Autonomic Intelligence Evolved Cooperative Networking

Chapter 4Function Level Relaying Techniques

4.1 Introduction

Following the previous chapter, where the notion of protocol level spatio-temporal processing was addressed, mostly pertaining to the developments of the physical layer such as the multiple-input multiple-output radio channel, space-time coding techniques, as well as their protocol level control logic, the time has come to move forward towards function level relaying techniques. First, conventional relaying and cooperative relaying are characterised, while the latter is further investigated from the viewpoints of forwarding strategy and protocol nature. This way, amplify-and-forward, decode-and-forward, and decode-and-reencode, as well as fixed, adaptive, and feedback protocol types are described. Then the focus shifts towards the topic of supportive protocols and collaborative protocols, presented as two subcategories of cooperation understood in a wider sense. Based on such a dual perception of what would normally be referred to as a cooperative protocol, it becomes possible to identify that the former can be considered as a preparatory phase for the latter, making the attempt at further classification highly constructive. Last, but not least, the concept of virtual antenna arrays is outlined, under the assumption of applying its most versatile multi-tier version where, based on a generalised cooperative transmission scheme, a special operation mode is presented in the form of distributed space-time block coding, ...