A unified view of diversity in multiantenna-multicarrier systems: analysis and adaptation strategies

Multicarrier and multiple transmit/receive antenna have become two key technologies underpinning most of the current development and research efforts towards ubiquitous high-throughput wireless communications. Both techniques can be used to increase the link throughput and/or to improve its robustness against channel fading and noise. This paper presents a unified bit error rate analysis for a particular flavour of multicarrier, namely, group-orthogonal code-division multiplex (GO-CDM), in combination with multiple Tx/Rx antennas. This system can be shown to encompass many of current wireless architectures and the analysis is general enough to incorporate the effects of channel frequency selectivity and Tx and/or Rx antenna correlation. The first main outcome of this paper is a general analytical framework suitable to study the effects of the different types of diversity in multicarrier systems. This analytical framework paves the way for the second main outcome of this study, namely, the design of effective reconfiguration strategies that serve to balance different system requirements (e.g., performance, complexity, delay). Particularly, it will be seen that the analytical results not only allows a-priori design decisions to be made, but it also provides an insight that enables the derivation of dynamic reconfiguration strategies that take into account instantaneous channel state information. The overall conclusion is that GO-CDM can play an important role in improving the performance of adaptive MIMO-OFDM systems.