Digital Filter Applications (Digital Filter Design Toolkit)

Filters are signal processing elements that alter the frequency spectrum of an input signal. You might use filters for the following applications:

• Attenuating noise in a signal where the noise power and signal power are concentrated at different frequencies. For example, you might use a notch filter to attenuate a 60 Hz powerline interference present in a signal.
• Extracting signal components from a signal that contains different signal components concentrated at different frequencies. For example, you might use a bandpass filter to extract a particular radio station signal from a broadband radio signal.
• Reshaping the frequency spectrum of the input signal. For example, you might use an A-weighting filter to approximate the frequency response of a human ear. As another example, you might use an equalizer filter to undo magnitude and phase distortion caused by passing a signal through a linear time-invariant communications channel.

You can use either fixed-point or floating-point arithmetic to implement digital signal processing systems. Although floating-point implementations are typically easier to design, fixed-point implementations are often less expensive and more efficient in power than floating-point implementations. Floating-point designs are typically appropriate in applications that run on desktop computers, and fixed-point designs are often more appropriate in embedded applications, in which you need to minimize cost or power consumption.