Joint Uplink/Downlink Resource Allocation and Data Offloading in OFDMA-Based Wireless Powered HetNets

TL;DR

This paper introduces a joint uplink/downlink resource allocation method in OFDMA-based HetNets with energy harvesting, data offloading, and TDD/FDD schemes, enhancing uplink data rates and network efficiency.

Contribution

It proposes a novel iterative algorithm for non-convex optimization in joint resource allocation and offloading, demonstrating convergence and performance improvements.

Findings

TDD scheme outperforms FDD in network performance.

Data offloading increases uplink sum data rate.

Proposed algorithm converges to a near-optimal solution.

Abstract

This paper considers joint uplink/downlink of an orthogonal frequency division multiple access (OFDMA)-based heterogeneous network (HetNet) consisting of a single macro base station (MBS), multiple femto base stations (FBSs) and access points (APs) where base stations (BSs) can offload data to APs and each mobile user (MU) is able to harvest the received energy using the simultaneous wireless information and power transfer (SWIPT) technique. We also suppose that the harvested energy of MUs are used for their uplink information transmission. We devise a radio resource allocation (RRA) algorithm to maximize the uplink sum data rate of MUs subject to a minimum required downlink data rate of each MU and maximum allowable transmit power of each BS, AP, and MU. More specifically, both the frequency division duplex (FDD) and time division duplex (TDD) schemes are investigated. The proposed non-convex optimization problems are solved using an iterative algorithm. It is also proved that the proposed algorithm converges to a near-optimal solution. Simulation results illustrate that the TDD scheme improves the performance compared to the FDD scheme. In addition, it is shown that utilizing the data offloading technique improves the uplink sum data rate of MUs compared to the scenario without any AP.