Energy-subchannel allocation for energy harvesting nodes in frequency-selective channels

We consider an energy harvesting network with multiple transmission links in a frequency-selective fading channel. We formulate the problem of joint energy and subchannel allocation for all transmitters over a scheduling period, as a mixed integer program. With the predictions of the harvested energy and subchannel gains, we propose an algorithm to efficiently obtain the energy-subchannel allocations for all links over the scheduling period based on controlled water-filling. The proposed algorithm is shown to be asymptotically optimal when the bandwidth of the subchannel goes to zero. Simulation results demonstrate that the performance of the proposed algorithm is close to the upper-bound on the optimal performance, which is also outperforms various heuristic allocation policies.