Overview of Amplify-and-Forward Relaying

Abstract

Amplify-and-Forward (AF) is a simple cooperative strategy for ad-hoc networks with critical power constraints. It involves an amplification of the received signal in the analogue domain at the relays without further signal processing. This chapter gives an overview of the basic AF protocols in the literature and discuss recent research contributions in this area. Based on some well-defined AF-based cooperative configurations, it focuses on the behaviour of AF in block-fading channels, in power allocation problems, in relay selection, and in cross-layer coordination. Mathematical models and outage probability simulations are used in order to show the enhancements of the presented AF techniques.