All of the digital filter examples given in the previous section can be written in the following general forms:
| Zero order: | yn = a0xn |
| First order: | yn = a0xn + a1xn-1 |
| Second order: | yn = a0xn + a1xn-1 + a2xn-2 |
Similar expressions can be developed for filters of any order.
| The constants a0, a1, a2,
... appearing in these expressions are called the filter coefficients.
The values of these coefficients determine the characteristics of a particular
filter.
The table opposite gives the values of the coefficients of each of the filters given as examples in the previous section. |
|
Next | Previous | DSP home page | Index