FPGA-based Implementation of Signal Processing Systems

2

DSP Fundamentals

2.1 Introduction

In the early days of electronics, signals were processed and transmitted in their natural form, typically an analogue signal created from a source signal such as speech, then converted to electrical signals before being transmitted across a suitable transmission media such as a broadband connection. The appeal of processing signals digitally was recognized quite some time ago for a number of reasons. Digital hardware is generally superior and more reliable than its analogue counterpart which can be prone to ageing and can give uncertain performance in production. DSP on the other hand gives a guaranteed accuracy and essentially perfect reproducibility (Rabiner and Gold 1975). In addition, there is considerable interest in merging the multiple networks that transmit these signals, such as the telephone transmission networks, terrestrial TV networks and computer networks, into a single or multiple digital transmission media. This provides a strong motivation to convert a wide range of information formats into their digital formats.

Microprocessors, DSP micros and FPGAs perform a suitable platform for processing such digital signals, but it is vital to understand a number of basic issues with implementing DSP algorithms on, in this case, FPGA platforms. These issues range from understanding both the sampling rates and computational rates of different applications with the aim of understanding how these requirements affect the final FPGA implementation, ...