Energy- and Spectral-Efficiency Tradeoff in Full-Duplex Communications

TL;DR

This paper explores the balance between energy efficiency and spectral efficiency in full-duplex cellular networks, deriving conditions and algorithms to optimize this tradeoff in single and multiuser scenarios.

Contribution

It provides a necessary condition for FD transceivers to outperform HD in EE-SE tradeoff, and develops an optimal algorithm for maximizing EE in multiuser settings.

Findings

FD transceivers can achieve better EE-SE tradeoff under certain conditions

The EE as a function of SE is quasi-concave, enabling optimal solutions

Numerical results verify the theoretical analysis and algorithm effectiveness

Abstract

This paper investigates the tradeoff between energyefficiency (EE) and spectral-efficiency (SE) for full-duplex (FD) enabled cellular networks.We assume that small cell base stations are working in the FD mode while user devices still work in the conventional half-duplex (HD) mode. First, a necessary condition for a FD transceiver to achieve better EE-SE tradeoff than a HD one is derived. Then, we analyze the EE-SE relation of a FD transceiver in the scenario of single pair of users and obtain a closed-form expression. Next, we extend the result into the multiuser scenario and prove that EE is a quasi-concave function of SE in general and develop an optimal algorithm to achieve the maximum EE based on the Lagrange dual method. Our analysis is finally verified by extensive numerical results.