A Framework for Implementation and Evaluation of Cooperative Diversity in Software-defined Radio

by Glenn J. Bradford Increasing data rates in wireless devices is particularly challenging due to the presence of many impairments in the medium, including multipath fading. Diversity techniques are a means of increasing transmission reliability in multipath environments. This thesis focuses on cooperative diversity, a concept that obtains spatial diversity via relaying. Cooperative diversity encompasses a broad range of issues, from the physical layer through network layer, making the emerging reconfigurable technology of software-defined radio ideal for experimentation. The main contribution of this work is the development of an extendable experimental framework for implementation and analysis of cooperative protocols. A decode-and-forward (DF) relay network is constructed and analyzed by means of received symbol distributions and bit error rate (BER) versus signal-to-noise ratio (SNR) curves. The former shows a shift in the distribution of instantaneous SNR for both simple and selective DF, while the latter indicates that only the selective scheme actually achieves a diversity gain.