Joint adaptive modulation and switching schemes for opportunistic cooperative networks

In this paper, we propose a novel scheme, which combines both advantages of adaptive modulation and the concept of distributed switching. Unlike previous incremental relaying protocols under adaptive modulation, we consider a more realistic scenario where the link providing higher spectral efficiency is chosen for data transmission. We also examine the outage probability, bit error rate, and spectral efficiency, which are important performance measures for the proposed system. Based on the derived expression and its approximate form, we demonstrate that the proposed network enhances the system performance in terms of spectral efficiency by around 3 dB, compared to the conventional incremental relaying networks. Finally, the derivation is validated through Monte Carlo simulations.