| Popis: |
In the following we consider channels, which can be modeled by a causal impulse response with finite duration, what we call finite impulse response (FIR) \(h(n)={\left\{ \begin{array}{ll}\begin{array}{ccc} h_{n} &{} ; &{} n=0,1,\ldots ,L\\ 0 &{} ; &{} else \end{array}&;\,\,\,\,\,h_{L}\ne 0\end{array}\right. }\) We say, h(n) owns the length \(L+1\), which is also the dimension of a corresponding signal vector. The channel parameters \(h_{n}\) shall be time-invariant. n represents discrete time. All properties of FIR filters known from signal processing apply. Furthermore, we study discrete-time input signals with finite duration, which can be described by a signal vector also called block of samples. Long signals will be structured block-wise and the principle of block-wise transmission is discussed in quite detail. Finally, we introduce a guard interval between the signal blocks by means of a prefix or a cyclic prefix and study important properties. |
