Finite Impulse Response Digital Filters

Figure: The general, causal, length $N=M+1$, finite-impulse-response (FIR) digital filter. For FIR filters, direct-form I and direct-form II are the same (see Chapter 9).

Figure 5.5 gives the signal flow graph for a general finite-impulse-response filter (FIR). Such a filter is also called a transversal filter, or a tapped delay line. The implementation is one example of a direct-form implementation of a digital filter.