Power control in ARQ transmission with wireless energy replenishment

In this paper, we focus on fundamental point-to-point wireless transmission with a reverse feedback channel for automatic repeat request (ARQ) and propose wireless energy replenishment (WER) for the transmitter with ACK or NACK signal sent back by the receiver. In such a case, transmission power control affects not only transmission reliability at the receiver but also WER performance at the transmitter and transmission sustainability. Hence, dynamic power control for the transmitter is investigated to optimize the expected number of transmitted bits in multiple timeslots and such a problem is modeled as a finite-horizon Markov decision process (MDP), which is further solved via the backward induction algorithm. We evaluate the transmission performance with impact of channel condition, WER performance, number of timeslots as well as modulation scheme and show that transmission with WER outperforms that without WER, especially for moderate channel condition.