Calculate Theoretical Covariance Matrix of AR(1) Blocks Process
Calculate Theoretical Covariance Matrix of AR(1) Blocks Process
This function allows us to calculate the theoretical covariance matrix of a non-stationary AR(1) blocks process.
covmat_ar1blocks(n_total, n_block, phi, sigma2)
Arguments
n_total: An integer indicating the length of the whole AR(1) blocks process.
n_block: An integer indicating the length of each block of the AR(1) blocks process.
phi: A double value for the autocorrection parameter phi.
sigma2: A double value for the variance parameter sigma2.
Returns
The theoretical covariance matrix of the AR(1) blocks process.
Note
This function helps calculate the theoretical covariance matrix of a non-stationary process, AR(1) blocks. It is helpful to calculate the theoretical allan variance of non-stationary processes, which can be used to compare with the theoretical allan variance of stationary processes as shown in "A Study of the Allan Variance for Constant-Mean Non-Stationary Processes" by Xu et al., 2017, IEEE Signal Processing Letters, 24(8): 1257–1260.