Throughput Optimal Multi-user Scheduling via Hierarchical Modulation

TL;DR

This paper presents a throughput-optimal scheduling algorithm using hierarchical modulation for two-user wireless networks, improving stability and capacity over traditional methods, with demonstrated lower delays in simulations.

Contribution

It introduces a novel throughput-optimal scheduling algorithm employing hierarchical modulation for two-user scenarios, surpassing conventional uniform modulation approaches.

Findings

Achieves larger rate region than Max-Weight algorithm.

Provides network stability for higher traffic loads.

Reduces delays in simulated high data rate environments.

Abstract

We investigate the network stability problem when two users are scheduled simultaneously. The key idea is to simultaneously transmit to more than one users experiencing different channel conditions by employing hierarchical modulation. For two-user scheduling problem, we develop a throughput-optimal algorithm which can stabilize the network whenever this is possible. In addition, we analytically prove that the proposed algorithm achieves larger achievable rate region compared to the conventional Max-Weight algorithm which employs uniform modulation and transmits a single user. We demonstrate the efficacy of the algorithm on a realistic simulation environment using the parameters of High Data Rate protocol in a Code Division Multiple Access system. Simulation results show that with the proposed algorithm, the network can carry higher user traffic with lower delays.