In particular, for broadband applications, where the signal bandwidth is a noticeable fraction of the carrier frequency and where sophisticated modulation and detection methods have to be used, the receiver does not only require a sufficient mean power but also a reasonable approximation of the impulse response \(w_{e}(t,s)\) or delay spread function \(g_{e}(t,\tau )\) of the equivalent time-variant baseband system. In the following, we consider the link budget design as given and focus on additional impairments, such as the frequency- and the time-dependent fading. Practical examples are modern cellular networks, where the carrier frequency and the signal bandwidth are around 2 and 0.1 GHz, respectively.