Energy efficiency of distributed cooperative relaying

Distributed cooperative relaying is an attractive method to combat fading in wireless communications because of its performance advantages, simplicity, scalability, and low overhead. In [1], the spectral efficiency of two previously proposed distributed relaying strategies is investigated: Timer-based Best-Select relaying and M-group Dis-STBC All-Select relaying. From the perspective of spectral efficiency, M-group Dis-STBC All-Select relaying outperforms Best-Select relaying; however, when every node in the decoded set retransmits the source message, much more power will be consumed. In this paper, the energy efficiency of these two relaying strategies is studied to provide a more comprehensive guide for system designers to determine which strategy fits a specific application. Numerical results indicate that, although Best-Select relaying conserves transmit power, in some cases, it is also less energy efficient than M-group Dis-STBC All-Select relaying.