Chapter 14
Project 5: Adaptive Filters
14.1 Theory
DIGITAL filters running in real-time can be very effective at removing undesirable noise or interference that is corrupting a signal. Some basic examples of FIR and IIR digital filters were first given in Chapters 3 and 4, and various implementations of digital filters were used in later chapters as well. Up until now, however, all the filters have been what are called “fixed coefficient” filters. That is, the response of the filters, once determined by the choice of coefficients, was fixed.1 The coefficients did not change over time. This is by far the most common type of digital filter.
While this technique can work quite well when the undesirable parts of the input are unchanging, ...
