Decoupled Heterogeneous Networks with Millimeter Wave Small Cells

TL;DR

This paper presents an analytical framework for heterogeneous networks combining sub-6GHz and mmWave small cells with decoupled access, analyzing coverage, rate, and interference effects to optimize network design.

Contribution

It introduces a stochastic geometry-based model that accounts for uplink power control and mmWave interference in decoupled HetNets with small cells, providing new insights into densification impacts.

Findings

mmWave interference becomes significant in dense small cell deployments

Different small cell types have distinct effects on network performance

Decoupled access improves coverage and rate in HetNets

Abstract

Deploying sub-6GHz network together with millimeter wave (mmWave) is a promising solution to simultaneously achieve sufficient coverage and high data rate. In the heterogeneous networks (HetNets), the traditional coupled access, i.e., the users are constrained to be associated with the same base station in both downlink and uplink, is no longer optimal, and the concept of downlink and uplink decoupling has recently been proposed. In this paper, we propose an analytical framework to investigate the traditional sub-6GHz HetNets integrating with mmWave small cells (SCells) with decoupled access, where both the uplink power control and mmWave interference are taken into account. Using the tools from stochastic geometry, the performance metrics of signal-to-interference-plus-noise ratio coverage probability, user-perceived rate coverage probability, and area sum rate are derived. The impact of the densification of different SCells on the network performance is also analyzed to give insights on the network design. Simulation results validate the accuracy of our analysis, and reveal that mmWave interference can not be neglected when the mmWave SCells are extremely dense and that different kinds of SCells have various effects on the network performance and thus need to be organized properly.