Mean-square consistency of statistical-function estimators for generalized almost-cyclostationary processes

In this paper, the problem of estimating second-order statistical functions for generalized almost-cyclostationary (GACS) processes is addressed. The class of such nonstationary processes includes, as a special case, the almost-cyclostationary (ACS) processes. ACS processes filtered by some linear time-variant channels are further examples. It is shown that, for GACS processes, the cyclic correlogram is a mean-square consistent estimator of the cyclic autocorrelation function. Moreover, well-known consistency results for ACS processes can be obtained by specializing the results of this paper.