Joint grid energy-throughput optimization for hybrid energy small cell access points

We consider a multiantenna small-cell network where access-points serving multiple users on the downlink and uplink channels. The access point is powered by both renewable and non-renewable energy sources. Its objective is to jointly maximize the throughput of the downlink users and minimize the amount of energy drawn from the non-renewable energy source while guaranteeing the quality of service to both downlink and uplink users. The quality of service of uplink user is achieved if all the received packets are decoded in a given time. Further, we assume that the energy used for sampling and decoding the received packets is not negligible due to the access point small range of operation. With this perspective, the optimal transmit power allocation and received packet decoding policy are investigated in offline and online settings. The joint optimization problem is solved using the dual decomposition method to find the optimal policy. Numerical simulations are conducted to evaluate the performance of the proposed offline and online algorithms. Simulation results shown significant gains compared to the greedy method.