) + ̄̄̄(k). What happens to the autocorrelations of Yt as the noise ratio ̄̄̄(k) / ̄X(k) gets larger?
Sri K.
Consider the time series model Xt defined as: Xt = 0.4Xt-1 + e_t + 0.3e_t-1, where the series e_t is a zero-mean white noise process with a constant variance of 2. (i) Derive the values of the autocorrelation function of Xt at lags 1, 2, and 3. (ii) Calculate the values of the partial autocorrelation function of Xt at lags 1 and 2.
Madhur L.
Consider 2 stochastic processes Yt and Zt, following the dynamics (dYt = b(t)Yt dWt, dZt = A(t)dt + B(t)dWt) Define a new stochastic process Xt as Xt = YtZt, write down the stochastic differential equation for dXt.
Recommended Textbooks
Elementary Statistics a Step by Step Approach
The Practice of Statistics for AP
Introductory Statistics
Transcript
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD