Next  |  Prev  |  Up  |  Top  |  Index  |  JOS Index  |  JOS Pubs  |  JOS Home  |  Search

Causal FIR Filters

From Eq.$ \,$ (5.6), we see also that the impulse response $ h(n)$ is always zero for $ n < 0$ . Recall from §5.3 that any LTI filter having a zero impulse response prior to time 0 is said to be causal. Thus, a tapped delay line such as that depicted in Fig.5.5 can only implement causal FIR filters. In software, on the other hand, we may easily implement non-causal FIR filters as well, based simply on the definition of convolution.


Next  |  Prev  |  Up  |  Top  |  Index  |  JOS Index  |  JOS Pubs  |  JOS Home  |  Search

[How to cite this work]  [Order a printed hardcopy]  [Comment on this page via email]

``Introduction to Digital Filters with Audio Applications'', by Julius O. Smith III, (September 2007 Edition).
Copyright © 2014-03-23 by Julius O. Smith III
Center for Computer Research in Music and Acoustics (CCRMA),   Stanford University
CCRMA