Online Power Allocation at Energy Harvesting Transmitter for Multiple Receivers with and without Individual Rate Constraints for OMA and NOMA Transmissions

TL;DR

This paper introduces an online power allocation method for energy harvesting transmitters serving multiple users with NOMA and OMA, optimizing sum rate without prior channel or energy statistics, suitable for real-time applications.

Contribution

It presents a novel Lyapunov-based online power allocation scheme that handles multiple users, QoS constraints, and both NOMA and OMA, without requiring statistical channel or energy info.

Findings

Achieves near-optimal sum rate performance in simulations.

Operates with low complexity suitable for real-time implementation.

Supports QoS constraints for individual users.

Abstract

In this paper, we propose an online power allocation scheme to maximize the time averaged sum rate for multiple downlink receivers with energy harvesting transmitter. The transmitter employs non-orthogonal multiple access (NOMA) and/or orthogonal multiple access (OMA) to transmit data to multiple users. Additionally, we consider the scenario where each individual user has a quality of service constraint on its required instantaneous rate. The decisions of total transmit power and power allocation for different users in a given time slot are obtained with the help of Lyapunov optimization technique. The proposed schemes do not require any statistical information of the channel states and the harvested energy. The proposed power allocation schemes entail in small complexity based power allocation decisions. Therefore, the proposed schemes can provide solutions in real time and are more suited for online power allocation problems where the system state parameters (e.g. channel state, harvested energy etc) change quickly. The performances of the proposed schemes are demonstrated with the help of simulation results.