This thesis work aims at analysing the performance of efficient cooperative techniques and of smart antenna aided solutions in the context of wireless networks. Particularly, original contributions include a performance analysis of distributed coding techniques for the physical layer of communication systems, the design of practical efficient coding schemes that approach the analytic limiting bound, the cross-layer design of cooperative medium access control systems that incorporate and benefit from advanced physical layer techniques, the study of the performance of such solutions under realistic network assumptions, and, finally the design of access protocols where nodes are equipped with smart antenna systems.
The objective of this thesis is to discuss the performance achieved by IEEE 802.11
networks, considering in detail their simulation and experimental analysis, as well as the implementation aspects. The original contribution of this dissertation involves three main research fields within the context of distributed wireless networks: the experimental and theoretical analysis of IEEE 802.11e networks in presence of quality of service mechanisms, the development and the simulation of backward compatible medium access control protocols in presence of smart antenna systems, and, finally, the implementation of the IEEE 802.11ag physical layer on software-defined radio platforms.
