Moving Average Filters

The moving average is the most common filter in DSP, mainly because it is the easiest digital
filter to understand and use. In spite of its simplicity, the moving average filter is optimal for
a common task: reducing random noise while retaining a sharp step response. This makes it the
premier filter for time domain encoded signals. However, the moving average is the worst filter
for frequency domain encoded signals, with little ability to separate one band of frequencies from
another. Relatives of the moving average filter include the Gaussian, Blackman, and multiplepass
moving average. These have slightly better performance in the frequency domain, at the
expense of increased computation time.
CHAPTER
Moving Average Filters
15

The moving average is the most common filter in DSP, mainly because it is the easiest digital
filter to understand and use. In spite of its simplicity, the moving average filter is optimal for
a common task: reducing random noise while retaining a sharp step response. This makes it the
premier filter for time domain encoded signals. However, the moving average is the worst filter
for frequency domain encoded signals, with little ability to separate one band of frequencies from
another. Relatives of the moving average filter include the Gaussian, Blackman, and multiple-
pass moving average. These have slightly better performance in the frequency domain, at the
expense of increased computation time.




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