Consistent estimation of Rayleigh fading channel second order statistics in the context of the wideband CDMA mode of the UMTS

We address the problem of second order statistics estimation of a selective Rayleigh channel in the context of the wideband CDMA mode of the UMTS. The data to be transmitted are sent over slots over which the channel is assumed to remain constant. Each slot contains a pilot symbol sequence from which the channel can be estimated. The covariance matrix of the channel is usually estimated by a denoised version of the empirical covariance matrix of the trained channel estimate. However, this estimate is not consistent in the UMTS context. We propose a new consistent estimate of the channel covariance matrix, and evaluate the performances of two Wiener-like channel estimation schemes based on the proposed estimate