Effective-Throughput Maximization for Wireless-Powered IoT Networks with Short Packets

Internet-of-Things (IoT) is a promising technology to connect massive machines and devices for future wireless communications. In this paper, we study a wireless-powered IoT network in which a hybrid access point (HAP) first transmits power to the IoT devices wirelessly, then the devices in turn transmit their data packets to the HAP using the harvested energy. Due to the limited amount of energy at the devices, the uplink data packets are in general short packets, thus conventional resource allocation based on Shannon capacity achieved by infinite-length packets is not optimal. In this paper, we first define a performance metric called effective-throughput for short packet communications (SPC), which balances the transmission rate and the packet error rate, then establish the effective-throughput maximization problem which optimizes the transmission time and packet error rate for the IoT devices under various practical constraints. Due to the non-convexity of the formulated problem, we develop an efficient algorithm to solve it iteratively, and provide theoretical analysis on the convergence. Simulation results show that the proposed algorithm achieves the similar performance as that of the exhaustive search method, and outperforms the benchmark schemes significantly.