Capacity pre-log of SIMO correlated block-fading channels

We establish an upper bound on the noncoherent capacity pre-log of temporally correlated block-fading single-input multiple-output (SIMO) channels. The upper bound matches the lower bound recently reported in Riegler et al. (2011), and, hence, yields a complete characterization of the SIMO noncoherent capacity pre-log, provided that the channel covariance matrix satisfies a mild technical condition. This result allows one to determine the optimal number of receive antennas to be used to maximize the capacity pre-log for a given block-length and a given rank of the channel covariance matrix.