Digital Design of Signal Processing Systems: A Practical Approach

4

Mapping on Fully Dedicated Architecture

4.1 Introduction

Although there are many applications that are commonly mapped on field-programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs), the primary focus of this book is to explore architectures and design techniques that implement real-time signal processing systems in hardware. A high data rate, secure wireless communication gateway is a good example of a signal processing system that is mapped in hardware. Such a device multiplexes several individual voice, data and video channels, performs encryption and digital modulation on the discrete signal, up-converts the signal, and digitally mixes it with an intermediate frequency (IF) carrier.

Thes types of digital design implement complex algorithms that operate on large amounts of data in real time. For example, a digital receiver for a G703 compliant E3 microwave link needs to demodulate 34.368Mbps of information that were modulated using binary phase-shift keying (BPSK) or quadrature phase shift keying (QPSK). The system further requires forward error-correction (FEC) decoding and decompression along with several other auxiliary operations in real time.

These applications can be conveniently conceived as a network of interconnected components. For effective HW mapping, these components should be placed to work independently of other components in the system. The Kahn Process Network (KPN) is the simplest way of synchronizing their interworking. Although ...