Energy-Aware Wireless Relay Selection in Load-Coupled OFDMA Cellular   Networks
  We investigate transmission energy minimization via optimizing wireless relay selection in orthogonal-frequency-division multiple access (OFDMA) networks. We take into account the impact of the load of cells on transmission energy. We prove the NP-hardness of the energy-aware wireless relay selection problem. To tackle the computational complexity, a partial optimality condition is derived for providing insights in respect of designing an effective and efficient algorithm. Numerical results show that the resulting algorithm achieves high energy performance. 
Lei You, Di Yuan, Nikolaos Pappas, Peter V\"arbrand
cs.IT math.IT