  We study the ergodic capacity of a frequency-selective Rayleigh fading
channel with correlated scattering, which finds application in the area of UWB.
Under an average power constraint, we consider a single-user, single-antenna
transmission. Coherent reception is assumed with full CSI at the receiver and
no CSI at the transmitter. We distinguish between a continuous- and a
discrete-time channel, modeled either as random process or random vector with
generic covariance. As a practically relevant example, we examine an
exponentially attenuated Ornstein-Uhlenbeck process in detail. Finally, we give
numerical results, discuss the relation between the continuous- and the
discrete-time channel model and show the significant impact of correlated
scattering.
