A Simple Approach to Digital Signal Processing

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Why Do It Digitally Anyway?

By now you have read about what DSP is and how it has developed over the last thirty years, but still know nothing about why you should use it. After all, it would be possible to use analog circuits to perform most of the work done by digital signal processors. Despite this, there has been a vast amount of money invested by semiconductor companies in developing ever faster chips for digital signal processing and an ever more eager uptake of these devices by designers. So just what is it about DSP that makes it so popular?

The answer is not short and clear-cut. There are many advantages in using digital techniques for general-purpose signal processing. These advantages also apply to more specific applications, but there are also some functions that may be performed by DSP that cannot be implemented in analog systems. The advantages of using digital techniques in signal processing fall into several broad categories: programmability, stability, repeatability, easier implementation of adaptive algorithms and the ability to implement error correcting codes and special functions such as linear phase filters. We may also consider data transmission, storage and compression as areas where digital processing has significant advantages over analog.

Looking at this list, it seems that DSP is the universal panacea. Unfortunately, life isn't that simple. There are limits to what can actually be done by realizable DSP systems, and there are even some areas in which ...