ABSTRACT
This Chapter gives detailed explanations of relay aided communication concept, with the description of techniques applied for the message processing and/or forwarding at relay stations. Incremental relay technique is proposed with a goal to increase spectral efficiency of fixed relaying protocols. Hybrid relay system assumes that relay stations are equipped to perform both amplify-and-forward and decode-and-forward relaying techniques. Amplify-and-Forward (AF) relay technique represents one of the two basic methods used for processing a signal received at the relay station. In AF relaying, relay station receives a signal from a source, amplifies it either with fixed gain or variable gain, and then forwards it toward a destination. In order to pursue with analyses of orthogonal frequency division multiplexing relay systems, it is necessary to systematize facts and numbers related with the performance of single-carrier relay systems.
