Optimizing feedback in energy harvesting MISO communication channels

In this work,¹ we consider the optimization of feedback in a point-to-point MISO channel with an energy harvesting (EH) receiver (RX). The RX is interested in feeding back the channel state to the transmitter (TX) to help improve the transmission rate, yet must spend the harvested energy wisely to do so. The objective is to maximize the throughput by a deadline, subject to EH constraints at the RX. The throughput metric considered is an upper bound on the ergodic capacity of beamforming with limited feedback. The optimization problem is shown to be concave and a simple algorithm for obtaining the optimal feedback bit allocation policy is devised. Numerical results show that the optimal feedback policy obtained for the modified problem outperforms the naive scheme for the original problem.