Interference Mitigation using Optimized Angle Diversity Receiver in LiFi Cellular Network

TL;DR

This paper investigates optimized angle diversity receiver structures, including pyramid and truncated pyramid designs, to mitigate inter-cell interference in LiFi networks, considering device orientation and diffuse signals, and compares combining schemes for improved performance.

Contribution

It introduces optimized ADR structures with analytical FOV bounds, compares SBC and MRC schemes, and demonstrates the advantages of double source systems over single source configurations.

Findings

SBC outperforms MRC in interference-limited scenarios.

Optimized ADR structures improve interference mitigation.

Double source systems outperform single source systems under certain conditions.

Abstract

Light-fidelity (LiFi) is an emerging technology for high-speed short-range mobile communications. Inter-cell interference (ICI) is an important issue that limits the system performance in an optical attocell network. Angle diversity receivers (ADRs) have been proposed to mitigate ICI. In this paper, the structure of pyramid receivers (PRs) and truncated pyramid receivers (TPRs) are studied. The coverage problems of PRs and TPRs are defined and investigated, and the lower bound of field of view (FOV) for each PD is given analytically. The impact of random device orientation and diffuse link signal propagation are taken into consideration. The performances of PRs and TPRs are compared and then optimized ADR structures are proposed. The performance comparison between the select best combining (SBC) and maximum ratio combining (MRC) is given under different noise levels. It is shown that SBC will outperform MRC in an interference limited system, otherwise, MRC is a preferred scheme. In addition, the double source system, where each LiFi AP consists of two sources transmitting the same information signals but with opposite polarity, is proved to outperform the single source (SS) system under certain conditions.