Handbook on Array Processing and Sensor Networks

CHAPTER 6

Implicit Training and Array Processing for Digital Communication Systems

Aldo G. Orozco-Lugo¹, Mauricio Lara¹, and Desmond C. McLernon²

¹ Cinvestav-IPN, México,

² University of Leeds, United Kingdom

6.1 INTRODUCTION

While the term array processing is well understood, the expression implicit training has recently appeared in the digital communications literature and its meaning should first be clearly defined. By implicit training (IT) we mean a strategy where a special sequence is embedded in the transmitted signal for the purpose of aiding the parameter estimation tasks at the receiver but in such a way that no additional bandwidth is required. Notice that this definition does not rule out the possibility of employing extra bandwidth for other purposes, as, for example, when channel coding or linear precoding techniques are used to mitigate deleterious channel effects. As the chapter proceeds, it will become apparent that many techniques proposed before under widely different names can now all be grouped under the umbrella definition of IT.

So this chapter deals with the use of IT techniques for parameter estimation and detection problems in digital communications systems that could employ array processing. The chapter starts with a description of the IT methodology and the kind of detection and estimation problems that appear in digital communications systems and that ...