Overview

As detailed in the previous chapter, information theory predicts that MIMO channels are able to provide huge gains in terms of reliability and transmission rate. In this chapter,

• we derive practical methodologies to achieve these gains

• we address how link performance and data rates may be increased through coding across space and time

• we present two design methodologies motivated by an error rate optimization perspective or by information theory

• we give an overview of schemes known as space-time codes and we discuss how they perform in terms of both error and transmission rates.

Two groups of encoding schemes are reviewed: space-time block coding (encoding is based on a block definition) and space-time trellis coding (codes are described by a trellis). Among space-time block codes, we discuss the broad class of Spatial Multiplexing (V-BLAST and D-BLAST) schemes, orthogonal and quasi-orthogonal codes, linear dispersion codes as well as the more recently developed algebraic codes. Regarding trellis codes, we consider the classical space-time trellis codes as well as the super-orthogonal space-time trellis codes.