On the Performance of CSI-Assisted Cooperative Communications over Generalized Fading Channels

Virtual antenna array (VAA) systems (also known as cooperative communications, cooperative diversity, cooperative relaying or antenna sharing systems) are a new and recently proposed kind of (cooperative) spatial diversity, which have been receiving a significant interest in various communities as a means for improving the performance of both infrastructure-based and ad-hoc-based transmission systems operating over multipath fading channels. In particular, in antenna sharing systems the mobile radios share their single-antennas to create a distributed virtual antenna array through distributed transmissions and distributed signal processing operations. Although cooperative wireless communications exhibit various design challenges and research opportunities at different protocol layers, in this contribution we mainly focus on physical layer issues. In particular, we propose a comprehensive and unified framework for performance analysis of multi-hop multi-branch wireless systems with channel state information (CSI-) assisted analog relays over generalized fading channels. The framework relies on the moment generating function (MGF-) approach for performance analysis of digital communication systems over fading channels and on some properties of the Laplace transform, which allow to develop a simple single-integral relation between the MGF of a random variable and the MGF of its inverse. Numerical and simulation results are also provided to substantiate the accuracy of the proposed framework.