Efficient Multirate Filtering

Contents	Abstract	Conclusion	Figures	FREE software
Introduction	Conversion	Narrow-Band	Half-Band	MATLAB Scipts

Conclusion:

Multirate techniques are used to improve a digital filter design and implementation.
The multirate approach increases the computation speed, decreases the overall filter order, and decreases power consumption.
Various multirate techniques can be used to reach the filter requirements regarding the magnitude and phase responses, sensitivity to coefficient accuracy, robustness, noise and overflow, computation speed, miniaturization and modularity of the realization structure or power consumption.

The basic multirate techniques suitable for filter design and implementations are polyphase decomposition, multistage filtering and frequency-response masking approach.
Usually, the multirate approach is the best solution for decimation and interpolation filters.
This way, computations are evaluated at a lower sampling rate, and overall filter complexity is considerably reduced.
An important application of multirate techniques is design and implementation of filters with sharp transition bands.
For some narrow-band filters, and wide-band filters with sharp transition bands, the multirate approach is the only reasonable solution.

Half-Band filters are basic building blocks in multirate systems.
In this chapter, the efficient and accurate design of FIR and IIR half-band filters is presented.

The application of multirate techniques in filter design and implementation is demonstrated through examples.
We combine the text with MATLAB script because MATLAB is a widely used programming language.
All programs have been tested under version 5.2 of MATLAB and version 4 of the Signal Processing Toolbox.
Software implementations using MATLAB agree with simulated multiplierless designs written as VHDL descriptions.

This Chapter is supported by the following websites which contain the MATLAB scripts:
http://kondor.etf.rs/~milic/emfhome.htm
http://kondor.etf.bg.ac.yu/~lutovac/emfhome.htm

Obtain by e-mail our FREE software MATLAB script files on Efficient Multirate Filtering.

Last updated September 9, 2008