TABLE OF CONTENTS The advancement of VLSI technology led to the proliferation of digital integrated circuits and systems which perform intricate signal processing in the digital domain.
Compared with analog signal processors, digital signal processors (DSPs) have numerous advantages. In digital systems, the signal is quantized into discrete levels, and a finite number of digital code-words are transmitted, most of the noise and interference added to the digital signal during processing or transmission can be removed. However, in analog systems any noise added to the signal is indistinguishable from it and hence can t be removed. Therefore, analog signal processing requires accurate components with precise tolerance. However, digital signal processing can tolerate less precise components making digital signal processors less susceptible to temperature, aging and manufacturing tolerances. Furthermore, digital systems allow more intricate signal processing and offer more extensive programmability than analog systems.
However, all naturally occurring signals that are encountered in the real world are analog signals. This necessitates the transformation of such signals from the analog domain to the digital domain to make use of the powerful computational processing power of the digital signal processors. The digital signal then has to be transformed back to the analog domain. This transformation is done by using analog-to-digital and digital-to-analog converters.
Figure 7.1 shows the block diagram of an analog-to-digital converter (ADC). The low-pass filter, which is known as the anti-alias filter, band-limits the analog signal so as to prevent aliasing from occurring in the sampler. The sampler discretizes the signal in the...
