Review of basic ideas from digital communication - Signal Processing and Optimization for Transceiver Systems - page 12

Review of basic ideas
from digital communication

2.1 Introduction

In this chapter we briefly review introductory material from the theory and
practice of digital communication. The reader familiar with such introductory
material can use this chapter primarily as a reference for later chapters. For
a more detailed treatement one should consult standard communication texts
such as Proakis [1995], Lathi [1998], or Haykin [2001].

2.1.1 Chapter overview

The schematic representation of digital communication systems described earlier
in Sec. 1.3 is reproduced in Fig. 2.1. As mentioned in that section, the input
symbol stream has sample values s ( n ) chosen from a finite set of values called the
symbol alphabet, constellation, or code words - we shall consistently use the term
constellation . In Sec. 2.2 we shall describe two commonly used constellations
called the PAM (pulse amplitude modulation) and the QAM (quadrature PAM)
constellations.

Given the symbol stream s ( n ) the transmitter generates the baseband wave-
form

∞

x ( t )= s ( n ) f ( t − nT ) ,

n = −∞

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