Non-Orthogonal Multiple Access for FSO Backhauling

TL;DR

This paper introduces a dynamic NOMA scheme for FSO backhauling that optimizes decoding order based on channel conditions, significantly improving outage performance over traditional methods.

Contribution

It proposes a novel dynamic NOMA scheme for FSO backhauling with channel-aware decoding order, enhancing outage performance analysis and providing closed-form expressions.

Findings

Dynamic NOMA outperforms orthogonal schemes.

Closed-form outage probability expressions derived.

Simulation confirms analytical results.

Abstract

We consider a free space optical (FSO) backhauling system which consists of two base stations (BSs) and one central unit (CU). We propose to employ non-orthogonal multiple access (NOMA) for FSO backhauling where both BSs transmit at the same time and in the same frequency band to the same photodetector at the CU. We develop a dynamic NOMA scheme which determines the optimal decoding order as a function of the channel state information at the CU and the quality of service requirements of the BSs, such that the outage probabilities of both BSs are jointly minimized. Moreover, we analyze the performance of the proposed NOMA scheme in terms of the outage probability over Gamma-Gamma FSO turbulence channels. We further derive closed-form expressions for the outage probability for the high signal-to-noise ratio regime. Our simulation results confirm the analytical derivations and reveal that the proposed dynamic NOMA scheme significantly outperforms orthogonal transmission and existing NOMA schemes.