# Joint Time-Frequency Splitting for Multiuser SWIPT OFDM Networks

## TL;DR

This paper introduces a joint time-frequency splitting strategy for multiuser OFDM systems with SWIPT, optimizing resource allocation to improve sum rate while satisfying QoS constraints.

## Contribution

It proposes a novel joint TFS method, transforming a nonconvex problem into a convex one and providing an efficient iterative solution.

## Key findings

- TFS outperforms traditional time-sharing methods.
- The proposed algorithm has low computational complexity.
- Numerical results confirm improved sum rate performance.

## Abstract

In this paper, we propose a joint time-frequency splitting (TFS) strategy for a multiuser orthogonal frequency division multiplexing (OFDM) system with simultaneous wireless information and power transfer (SWIPT). In TFS, the time sharing factors for each user on different subcarriers are optimized via maximizing the sum rate of users with both information and energy quality of service (QoS) constraints. Though the original problem is nonconvex, we first transform it into an equivalent convex problem through an appropriate variable transformation. Then, we present an iterative algorithm based on semi closed form with low complexity. Numerical results show that the proposed TFS outperforms the conventional time-sharing and subcarrier-separation strategies.