Energy Minimization in Cooperative Relay Networks With Sleep Modes
The authors consider a cooperative relay network where a source node communicates to a destination node with the help of multiple Relay Nodes (RNs). RNs are assumed to be able to work in either active mode or sleep mode. To minimize the total energy consumption, working modes of RNs and power allocation need to be optimized. Based on the time scales of mode transition, they formulate two different energy minimization problems. In the case of fast transition, where the transition can be applied in each frame, the problem is shown to be a super-modular minimization problem. They propose a relaxation based algorithm with a provable performance bound.