This volumes discusses various aspects regarding the capacity/achievable
data rate of stationary Rayleigh fading channels. First, it analyses
bounds on the achievable data rate with zero-mean proper Gaussian input
symbols, which are capacity achieving in the coherent case, i.e., in
case of perfect channel knowledge at the receiver. These bounds are
tight in the sense that the difference between the upper and the lower
bound is bounded for all SNRs. The lower bound converges to the coherent
capacity for asymptotically small channel dynamics. Furthermore, these
bounds are extended to the case of multiple-input multiple-output (MIMO)
channels and to the case of frequency selective channels. In a further
part, the present work studies the achievable rate with receivers based
on synchronized detection and a code-aided channel estimation. For a
specific type of such a receiver an approximate upper bound on the
achievable rate is derived. The comparison of this approximate upper
bound and the achievable data rate with receivers using synchronized
detection based on a solely pilot based channel estimation gives an
approximate upper bound on the possible gain by using this kind of
code-aided channel estimation in comparison to the conventional receiver
using a solely pilot based channel estimation. In addition, the
achievable data rate with an optimal joint processing of pilot and data
symbols is studied and a lower bound on the achievable rate for this
case is derived. In this context, it is also shown which part of the
mutual information of the transmitter and the receiver is discarded when
using the conventional receiver with synchronized detection based on a
solely pilot based channel estimation.